Integrin β3-Mediated Cell Senescence Associates with Gut Inflammation and Intestinal Degeneration in Models of Alzheimer's Disease

The up-regulation of PTBP1 expression level in patients with Insomnia by senile dementia and promote cuproptosis of nerve cell by SLC31A1

Alzheimer's disease (AD), often referred to as the modern-day scourge, stands as a significant health challenge characterized by high rates of disability and mortality, particularly among the geriatric population. Thus, the present study investigated the precise details of PTBP1 involvement in cuproptosis of nerve cell of patients with Insomnia by senile dementia (ISD). Patients with ISD, early mild cognitive impairment (EMCI) and Normal healthy volunteers were obtained. In the context of ISD, the elevated PTBP1 mRNA expressions were observed in patient samples, correlating positively with diminished cognitive function as measured by the Mini-Mental State Examination (MMSE) and increased geriatric depression scale scores. The pivotal role of PTBP1 was further underscored by its inhibitory effects in a mice model, which prevented the development of senile dementia, and its influence on neuronal cell proliferation and ROS-induced oxidative stress in vitro. Additionally, PTBP1's regulatory capacity on the cuproptosis of nerve cells and its modulation of SLC31A1 expression, through effects on ubiquitination, were revealed. The stability of PTBP1, critical for its function, was enhanced by the m6A modification mediated by METTL3, highlighting a complex regulatory network in the pathogenesis of ISD. These data confirmed that PTBP1 plays a pivotal role in promoting the oxidative response and cuproptosis in Alzheimer's disease models via the SLC31A1 pathway. The findings suggest that PTBP1 could serve as a potential biomarker for the diagnosis and prognostic evaluation of ISD and AD, paving the way for the development of novel therapeutic strategies targeting this protein.

Exploring Potential Medications for Alzheimer's Disease with Psychosis by Integrating Drug Target Information into Deep Learning Models: A Data-Driven Approach

Approximately 50% of Alzheimer's disease (AD) patients develop psychotic symptoms, leading to a subtype known as psychosis in AD (AD + P), which is associated with accelerated cognitive decline compared to AD without psychosis. Currently, no FDA-approved medication specifically addresses AD + P. This study aims to improve psychosis predictions and identify potential therapeutic agents using the DeepBiomarker deep learning model by incorporating drug-target interactions. Electronic health records from the University of Pittsburgh Medical Center were analyzed to predict psychosis within three months of AD diagnosis. AD + P patients were classified as those with either a formal psychosis diagnosis or antipsychotic prescriptions post-AD diagnosis. Two approaches were employed as follows: (1) a drug-focused method using individual medications and (2) a target-focused method pooling medications by shared targets. The updated DeepBiomarker model achieved an area under the receiver operating curve (AUROC) above 0.90 for psychosis prediction. A drug-focused analysis identified gabapentin, amlodipine, levothyroxine, and others as potentially beneficial. A target-focused analysis highlighted significant proteins, including integrins, calcium channels, and tyrosine hydroxylase, confirming several medications linked to these targets. Integrating drug-target information into predictive models improves the identification of medications for AD + P risk reduction, offering a promising strategy for therapeutic development.

Associations of combined accelerated biological aging and genetic susceptibility with incident dementia: a prospective study in the UK Biobank

BACKGROUND

Accelerated biological aging has been verified to be a critical risk factor for a number of age-related diseases, but its role in dementia remained unclear. Whether it modified the effects of genetic factors was also unknown. This study evaluated the associations between accelerated biological aging and dementia and the moderating role of accelerated biological aging in the genetic susceptibility to the disease.

METHODS

We included 200,731 participants in the UK biobank. Nine clinical blood biomarkers and chronological age were used to calculate Phenotypic age acceleration (PhenoAgeAccel), which is a novel indicator for accelerated biological aging. The associations of PhenoAgeAccel with dementia, both young-onset and late-onset dementia, were assessed by Cox proportional hazard models. Apolipoprotein E (APOE) alleles and polygenic risk scores (PRS) were used to evaluate the genetic risk of dementia. The interactions between genetic susceptibility and biological aging were tested on both multiplicative and additive scales.

