Maraviroc Fights Middle-Aged Memory Loss

News
#1

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UCLA researchers have discovered a key molecular mechanism behind memory linking. They’ve also identified a way to restore this brain function in middle-aged mice – and an FDA-approved drug that achieves the same thing.

Boosting CCR5 gene expression in the brains of middle-aged mice interfered with memory linking. The animals forgot the connection between the two cages.

When the scientists deleted the CCR5 gene in the animals, the mice were able to link memories that normal mice could not.

Silva had previously studied the drug, maraviroc, which the U.S. Food and Drug Administration approved in 2007 for the treatment of HIV infection. His lab discovered that maraviroc also suppressed CCR5 in the brains of mice.

“When we gave maraviroc to older mice, the drug duplicated the effect of genetically deleting CCR5 from their DNA,” said Silva, a member of the UCLA Brain Research Institute. “The older animals were able to link memories again.”

Research Paper:

Nature: CCR5 closes the temporal window for memory linking

https://www.nature.com/articles/s41586-022-04783-1

Maraviroc Drug Information

11 Likes
#2

A Pill to Heal the Brain Could Revolutionize Neuroscience

Neurologists are exploring medications that would help the brain recover after a stroke or traumatic injury.

https://www.nytimes.com/2025/09/04/science/neuroscience-brain-injury-pill.html?smid=nytcore-ios-share&referringSource=articleShare

@RapAdmin This suggests translational relevance in humans! See details re: Israeli study.

3 Likes
#3

Seems like something anyone who has interest in maintaining / improving their middle-aged memory, or anyone who had a stroke recently would want to research more.

Perhaps something we want to try for memory improvement, or keep in the bathroom cupboard in case of stroke (like aspirin)? It was available easily from India (at least until recently):

From recent The NY Times article linked to above:

The foundation connected them to Dr. Einor Ben Assayag, a neurologist at Tel Aviv University in Israel who was tracking a cohort of 600 stroke patients to see which ones developed dementia.

Amazingly, she had kept blood samples of every patient, in addition to cognitive evaluations over time. When she analyzed her data, she found that patients with some form of the CCR5 mutation had better language, memory and attention scores. This was groundbreaking: They had identified the first gene associated with stroke recovery.

But the researchers had more than just a target; they also had a drug that mimicked the mutation. Tawnie Silva, Dr. Silva’s wife and a researcher in his lab, had found it while researching the mutant mouse strain: a little-known H.I.V. treatment that had been approved by the Food and Drug Administration in 2007. It was called Maraviroc.

“I mean, that’s a unicorn kind of thing,” Dr. Silva said. “That’s incredibly rare.”

As it turned out, the CCR5 receptor was also known as the portal that H.I.V. binds to in order to enter cells. In the 2000s, as the deadly virus gained resistance to older medications, Pfizer developed a drug that blocked this portal and protected cells from infection.

But no one had looked at what Maraviroc might be doing in the brain. In 2019, Dr. Carmichael laid out three lines of evidence showing that Maraviroc boosted neuroplasticity after brain injury, and published his findings in a landmark paper in the journal Cell.

…

Maraviroc is not a perfect drug, Dr. Carmichael said. It does cross the blood-brain barrier, but only in limited amounts. That’s why his allegiance is not to one drug, but to laying the groundwork for future therapies by deepening the understanding of the brain’s recovery systems.

He recently identified a drug that produced a similar effect in the brain, leading to better motor recovery in mice. While promising, it would take years and “a lot of non-sexy science” to bring this “neurorehabilitation pill” to market, he said.

If any of these therapies make it to F.D.A. approval, it could change not only the way doctors treat brain injury patients, but also the way those patients imagine their own futures.

