👤 Saksham Bansal

Class B1 GPCRs are crucial to maintaining homeostasis along a multitude of vital biochemical pathways. Understanding the activation mechanism of these proteins at both a family and clade-specific level is particularly relevant for designing multi-target agonists, as exemplified by recently designed dual-agonists for GLP-1R and GIPR, for treating obesity. Here, we use 6 milliseconds of unbiased all-atom MD simulations of GCGR, GLP1R, PAC1R, SCTR, PTH1R and CALCR from the four different clades of Class B1 GPCRs to establish the universal mechanism of their activation. We show that the activation of Class B1 GPCRs involves a clade-independent intermediate state characterized by the outward movement of helix 6. We use a combination of Markov state models and transition path theory to show that the activation of these proteins occurs at a millisecond timescale. We identify characteristic molecular locks that are conserved at a clade-level, showcasing the uniqueness among the activation mechanisms of these proteins. We show that these proteins show similar inactive and active states, but show unique activation mechanisms at a residue level. These sites can be targeted directly or allosterically to design therapeutics targeting a specific clade of proteins. Thus, this study provides an integrated atomistic view of the activation for Class B1 GPCRs from a mechanistic, thermodynamic and kinetic perspective. Show less

Studies suggest that obesity is linked to both autonomic nervous system dysfunction and cognitive impairment, but the specific quantitative associations are not well explored. This study was proposed to explore the quantification of different neurocognitive signatures and heart rate variability (HRV) parameters with increasing body weight among metabolically healthy obese participants for better analytical predictors. The present research is a cross-sectional study, including a total of 101 ( Significant changes were observed for neurocognitive performances and HRV indices for the metabolically healthy obese group compared with the control group. With the association heatmaps, BMI was found to be significantly negatively associated with the BDNF and high-frequency band (HF band, ms The findings of the present study support that HRV could be a valuable early non-invasive tool for future cognitive decline in a population with metabolically healthy obesity. The study was registered at Clinical Trial Registry of India (CTRI/2022/10/046935). Show less

Alzheimer's disease (AD) is a progressive and complicated neurodegenerative disorder that mostly affects the elderly and is characterized by memory loss, cognitive dysfunction, accumulation of amyloid beta (Aβ) plaques, neurofibrillary tangles, and cholinergic deficits. Current therapies used for AD, such as acetylcholinesterase inhibitors and NMDA receptor antagonist memantine, can only provide temporary or symptomatic relief, but they do not stop or reverse the progression of the disease. Numerous pathogenic hypotheses have been proposed to explain this mechanism; however, the amyloid cascade hypothesis remains the most widely accepted theory, as it suggests that β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) plays a critical role in the generation of Aβ peptides. Therefore, BACE1 may be a key therapeutic target. This review primarily focuses on the key role of BACE1 in AD pathogenesis and describes the development of its inhibitors over three generations, explaining their structure, design, and pharmacological properties. While the first generation lacked brain penetration, the second-generation improved potency but encountered clinical trial failures due to adverse effects. The third generation of these drugs was designed to achieve a balance between efficacy, selectivity, and safety. Additionally, we review the promising molecules currently under clinical investigation, highlighting both their therapeutic potential and the challenges that remain in developing effective disease-modifying therapies for AD treatment. Show less

Oligodendrocytes (OLs) generate myelin sheaths around axons and maintain them to facilitate the propagation of action potentials and support neuronal metabolism and synaptic function. Previously, we have shown that Fibroblast Growth Factor Receptor-1 and -2 (FGFR1/2) signaling is required for oligodendrocyte precursor cell (OPC) expansion, promoting myelin growth during developmental myelination and maintaining myelin/axonal integrity in the spinal cord during adulthood. However, whether OL-lineage cells may affect neuronal synaptic functions and impact memory/learning during adulthood/aging remained largely unknown. Here, we showed that FGFR1/2 signaling in OPCs and OLs is required throughout adulthood and is critical for the long-term maintenance of synaptic activity and memory. Specifically, the lack of FGFR1/2 signaling within OL-lineage cells resulted in the impairment of long-term potentiation (LTP), a reduction in docked synaptic vesicles at the synaptic terminals, deficits in hippocampal-based memory and learning, and β-APP accumulation in older animals. Importantly, we found that there was no loss of OPCs or OLs, myelin degeneration, astrogliosis, microglial activation, or reduction in myelin thickness in the adult hippocampus of mutant mice. Furthermore, the tamoxifen-inducible loss of FGFR1/2 signaling during adulthood also impaired LTP. In addition, the conditional ablation of either FGFR1 or FGFR2 individually in the OL-lineage cells impaired LTP during adulthood, although at different levels. Thus, these observations bring up the possibility that FGFR1/2 signaling in OL-lineage cells may play a potentially novel, previously unrecognized role in OL-neuron communication for the maintenance of synaptic plasticity and memory functions in the normal adult/aging brain. Show less

