Month: August 2023

Categories : Medical Research & Technology Metabolic DisordersTags :

‘We Will Rock You’: The Special Cells that Secrete Insulin to Music

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Freddie Mercury performing with Queen in 1977. Source: Wikimedia Commons

Music has often been touted as a soothing treatment to aid healing. Now, researchers at ETH Zurich in Basel have come up with another medical approach. They have developed a novel method to get music to make specially designed cells secrete insulin. They found that this works especially well with the bass rhythm “We Will Rock You,” a global hit by British rock band, Queen.

Diabetics depend on an external supply of insulin via injection or pump. Researchers led by Martin Fussenegger from the Department of Biosystems Science and Engineering at ETH Zurich in Basel want to make the lives of these people easier and are looking for solutions to produce and administer insulin directly in the body. Any alternatives must be able to release insulin in controlled quantities on command.

One such solution the scientists are pursuing is enclosing insulin-producing designer cells in capsules that can be implanted in the body. To be able to control from the outside when and how much insulin the cells release into the blood, researchers have studied and applied different triggers in recent years: light, temperature and electric fields.

Equipping cells to receive sound waves

To make the insulin-producing cells receptive to sound waves, the researchers used a protein from the bacterium E. coli. Such proteins respond to mechanical stimuli and are common in animals and bacteria. The protein is located in the membrane of the bacterium and regulates the influx of calcium ions into the cell interior. The researchers incorporated the blueprint of this bacterial ion channel into human insulin-producing cells, letting these cells create the ion channel themselves and embed it in their membrane.

As the scientists have been able to show, the channel in these cells opens in response to sound, allowing positively charged calcium ions to flow into the cell. This leads to a charge reversal in the cell membrane, which in turn causes the tiny insulin-filled vesicles inside the cell to fuse with the cell membrane and release the insulin to the outside.

Turn up the bass

In cell cultures, the researchers first determined which frequencies and volume levels activated the ion channels most strongly. They found that volume levels around 60 decibels (dB) and bass frequencies of 50 hertz were the most effective in triggering the ion channels. To trigger maximum insulin release, the sound or the music had to continue for a minimum of three seconds and pause for a maximum of five seconds. If the intervals were too far apart, substantially less insulin was released.

Finally, the researchers looked into which music genres caused the strongest insulin response at a volume of 85dB. Rock music with booming bass like the song “We Will Rock You,” from Queen, came out on top, followed by the soundtrack to the action movie The Avengers. The insulin response to classical music and guitar music was rather weak by comparison.

“We Will Rock You” triggered roughly 70% of the insulin response within five minutes, and all of it within 15 minutes. This is comparable to the natural glucose-induced insulin response of healthy individuals, Fussenegger says.

Sound source must be directly above the implant

To test the system as a whole, the researchers implanted the insulin-producing cells into mice and placed the animals so that their bellies were directly on the loudspeaker. This was the only way the researchers could observe an insulin response. If, however, the animals were able to move freely in a “mouse disco,” the music failed to trigger insulin release.

“Our designer cells release insulin only when the sound source with the right sound is played directly on the skin above the implant,” Fussenegger explains. The release of the hormone was not triggered by ambient noise such as aircraft noise, lawnmowers, fire brigade sirens or conversations.

Ambient noise won’t do

As far as he can tell from tests on cell cultures and mice, Fussenegger sees little risk that the implanted cells in humans would release insulin constantly and at the slightest noise.

Another safety buffer is that insulin depots need four hours to fully replenish after they have been depleted. So even if the cells were exposed to sound at hourly intervals, they would not be able to release a full load of insulin each time and thereby cause life-threatening hypoglycaemia. “It could, however, cover the typical needs of a diabetes patient who eats three meals a day,” Fussenegger says. He explains that insulin remains in the vesicles for a long time, even if a person doesn’t eat for more than four hours. “There’s no depletion or unintentional discharge taking place.”

