Summary: For years, scientists treated “neuroinflammaging” — the slow, chronic inflammation linked to brain fog and memory loss — as an unavoidable aspect of aging. A new landmark study suggests that this process can be reversed. Researchers have developed a non-invasive intranasal therapy that delivers microscopic biological parcels directly to the brain. After just two doses, the treatment markedly reduced chronic inflammation, revitalized mitochondrial function, and restored memory and cognitive performance in aged models.
The therapy uses extracellular vesicles (EVs) loaded with regulatory microRNAs. Delivered through a nasal spray, these EVs reach the hippocampus and modulate immune and inflammatory pathways, producing rapid and lasting improvements in brain function.
Key Facts
- Fast, durable benefit: Noticeable cognitive gains occurred within weeks and persisted for months after only two intranasal doses.
- Effective across sexes: The treatment produced comparable results in both male and female models.
- Behavioral recovery: Treated animals regained the ability to recognize familiar items and respond to changes in their surroundings — signs of restored hippocampal function.
- Broad potential: Beyond age-related decline, the approach may be adaptable to support recovery after stroke or slow neurodegenerative diseases such as Alzheimer’s.
- Patent pending: Texas A&M has filed a U.S. patent, signaling movement toward clinical development.
Source: Texas A&M
Imagine your brain as a finely tuned engine that can run hot over time.
As we age, small, persistent pockets of inflammation build up in the hippocampus, producing a fog that interferes with thinking, forming memories, and adapting to new environments. This chronic inflammation also raises the risk of neurodegenerative conditions such as Alzheimer’s disease.
Scientists refer to this gradual process as neuroinflammaging. A team at Texas A&M’s Naresh K. Vashisht College of Medicine reports that intranasal delivery of human neural stem cell–derived EVs can substantially reverse that inflammatory state and restore cellular and cognitive function in aged models.
Led by Dr. Ashok Shetty, along with senior scientists Dr. Madhu Leelavathi Narayana and Dr. Maheedhar Kodali, the group demonstrated that two intranasal doses of EVs reduced markers of brain inflammation, improved mitochondrial health, and significantly enhanced memory-related behavior. These effects emerged within weeks and lasted for months.
Their results, published in the Journal of Extracellular Vesicles, could change how researchers approach brain aging and open a path to noninvasive therapies for age-related cognitive decline.
“Age-related brain disorders like dementia represent a major global health challenge,” Shetty said. “Our findings indicate that aspects of brain aging are reversible, offering a way to preserve mental sharpness, social engagement, and quality of life.”
From brain fog to restored focus: implications for cognitive therapy
If translated to humans, a simple two-dose nasal treatment could transform care for aging brains. This noninvasive approach could reduce reliance on long-term medications or invasive procedures, and it may be easier to scale and deliver to wide populations.
The public-health implications are significant. In the United States, new dementia cases are projected to rise substantially in coming decades, creating an urgent need for effective interventions that prevent or reverse cognitive decline.
“We need innovative therapies and policies to reduce both the incidence and severity of neurodegenerative diseases,” Shetty said. “This method produced consistent outcomes across sexes, which is uncommon in biomedical studies and encouraging for broader applicability.”
The team envisions future uses beyond normal aging — for instance, helping stroke survivors regain lost function or slowing disease progression in conditions like Alzheimer’s.
“Our goal is successful brain aging: to keep people alert, engaged, and connected as they grow older,” Shetty added.
How the therapy rewires the brain
The therapy centers on extracellular vesicles, tiny biological carriers that transport microRNAs and other molecular cargo. MicroRNAs regulate gene networks and signaling pathways that control inflammation and cellular metabolism.
Delivered intranasally, these EVs travel along olfactory pathways to the hippocampus, bypassing the blood–brain barrier. Once inside, microRNA cargo targets inflammatory drivers such as the NLRP3 inflammasome and the cGAS–STING pathway, dampening chronic immune activation.
At the cellular level, the therapy restored mitochondrial function — effectively recharging neurons’ energy systems. Reduced oxidative stress and improved mitochondrial respiratory chain integrity enhance neurons’ ability to process and store information.
