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Biology subjects

Prasoon, P.

Publications and source records attributed to Prasoon, P..

7 recordsLinked to original sources

TNFR2 Agonism as a Sex-Specific Therapy for Novel Osteoarthritis-Induced Cardiac Dysfunction

Osteoarthritis (OA), a degenerative joint disease, is associated with increased systemic inflammation, chronic pain, and cardiovascular dysfunction. Epidemiological evidence establishes that OA increases the risk of cardiovascular disease (CVD) threefold, yet the causal role of OAs contributions remains underexamined. We assessed cardiac function longitudinally following destabilization of the medial meniscus (DMM) surgery to induce osteoarthritis in mice. DMM-mice exhibited significant, sexually dimorphic alterations in echocardiographic parameters. Female DMM mice developed impaired relaxation with altered E/A ratios, increased E/e ratios, and prolonged intraventricular relaxation time with no change in ejection fraction, while male DMM mice showed progressive systolic dysfunction with decreasing ejection fraction, increased E/e ratio, and prolonged intraventricular contraction time. Transcriptomic profiles and biochemical analyses demonstrated divergent cellular responses involving fibrosis and oxidative stress in female mice, whereas autophagic and apoptotic responses were observed in male mice. Using a tumor necrosis factor 2 (TNFR2) agonist shown to reduce systemic inflammation, we investigated its potential therapeutic role in the context of OA-induced cardiovascular dysfunction. TNFR2 agonism proved to be effective both prophylactically and therapeutically for female diastolic dysfunction. While prophylactic and therapeutic administration delayed male systolic dysfunction, the efficacy declined over time. Our findings demonstrate evidence of a novel sexually dimorphic model of OA-induced CVD that recapitulates the sexually dimorphic pattern of patient phenotypes and a promising new therapeutic approach to CVD. Translational RelevanceOsteoarthritis patients have higher, often unrecognized, cardiovascular risk, yet preclinical models linking joint disease to cardiac dysfunction remain unexplored. Using a murine preclinical model of OA reveals the key findings. First, OA alone drives sex-specific cardiac phenotypes - females develop diastolic dysfunction, whereas males develop progressive systolic impairment. Second, selective TNFR2 agonism prevents and reverses OA-induced diastolic dysfunction in female mice and delays systolic decline in males. These findings suggest sex-dependent cardiac monitoring in OA patients and indicate that TNFR2-targeted therapy will likely be a sex-informed intervention to provide cardioprotective benefit. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/736778v3_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@819a80org.highwire.dtl.DTLVardef@c6646eorg.highwire.dtl.DTLVardef@eb86aborg.highwire.dtl.DTLVardef@d68292_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

Sex-Specific Characterization of a Novel Osteoarthritis-Induced Heart Failure Model in Mice

Chronic low-grade inflammation is increasingly recognized as a key driver of heart failure (HF) progression; however, the direct contribution of systemic inflammatory disorders such as osteoarthritis (OA) remains unclear. Here, we establish a murine model of OA-induced HF using destabilization of the medial meniscus (DMM) to induce systemic inflammation and sex-specific cardiac remodeling. Longitudinal echocardiography revealed that females develop diastolic dysfunction with preserved ejection fraction, resembling HFpEF, whereas males exhibit progressive systolic impairment, consistent with a transitional HFmrEF-to-HFrEF phenotype. Morphometric and histological analyses confirmed concentric hypertrophy in females and eccentric remodeling in males. Transcriptomic profiling identified distinct molecular programs--females upregulated extracellular matrix, cytoskeletal, and calcium-handling genes, while males showed enrichment of inflammatory and immune signaling pathways. Immunoblot analyses further validated these sex-specific molecular signatures: females displayed increased ANP, BNP, Sirt1, and AMPK expression, consistent with metabolic resilience and fibrotic remodeling, whereas males exhibited elevated p38 MAPK, NF-{kappa}B, LC3B, and cleaved caspase-3, reflecting heightened inflammation, autophagy, and apoptosis. Both sexes demonstrated downregulation of mitochondrial and lipid metabolic proteins, indicating convergent energetic stress. Collectively, these findings identify OA as a systemic inflammatory driver of heart failure, delineate the molecular and proteomic basis of sex-dependent cardiac remodeling, and introduce a translational preclinical model that recapitulates the clinical heterogeneity of HFpEF and HFmrEF/HFrEF, providing a foundation for mechanistic and therapeutic exploration.

molecular biology↗

Aligning with the predecessors and counterarguments: A systematic review of the anatomical correlates for the newly discovered meningeal layer in the existing literature