As a proof of concept only, clinical application is a long way off, but it shows that genetic networks can be controlled by mechanical stimuli such as sound waves. Whether this principle will ever be put to practical use depends on whether a pharmaceutical company is interested in doing so. It could, after all, be applied broadly: the system works not only with insulin, but with any protein that lends itself to therapeutic use.

Source: ETH Zurich

Categories : Cancer GastrointestinalTags :

How High-fat Diets Affect Gut Bacteria and Increase Colorectal Cancer Risk

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Gut Microbiome. Credit Darryl Leja National Human Genome Research Institute National Institutes Of Health

The increasing rate of obesity and high-fat diets are suspected to be behind the growing rates of colorectal cancers in people aged under 50. Now, in a study published in Cell Reports, researchers at have discovered how high-fat diets can change gut bacteria and alter digestive molecules called bile acids that are modified by those bacteria, predisposing mice to colorectal cancer.

In the study, researchers from the Salk Institute and UC San Diego found increased levels of specific gut bacteria in mice fed high-fat diets. They showed that those gut bacteria alter the composition of the bile acid pool in ways that cause inflammation and affect the replenishment rate of intestinal stem cells replenish.

“The balance of microbes in the gut is shaped by diet, and we are discovering how alterations in the gut microbial population (the gut microbiome) can create problems that lead to cancer,” says co-senior author and Professor Ronald Evans, director of Salk’s Gene Expression Laboratory. “This paves the way toward interventions that decrease cancer risk.”

In 2019, Evans and his colleagues showed in mice how high-fat diets boosted the overall bile acid levels. The shift in bile acids, they found, shut down a key protein in the gut, the Farnesoid X receptor (FXR). and increased the prevalence of cancer.

However, there were still missing links in the story, including how the gut microbiome and bile acids are changed by high-fat diets.

In the new work, Evans’ group teamed up with the labs of Rob Knight and Pieter Dorrestein at UC San Diego to examine the microbiomes and metabolomes (collections of dietary and microbially derived small molecules) in the digestive tracks of animals on high-fat diets. They studied mice genetically more susceptible to colorectal tumours.

The scientists discovered that although mice fed high-fat diets had more bile acids in their guts, it was a less diverse collection with a higher prevalence of certain bile acids that had been changed by gut bacteria. They also showed that these modified bile acids affected the proliferation of stem cells in the intestines. Without frequent replenishment, they accumulate mutations – a key step toward encouraging the growth of cancers, which often arise from these stem cells.

“We are only just beginning to understand these bacterially-conjugated bile acids and their roles in health and disease,” says co-author Michael Downes, a staff scientist at Salk.

There were also striking differences in the microbiomes of the mice on high-fat diets: the collections of gut bacteria in these mice’s digestive tracts were less diverse and contained different bacteria than the microbiomes of mice not on high-fat diets. Two of these bacteria – Ileibacterium valens and Ruminococcus gnavus – were able to produce these modified bile acids.

The scientists were surprised to discover that a high-fat diet actually had a greater impact on the microbiome and modified bile acids than a genetic mutation that increases cancer susceptibility in the animals.

“We’ve pinpointed how high-fat diet influences the gut microbiome and reshapes the bile acids pool, pushing the gut into an inflamed, disease-associated state,” says co-first author Ting Fu, a former postdoctoral fellow in the Evans lab.

The researchers believe high-fat diets change the composition of the microbiome, encouraging the growth of bacteria like I. valens and R. gnavus. In turn, that boosts levels of modified bile acids. In a vicious cycle, those bile acids create a more inflammatory environment that can further change the makeup of gut bacteria.

“We’ve deconstructed why high-fat diets aren’t good for you, and identified specific strains of microbes that flare with high-fat diets,” says Evans, March of Dimes Chair in Molecular and Developmental Biology. “By knowing what the problem is, we have a much better idea of how to prevent and reverse it.”

