Browsing by Author "Arijit Chakraborty"

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Duplications in 19p13.3 are associated with male infertility
(Springer New York LLC, 2019) Vertika Singh; Renu Bala; Arijit Chakraborty; Singh Rajender; Sameer Trivedi; Kiran Singh
Purpose: To identify genomic imbalances and candidate loci in idiopathic male infertility. Methods: Affymetrix CytoScan 750K Array was used to analyze genomic imbalances and candidate loci in 34 idiopathic infertile cases of different phenotypes (hypo-spermatogenesis, n = 8; maturation arrest, n = 7; and Sertoli cell-only syndrome, n = 13, severe oligozoospermia, n = 6, and 10 normozoospermic fertile men). Ten ethnically matched controls were screened for comparison. Results: The cytogenetic array analysis detected a genomic gain at the 19p13.3 region in 9 (26.47%) cases, with the highest frequency in patients with Sertoli cell-only syndrome (SCOS) (38%). Its complete absence in the control group suggests its likely pathogenic nature. In addition to Y-classical, micro, and partial deletions, the duplication in 19p13.3 could serve as a unique biomarker for evaluation of infertility risk. The common region across the individuals harboring the duplication identified STK11, ATP5D, MIDN, CIRBP, and EFNA2 genes which make them strong candidates for further investigations. The largest duplicated region identified in this study displayed a major network of 7 genes, viz., CIRBP, FSTL3, GPX4, GAMT, KISS1R, STK11, and PCSK4, associated with reproductive system development and function. The role of chance was ruled out by screening of ethnically matched controls. Conclusion: The result clearly indicates the significance of 19p13.3 duplication in infertile men with severe testicular phenotypes. The present study underlines the utility and significance of whole genomic analysis in the cases of male infertility which goes undiagnosed due to limitations in the conventional cytogenetic techniques and for identifying genes that are essential for spermatogenesis. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
Excess iodine impairs spermatogenesis by inducing oxidative stress and perturbing the blood testis barrier
(Elsevier Inc., 2020) Arijit Chakraborty; Vertika Singh; Kiran Singh; Singh Rajender
Approximately 2 billion people worldwide are susceptible to iodine deficiency. Iodine deficiency has largely been tackled by iodine fortification in salt; however indiscriminate use of iodine raises the risk of iodine toxicity. In this study, we aimed to investigate the molecular mechanisms underlying adverse effect of excess iodine on spermatogenesis. Sprague Dawley (SD) rats were orally administered with 0.7 mg potassium iodide (KI)/100 g Bw and 3.5 mg potassium iodide (KI)/100 g Bw for a period of 60 days. This resulted in significant loss of sperm count and motility. Molecular investigations provided evidence for the generation of oxidative stress with high SOD levels, reduced Nrf2, HO-1 and increased NF-kB and Follistatin. Further investigations showed increased apoptosis evidenced by reduced expression of anti-apoptotic (BCL-2, Survivin), increased expression of pro-apoptotic (Bid, Bax) markers, and increased expression of p53 and other modulators/effectors of apoptosis (cytochrome c, cleaved PARP, caspase3 and caspase9). Analysis of the blood testis barrier proteins showed reduced expression of tight junction (JAM-A, Tricellulin), ectoplasmic specialization (Integrin- β1), adherens junction (N-Cadherin, E-cadherin, β-catenin) proteins, and reduced expression of other junction protein coding genes (Claudin1, Claudin 5, Occludin, ZO-1, Testin, Fibronectin, CAR-F). Focal adhesion kinase (FAK) and key regulators of spermatogenesis (c-Kit receptor, androgen receptor) were also parallelly decreased. Further investigation showed reduced expression of germ cell proliferation and differentiation markers (PCNA, Cyclin D1, c-Kit, Cdk-4). These findings collectively explain the loss of spermatogenesis under excess iodine conditions. In conclusion, excess iodine causes loss of spermatogenesis by inducing oxidative stress and disrupting the blood testis barrier and cytoskeleton. © 2020
SNPs in ERCC1, ERCC2, and XRCC1 genes of the DNA repair pathway and risk of male infertility in the Asian populations: association study, meta-analysis, and trial sequential analysis
(Springer New York LLC, 2019) Vertika Singh; Sandeep Kumar Bansal; D.V.S. Sudhakar; Neelabh; Arijit Chakraborty; Sameer Trivedi; Gopal Gupta; Kumarasamy Thangaraj; Singh Rajender; Kiran Singh