Few HIV-specific epitopes restricted by non-classical HLA-E have been described, and even less is known about the functional profile of responding CD8+ T cells (CD8s). This study evaluates the functional characteristics of CD8s targeting the Gag epitope KF11 (KAFSPEVIPMF) restricted by either HLA-E (E-CD8s) or HLA-B57 (B57-CD8s). CD8s from 8 people with HIV (PWH) were cocultured with KF11 peptide presented by cell lines expressing HLA-B*57:01, HLA-E*01:01, or HLA-E*01:03. CD8 responses were analyzed using single-cell RNA and TCR sequencing. Supernatants were also assessed for soluble protein profiling. HLA-I multimers were developed to identify CD8s restricted by HLA-B57 and/or HLA-E ex vivo. B57-CD8s secreted higher levels of cytotoxic cytokines such as IFN-γ, whereas E-CD8s produced more chemotactic cytokines, including RANTES, CXCL10 (IP-10), and IL-27, findings that were corroborated through single-cell RNA sequencing. TCR clonotypes stimulated by KF11 were cross-restricted by HLA-B*57 and HLA-E*01:03 as demonstrated by in vitro T cell reporter assays and ex vivo multimer screening. Ex vivo CD8s were singly restricted by HLA-B57 and HLA-E, with dual restriction only observed in PWH with lower viral load. These findings demonstrate that certain HIV-specific CD8s in PWH exhibit dual restriction by HLA-B*57 and HLA-E*01:03, leading to functionally distinct immune responses depending on the restricting allele(s). Show less

Pancreatic cancer (PC) is among the deadliest malignancies, characterized by poor treatment response. Natural bioactive compounds, such as Morin, a flavonoid, have gained interest as potential therapeutic agents due to their anticancer properties but remain unexplored in PC. This study investigates the anticancer effects of Morin on PC cells, particularly its ability to induce mitophagy via the PINK1/Parkin pathway and modulate mitochondrial function and cancer stemness. PANC-1 cells were treated with Morin, and its impact on tumorigenic potential was evaluated using in vitro assays, including cell viability, colony formation, migration, invasion, and spheroid formation, as well as in vivo studies in a nude mice model. Mitochondrial function and apoptosis were assessed through flow cytometry, gene expression analysis, PCR microarrays, transmission electron microscopy (TEM), immunofluorescence, ELISA, western blotting, and molecular docking. Morin exhibited dose-dependent cytotoxicity, significantly reducing viability, colony formation, migration, and invasion in PC. It downregulated mesenchymal and stemness markers (N-cadherin, SNAI1, ZEB1, SOX2, NANOG, OCT4) while upregulating E-cadherin. Morin disrupted spheroid morphology and decreased ALDH activity, indicating reduced cancer stemness. Additionally, Morin-induced mitochondrial dysfunction, as evidenced by decreased membrane potential, ATP synthase activity, and mitochondrial mass, along with increased mitochondrial superoxide production. Upregulation of mitophagy markers (PINK1, Parkin, pAMPK, LC3A/B) and downregulation of fusion (MFN2) confirmed PINK1-mediated mitophagy. Apoptosis induction was supported by Annexin V/PI staining, TEM, elevated caspase-3/-9 levels, and cytochrome c release. Molecular docking confirmed strong Morin-PINK1 interaction. Morin induces mitophagy, promotes apoptosis, and suppresses cancer invasiveness in PC cells, highlighting its potential as an adjuvant therapeutic agent. Future clinical studies are warranted to evaluate its relevance. Show less

Genome-wide association studies (GWAS) have identified common variants associated with metabolic dysfunction-associated steatotic liver disease (MASLD). However, rare coding variant studies have been limited by phenotyping challenges and small sample sizes. We test associations of rare and ultra-rare coding variants with proton density fat fraction (PDFF) and MASLD case-control status in 736,010 participants of diverse ancestries from the UK Biobank, All of Us, and BioMe and performed a trans-ancestral meta-analysis. We then developed models to accurately predict PDFF and MASLD status in the UK Biobank and tested associations with these predicted phenotypes to increase statistical power. The trans-ancestral meta-analysis with PDFF and MASLD case-control status identifies two single variants and two gene-level associations in APOB, CDH5, MYCBP2, and XAB2. Association testing with predicted phenotypes, which replicates more known genetic variants from GWAS than true phenotypes, identifies 16 single variants and 11 gene-level associations implicating 23 additional genes. Two variants were polymorphic only among African ancestry participants and several associations showed significant heterogeneity in ancestry and sex-stratified analyses. In total, we identified 27 genes, of which 3 are monogenic causes of steatosis (APOB, G6PC1, PPARG), 4 were previously associated with MASLD (APOB, APOC3, INSR, PPARG), and 23 had supporting clinical, experimental, and/or genetic evidence. Our results suggest that trans-ancestral association analyses can identify ancestry-specific rare and ultra-rare coding variants in MASLD pathogenesis. Furthermore, we demonstrate the utility of machine learning in genetic investigations of difficult-to-phenotype diseases in trans-ancestral biobanks. Show less