In the future, the team will study how quickly the microbiome and bile acids change after an animal begins eating a high-fat diet. They also plan to study ways to reverse the cancer-associated effects of a high-fat diet by targeting FXR – the protein that they previously discovered to be associated with bile acid changes.

Source: Salk Institute

Categories : Ageing Metabolic DisordersTags :

In Animal Studies, Metformin Extends Lifespan

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Photo by Towfiqu Barbhuiya on Unsplash

Researchers have discovered that the common antidiabetic drug metformin not only lowers blood sugar levels but has revealed to extend lifespan in C. Elegans, an animal model that shares similar metabolic systems with humans and are often used to model human diseases.

This study, led by investigators at Massachusetts General Hospital (MGH), reveals that metformin promotes longevity by stimulating the body’s production of ether lipids, a major structural component of cell membranes.

The findings, which are published in eLife, suggest that boosting production of ether lipids in humans may support healthy aging and reduce the impact of aging-related diseases.

To identify the genes required to enable lifespan extension in response to metformin and its sister drug phenformin (drugs called biguanides), the scientists silenced individual genes in the roundworm Caenorhabditis elegans (which shares over 80% of its proteins with humans and has an average lifespan of about two weeks) and examined what happens to the altered worms after exposure to the medications.

The experiments reveal that genes that increase production of ether lipids are required to extend lifespan in response to the biguanides. Inactivation of the genes that encode for these enzymes completely prevented the longevity-promoting effects of biguanides. Importantly, inactivation of these genes prevented lifespan extension in a variety of situations that are also known to promote longevity, including dietary restriction.

The team also found that increasing ether lipid synthesis alone (by overexpressing a single, key ether lipid biosynthetic enzyme called fard-1) was sufficient to extend C. elegans’ lifespan, orchestrating a metabolic stress defense response through a factor called SKN-1, which is the worm counterpart to the mammalian protein Nrf. This response altered metabolism to promote a longer lifespan.

“Our study implicates promotion of ether lipid biosynthesis as a novel therapeutic target to promote healthy aging. This suggests that dietary or pharmacologic intervention to promote ether lipid synthesis might one day represent a strategy to treat aging and aging-related diseases,” says senior author Alexander A. Soukas, MD, PhD, an Associate Professor at Harvard Medical School.

“Because our studies focused solely on interventions in C. elegans, further studies in mammalian models (such as human cells and mice), epidemiological observation, and rigorous clinical trials are required to determine the viability of promoting ether lipid synthesis to promote human health-span and lifespan.”

Source: Massachusetts General Hospital

Categories : HospitalsTags :

The Hospital Association of South Africa Welcomes the Day Hospital Association as a Member

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Photo by RDNE Stock project

The Day Hospital Association of South Africa (DHASA) has joined the Hospital Association of South Africa (HASA), the representative organisation of private hospital groups in the country, including Netcare, Mediclinic, Life Healthcare, Lenmed, Joint Medical Holdings, and a range of leading facilities across the country like Zuid-Afrikaans Hospital and Arwyp Medical Centre.

Among the Day Hospital Association of South Africa members are the Advanced Health chain, Cure Day Hospitals, and various leading treatment facilities situated nationwide.

According to HASA Chief Executive Officer Dr Dumisani Bomela, DHASA perspectives on healthcare reform issues, like the National Health Insurance, will contribute to a rich healthcare reform discussion. 

He says, “Through HASA, the Day Hospital Association can provide additional critical perspectives that we believe are required in the collaborative approach that we are engaging in with Government to build a strong and accessible healthcare system for all in South Africa. We completely believe that the excellent leadership of DHASA will make full use of their membership in HASA to make their important contribution.”

The Chairman of the Day Hospital Association of South Africa, Raymond Foster, says “We are excited to be associated with HASA. We are confident that HASA will meet the expectations of our members.”