RESULTS

These findings showed individuals who were in the highest quartile of PhenoAgeAccel had a higher risk with incidence of dementia compared to individuals in the lowest quartile of PhenoAgeAccel (HR: 1.145 (95% CI: 1.050, 1.249)). Individuals with biologically older had a higher risk of dementia than individuals with biologically younger (HR: 1.069 (95% CI: 1.004, 1.138)). Furthermore, compared to individuals with biologically younger and low APOE ε4-related genetic risk, individuals with biologically younger and high APOE ε4-related genetic risk (HR:3.048 (95% CI: 2.811, 3.305)) had a higher risk of dementia than individuals with biologically older and high APOE ε4-related genetic risk (HR: 2.765 (95% CI: 2.523, 3.029)). Meanwhile, referring to low dementia PRS and biologically younger, the risk of dementia increased by 72.7% (HR: 1.727 (95% CI: 1.538, 1.939) in the biologically younger and high PRS group and 58.7% (HR: 1.587 (95% CI: 1.404, 1.793) in the biologically older and high PRS group, respectively. The negative interactions between PhenoAgeAccel with APOE ε4 and PRS were also tested on the additive scale.

CONCLUSIONS

Accelerated biological aging could bring the extra risk of dementia but attenuate the effects of genetic risk on dementia. These findings provide insights for precise prevention and intervention of dementia.

The role of cellular senescence in neurodegenerative diseases

Increasing evidence has revealed that cellular senescence drives NDs, including Alzheimer's disease (AD) and Parkinson's disease. Different senescent cell populations secrete senescence-associated secretory phenotypes (SASP), including matrix metalloproteinase-3, interleukin (IL)-1α, IL-6, and IL-8, which can harm adjacent microglia. Moreover, these cells possess high expression levels of senescence hallmarks (p16 and p21) and elevated senescence-associated β-galactosidase activity in in vitro and in vivo ND models. These senescence phenotypes contribute to the deposition of β-amyloid and tau-protein tangles. Selective clearance of senescent cells and SASP regulation by inhibiting p38/mitogen-activated protein kinase and nuclear factor kappa B signaling attenuate β-amyloid load and prevent tau-protein tangle deposition, thereby improving cognitive performance in AD mouse models. In addition, telomere shortening, a cellular senescence biomarker, is associated with increased ND risks. Telomere dysfunction causes cellular senescence, stimulating IL-6, tumor necrosis factor-α, and IL-1β secretions. The forced expression of telomerase activators prevents cellular senescence, yielding considerable neuroprotective effects. This review elucidates the mechanism of cellular senescence in ND pathogenesis, suggesting strategies to eliminate or restore senescent cells to a normal phenotype for treating such diseases.

Reverse vaccinology-based multi-epitope vaccine design against Indian group A rotavirus targeting VP7, VP4, and VP6 proteins

Rotavirus, a primary contributor to severe cases of infantile gastroenteritis on a global scale, results in significant morbidity and mortality in the under-five population, particularly in middle to low-income countries, including India. WHO-approved live-attenuated vaccines are linked to a heightened susceptibility to intussusception and exhibit low efficacy, primarily attributed to the high genetic diversity of rotavirus, varying over time and across different geographic regions. Herein, molecular data on Indian rotavirus A (RVA) has been reviewed through phylogenetic analysis, revealing G1P[8] to be the prevalent strain of RVA in India. The conserved capsid protein sequences of VP7, VP4 and VP6 were used to examine helper T lymphocyte, cytotoxic T lymphocyte and linear B-cell epitopes. Twenty epitopes were identified after evaluation of factors such as antigenicity, non-allergenicity, non-toxicity, and stability. These epitopes were then interconnected using suitable linkers and an N-terminal beta defensin adjuvant. The in silico designed vaccine exhibited structural stability and interactions with integrins (αvβ3 and αIIbβ3) and toll-like receptors (TLR2 and TLR4) indicated by docking and normal mode analyses. The immune simulation profile of the designed RVA multiepitope vaccine exhibited its potential to trigger humoral as well as cell-mediated immunity, indicating that it is a promising immunogen. These computational findings indicate potential efficacy of the designed vaccine against rotavirus infection.

