Neurons in the brain of an Alzheimer’s patient, with plaques caused by tau proteins. Credit: NIH
A study led by researchers in the University of Florida College of Pharmacy has found that a pair of popular glucose-lowering medications may have protective effects against the development of Alzheimer’s disease and related dementias in patients with Type 2 diabetes.
In research published in JAMA Neurology on April 7, UF researchers studied Medicare claims data of older adults with Type 2 diabetes to assess the association among glucagon-like peptide-1 receptor agonists, or GLP-1RAs, sodium-glucose cotransporter-2 inhibitors, or SGLT2is, and the risk of Alzheimer’s disease and related dementias.
The research is supported by funding from the National Institute on Aging and the National Institute of Diabetes and Digestive and Kidney Diseases, both part of the National Institutes of Health.
The data showed a statistically significant association between a lower risk of Alzheimer’s and the use of GLP-1RAs and SGLT2is compared with other glucose-lowering medications. According to the researchers, the findings indicated that the two drugs may have neuroprotective effects for people without diabetes and may help slow the rate of cognitive decline in Alzheimer’s patients.
Serena Jingchuan Guo, MD, PhD, an assistant professor of pharmaceutical outcomes and policy and the study’s senior author, said these findings may point to new therapeutic uses for drugs commonly used to treat Type 2 diabetes and obesity.
“It’s exciting that these diabetes medications may offer additional benefits, such as protecting brain health,” Guo said. “Based on our research, there is promising potential for GLP-1RAs and SGLT2is to be considered for Alzheimer’s disease prevention in the future. As use of these drugs continues to expand, it becomes increasingly important to understand their real-world benefits and risks across populations.”
As the study only included patients with Type 2 diabetes, Guo said next steps include evaluating the effects of the two drugs in broader populations by using recent, real-world data that captures their growing use in clinical settings.
“Future research should focus on identifying heterogeneous treatment effects – specifically, determining which patients are most likely to benefit and who may be at greater risk for safety concerns,” Guo said.
A University of Iowa-led research team has found that urinary incontinence may be associated with a greater risk for cardiovascular disease in women.
Urinary incontinence is a common condition, especially in older adults. Previous studies have stated that it can affect between 38% and 60% of women. The researchers aimed to find out whether urinary incontinence was linked to a decline in physical activity, which can lead to a host of health issues, including greater risk for cardiovascular disease.
In the study, the researchers – led by Lisa VanWiel, assistant professor at the University of Wisconsin-La Crosse who in April earned her doctorate in health and human physiology from Iowa – analysed medical records over two years from more than 20 000 female patients in the Hartford Healthcare system in Connecticut. Of those patients, 5.4% reported through a questionnaire to have urinary incontinence. All patients were asked to rate their level of physical activity in the questionnaire.
The researchers found that the respondents with urinary incontinence did not report engaging in less physical activity than those who did not have the condition. But the team did find an association between patients with urinary incontinence and cardiovascular disease risk factors or events, such as dyslipidemia, type 2 diabetes, and stroke.
“There is an association between incontinence and cardiovascular disease (CVD) risk,” the study authors write. “Women should be screened for incontinence regularly as it may contribute to CVD risk, and women with CVD risk factors should be screened for undiagnosed incontinence.”
New insights into dopamine in focal cortical dysplasia: For the first time, a research team in Bonn is systematically investigating the role of the dopamine system in a common form of therapy-resistant epilepsy. Their research, published in Brain, has found major changes in the signalling pathway in a brain malformation linked to treatment-resistant epilepsy.
Focal cortical dysplasia (FCD) type 2 is a congenital malformation of the cerebral cortex associated with hard-to-treat epilepsy. In the affected areas, nerve cells and their layer structures are arranged abnormally, impeding drug therapy. A research team from the University Hospital Bonn (UKB) and the University of Bonn, in collaboration with the German Center for Neurodegenerative Diseases (DZNE), has now found evidence of profound changes in the dopamine system in FCD type 2.
Dopamine is a central neurotransmitter that regulates attention, learning and the excitability of neuronal networks, among other things. Whether and how this system is affected by FCD has so far remained largely unclear. The current study shows that the dopaminergic supply in the affected brain areas is altered. In addition, an increased expression of certain dopamine receptors was observed – both in human tissue and in a corresponding mouse model.