Purpose: We investigated if substitutions in the ERCC1, ERCC2, and XRCC1 genes of the DNA repair pathway correlate with non-obstructive azoospermia and male infertility. Methods: A total of 548 azoospermic infertile males and 410 fertile controls were genotyped for XRCC1 399A > G, 280G > A, and ERCC1 C > A 3′ UTR and 541 azoospermic infertile males and 416 fertile controls were genotyped for ERCC2 751A > C using iPLEX Gold Assay. Meta-analyses were performed on XRCC1 399A > G (1022 cases and 1004 controls), ERCC1 C > A 3′ UTR (879 cases and 1059 controls), and ERCC2 751A > C (914 cases and 850 controls) polymorphisms to quantitatively estimate the significance of the association between these polymorphisms and the risk of infertility. Results: Statistically significant association between ERCC2 751A > C SNP and male infertility was found using the codominant model (p = 0.03). Results of meta-analysis suggested a lack of correlation with male infertility risk, which could be due to pooling of studies from different ethnic populations. Due to limited the number of studies, a stratified analysis for different ethnic groups could not be performed. Conclusion (s): In conclusion, AA genotype of 751A > C SNP in ERCC2 correlated with a higher risk of male infertility and may contribute to an increased risk of azoospermia and male infertility in Indian men. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
Wnt5a signaling promotes host defense against leishmania donovani infection
(American Association of Immunologists, 2017) Arijit Chakraborty; Sony Priya Kurati; Sushil K. Mahata; Shyam Sundar; Syamal Roy; Malini Sen
Leishmania donovani infects macrophages, disrupting immune homeostasis. The underlying mechanism that sustains infection remains unresolved. In view of the potential of Wnt5a signaling to support immune homeostasis, we evaluated the interrelationship of Wnt5a signaling and Leishmania donovani infection. Upon infecting macrophages separately with antimony drug-sensitive and -resistant L. donovani, we noted disruption in the steady-state level of Wnt5a. Moreover, inhibition of Wnt5a signaling by small interfering RNA transfection in vitro or by use of inhibitor of Wnt production in vivo led to an increase in cellular parasite load. In contrast, treatment of macrophages with recombinant Wnt5a caused a decrease in the load of antimony-sensitive and -resistant parasites, thus confirming that Wnt5a signaling antagonizes L. donovani infection. Using inhibitors of the Wnt5a signaling intermediates Rac1 and Rho kinase, we demonstrated that Wnt5a-mediated inhibition of parasite infection in macrophages is Rac1/Rho dependent. Furthermore, phalloidin staining and reactive oxygen species estimation of Wnt5a-treated macrophages suggested that a Wnt5a-Rac/Rho-mediated decrease in parasite load is associated with an increase in F- actin assembly and NADPH oxidase activity. Moreover, live microscopy of L. donovani-infected macrophages treated with Wnt5a demonstrated increased endosomal/lysosomal fusions with parasite-containing vacuoles (parasitophorous vacuoles [PV]). An increase in PV- endosomal/lysosomal fusion accompanied by augmented PV degradation in Wnt5a-treated macrophages was also apparent from transmission electron microscopy of infected cells. Our results suggest that, although L. donovani evades host immune response, at least in part through inhibition of Wnt5a signaling, revamping Wnt5a signaling can inhibit L. donovani infection, irrespective of drug sensitivity or resistance. Copyright © 2017 by The American Association of Immunologists, Inc.
XRCC1 deficiency correlates with increased DNA damage and male infertility
(Elsevier B.V., 2019) Vertika Singh; Sujit Kumar Mohanty; Priyanka Verma; Arijit Chakraborty; Sameer Trivedi; Singh Rajender; Kiran Singh
High fidelity DNA repair is critical to sustain the genomic integrity and quality of developing germ cells. Deficiencies in DNA repair machinery may result in increased DNA damage in germ cell leading to abnormal spermatogenesis and infertility. X-ray repair cross-complementing group 1 (XRCC1) is a testis enriched protein that plays a crucial role in the DNA base excision repair (BER) pathway. The aim of this study was to analyze the level of XRCC1 transcript and protein in infertile men and its association with DNA damage in sperm. A total of eighty infertile patients with different infertile phenotypes (Azoospermia, n = 30; Severe oligozoospermia, n = 25; Severe oligoasthenozoospermia, n = 25) and age-matched controls (normal spermatogenesis [NS], n = 15 and fertile controls, n = 10) were recruited. γ-H2 AX protein levels were analyzed to estimate the DNA damage in sperm. XRCC1 transcript levels in cases and controls were determined by qRT-PCR. XRCC1 and γ-H2 AX proteins were immunohistochemically analyzed in testicular biopsy sections obtained from NOA patients and OA controls. The determination of XRCC1 and γ-H2 AX protein levels was performed with Western blots. The results revealed reduced expression of XRCC1 mRNA and protein in infertile individuals as compared to controls (p < 0.001). γ-H2 AX levels were significantly increased in infertile cases as compared to controls, indicating increased DNA damage in infertile men. The results indicate decreased expression of the XRCC1 gene in infertile patients which may be one of the factors associated with impaired spermatogenesis and infertility. © 2019 Elsevier B.V.