Other Related News articles:

Indian Sources and Pricing

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Related Papers:

Parvalbumin interneurons regulate rehabilitation-induced functional recovery after stroke and identify a rehabilitation drug

https://www.nature.com/articles/s41467-025-57860-0

CCR5 closes the temporal window for memory linking

Real-world memories are formed in a particular context and are often not acquired or recalled in isolation1,2,3,4,5. Time is a key variable in the organization of memories, as events that are experienced close in time are more likely to be meaningfully associated, whereas those that are experienced with a longer interval are not1,2,3,4. How the brain segregates events that are temporally distinct is unclear. Here we show that a delayed (12–24 h) increase in the expression of C-C chemokine receptor type 5 (CCR5)—an immune receptor that is well known as a co-receptor for HIV infection6,7—after the formation of a contextual memory determines the duration of the temporal window for associating or linking that memory with subsequent memories. This delayed expression of CCR5 in mouse dorsal CA1 neurons results in a decrease in neuronal excitability, which in turn negatively regulates neuronal memory allocation, thus reducing the overlap between dorsal CA1 memory ensembles. Lowering this overlap affects the ability of one memory to trigger the recall of the other, and therefore closes the temporal window for memory linking. Our findings also show that an age-related increase in the neuronal expression of CCR5 and its ligand CCL5 leads to impairments in memory linking in aged mice, which could be reversed with a Cc r5 knockout and a drug approved by the US Food and Drug Administration (FDA) that inhibits this receptor, a result with clinical implications. Altogether, the findings reported here provide insights into the molecular and cellular mechanisms that shape the temporal window for memory linking.

Paywalled paper:

https://www.nature.com/articles/s41586-022-04783-1

Maraviroc-Cognitive-Vitality-For-Researchers.pdf (351.9 KB)

2 Likes
#4

This seems like a product that people could try themselves, doing comprehensive memory testing pre and post dosing, to test and gauge effectiveness. The side effects seem pretty benign, and smaller doses could be tried before working up to higher doses.

The FDA approved maraviroc in 2007 as an antiretroviral drug (ARV) for people with HIV infection.

HOW IS MARAVIROC TAKEN?

Maraviroc is taken by mouth as a tablet or oral solution. The recommended dosage of maraviroc for adults depends upon what other medications are taken. The dosages are:

    • 300 mg daily, taken as 150 mg twice daily
    • 600 mg daily, taken as 300 mg twice daily
    • 1,200 mg daily, taken as 600 mg twice daily

The standard dose is 600 mg daily taken as 300 mg twice daily, in combination with other ARVs. Your healthcare provider will decide which dosage regimen is best for you based on your medical conditions and the other medicines you take.

WHAT ARE THE SIDE EFFECTS?

When you start any ARV, you may have temporary side effects such as headaches, nausea, indigestion, or a general sense of feeling ill. These side effects usually get better or disappear over time.

The most common side effects of maraviroc in adults are colds and cold-like symptoms, cough, fever, rash, bloating and gas, indigestion, constipation, and dizziness.

Maraviroc can cause serious side effects including:

Serious liver problems (liver toxicity). Some people who take maraviroc can develop a severe rash or an allergic reaction before liver problems happen and may be life-threatening. Stop taking maraviroc and call your healthcare provider right away if you get any of the following signs or symptoms of liver problems:

    • An itchy rash on your body (allergic reaction)
    • Your skin or the white part of your eyes turns yellow (jaundice)
    • Dark or “tea-colored” urine
    • Pale colored stools (bowel movements)
    • Nausea or vomiting
    • Pain, aching, or tenderness on the right side of your stomach area

Your healthcare provider will do blood tests to check your liver before you begin treatment with maraviroc and as needed during treatment with maraviroc.

Severe skin rash and allergic reactions. Severe and potentially life-threatening skin reactions and allergic reactions have been reported in some people taking maraviroc. If you develop a rash with any of the following symptoms, stop using maraviroc and contact your healthcare provider right away:

    • Fever
    • Generally ill feeling
    • Muscle aches
    • Blisters or sores in your mouth
    • Blisters or peeling of the skin
    • Redness or swelling of the eyes
    • Swelling of the mouth, face, or lips
    • Problems breathing
    • Yellowing of the skin or whites of your eyes
    • Dark or tea-colored urine
    • Pain, aching, or tenderness on the right side below the ribs
    • Loss of appetite
    • Nausea/vomiting

Heart problems, including heart attack.

Low blood pressure when standing up (postural hypotension). Low blood pressure can cause dizziness or fainting. You should avoid driving or operating heavy machinery if you have dizziness during treatment with maraviroc.