Evidence of disturbed modulation in the developing cortex
“Our data suggest a disrupted dopaminergic system in FCD type 2,” explains Norisa Meli, a doctoral student at the University of Bonn at the Institute for Reconstructive Neurobiology at the UKB and first author of the study. ”Particularly striking was the significantly increased expression of dopaminergic receptors in the neurons that are central role to the disease process.”
These changes could play a role in the development of epileptic seizures – and possibly also explain why many sufferers also experience concentration problems or mood swings.
“Dopamine modulates the excitability of neuronal networks and their formation in the developing cortex,” emphasizes Prof. Sandra Blaess, Professor of Neurodevelopment at UKB and member of the TRA ‘Life & Health’ at the University of Bonn. ”Our results show that this modulation may be disturbed in FCD type 2 – an aspect that has hardly been investigated to date.”
Prof. Albert Becker, Head of Department at the Institute for Cellular Neuroscience II at the UKB and also a member of the TRA “Life & Health” at the University of Bonn, adds: “These findings broaden our understanding of the complex neuropathology of dysplasias. They provide important clues for new potential therapeutic approaches that could go beyond the mere control of seizures.”
The study combines comprehensive molecular analyses of human tissue samples with a preclinical mouse model that replicates the genetic changes in FCD type 2. The researchers hope that these results will contribute to more targeted and effective treatment strategies in the long term.
Retina showing reticular pseudodrusen. Although they can infrequently appear in individuals with no other apparent pathology, their highest rates of occurrence are in association with age-related macular degeneration (AMD), for which they hold clinical significance by being highly correlated with end-stage disease sub-types, choroidal neovascularisation and geographic atrophy. Credit: National Eye Institute
A new study by Brown University researchers suggests that gold nanoparticles might one day be used to help restore vision in people with macular degeneration and other retinal disorders.
In a study published in the journal ACS Nano and supported by the National Institutes of Health, the research team showed that nanoparticles injected into the retina can successfully stimulate the visual system and restore vision in mice with retinal disorders. The findings suggest that a new type of visual prosthesis system in which nanoparticles, used in combination with a small laser device worn in a pair of glasses or goggles, might one day help people with retinal disorders to see again.
“This is a new type of retinal prosthesis that has the potential to restore vision lost to retinal degeneration without requiring any kind of complicated surgery or genetic modification,” said Jiarui Nie, research leader and now a postdoctoral researcher. “We believe this technique could potentially transform treatment paradigms for retinal degenerative conditions.”
Nie performed the work while working in the lab of Jonghwan Lee, an associate professor in Brown’s School of Engineering and a faculty affiliate at Brown’s Carney Institute for Brain Science, who oversaw the work and served as the study’s senior author.
Retinal disorders like macular degeneration and retinitis pigmentosa affect millions of people in the U.S. and around the world. These conditions damage light-sensitive cells in the retina called photoreceptors — the “rods” and “cones” that convert light into tiny electric pulses. Those pulses stimulate other types of cells further up the visual chain called bipolar and ganglion cells, which process the photoreceptor signals and send them along to the brain.
This new approach uses nanoparticles injected directly into the retina to bypass damaged photoreceptors. When infrared light is focused on the nanoparticles, they generate a tiny amount of heat that activates bipolar and ganglion cells in much the same way that photoreceptor pulses do. Because disorders like macular degeneration affect mostly photoreceptors while leaving bipolar and ganglion cells intact, the strategy has the potential to restore lost vision.
In this new study, the research team tested the nanoparticle approach in mouse retinas and in living mice with retinal disorders. After injecting a liquid nanoparticle solution, the researchers used patterned near-infrared laser light to project shapes onto the retinas. Using a calcium signal to detect cellular activity, the team confirmed that the nanoparticles were exciting bipolar and ganglion cells in patterns matched the shapes projected by the laser.
The experiments showed that neither the nanoparticle solution nor the laser stimulation caused detectable adverse side effects, as indicated by metabolic markers for inflammation and toxicity. Using probes, the researchers confirmed that laser stimulation of the nanoparticles caused increased activity in the visual cortices of the mice — an indication that previously absent visual signals were being transmitted and processed by the brain. That, the researchers say, is a sign that vision had been at least partially restored, a good sign for potentially translating a similar technology to humans.