Categories : Healthcare Politics and RegulationsTags :

SAHPRA Earns a Regulatory Accolade of Note

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Gloved hand holding vial of Janssen COVID vaccine
Photo by Spencer Davis on Unsplash

The South African Health Products Regulatory Authority (SAHPRA) has been designated as a Regional Centre of Regulatory Excellence (RCORE) for Vaccines Regulatory Oversight for a period of four (4) years in the following functions:

  • Overarching Regulatory Systems
  • Marketing Authorisation and Registration
  • Vigilance
  • Market Surveillance and Control
  • Licensing of Premises
  • Regulatory Inspections
  • Laboratory Access and Testing
  • Clinical Trials
  • Lot Release

The rationale behind the African Union Development Agency, New Partnership for Africa’s Development (AUDA-NEPAD) designating RCOREs is to support continent-wide regulatory systems strengthening through leveraging capacity in better resourced regulators. The reality of medicine regulatory capacity limitation on the continent continues to hinder access to essential medicines as well as limit progress in regulatory harmonisation efforts. The intention is to address this regulatory gap and ensure the acceleration and strengthening of regional medicines regulatory harmonisation initiatives. RCOREs are required to support regulatory workforce strengthening through training in regulatory functions and enhance skills through hands-on training and exchange programmes amongst National Medicines Regulatory Authorities.

About RCOREs

The Regional Centres of Regulatory Excellence (RCOREs) is an initiative of the AUDA-NEPAD. As part of its mandate to strengthen regulatory capacity development in Africa, AUDA-NEPAD through its AMRH programme has designated 11 RCOREs in eight different regulatory functions which include:

  • Pharmacovigilance
  • Training in core regulatory functions
  • Quality assurance and quality control of medicines
  • Medicine registration and evaluation, quality assurance/quality control and clinical trials oversight
  • Licensing of the manufacture, import, export, distribution and inspection and surveillance of manufacturers, importers, wholesalers and dispensers of medicine
  • Clinical trials oversight
  • Registration and evaluation and clinical trials oversight
  • Medicine evaluation and registration

Source: SAHPRA

Categories : Gender GeneticsTags :

Scientists Finally Create an Accurate Map of the Y Chromosome

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Photo by Sangharsh Lohakare on Unsplash

Long overlooked by genetics, the Y chromosome is surprisingly quite challenging to sequence, and so its contributions to health and disease remain largely unknown. For the first time, the complete sequences of 43 human Y chromosomes from lineages from around the globe provides an essential step forward in understanding the roles of the Y chromosome in human evolution and biology. The researchers behind the effort published their findings in two papers in Nature.

Even as the field of human genomics forged ahead at an astonishing pace, the Y chromosome has long remained overlooked. It has been postulated that the human sex chromosomes once originated from a pair of structurally similar chromosomes, but subsequently one of the sex chromosomes, the ancestral Y chromosome, underwent significant degradation, losing 97%of its former complement of genes over many millions of years. This peculiar evolutionary trajectory has given rise to speculation that the human Y chromosomes might eventually disappear completely, albeit millions of years from now, and we already observe that some biological males do lose them in dividing cells as they age, with unclear health consequences.

In practical terms, the Y chromosome contains a large proportion of repetitive and heterochromatic (highly condensed, gene-poor and not transcribed to messenger RNA) sequences, making it exceptionally difficult to fully sequence. Using sequencing methods that can cover long, continuous sequences, the Telomere-to-Telomere (T2T) consortium has now published the first complete Y chromosome assembly from a single individual of European descent in Nature. At the same time, a team led by Jackson Laboratory (JAX) Professor and The Robert Alvine Family Endowed Chair Charles Lee, PhD, FACMG, has published, also in Nature, the assembled Y chromosomes from 43 unrelated males, with nearly half coming from African lineages. These two papers provide intriguing insights into human Y chromosomes, reveal the highly variable nature of Y chromosomes across individuals, and provide an important foundation for future studies on how they may be contributing to certain disorders and diseases.