Chronic low-dose deltamethrin exposure induces colon injury and aggravates DSS-induced colitis via promoting cellular senescence

OBJECTIVE

Deltamethrin (DLM) is a commonly used insecticide, which is harmful to many organs. Here, we explored the effects of chronic low-dose DLM residues on colon tissue and its potential mechanism.

METHODS

The mice were given long-term low-dose DLM by intragastric administration, and the body weights and disease activity index (DAI) scores of the mice were regularly recorded. The colon tissues were then collected for hematoxylin-eosin, immunofluorescence and immunohistochemistry staining. Besides, the RNA sequencing was performed to explore the potential mechanism.

RESULTS

Our results showed that long-term exposure to low-dose DLM could cause inflammation in mice colon tissue, manifested as weight loss, increased DAI score, increased apoptosis of colonic epithelial cells, and increased infiltration of inflammatory cells. However, we observed that after long-term exposure to DLM and withdrawal for a period of time, although apoptosis was restored, the recovery of colon inflammation was not ideal. Subsequently, we performed RNA sequencing and found that long-term DLM exposure could lead to the senescence of some cells in mice colon tissue. The results of staining of cellular senescence markers in colon tissue showed that the level of cellular senescence in the DLM group was significantly increased, and the p53 signalling related to senescence was also significantly activated, indicating that cellular senescence played a key role in DLM-induced colitis. We further treated mice with quercetin (QUE) after long-term DLM exposure, and found that QUE could indeed alleviate DLM-induced colitis. In addition, we observed that long-term accumulation of DLM could aggravate DSS-induced colitis in mice, and QUE treatment could reverse this scenario.

CONCLUSION

Continuous intake of DLM caused chronic colitis in mice, and the inflammation persisted even after discontinuation of DLM intake. This was attributed to the induction of cellular senescence in colon tissue. Treatment with QUE alleviated DLM-induced colitis by reducing cellular senescence. Long-term DLM exposure also aggravated DSS-induced colitis, which could be mitigated by QUE treatment.

Upregulation of Integrin beta-3 in astrocytes upon Alzheimer's disease progression in the 5xFAD mouse model

Integrins are receptors that have been linked to various brain disorders, including Alzheimer's disease (AD), the most prevalent neurodegenerative disorder. While Integrin beta-3 (ITGB3) is known to participate in multiple cellular processes such as adhesion, migration, and signaling, its specific role in AD remains poorly understood, particularly in astrocytes, the main glial cell type in the brain. In this study, we investigated alterations in ITGB3 gene and protein expression during aging in different brain regions of the 5xFAD mouse model of AD and assessed the interplay between ITGB3 and astrocytes. Primary cultures from adult mouse brains were used to gain further insight into the connection between ITGB3 and amyloid beta (Aβ) in astrocytes. In vivo studies showed a correlation between ITGB3 and the astrocytic marker GFAP in the 5xFAD brains, indicating its association with reactive astrocytes. In vitro studies revealed increased gene expression of ITGB3 upon Aβ treatment. Our findings underscore the potential significance of ITGB3 in astrocyte reactivity in the context of Alzheimer's disease.

Implication of integrin α5β1 in senescence of SK-Mel-147 human melanoma cells

Downregulation of α5β1 integrin in the SK-Mel-147 human melanoma culture model sharply inhibits the phenotypic manifestations of tumor progression: cell proliferation and clonal activity. This was accompanied by a 2-3-fold increase in the content of SA-β-Gal positive cells thus indicating an increase in the cellular senescence phenotype. These changes were accompanied by a significant increase in the activity of p53 and p21 tumor suppressors and components of the PI3K/Akt/mTOR/p70 signaling pathway. Pharmacological inhibition of mTORC1 reduced the content of SA-β-Gal positive cells in the population of α5β1-deficient SK-Mel-147 cells. A similar effect was observed with pharmacological and genetic inhibition of the activity of Akt1, one of the three Akt protein kinase isoenzymes; suppression of other Akt isozymes did not affect melanoma cell senescence. The results presented in this work and previously obtained indicate that α5β1 shares with other integrins of the β1 family the function of cell protection from senescence. This function is realized via regulation of the PI3K/Akt1/mTOR signaling pathway, in which Akt1 exhibits a non-canonical activity.