For human use, the researchers envision a system that combines the nanoparticles with a laser system mounted in a pair of glasses or goggles. Cameras in the goggles would gather image data from the outside world and use it to drive the patterning of an infrared laser. The laser pulses would then stimulate the nanoparticles in people’s retinas, enabling them to see.
The approach is similar to one that was approved by the Food and Drug Administration for human use a few years ago. The older approach combined a camera system with a small electrode array that was surgically implanted in the eye. The nanoparticle approach has several key advantages, according to Nie.
For starters, it’s far less invasive. As opposed to surgery, “an intravitreal injection is one of the simplest procedures in ophthalmology,” Nie said.
There are functional advantages as well. The resolution of the previous approach was limited by the size of the electrode array — about 60 square pixels. Because the nanoparticle solution covers the whole retina, the new approach could potentially cover someone’s full field of vision. And because the nanoparticles respond to near-infrared light as opposed to visual light, the system doesn’t necessarily interfere with any residual vision a person may retain.
More work needs to be done before the approach can be tried in a clinical setting, Nie said, but this early research suggests that it’s possible.
“We showed that the nanoparticles can stay in the retina for months with no major toxicity,” Nie said of the research. “And we showed that they can successfully stimulate the visual system. That’s very encouraging for future applications.”
Even vegans who get enough total protein may fall short for some essential amino acids
In New Zealand study, 3 in 4 vegans ate sufficient protein, but half didn’t meet daily lysine and leucine requirements
In a new study of people with long-term vegan diets, most ate an adequate amount of total daily protein, but a significant proportion did not meet required levels of the amino acids lysine and leucine. Bi Xue Patricia Soh and colleagues at Massey University, New Zealand, present these findings in the open-access journal PLOS One on April 16, 2025.
Proteins are made up of various molecular “building blocks” known as amino acids. While the human body can synthesise most of the amino acids we need to live, we completely rely on the food we eat to provide the nine “indispensable amino acids” we cannot make ourselves. Typically, plant-based foods have more varied levels of indispensable amino acids that the body can use, as compared to animal-sourced foods, so they are of particular concern in vegan diets.
However, most prior research on protein in vegan diets has not considered specific amino acids nor the digestibility of different foods, which accounts for the fact that not all of what we eat, including amino acids, is fully utilised by the body.
To help deepen understanding of amino acid intake in vegan diets, Soh and colleagues analysed detailed, four-day food diaries kept by 193 long-term vegans living in New Zealand. They used information from the United States Department of Agriculture and the New Zealand FoodFiles database to calculate participants’ intake of different amino acids from the different foods they ate.
The analysis showed that about three quarters of participants met daily total protein requirements. Accounting for body weight, intake of all indispensable amino acids also met requirements.
However, when considering digestibility, only about half of the participants met daily requirements for lysine and leucine levels, making them the most limiting indispensable amino acids in the study. Among the food types consumed by participants, legumes and pulses were the biggest contributors to overall protein and lysine intake.
These findings underscore that meeting total daily protein requirements does not necessarily mean meeting indispensable amino acid requirements. On the basis of their findings, the researchers call for future research to explore how intake of leucine and lysine could be boosted for vegans in a nutritionally balanced manner.
The authors add: “Vegan diets are the most restrictive form of plant-based eating, relying entirely on plant sources for all nutrients. Achieving high protein quality on a vegan diet requires more than just consuming enough protein – it also depends on the right balance and variety of plant foods to supply all the amino acids in the quantities that our body needs. Prolonged deficiencies in these essential nutrients can negatively affect overall protein balance, muscle maintenance and other physiological functions, especially in more vulnerable populations.”
“In our study, lysine and leucine were the most commonly under-consumed amino acids in our vegan cohort and fall below the daily requirements needed by our body. This is because many plant foods generally contain lower quantities of these amino acids that can be absorbed and utilised by the body. However, the inclusion of legumes, nuts and seeds emerged as valuable plant sources – not only to support overall protein intake but also to specifically increase lysine and leucine quantities in a vegan diet.”