The need for long reads

Standard short-read genomic sequencing technologies require breaking genomic DNA into short (~250-base-long) fragments. These fragments are then reassembled into the full genome of more than 3 billion base pairs across 46 chromosomes in humans. The method is very accurate and works well for most, but not all, of the genome. Almost all “complete” human genome sequences, including the current reference genome sequence (known as GRCh38), are actually only about 90% complete, because it is difficult to assemble the highly repetitive and other complex sections accurately. GRCh38 falls particularly short for the Y chromosome, as it barely assembles half of that chromosome.

As a result, while the much larger and gene-rich X chromosome has been extensively studied, the Y chromosome has been often overlooked outside of male-based fertility studies. In a significant step forward for the genomics field, scientists from JAX, including first author and JAX Associate Research Scientist, Pille Hallast, PhD, with collaborators from Clemson University, Heinrich Heine University (Germany) and more, have now revealed a full picture of the Y chromosome’s key characteristics and differences between individuals for the first time. Of note is the striking variation in size and structure across the 43 Y chromosomes sequenced that covered 180 000 years of human evolution and range from 45.2 million to 84.9 million base pairs in length.

The inclusion of 43 different individuals representing diverse Y lineages allowed the researchers to redefine inter-chromosomal region boundaries and identify large-scale variations at an unprecedented resolution and clarity. The study also revealed an unexpected degree of structural variation across the Y chromosomes. For example, half of the euchromatin (gene-rich region) of the sequenced chromosomes carries large recurrent inversions (segments that contain the same nucleotide sequences but oriented in the opposite direction) at a rate much higher than anywhere else in the genome. The study further identified regions of the Y chromosome that demonstrate little single nucleotide variation but show high gene copy number variation for specific gene families. Other gene families tended to maintain their copy numbers, however, consistent with their roles in fertility and normal development.

Role in overall health

“Having fully resolved Y chromosome sequences from multiple individuals is essential in order for us to begin to understand how this variation can affect function” says Hallast. “The degree of structural variation between individuals came as a big surprise to me, even though the nucleotide sequences within the Y chromosome genes are comparatively conserved. The variable gene copy numbers in certain gene families and extremely high inversion rates are almost certain to hold significant biological and evolutionary roles.”

The Y chromosome’s contributions to male health are poorly understood. Some unexpected indications of its importance to human health have recently come into focus in two new research studies that collectively implicate the Y chromosome in aggressive features of colorectal and bladder cancers in men. Indeed, one of the studies showed that tumors that had lost the Y chromosomes can more effectively evade T cell immunity, are infiltrated with higher numbers of dysfunctional CD8+ T cells, and are more responsive to anti-PD1 treatments compared to similar tumors retaining the Y chromosome.

“Research is emerging that shows proper Y chromosome gene function is incredibly important for the overall health of men,” says Lee, senior author on the paper. “Our study enables the inclusion of the full Y chromosome in all future studies when sequencing male genomes to understand health and disease.”

Source: Jackson Laboratory

Categories : COVID Medical IndustryTags :

From Molecule to the Shelf

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Bada Pharasi, CEO of The Innovative Pharmaceutical Association of South Africa (IPASA)

Lessons from the COVID-19 pandemic have underlined the importance of continued investment into pharmaceutical innovation and R&D to not only bring life-saving medications to those in need, but to improve public health outcomes, writes Bada Pharasi, CEO of The Innovative Pharmaceutical Association of South Africa (IPASA).

From treatments for cancer, cardiovascular diseases and more recently, the COVID-19 vaccine, the pharmaceutical industry has made significant progress in the development of over 470 medications in the last 10 years alone.1

While the innovative pharmaceutical process typically takes between 10 and 15 years from discovery to regulatory approval2 – owing to factors including immense R&D costs, regulatory compliance, and the protection of patents3 – the fast-tracked development and approval of COVID-19 vaccines laid bare the need for pharmaceutical companies to be prepared to mitigate the risk of future outbreaks – and this means continued investment in innovation and R&D.

