Biology subjects

Bhattacharya, I.

Publications and source records attributed to Bhattacharya, I..

6 recordsLinked to original sources

bioRxiv2025

NOR1 and Mitophagy: An Insight into Sertoli Cell Function Regulating Spermatogenesis

The development and differentiation of germ cell (Gc) is supported by the Sertoli cel (Sc). We previously reported that a developmental switch in Sc around 12 days of age onwards in rats. During the process of differentiation of Sc, the differential expression of mitophagy-related genes and its role in male fertility is poorly understood. To address this gap, we evaluated the microarray dataset GSE48795 to identify 12 mitophagy-related hub genes - Egfr, Bcl2, Ccl2, Mmp2, Igf1, Fgf7, Apoe, Fos, Cxcl12, Ocln, Dcn, and Snca. We identify NOR1 as a potential mitophagy-related gene of interest due to its strong regulatory association with two hub genes Bcl2 and Fos. To determine the importance of our analysis of finding key mitophagy-related genes, we generated a transgenic rat model with Sc-specific knockdown of NOR1 during puberty. Adult male transgenic rats were found to be infertile due to impaired spermatogenesis, indicating a critical role for NOR1 in Sc function. These findings suggest that mitophagy-related genes may play an important role in the differentiation of Sc and thereby, regulate male fertility.

cell biology↗

bioRxiv2024

Overexpression of enhanced yellow fluorescent protein fused with Channelrhodopsin-2 causes contractile dysfunction in skeletal muscle

Skeletal muscle activation using optogenetics has emerged as a promising technique for inducing noninvasive muscle contraction and assessing muscle function both in vivo and in vitro. Transgenic mice overexpressing the optogenetic fusion protein, Channelphodopsin2-EYFP (ChR2-EYFP) in skeletal muscle are widely used; however, overexpression of fluorescent proteins can negatively impact the functionality of activable tissues. In this study, we characterized the contractile properties of ChR2-EYFP skeletal muscle and introduced the ChR2-only mouse model that expresses light-responsive ChR2 without the fluorescent EYFP in their skeletal muscles. We found a significant reduction in the contractile ability of ChR2-EYFP muscles compared to ChR2-only and WT mice, observed under both electrical and optogenetic stimulation paradigms. Bulk RNAseq identified downregulation of genes associated with transmembrane transport and metabolism in ChR2-EYFP muscle, while the ChR2-only muscle did not demonstrate any notable deviations from WT muscle. The RNAseq results were further corroborated by a reduced protein-level expression of ion-channel-related HCN2 in ChR2-EYFP muscles and gluconeogenesis-modulating FBP2 in both ChR2-EYFP and ChR2-only muscles. Overall, this study reveals an intrinsic skeletal dysfunction in the widely used ChR2-EYFP mice model and underscores the importance of considering alternative optogenetic models, such as the ChR2-only, for future research in skeletal muscle optogenetics.

physiology↗

bioRxiv2023

Single protein molecules separation, tracking and counting in ultra-thin silicon channels

Emerging single-molecule protein sensing techniques are ushering in a transformative era in biomedical research. Nevertheless, challenges persist in realizing ultra-fast full-size protein sensing, including loss of molecular integrity due to protein fragmentation, biases introduced by antibodies affinity, identification of proteoforms and low throughputs. Here, we introduce a single-molecule method for parallel protein separation and tracking, yielding multi-dimensional molecular properties used for their identification. Proteins are tagged by dual amino-acid specific labels and are electrophoretically separated by their mass/charge in custom-designed silicon nano-channel. This approach allows us to analyze thousands of individual proteins within a few minutes by tracking their motion during the migration. We demonstrate the power of the method by quantifying a cytokine panel for host-response discrimination between viral and bacterial infections. Moreover, we show that two clinically-relevant splice isoforms of VEGF can be accurately quantified from human serum samples. Being non-destructive and compatible with full-length intact proteins, this method opens up new ways for antibody-free single protein molecule quantification.

biophysics↗

bioRxiv2021

OPTN limits herpes stromal keratitis severity and demyelination through negative regulation of IL-17 and hyperinflammatory T-cell response

Herpes stromal keratitis (HSK) is a result of the inflammatory sequelae following primary and recurrent Herpes simplex virus type-1 (HSV-1) infections. This pathology is known to be mediated by immunopathogenic T cell responses against viral antigens, however most individuals infected with HSV-1 never exhibit signs of this immunopathology. Recent studies have identified the host restriction factor, optineurin (OPTN), as an inhibitor of viral spread in the central nervous system, protecting hosts from viral encephalopathy. In an HSV-1 corneal infection mouse model on OPTN knockout mice, we assess the contribution of OPTN to ameliorating the clinical manifestations of HSK. We identify that OPTN protects the host from loss of ocular and whisker sensitivity and opacification of the cornea. scRNA-seq of the trigeminal ganglion (TG) reveals that transcription changes to the peripheral neurons and immune cell populations drive the expression of Il-17A in CD4 and CD8 T cells, as well as increased infiltration of T cells into the TG. This leads to demyelination and the observed HSK pathology.

immunology↗

bioRxiv2021

Deletion of Fibroblast growth factor 9 globally and in skeletal muscle results in enlarged tuberosities at sites of deltoid tendon attachments

The growth of most bony tuberosities, like the deltoid tuberosity (DT), rely on the transmission of muscle forces at the tendon-bone attachment during skeletal growth. Tuberosities distribute muscle forces and provide mechanical leverage at attachment sites for joint stability and mobility. The genetic factors that regulate tuberosity growth remain largely unknown. In mouse embryos with global deletion of fibroblast growth factor 9 (Fgf9), the DT size is notably enlarged. In this study, we explored the tissue-specific regulation of DT size using both global and targeted deletion of Fgf9. We showed that cell hypertrophy and mineralization dynamics of the DT, as well as transcriptional signatures from skeletal muscle but not bone, were influenced by the global loss of Fgf9. Loss of Fgf9 during embryonic growth led to increased chondrocyte hypertrophy and reduced cell proliferation at the DT attachment site. This endured hypertrophy and limited proliferation may explain the abnormal mineralization patterns and locally dysregulated expression of markers of endochondral development in Fgf9null attachments. We then showed that targeted deletion of Fgf9 in skeletal muscle leads to postnatal enlargement of the DT. Taken together, we discovered that Fgf9 may play an influential role in muscle-bone crosstalk during embryonic and postnatal development.

developmental biology↗

bioRxiv2020

Retromer retrieves the Wilson Disease protein, ATP7B from lysosomes in a copper-dependent mode

ATP7B utilizes lysosomal exocytosis to export copper from hepatocytes. We investigated the fate of ATP7B, post-copper export. At high copper ATP7B traffics to lysosomes and upon subsequent copper chelation, returns to Trans Golgi Network. At high copper, ATP7B co-localizes with lysosomal marker, Lamp1 and the core member of retromer complex, Vps35. Knocking down VPS35 did not alter copper-responsive vesicularization of ATP7B; rather upon subsequent copper chelation, ATP7B failed to relocalize to TGN that could be rescued by overexpressing wtVPS35. Using super-resolution microscopy and proximity ligation assays we demonstrate that VPS35 and ATP7B are juxtaposed on the same lysosomal compartment and their interaction is indirect. Utilizing in-cell photoamino acid-based UV-crosslinking and subsequent immunoprecipitation, we detected ATP7B and retromer subunits, VPS35 and VPS26 in a large complex in high copper conditions, hence confirming their interaction. We demonstrate that retromer regulates lysosome to TGN trafficking of the copper transporter ATP7B and it is dependent upon cellular copper level.

cell biology↗