Source: maraviroc (Selzentry) – International Association of Providers of AIDS Care

1 Like
#5

Interesting information on the Maraviroc study for stroke patients:

The Canadian Maraviroc Randomized Controlled Trial To Augment Rehabilitation Outcomes After Stroke (CAMAROS)

Experimental: Maraviroc (Celsentri)

Maraviroc (Celsentri) will be administered to this group. Participants will be administered a dose of 300mg to be taken twice per day for the duration of the exercise intervention (8 weeks).

Exclusion Criteria:

  1. Pre-stroke modified Rankin score ≥ 2
  2. Limited resources or illness that will not enable a return to living outside of a facility
  3. History of dementia
  4. History of hepatitis or elevated hepatic transaminases or bilirubin
  5. History of renal insufficiency or creatinine clearance (eGFR) < 60mL / min / 1.73m2
  6. Cancer or other chronic illness that makes 1-year survival unlikely or will detract from the ability to carry out exercise and skills practice
  7. Existing pre-stroke serious disabling disease (e.g., Parkinson’s disease, severe traumatic brain injury, amputation)
  8. Seizure related to stroke
  9. Acute or chronic epilepsy
  10. Currently taking any of the following anticonvulsant medications:
  • Carbamazepine
  • Phenobarbital
  • Phenytoin
  1. Pregnant, breastfeeding, or positive test for pregnancy at baseline
  2. Women of childbearing potential who are not using one highly effective form of contraception or two forms of effective contraception
  3. Known HIV positivity
  4. Currently taking any of the following antifungal and/or antibacterial medications:
  • Ketoconazole
  • Itraconazole
  • Voriconazole
  • Rifampin
  • Clarithromycin
  • Rifabutin + Protease Inhibitor
  1. Currently taking St. John’s Wort
  2. Currently taking Paxlovid

Full study information:

https://clinicaltrials.gov/study/NCT04789616

#6

from the NYT article it sounds as though humans with the mutation that mimics Maraviroc’s effects have lower dementia incidence and learn better. So it might not just be something to collect dust on the shelf until a stroke happens.

2 Likes
#7

Absolutely. This definitely is worthy of some additional research.

Here is the AI summary of the paper mentioned earlier where they looked at the role of CCR5 in memory:

CCR5 closes the temporal window for memory linking

Here’s a detailed summary of the paper “CCR5 closes the temporal window for memory linking” (Shen et al., Nature, 2022):

Introduction

The study explores how the brain determines whether two experiences occurring close in time are stored as linked memories or kept separate. Normally, events close in time can trigger each other’s recall (a phenomenon called memory linking), while events far apart are stored independently. The authors focus on the role of CCR5, a receptor better known for its role in immune responses and as a co-receptor for HIV, in regulating this temporal linking process.

Key Findings

1. CCR5 Expression Increases After Learning

  • Using contextual fear conditioning in mice, the authors showed that CCR5 and its ligand CCL5 become more highly expressed in hippocampal neurons (specifically in the dorsal CA1 region) about 12–24 hours after learning.
  • This increase occurs mainly in excitatory neurons, not in microglia.
  • The delayed CCR5 activity aligns with the closing of the window during which two memories can be linked.

2. CCR5 Determines the Temporal Window for Memory Linking

  • Behavioral experiments:

    • Mice exposed to two contexts within 5 hours linked the memories (recall of one triggered recall of the other).
    • When contexts were separated by 1–7 days, linking was much weaker.

  • Manipulation experiments:

    • Artificially increasing CCR5 activity (via CCL5 infusion or optogenetic activation) shortened the linking window.
    • Suppressing CCR5 (via shRNA knockdown or genetic knockout) extended the linking window, allowing memories separated by several days to still be linked.

3. Mechanism: CCR5 Reduces Neuronal Excitability and Memory Overlap

  • CCR5 activation decreases excitability of hippocampal neurons.
  • Reduced excitability means neurons from a first memory are less likely to be reused for a second memory, lowering ensemble overlap.
  • This reduced overlap explains why memories separated by longer times are stored independently instead of being linked.
  • In CCR5 knockouts, neuronal ensembles for different memories had much more overlap, keeping them linked even when temporally distant.