The pandemic underlined the need for countries to be prepared for outbreaks on the horizon. To ensure we can meet the next challenge, pharmaceutical innovations must match the pace at which diseases mutate. This kind of innovation is non-negotiable and requires continued investment as a safeguard against losing lives and endangering South Africa’s fragile healthcare system.

As we are in the midst of a cholera epidemic, as well as the recent measles outbreak,4 it’s important to continue driving innovation to treat diseases, with medicines developed by innovative pharmaceutical companies benefiting millions across the country every day.

This is evidenced by mortality rates for HIV/AIDS and TB in the country falling by 59.2% and 55.7% between 2007 and 2017, with at least 60 new medicines currently in the R&D pipeline to treat TB.5

While patents in pharmaceutical innovation protect the originators’ intellectual property, it is important that innovative medications be developed to ensure a continuous pipeline of access to generics once the patent has lost its exclusivity. This will drive consumer accessibility and affordability of life-saving treatments and medications that may otherwise be unattainable for many.

As we continue racing against the proverbial clock in protecting against current and future diseases, pharmaceutical companies should continue to invest in innovation and R&D to outsmart existing dreaded diseases, and provide agility and preparedness should the next unknown pandemic threaten. Our health, and lives, depend on it.

References:
1. #AlwaysInnovating: The pharmaceutical innovation journey [Internet]. IFPMA. 2023 [cited 2023 Jun 28]. Available from: https://www.ifpma.org/initiatives/alwaysinnovating/
2. Derep M. What’s the average time to bring a drug to market in 2022? [Internet]. N-SIDE; 2022 [cited 2023 Jun 28]. Available from: https://lifesciences.n-side.com/blog/what-is-the-average-time-to-bring-a-drug-to-market-in-2022
3. Ancliff S. 10 challenges facing the pharmaceutical industry in 2024 [Internet]. [cited 2023 Jun 29]. Available from: https://blog.i-nexus.com/10-challenges-facing-the-pharmaceutical-industry
4. Yoganathan V. Prepare for more pandemics in the future, experts warn [Internet]. Juta MedicalBrief. Medical Brief; 2023 [cited 2023 Jun 30]. Available from: https://www.medicalbrief.co.za/prepare-for-more-pandemic-in-the-future-experts-warn/
5. South Africa – the innovative hub for pharmaceutical development [Internet]. B2B Central. New Media; 2021 [cited 2023 Jun 29]. Available from: https://www.b2bcentral.co.za/why-south-africa-is-an-innovation-hub-for-pharmaceuticals/

Categories : NeurologyTags :

A Hidden Mathematical Rule Governs the Distribution of Neurons in the Brain

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Neuron densities in cortical areas in the mammalian brain follow a consistent distribution pattern. Image: Morales-Gregorio

Human Brain Project (HBP) researchers have uncovered how neuron densities are distributed across and within cortical areas in the mammalian brain. As reported in Cerebral Cortex, they have revealed a fundamental organisational principle of cortical cytoarchitecture: the ubiquitous lognormal distribution of neuron densities.

Numbers of neurons and their spatial arrangement play a crucial role in shaping the brain’s structure and function. Yet, despite the wealth of available cytoarchitectonic data, the statistical distributions of neuron densities remain largely undescribed. This new study from the HBP at Forschungszentrum Jülich and the University of Cologne (Germany) study advances our understanding of the organisation of mammalian brains.

The team accessed 9 publicly available datasets of seven species: mouse, marmoset, macaque, galago, owl monkey, baboon and human. After analysing the cortical areas of each, they found that neuron densities within these areas follow a consistent pattern – a lognormal distribution, pointing to a fundamental organisational principle underlying the densities of neurons in the mammalian brain.

A lognormal distribution is a statistical distribution characterised by a skewed bell-shaped curve. It arises, for instance, when taking the exponential of a normally distributed variable. It differs from a normal distribution in several ways. Most importantly, the curve of a normal distribution is symmetric, while the lognormal one is asymmetric with a heavy tail.