A recent study reported the existence of a subarachnoid lymphatic-like membrane (SLYM) -an intermediate leptomeningeal layer between the arachnoid and pia mater in mice and human brains - dividing the subarachnoid space (SAS) into two functional compartments. Despite being a macroscopic structure, how it missed detection in previous studies is surprising. We systematically reviewed the published reports in animals and humans to explore whether prior descriptions of this meningeal layer have existed. An electronic search was conducted in PubMed/Medline, EMBASE, Google Scholar, Science Direct, and Web of Science databases using combinations of MeSH terms and keywords with Boolean operators from inception until 31st Dec 2023. We found at least eight studies that provided structural evidence of an intermediate leptomeningeal layer in the brain or spinal cord. However, unequivocal descriptions for this layer all along the central nervous system were scarce. Obscured names were used to describe it, i.e., the epipial layer, intermediate meningeal layer, intermediate lamella, and outer pial layer. Its microscopic/ultrastructural details closely resembled the SLYM. Further, we examined the counterarguments in current literature that are skeptical of this layers existence. Considering the significant physiological/clinical implications, exploring further structural and functional details of the new meningeal layer is a need of the hour.

neuroscience↗

Endogenous μ-opioid - neuropeptide Y Y1 receptor synergy silences chronic postoperative pain

Tissue injury creates a delicate balance between latent pain sensitization (LS) and compensatory endogenous analgesia. Inhibitory G protein-coupled receptor (GPCR) interactions that oppose LS, including -opioid receptor (MOR) and neuropeptide Y Y1 receptor (Y1R) activity, persist in the spinal cord dorsal horn (DH) for months, even after the resolution of normal pain thresholds. Here, we demonstrate that following recovery from surgical incision, a potent endogenous analgesic synergy between MOR and Y1R activity persists within DH interneurons to reduce the intensity and duration of latent postoperative hyperalgesia and ongoing pain. Failure of such endogenous GPCR signaling to maintain LS in remission may underlie the transition from acute to chronic pain states.

neuroscience↗

NRP1 and furin as putative mediators of SARS-CoV-2 entry into human brain cells

COVID-19 has prominent neurological manifestations including psychiatric symptoms, indicating significant synaptic pathology. Surprisingly, existing evidence suggests negligible expression of the key SARS-CoV-2 host cell entry mediators ACE2 and TMPRSS2 in human brain, which complicates understanding of the pathomechanisms of the neuropsychiatric manifestations in COVID-19. Recent studies suggested that an alternative host-cell entry receptor, NRP1, can mediate entry of furin cleaved SARS-CoV-2 spike proteins into the host cells. However, the role of NRP1 and furin in mediating SARS-CoV-2 entry in human brain cells has been least explored and remains a lacuna in the literature. We performed an in silico analysis of the transcriptomic and proteomic expressions of SARS-CoV-2 host-cell entry receptors and associated tissue proteases in human brain tissue, using the publically available databases. Based on the expression analysis, SARS-CoV-2 entry in human brain cells is likely to be mediated through NRP1 and furin. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=198 HEIGHT=200 SRC="FIGDIR/small/476893v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@1c818baorg.highwire.dtl.DTLVardef@1cf7c0corg.highwire.dtl.DTLVardef@d92e19org.highwire.dtl.DTLVardef@61866a_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Fast A-type currents shape a rapidly adapting form of delayed short latency firing of excitatory superficial dorsal horn neurons that express the NPY Y1 receptor