4. Age-Related Effects

  • Older mice naturally show higher CCR5 and CCL5 expression in hippocampal neurons, which correlates with poorer memory linking, even when events are only hours apart.
  • Blocking CCR5 genetically (knockout mice) or pharmacologically with maraviroc (an FDA-approved CCR5 inhibitor used in HIV treatment) rescued memory linking in aged mice.
  • This finding suggests CCR5 contributes to age-related cognitive decline and may be a therapeutic target.

Broader Implications

  • The research identifies CCR5 as a molecular “brake” on memory linking.
  • By closing the linking window, CCR5 prevents unrelated events far apart in time from being stored as connected.
  • Dysregulation of this system may contribute to psychiatric disorders like PTSD or schizophrenia, where abnormal memory linking occurs.
  • Clinically, the ability of maraviroc to rescue memory linking in older mice hints at possible future treatments for age-related memory impairments.

Conclusion

The study shows that CCR5 acts as a regulator that closes the temporal window of memory linking by reducing neuronal excitability and decreasing overlap between memory ensembles. This mechanism helps the brain separate distinct events but may also underlie age-related memory deficits. The fact that an FDA-approved CCR5 blocker can reverse these effects highlights the therapeutic potential of targeting CCR5 in memory-related disorders.

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Original paper"
https://www.nature.com/articles/s41586-022-04783-1

Memory Improvements Seen in Study

The paper (Shen et al., Nature, 2022) does not quantify memory improvements from CCR5 inhibition in terms of a precise percentage or standardized effect size. However, it provides clear behavioral evidence in mice that blocking CCR5 substantially improves memory linking ability:

Key Evidence

  • Wild-type mice: Could only link two contextual memories if they were separated by about 5 hours. If the memories were separated by 1–7 days, the animals failed to link them (freezing behavior in the earlier context dropped to baseline levels).
  • CCR5 knockdown or knockout mice: Retained the ability to link memories even when they were separated by two or seven days, showing strong freezing responses comparable to the more recent memories.
  • Aged mice: Normally show impaired memory linking even at short intervals (5 hours). When treated with maraviroc (an FDA-approved CCR5 antagonist), or in CCR5 knockout animals, the memory linking deficit was reversed: aged animals regained the ability to link memories that they otherwise could not.

Interpretation

  • Extent of improvement: CCR5 inhibition extended the memory linking window from hours (in wild-type mice) to several days (in CCR5 knockouts or inhibitor-treated mice).
  • In aging, where memory linking was impaired even at short intervals, CCR5 inhibition restored performance to a level comparable to young mice.
  • The paper demonstrates robust functional recovery, but does not translate this into a numerical “percent improvement” that could be applied directly to humans.

Clinical Implication

The results suggest that CCR5 inhibitors (like maraviroc) might significantly enhance memory flexibility and linking, especially in aging or disease contexts, but the magnitude of improvement is currently only shown qualitatively in animal models.

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#8

A study looking at CCR5 in APOE4 genetic risk situations:

Here’s a detailed summary of the paper “CCR5 deficiency normalizes TIMP levels, working memory, and gamma oscillation power in APOE4 targeted replacement mice” (Greco et al., Neurobiology of Disease, published April 2023) (PMC):

Background & Rationale

  • The APOE4 allele is the primary genetic risk factor for Alzheimer’s disease (AD), elevating risk in a dose-dependent manner. Even in cognitively normal elderly individuals, APOE4 is linked to cognitive decline (PMC).
  • In mice engineered to express human APOE4 (targeted replacement or TR mice), researchers observe:
    • Reduced dendritic complexity, which likely impairs neuronal connectivity.
    • Deficits in learning and memory tasks.
    • Lower power in gamma oscillations, a neural rhythm (typically 20–55 Hz) that supports memory and cognitive processes (PMC, PubMed).
  • The extracellular matrix (ECM) in the brain, particularly dense structures around neurons termed perineuronal nets (PNNs), can limit neuroplasticity and reduce gamma power. This effect can be reversed through enzymatic ECM degradation (PMC).
  • The chemokine CCL5 promotes ECM deposition (demonstrated in peripheral organs) and can impair neuronal excitability and plasticity. Its receptor, CCR5, is linked with reduced brain plasticity (PMC).
  • Tissue inhibitors of metalloproteinases (TIMPs) suppress MMPs—enzymes that degrade ECM—thereby promoting ECM buildup and potentially limiting neuroplasticity (PMC).

