Biology subjects

Gowda, A.

Publications and source records attributed to Gowda, A..

5 recordsLinked to original sources

bioRxiv2026

The rhomboid-like pseudoprotease TMEM115 defines a two-factor mechanism for Rab6A effector recruitment

Protein trafficking and organelle identity depends on precise localisation of membrane proteins, anchored by small GTPases that bind to specific cellular compartments. Here we show that the rhomboid-like pseudoprotease TMEM115 defines an unexpected two-factor system with Rab6A to target the golgin TMF1. In the absence of TMEM115, TMF1 is delocalised from the rim of the Golgi apparatus; instead, it is retained in Golgi-targeting vesicles. TMEM115, TMF1, and Rab6A assemble into a ternary complex which, in striking contrast to canonical rhomboid-like mechanisms, is independent of transmembrane domain interactions. Disruption of the TMEM115-Rab6A-TMF1 complex affects the efficiency of trafficking of proteins from the Golgi; moreover, human disease-associated mutations target the interfaces of this ternary complex, thereby delocalising TMF1 from the Golgi. Finally, loss of TMEM115 in Drosophila causes abnormal Golgi morphology, and mouse knockouts undergo perinatal death. We propose that two-factor effector recruitment defines a mechanism for precise Rab GTPase-mediated membrane targeting.

cell biology↗

bioRxiv2025

Efficient elimination of microbial infections in wounds using plasma activated water hydrogel

Surgical site infections are among the most common postoperative complications and remain a major global health concern, further intensified by increasing antimicrobial resistance. Plasma-activated water (PAW) has emerged as a novel antimicrobial strategy, though earlier studies suggested its activity depends on an acidic pH. To overcome this limitation, we previously developed a high-strength, neutral pH-buffered formulation (hs-PAbW) optimized for human clinical use, which preserved strong antimicrobial properties. In the present work, we created a hydrogel incorporating hs-PAbW at a bactericidal yet non-cytotoxic concentration (hs-PAbW-20) and evaluated its therapeutic performance in mouse wound models. In Balb/c mice, hs-PAbW-20 gel markedly reduced Pseudomonas aeruginosa and Staphylococcus aureus loads, demonstrating efficacy comparable to neomycin and soframycin. The gel also enhanced wound closure by regulating key genes involved in tissue repair. In a diabetic C57BL/6 model, hs-PAbW-20 gel similarly lowered P. aeruginosa burden and accelerated healing. Collectively, these results highlight hs-PAbW-20 gel as a promising next-generation wound therapy capable of addressing the shortcomings of traditional antibiotic-based treatments.

microbiology↗

bioRxiv2025

Essential Role of Protein Kinase R in the Pathogenesis of Pulmonary Veno-occlusive Disease

Pulmonary veno-occlusive disease (PVOD) is a rare and severe subtype of pulmonary arterial hypertension, marked by progressive remodeling of small pulmonary arteries and veins with no therapies. Using a mitomycin C (MMC)-induced rat model, we previously demonstrated that protein kinase R (PKR)-mediated integrated stress response (ISR) drives endothelial dysfunction and vascular remodeling. To determine if PKR is the sole mediator of ISR and the pathogenesis, we treated control (Ctrl) and PKR knockout (KO) mice with the same dose of MMC. Consistent with rat data, Ctrl mice displayed ISR activation, vascular remodeling, and pulmonary hypertension after MMC treatment, while KO mice showed none of these phenotypes. Proteomic analysis revealed that MMC-mediated ISR activation attenuates protein synthesis in Ctrl but not in KO mice. These findings underscore the significance of PKR-dependent ISR activation and subsequent perturbation of proteostasis as central mechanisms driving PVOD pathogenesis and identifying PKR as a promising therapeutic target.

cell biology↗

bioRxiv2025

A Cross-Species Atlas of the Dorsal Vagal Complex Reveals Neural Mediators of Cagrilintide's Effects on Energy Balance

Amylin analogs, including potential anti-obesity therapies like cagrilintide, act on neurons in the brainstem dorsal vagal complex (DVC) that express calcitonin receptors (CALCR). These receptors, often combined with receptor activity-modifying proteins (RAMPs), mediate the suppression of food intake and body weight. To understand the molecular and neural mechanisms of cagrilintide action, we used single-nucleus RNA sequencing to define 89 cell populations across the rat, mouse, and non-human primate caudal brainstem. We then integrated spatial profiling to reveal neuron distribution in the rat DVC. Furthermore, we compared the acute and long-term transcriptional responses to cagrilintide across DVC neurons of rats, which exhibit strong cagrilintide responsiveness, and mice, which respond poorly to cagrilintide over the long term. We found that cagrilintide promoted long-term transcriptional changes, including increased prolactin releasing hormone (Prlh) expression, in the nucleus of the solitary tract (NTS) Calcr/Prlh cells in rats, but not in mice, suggesting the importance of NTS Calcr/Prlh cells for sustained weight loss. Indeed, activating rat area postrema Calcr cells briefly reduced food intake but failed to decrease food intake or body weight over the long term. Overall, these results not only provide a cross-species and spatial atlas of DVC cell populations but also define the molecular and neural mediators of acute and long-term cagrilintide action.

bioinformatics↗

bioRxiv2021

Significance of Oct-4 transcription factor as a pivotal therapeutic target for CD44+/24- mammary tumour initiating cells; aiming at the root of the recurrence

Breast cancer (BC) remains one of the deadliest and frequently diagnosed metastatic cancers worldwide. Cancer stem cells (CSCs) are the cell population within the tumour niche, having an epithelial to mesenchymal (EMT) transition phenotype, high self-renewal, vigorous metastatic capacity, drug resistance, and tumour relapse. Identification of targets for induction of apoptosis is essential to provide novel therapeutic approaches in BC. Our earlier studies showed that Vitamin C induces apoptotic cell death by losing redox balance in TNBC CSCs. In this study, we have attempted to identify previously unrecognized CSC survival factors that can be used as druggable targets for bCSCs apoptosis regulators isolated from the TNBC line, MDA MB 468. After a thorough literature review, Oct-4 was identified as the most promising marker for its unique abundance in cancer and absence in normal cells and the contribution of Oct-4 to the sustenance of cancer cells. We then validated a very high expression of Oct-4 in the MDA MB 468 bCSCs population using flow-cytometry. The loss of Oct-4 was carried out using siRNA-mediated knockdown in the bCSCs, followed by assessing for cellular apoptosis. Our results indicated that Oct-4 knockdown induced cell death, changes in cellular morphology, inhibited mammosphere formation, and positive for Annexin-V expression, thereby indicating the role of Oct-4 in bCSC survival. Moreover, our findings also suggest the direct interaction between Oct-4 and Vitamin C using in silico docking. This data, hence, contributes towards novel information about Oct-4 highlighting this molecule as a novel survival factor in bCSCs.

cancer biology↗