Neuroanatomical and behavioral evidence indicates that neuropeptide Y Y1 receptor-expressing interneurons (Y1-INs) in the superficial dorsal horn (SDH) are predominantly excitatory and contribute to chronic pain. Using an adult ex vivo spinal cord slice preparation from Y1eGFP reporter mice, we characterized firing patterns in response to steady state depolarizing current injection of GFP-positive cells in lamina II, the great majority of which expressed Y1 mRNA (88%). Randomly sampled and Y1eGFP neurons exhibited five firing patterns: tonic (TF), initial burst (IBF), phasic (PF), delayed short-latency <180 ms (DSLF), and delayed long-latency >180 ms (DLLF). When studied at resting membrane potential, most RS neurons exhibited delayed firing, while most Y1eGFP neurons exhibited phasic firing and not delayed firing. A preconditioning membrane hyperpolarization produced only subtle changes in the firing patterns of randomly sampled neurons, but dramatically shifted Y1eGFP neurons to DSLF (46%) and DLLF (24%). In contrast to randomly sampled DSLF neurons which rarely exhibited spike frequency adaptation, Y1eGFP DSLF neurons were almost always rapidly adapting, a characteristic of nociceptive-responsive SDH neurons. Rebound spiking was more prevalent in Y1eGFP neurons (6% RS vs 32% Y1eGFP), indicating enrichment of T-type calcium currents. Y1eGFP DSLF neurons exhibited fast A-type potassium currents that are known to delay or limit action potential firing, and these were of smaller current density as compared to randomly sampled DSLF neurons. Our results inspire future studies to determine whether tissue or nerve injury downregulates channels that contribute to A-currents, thus potentially unmasking T-type calcium channel activity and membrane hyperexcitability in Y1-INs, leading to persistent pain. KEYPOINTSO_LINeuropeptide Y Y1 receptor-expressing neurons in the dorsal horn of the spinal cord contribute to chronic pain. C_LIO_LIFor the first time, we characterized the firing patterns of Y1-expressing neurons in Y1eGFP reporter mice. C_LIO_LIUnder hyperpolarized conditions, most Y1eGFP neurons exhibited fast A-type potassium currents and delayed, short-latency firing (DSLF). C_LIO_LIY1eGFP DSLF neurons were almost always rapidly adapting and often exhibited rebound spiking, characteristics of spinal pain neurons under the control of T-type calcium channels. C_LIO_LIThese results inspire future studies to determine whether tissue or nerve injury downregulates the channels that underlie A-currents, thus unmasking membrane hyperexcitability in Y1- expressing dorsal horn neurons, leading to persistent pain C_LI

neuroscience↗

Relevance of enriched expression of SARS-CoV-2 binding receptor ACE2 in gastrointestinal tissue with pathogenesis of digestive symptoms, diabetes-associated mortality, and disease recurrence in COVID-19 patients

IntroductionCOVID-19 is caused by a new strain of coronavirus called SARS-coronavirus-2 (SARS-CoV-2), which is a positive sense single strand RNA virus. In humans, it binds to angiotensin converting enzyme 2 (ACE2) with the help a structural protein on its surface called the S-spike. Further, cleavage of the viral spike protein (S) by the proteases like transmembrane serine protease 2 (TMPRSS2) or Cathepsin L (CTSL) is essential to effectuate host cell membrane fusion and virus infectivity. COVID-19 poses intriguing issues with imperative relevance to clinicians. The pathogenesis of GI symptoms, diabetes-associated mortality, and disease recurrence in COVID-19 are of particular relevance because they cannot be sufficiently explained from the existing knowledge of the viral diseases. Tissue specific variations of SARS-CoV-2 cell entry related receptors expression in healthy individuals can help in understanding the pathophysiological basis the aforementioned collection of symptoms. Materials and MethodsThe data were downloaded from the Human Protein Atlas available at (https://www.proteinatlas.org/humanproteome/sars-cov-2) and the tissue specific expressions (both mRNA and protein) of ACE2 and TMPRSS2 as yielded from the studies with RNA sequencing and immunohistochemistry (IHC) were analyzed as a function of the various components of the digestive tract. A digestive system specific functional enrichment map of ACE2 gene was created using g:profiler (https://biit.cs.ut.ee/gprofiler/gost) utility and the data were visualized using Cytoscape software, version 3.7.2 (https://cytoscape.org/). ResultsThe correlated expression (transcriptomic and proteomic) of ACE2 (to which SARS-CoV-2 binds through the S-spike) was found to be enriched in the lower gastrointestinal tract (GIT) (highest in small intestine, followed by colon and rectum), and was undetectable in the upper GIT components: mouth cavity (tongue, oral mucosa, and salivary glands), esophagus, and stomach. High expression of ACE2 was noted in the glandular cells as well as in the enterocytes in the lining epithelium (including brush border epithelium). Among other digestive system organs, Gall bladder (GB) showed high expression of ACE2 in glandular cells, while any protein expression was undetectable in liver and pancreas. TMPRSS2 was found enhanced in GIT and exocrine glands of pancreas, and co-localized with ACE2 in enterocytes. ConclusionsBased on the findings of this study and supportive evidence from the literature we propose that a SARS-CoV-2 binding with ACE2 mediates dysregulation of the sodium dependent nutrient transporters and hence may be a plausible basis for the digestive symptoms in COVID-19 patients. ACE2 mediated dysregulation of sodium dependent glucose transporter (SGLT1 or SLC5A1) in the intestinal epithelium also links it to the pathogenesis of diabetes mellitus which can be a possible reason for the associated mortality in COVID-19 patients with diabetes. High expression of ACE2 in mucosal cells of the intestine and GB make these organs potential sites for the virus entry and replication. Continued replication of the virus at these ACE2 enriched sites may be a basis for the disease recurrence reported in some, thought to be cured, patients. Graphical Abstract O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

pathology↗