Objective: To examine whether the CCL5–CCR5 axis and elevated TIMPs contribute to the cognitive and neural dysfunction in APOE4, and whether reducing CCR5 would reverse these deficits.

Key Experiments & Findings

1. Elevated CCL5 and TIMPs in APOE4

  • Human data: CSF from APOE4 individuals showed higher levels of CCL5 and TIMP‑1/TIMP‑3, compared to APOE3 carriers (PubMed).
  • APOE4 TR mice similarly displayed increased CCL5 and TIMP‑1 in brain lysates and astrocyte-conditioned media (PMC).

This suggests an environment with reduced ECM degradation—an anti-plasticity milieu—in APOE4 subjects.

2. CCR5 Knockout Enhances Neural Activity

  • Mice lacking CCR5 showed significantly increased EEG gamma power (20–55 Hz) compared to wild-type controls (p = 0.0063) (PMC).
  • In APOE4/TR + CCR5 KO heterozygous mice, gamma power was significantly higher than in APOE4/TR with functional CCR5 (p = 0.0062) (PMC).

3. CCR5 Reduction Restores TIMP Levels and Cognitive Function

  • Normalization of TIMP‑1 levels was observed in APOE4/CCR5 KO mice compared to APOE4 counterparts (PMC).
  • Behaviorally, APOE4/CCR5 KO mice demonstrated improved working memory (T-maze tests) and enhanced long-term memory (fear conditioning tasks), relative to APOE4 control mice (PMC).

Interpretation & Mechanistic Insight

  • The study highlights a CCR5–CCL5–TIMP pathway that contributes to ECM accumulation and consequent plasticity and cognitive deficits in APOE4 contexts.
  • By knocking out CCR5, researchers observed:
    • Reduced TIMP levels (allowing more ECM degradation),
    • Elevated gamma oscillation power (reflecting increased neural synchrony and excitability),
    • And notably, rescued memory and learning performance.
  • These results suggest that ECM modulation via the CCR5 axis is pivotal in mediating APOE4-related cognitive dysfunction.

Summary Table

Component Finding
APOE4 effects ↑ CCL5 and TIMPs in CSF and brain; ↓ gamma power, dendritic complexity, and learning
CCR5 knockout effect ↑ gamma oscillations; normalization of TIMP levels
Cognitive outcomes Improved working and long-term memory in APOE4/CCR5 KO mice
Mechanism CCR5-mediated ECM accumulation restricts neuroplasticity; its reduction restores plasticity and function

Significance & Implications

  • The study elegantly links APOE4 genetic risk to downstream molecular and circuit-level changes—via ECM regulators—that impair cognitive function.
  • It reveals CCR5 as a potential therapeutic target: inhibiting CCR5 might reduce ECM constraints, enhance neural oscillations, and reverse memory deficits in APOE4 carriers.
  • These insights add a novel dimension to AD research by emphasizing the role of ECM and synaptic milieu, beyond hallmark amyloid and tau pathology.
1 Like
#9

Another recent paper:

The contributing role of CCR5 in dementia

Here’s a detailed, college-level summary of the review article “The contributing role of CCR5 in dementia” (Zheng et al., Frontiers in Neurology, 2025) — an in-depth exploration of how C‑C chemokine receptor 5 (CCR5) influences cognitive decline across multiple dementia-related conditions:

Overview & Context

  • Dementia refers to the progressive impairment of cognitive faculties—such as memory, language, attention, orientation, and judgment—with rising prevalence worldwide, projected to affect over 150 million people by 2050 (PMC).
  • CCR5 is a G-protein-coupled receptor (GPCR) widely known for its role in immune function and as an HIV co-receptor. It also plays a key role in learning and memory by regulating synaptic plasticity (PMC).
  • The review compiles animal and human studies examining CCR5’s influence on:
    • Basic learning and memory processes,
    • HIV-associated neurocognitive disorder (HAND),
    • Alzheimer’s disease (AD),
    • Stroke and vascular dementia,
    • Multiple sclerosis (MS),
    • Frontotemporal dementia (FTD),
    • Dementia with Lewy bodies (DLB),
    • Parkinson’s disease with dementia (PDD) (PMC).