These findings are relevant for modelling the brain accurately. “Not least because the distribution of neuron densities influences the network connectivity,” says Sacha van Albada, leader of the Theoretical Neuroanatomy group at Forschungszentrum Jülich and senior author of the paper. “For instance, if the density of synapses is constant, regions with lower neuron density will receive more synapses per neuron,” she explains. Such aspects are also relevant for the design of brain-inspired technology such as neuromorphic hardware.

“Furthermore, as cortical areas are often distinguished on the basis of cytoarchitecture, knowing the distribution of neuron densities can be relevant for statistically assessing differences between areas and the locations of the borders between areas,” van Albada adds.

These results are in agreement with the observation that surprisingly many characteristics of the brain follow a lognormal distribution. “One reason why it may be very common in nature is because it emerges when taking the product of many independent variables,” says Alexander van Meegen, joint first author of the study. In other words, the lognormal distribution arises naturally as a result of multiplicative processes, similarly to how the normal distribution emerges when many independent variables are summed.

“Using a simple model, we were able to show how the multiplicative proliferation of neurons during development may lead to the observed neuron density distributions” explains van Meegen.

According to the study, in principle, cortex-wide organisational structures might be by-products of development or evolution that serve no computational function; but the fact that the same organisational structures can be observed for several species and across most cortical areas suggests that the lognormal distribution serves some purpose.

“We cannot be sure how the lognormal distribution of neuron densities will influence brain function, but it will likely be associated with high network heterogeneity, which may be computationally beneficial,” says Aitor Morales-Gregorio, first author of the study, citing previous works that suggest that heterogeneity in the brain’s connectivity may promote efficient information transmission. In addition, heterogeneous networks support robust learning and enhance the memory capacity of neural circuits.

Source: Human Brain Project

Categories : Neurodegenerative DiseasesTags :

Study Shows that Intermittent Fasting Might Improve Alzheimer’s Symptoms

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Photo by Matteo Vistocco on Unsplash

Circadian disruption is a hallmark of Alzheimer’s disease, affecting nearly 80% of patients with issues such as difficulty sleeping and worsening cognitive function at night. Currently there are no treatments for Alzheimer’s that target this aspect of the disease.

A new study in Cell Metabolism from researchers at University of California San Diego School of Medicine has shown in mice that it is possible to correct the circadian disruptions seen in Alzheimer’s disease with time-restricted feeding, a type of intermittent fasting focused on limiting the daily eating window without limiting the amount of food consumed.

In the study, mice that were fed on a time-restricted schedule showed improvements in memory and reduced accumulation of amyloid proteins in the brain. The authors say the findings will likely result in a human clinical trial.

“For many years, we assumed that the circadian disruptions seen in people with Alzheimer’s are a result of neurodegeneration, but we’re now learning it may be the other way around – circadian disruption may be one of the main drivers of Alzheimer’s pathology,” said senior study author Paula Desplats, PhD, professor at UC San Diego School of Medicine. “This makes circadian disruptions a promising target for new Alzheimer’s treatments, and our findings provide the proof-of-concept for an easy and accessible way to correct these disruptions.”

People with Alzheimer’s experience a variety of disruptions to their circadian rhythms, including changes to their sleep/wake cycle, increased cognitive impairment and confusion in the evenings, and difficulty falling and staying asleep.

“Circadian disruptions in Alzheimer’s are the leading cause of nursing home placement,” said Desplats. “Anything we can do to help patients restore their circadian rhythm will make a huge difference in how we manage Alzheimer’s in the clinic and how caregivers help patients manage the disease at home.”

Boosting the circadian clock is an emerging approach to improving health outcomes, and one way to accomplish this is by controlling the daily cycle of feeding and fasting. The researchers tested this strategy in a mouse model of Alzheimer’s disease, feeding the mice on a time-restricted schedule where they were only allowed to eat within a six-hour window each day. For humans, this would translate to about 14 hours of fasting each day.