BACE-1 is a prime therapeutic target for treatment of Alzheimer disease as it cleaves the β-site of APP leading to formation of amyloid plaques. A dataset of 229 benzo-fused heterocyclic compounds reported as BACE-1 inhibitors was utilized to develop various QSAR models (regression and classification) utilizing Monte Carlo algorithm. The dataset was randomly split into different sets for generation of models. The IIC and CCC were calculated to increase the predictive ability of generated models. Among various models, split-1 of Model-1 demonstrated the highest robustness and predictive accuracy for pIC Show less

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant genetic disorder characterized by left ventricular hypertrophy and variable clinical manifestations, including asymptomatic states and sudden cardiac death (SCD). Data on its phenotype and genotype in the Indian population remain limited. We studied 113 patients diagnosed with HCM. All underwent clinical assessment, 24-h Holter monitoring, echocardiography, and cardiac MRI. Genetic testing was performed in 80 patients. Clinical and imaging features were compared between genotype-positive and genotype-negative groups. The mean age was 47 ± 10.8 years, with 82.6 % being males. Dyspnoea and chest pain were the most frequent symptoms. Obstructive HCM was seen in 70 (61.9 %) patients. Cardiac MRI showed late gadolinium enhancement >15 % in 13 (23.2 %) and apical aneurysms in 2 (3.5 %). Genetic mutations were detected in 40 (50 %) patients, with MYBPC3 (33 %) and MYH7 (26.8 %) being most common. Genotype-positive individuals more frequently had chest pain, a family history of SCD, and more severe hypertrophy. In this Indian HCM cohort, the condition predominantly affected males. Genotype-positive patients exhibited more severe hypertrophy and adverse clinical profiles, underscoring the importance of genetic screening in risk stratification. Show less

Primary cilia are conserved organelles that integrate extracellular cues into intracellular signals and are critical for diverse processes, including cellular development and repair responses. Deficits in ciliary function cause multisystemic human diseases known as ciliopathies. In the eye, atrophy of the retinal pigment epithelium (RPE) is a common feature of many ciliopathies. However, the roles of RPE cilia in vivo remain poorly understood. In this study, we first found that mouse RPE cells only transiently form primary cilia. We then examined the RPE in the mouse model of Bardet-Biedl Syndrome 4 (BBS4), a ciliopathy associated with retinal degeneration in humans, and found that ciliation in BBS4 mutant RPE cells is disrupted early during development. Next, using a laser-induced injury model in vivo, we found that primary cilia in RPE reassemble in response to laser injury during RPE wound healing and then rapidly disassemble after the repair is completed. Finally, we demonstrated that RPE-specific depletion of primary cilia in a conditional mouse model of cilia loss promoted wound healing and enhanced cell proliferation. In summary, our data suggest that RPE cilia contribute to both retinal development and repair and provide insights into potential therapeutic targets for more common RPE degenerative diseases. Show less

Venous thrombo-embolism (VTE) is multi-factorial disease involving several genetic and acquired risk factors responsible for its onset. It may occur spontaneously upon climbing at High Altitude (HA). Several studies demonstrated that hypoxic conditions prevailing at HA pose an independent risk factor for VTE; however, molecular mechanism remains unknown. Present study aims to identify genes associated with HA-induced VTE pathophysiology using real time TaqMan Low-Density Array (TLDA) of known candidate genes. Gene expression of total 93 genes were studied and analyzed in patients of VTE from HA (HA-VTE) and from sea level (SL-VTE) in comparison to respective controls. Both HA-VTE and SL-VTE patients showed up-regulation of 37 genes involved in blood coagulation cascade, clot formation, platelet formation, endothelial response, angiogenesis, cell adhesion and calcium channel activity. Seven genes including ACE, EREG, C8A, DLG2, USF1, F2 and PCDHA7 were up-regulated in both HA-controls and VTE patients (both HA-VTE and SL-VTE) indicating their role during VTE event and also upon HA exposure. Ten genes; CDH18, FGA, EDNBR, GATA2, MAPK9, BCAR1, FRK, F11, PCDHA1 and ST8SIA4 were uniquely up-regulated in HA-VTE. The differentially expressed genes from the present study could be determining factors for HA-VTE susceptibility and provide insights into VTE occurrence at HA. Show less