1. CCR5 in Learning & Memory

  • CCR5 is abundantly expressed in brain regions essential to learning, particularly the hippocampal CA1 and cortex, with a predominance in microglia (PMC).
  • It generally suppresses synaptic plasticity, memory formation, and long-term potentiation (LTP), by downregulating MAPK and CREB signaling pathways.
  • Knockout or pharmacological inhibition (e.g., with maraviroc) of CCR5 enhances LTP and improves learning and memory; overexpression impairs them (PMC).
  • CCR5 inhibition also extends the “memory linking window”—the time frame during which two distinct memories can become linked—and reverses related age-associated impairments (PMC).

2. CCR5 in HIV-Associated Neurocognitive Disorder (HAND)

  • HAND affects around 40% of people living with HIV and includes deficits in learning, memory, motor skills, and cognitive processing (PMC).
  • CCR5 facilitates HIV entry into microglia/macrophages and contributes to neuroinflammation, release of neurotoxins, and synaptic dysfunction via p38 MAPK signaling, glutamate excitotoxicity, and oxidative stress (PMC).
  • CCR5 knockouts or antagonists reduce microglial activation and neurotoxicity, mitigating HAND-associated cognitive deficits (PMC).

3. CCR5 in Alzheimer’s Disease (AD)

  • Both human AD brains and AD animal models show elevated CCR5 and its ligands (CCL3, CCL4, CCL5), suggesting active involvement in disease pathology (PMC).
  • In experimental settings, CCR5 knockout mice resist Aβ-induced memory impairment, with reduced glial activation and lower expression of neuroinflammation mediators like iNOS and COX-2 (PMC).
  • CCR5 activation drives neuroinflammation and impairs autophagy via PI3K-AKT-mTORC1 signaling, exacerbating tau and Aβ accumulation; blocking CCR5 or its ligands restores autophagy and preserves cognitive function in tauopathy models (PubMed).
  • However, some studies suggest that CCR5 deficiency may worsen pathology under certain conditions—possibly via compensatory CCR2 upregulation, astrocyte activation, Aβ accumulation, and neuronal apoptosis (PMC).

4. CCR5 in Stroke, Traumatic Brain Injury (TBI), & Vascular Dementia

  • Stroke and TBI commonly lead to cognitive impairment or dementia.
  • In some studies, deleting CCR5 results in larger infarct size and more neuronal death. Yet others show CCR5 knockdown or pharmacologic inhibition improves motor and cognitive recovery, possibly by promoting CREB and DLK-dependent synaptic repair (PMC).
  • The CCR5-Δ32 polymorphism—a naturally occurring non-functional variant—when found alongside APOEε4, is associated with increased susceptibility to vascular and mixed dementia; in neurons, CCR5 might confer protection against oxidative stress-induced damage, indicating a potentially protective role in vascular contexts (PMC).

5. CCR5 in Multiple Sclerosis (MS)

  • In MS and experimental autoimmune encephalomyelitis (EAE) models, CCR5 expression is elevated in inflammatory lesions, especially in infiltrating immune cells and microglia (PMC).
  • Maraviroc treatment or CCR5 inhibition reduces EAE severity, inflammatory response, demyelination, and neuronal damage via NF-κB and Notch pathway modulation—pointing toward therapeutic potential in MS (PMC).

6. CCR5 in FTD, DLB, & PDD

  • Frontotemporal dementia (FTD): Peripheral cells of FTD patients show reduced CCR5 and CCL3 expression, hinting at a limited but as-yet unclear peripheral role (PMC).
  • Dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD): α‑synuclein (αSyn) accumulation impairs dendritic spine integrity via CCR5-dependent mechanisms; blocking CCR5 reverses these synaptic disruptions in preclinical models (PMC).