Behavioral testing supported these molecular findings: treated animals showed improved recognition of familiar objects, better identification of novelty, and greater adaptability to changed environments compared with controls.
“We saw the brain’s repair mechanisms engage and reduce inflammation, allowing neuronal circuits to function more effectively,” Narayana said.
The researchers also identified specific microRNAs in the EVs — including miRNA-30e-3p and miRNA-181a-5p — that appear responsible for inhibiting the NLRP3 inflammasome and the STING pathway, respectively.
Encouraged by these results, the team has filed a U.S. patent to protect the approach and support future clinical development.
Behind the discovery
This work highlights Texas A&M’s capabilities in translational neuroscience and reflects collaboration with the National Institute on Aging. Funding and multidisciplinary expertise helped move the concept from laboratory research toward a therapy that could be tested in clinical trials.
“We are not only deciphering biological mechanisms but also translating our discoveries into practical treatments,” Shetty said. “Partnerships and resources are essential to develop solutions that can improve lives.”
By showing that the brain’s aging process can be modulated and partially reversed, this research opens a new chapter in cognitive health — one where age-related decline is no longer viewed as unavoidable, but as a condition we can actively treat.
Key Questions Answered:
A: Most drugs are blocked by the blood–brain barrier. This spray uses extracellular vesicles—small, naturally occurring particles the brain recognizes. Delivered through the nose, they travel along olfactory pathways directly into the hippocampus, bypassing the barrier.
A: No. In behavioral tests, older animals treated with the EVs regained cognitive abilities similar to younger subjects. The treatment reduced microglial-driven inflammation and restored neuronal function, effectively resetting aspects of brain aging.
A: The results are promising but currently limited to preclinical models. The therapy is in the research and patent stage, and clinical trials will be needed to determine safety and efficacy in people. Given the noninvasive delivery and cross-sex effectiveness, researchers anticipate advancement toward clinical testing.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full.
- Additional context was added by staff contributors.
About this brain aging research news
Author: Zaid Elayyan
Source: Texas A&M
Contact: Zaid Elayyan – Texas A&M
Image: Image credit: Neuroscience News
Original Research: Open access.
“Intranasal Human NSC-Derived EVs Therapy Can Restrain Inflammatory Microglial Transcriptome, and NLRP3 and cGAS-STING Signalling, in Aged Hippocampus” by Leelavathi N. Madhu et al., Journal of Extracellular Vesicles.
DOI: 10.1002/jev2.70232
Abstract
Intranasal Human NSC-Derived EVs Therapy Can Restrain Inflammatory Microglial Transcriptome, and NLRP3 and cGAS-STING Signalling, in Aged Hippocampus
Neuroinflammaging is a moderate, chronic, sterile inflammation of the hippocampus that contributes to age-related cognitive decline. It involves activation of the NLRP3 inflammasome and the cGAS–STING pathway, which triggers type I interferon signaling. Extracellular vesicles from human induced pluripotent stem cell–derived neural stem cells (hiPSC-NSC-EVs) carry therapeutic microRNAs that can reduce neuroinflammation.
This study evaluated late middle-aged (18-month-old) male and female C57BL/6J mice that received two intranasal doses of hiPSC-NSC-EVs and were assessed at 20.5 months. Compared with vehicle-treated animals, EV-treated hippocampi showed reduced astrocyte hypertrophy, fewer microglial clusters, lower oxidative stress, increased antioxidant proteins, and elevated expression of genes that support mitochondrial respiratory chain integrity.
The therapy lowered proteins associated with activation of the NLRP3 inflammasome, p38/MAPK, the cGAS–STING–IFN-1 axis, and JAK–STAT signaling. In vitro assays demonstrated that miRNA-30e-3p and miRNA-181a-5p in the EVs can inhibit NLRP3 and STING activation, respectively. Single-cell RNA sequencing seven days after treatment revealed widespread transcriptomic changes in microglia, including upregulation of genes for oxidative phosphorylation and downregulation of proinflammatory signaling genes. These molecular changes corresponded with improved cognitive and memory function.
In summary, intranasal hiPSC-NSC-EV therapy given in late middle age can reduce proinflammatory microglial programs and signaling cascades that drive neuroinflammaging in the hippocampus, leading to better brain function in old age.