Compared to control mice who were provided food at all hours, mice fed on the time-restricted schedule had better memory, were less hyperactive at night, followed a more regular sleep schedule and experienced fewer disruptions during sleep. The test mice also performed better on cognitive assessments than control mice, demonstrating that the time-restricted feeding schedule was able to help mitigate the behavioral symptoms of Alzheimer’s disease.

The researchers also observed improvements in the mice on a molecular level. In mice fed on a restricted schedule, the researchers found that multiple genes associated with Alzheimer’s and neuroinflammation were expressed differently. They also found that the feeding schedule helped reduce the amount of amyloid protein that accumulated in the brain. Amyloid deposits are one of the most well-known features of Alzheimer’s disease.

Because the time-restricted feeding schedule was able to substantially change the course of Alzheimer’s in the mice, the researchers are optimistic that the findings could be easily translatable to the clinic, especially since the new treatment approach relies on a lifestyle change rather than a drug.

“Time-restricted feeding is a strategy that people can easily and immediately integrate into their lives,” said Desplats. “If we can reproduce our results in humans, this approach could be a simple way to dramatically improve the lives of people living with Alzheimer’s and those who care for them.”

Categories : Cardiovascular Disease PaediatricsTags :

Sedentary Time in Children Linked to Later Cardiovascular Damage

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Photo by Victoria Akvarel on Pexels

Hours of inactivity during childhood could be setting the stage for heart attacks and strokes later in life, according to research presented at ESC Congress 2023. The large cohort study found that sedentary time accumulated from childhood to young adulthood was associated with heart damage – even in those with normal weight and blood pressure.

“All those hours of screen time in young people add up to a heavier heart, which we know from studies in adults raises the likelihood of heart attack and stroke,” said study author Dr Andrew Agbaje of the University of Eastern Finland, Kuopio, Finland. “Children and teenagers need to move more to protect their long-term health.”

This was the first study to investigate the cumulative effect of smartwatch-assessed sedentary time in young people and cardiac damage later in life. It was conducted as part of the Children of the 90s study, which began in 1990/1991 and is one of the world’s largest cohorts with lifestyle measurements from birth.

At 11 years of age, children wore a smartwatch with an activity tracker for seven days. This was repeated at 15 years of age and again at 24 years of age. The weight of the heart’s left ventricle was assessed by echocardiography, a type of ultrasound scan, at 17 and 24 years of age and reported in grams relative to height (g/m2.7). The researchers analysed the association between sedentary time between 11 and 24 years of age and heart measurements between 17 and 24 years of age after adjusting for factors that could influence the relationship including age, sex, blood pressure, body fat, smoking, physical activity and socioeconomic status.

The study included 766 children, of whom 55% were girls and 45% were boys. At 11 years of age, children were sedentary for an average of 362 minutes a day, rising to 474 minutes a day in adolescence (15 years of age), and 531 minutes a day in young adulthood (24 years of age). This means that sedentary time increased by an average of 169 minutes (2.8 hours) a day between childhood and young adulthood.

Each one-minute increase in sedentary time from 11 to 24 years of age was associated with a 0.004g/m2.7 increase in left ventricular mass between 17 to 24 years of age. When multiplied by 169 minutes of additional inactivity this equates to a 0.7g/m2.7 daily rise, the equivalent of a 3 gram increase in left ventricular mass between echocardiography measurements at the average height gain. A previous study in adults found that a similar increase in left ventricular mass (1g/m2.7) over a seven-year period was associated with a two-fold increased risk of heart disease, stroke, and death.4

Dr. Agbaje said: “Children were sedentary for more than six hours a day and this increased by nearly three hours a day by the time they reached young adulthood. Our study indicates that the accumulation of inactive time is related to heart damage regardless of body weight and blood pressure. Parents should encourage children and teenagers to move more by taking them out for a walk and limiting time spent on social media and video games. As Martin Luther King Jr. once said, ‘If you can’t fly, run. If you can’t run, walk. If you can’t walk, crawl. But by all means keep moving.'”

Source: European Society of Cardiology