Summary Table

Dementia Context CCR5 Role & Effect
Learning & Memory Inhibits synaptic plasticity; blocking enhances learning
HAND (HIV-related) Mediates inflammation and neurotoxicity
Alzheimer’s Disease (AD) Promotes neuroinflammation & impairs autophagy; blocking can protect
Stroke/TBI/Vascular Dementia Mixed roles: may aid or hinder recovery
Multiple Sclerosis (MS) Drives demyelination/inflammation; inhibition is neuroprotective
FTD, DLB, PDD CCR5 linked to synaptic disruption; antagonism preserves synaptic integrity

Conclusion & Outlook

  • CCR5 extends beyond its immune origins to key modulation of synaptic plasticity and cognitive systems.
  • Across many forms of dementia—from neurodegenerative to vascular—CCR5 is generally tied to cognitive impairment; inhibiting CCR5 is often beneficial, albeit with nuanced exceptions where it may also serve protective roles.
  • Given this complexity, CCR5 remains a compelling but delicate therapeutic target—one that demands context-specific strategies and a richer understanding of its dualistic effects in brain health.

Would you like a diagram mapping the signaling pathways (e.g., CCR5 → MAPK/CREB, ← inflammation, → autophagy, etc.), or an analysis comparing CCR5 inhibitors like maraviroc vs DAPTA?

1 Like
#10

Sounds very interesting so paging @DrFraser —however this AI-generated tidbit surely must be wrong. To help, it must be doing the opposite of inhibiting synaptic plasticity, no?

#11

@medaura CCR5 inhibits synaptic plasticity, but Maraviroc inhibits CCR5 (technically it’s a negative allosteric modulator) so its net effect would generally be increased synaptic plasticity.

1 Like
#12

Right, I thought for a moment the AI-summary were on the effects of Maraviroc. So double negative :wink:

1 Like
#13

It’s a very interesting drug. It seems most people have overlooked it, but here’s another recent study that showed CCR5 as a factor promoting skeletal muscle aging, as well as showing some impressive effects in this regard of mararviroc on aged mice:

2 Likes
#14

Also makes me wonder if intranasal delivery is the way to go — bypass any liver toxicity side effects and get around the poor BBB penetration. I’d love to see a trial of this paired with rifampicin, intranasally. Same profile of side effects too.

1 Like
#15

In that case maybe it’s worth taking systematically and not just up the nose.

1 Like
#16

A summary of that paper:

You’re referring to the paper “Multiomics and cellular senescence profiling of aging human skeletal muscle uncovers Maraviroc as a senotherapeutic approach for sarcopenia” (Li et al., Nature Communications, published July 5, 2025; PMCID: PMC12228793) (PMC).

Here’s a focused and detailed summary highlighting the role of Maraviroc:

Study Context & Aims

  • Goal: To map cellular senescence at single-nucleus resolution in aging human skeletal muscle, and to explore new pharmacological strategies (senotherapeutics) for age-related muscle degeneration (sarcopenia) (PMC).
  • Approach: Combined single-nucleus RNA-seq (snRNA-seq) and ATAC-seq to generate a senescence atlas—capturing transcriptomic and epigenomic diversity across senescent cell types in human muscle (PMC).

Key Findings

1. Heterogeneity of Senescent Cells

  • The study revealed significant within- and between-cell population variability in expression profiles and epigenetic regulation of senescent cells in skeletal muscle (PMC).
  • SASP (Senescence-Associated Secretory Phenotype) factors—including cytokines, chemokines, growth factors—varied significantly based on cell type and senescence stage (PMC).

2. Regulatory Mechanisms

  • The researchers identified transcription factors, notably from the AP-1 family (e.g., JUNB, ATF3), that regulate the induction of the SASP and senescence states (PMC).

3. Maraviroc as a Senotherapeutic

  • Crucially, the study discovered that Maraviroc (MVC)—a clinically approved CCR5 antagonist—showed potential to mitigate senescence and inflammation in aged muscle, marking it as a possible pharmacological intervention for sarcopenia (PMC).
  • The authors reference prior findings where MVC demonstrated anti-inflammatory effects in the context of Duchenne muscular dystrophy models, suggesting MVC’s dual role in addressing both senescence and inflammation (PMC).

Summary Table: MVC’s Role in This Study

Feature Details
Senescence mapping Multiomics profiling of aging human muscle cells
Key regulators AP-1 family TFs such as JUNB and ATF3
Maraviroc effect Identified as senotherapeutic, reducing senescent/inflammatory markers in muscle
Functional implication Potential drug to treat sarcopenia by targeting CCR5-linked pathways

Implications & Significance

  • Therapeutic Potential: Maraviroc emerges as an actionable candidate for combating muscle aging and sarcopenia—leveraging its known safety profile from HIV treatment to target muscle senescence and inflammation.
  • Mechanistic Insight: The study links CCR5 signaling (the target of MVC) to muscle aging, suggesting that modulation of this pathway may temper SASP-driven niche dysfunction and tissue decline.
  • Broader Relevance: Given the pressing need for interventions in age-related functional loss, repurposing Maraviroc presents an attractive and translationally viable strategy.
#17

What was the effect size though? I’m dead beat today and happy to be lazily spoonfed the AI answers.

1 Like
#18

Yes — the paper does report quantitative effect sizes for using Maraviroc (MVC) as a senomorphic intervention in aged mice models of sarcopenia.

High-Dose, Short-Term (HDST) MVC Treatment (10 mg/kg for 3 months):

  • Muscle mass: Tail‐tailed (TA) muscle weight relative to body weight increased by ~28.0 % in MVC-treated mice versus DMSO controls (PubMed Central).

  • Muscle fiber (CSA): Cross‐sectional area increased by ~15.5 % (PubMed Central).

  • Grip strength: Improved by ~15.8 %, and MVC attenuated the decline in grip strength by ~19.8 % (PubMed Central).

  • Treadmill running:

Additionally, the treatment modestly increased MuSC (muscle stem cell) population (from 3.39 % to 3.91 %), and reduced macrophage presence (from 1.09 % to 0.89 %) (PubMed Central).

Single-cell RNA-seq data revealed reduction in senescent cell proportions across multiple cell types:

  • MuSCs: 17.6 % versus 20.1 %
  • FAPs: 15.8 % versus 19.3 %
  • ECs: 16.7 % versus 21.9 %
  • SMCs: 20.1 % versus 31.1 % (PubMed Central)

These reductions were accompanied by decreased p21 mRNA expression and dampened SASP-mediated intercellular signaling, including CXCL-pathway interactions and CCR5 axis activity (PubMed Central).

Low-Dose, Long-Term (LDLT) MVC Treatment (2 mg/kg for 6 months):

This regimen also delivered noticeable improvements in muscle morphology, function, and niche integrity in aged mice—though precise percentage effect sizes are primarily presented within supplementary figures and not tabulated in the main text (PubMed Central).

Summary Table: MVC Effect Sizes (HDST Regimen)

Outcome Effect Size
TA muscle mass (vs control) +28.0 %
Fiber cross-sectional area +15.5 %
Grip strength (absolute) +15.8 %
Grip strength decline (Δ) −19.8 %
Max running speed +26.4 %
Running distance +50.0 %
MuSC proportion ↑ from 3.39 % to 3.91 %
Macrophage proportion ↓ from 1.09 % to 0.89 %
Senescent cell proportions Reduced across MuSCs, FAPs, ECs, SMCs

In summary, the study provides clear, measurable effect sizes, demonstrating that Maraviroc significantly enhances muscle mass and function, reduces senescence markers, and improves the muscle niche in aged mice when given at a high dose for a short term.

If you’d like, I can help you delve into the supplemental figures or compare these findings with other senotherapeutic studies!

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#19

Very cool stuff.
Had a few questions:

  1. Is this drug rated the highest out of infections and infestation type drugs (antivirals, antibacterials etc) for memory/brain related issues that you have come across?

  2. Any thoughts on longevity protocols with people using antiviral drugs if they do not have the specific condition they are used for example: HIV?
    I’ve seen 1 chart here a while ago that showed antiviral drugs good for dna damage (reverse transcriptase inhibitors).
    Now Maraviroc for memory.
    It would not surprise me if more people started to use various combinations of infections and infestation type drugs in their longevity protocols.

#20

FWIW…

Least expensive cost {as of 09/07/2025] in the US, a prescription is required - off label - out of pocket cost with GoodRx code in the NY area.

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