Publications by authors named "Gundappa Saha"

Clonal hematopoiesis of indeterminate potential (CHIP) arises from aging-associated acquired mutations in hematopoietic progenitors, which display clonal expansion and produce phenotypically altered leukocytes. We associated CHIP-DNMT3A mutations with a higher prevalence of periodontitis and gingival inflammation among 4,946 community-dwelling adults. To model DNMT3A-driven CHIP, we used mice with the heterozygous loss-of-function mutation R878H, equivalent to the human hotspot mutation R882H.

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Article Synopsis
  • - Tumors often develop in oxygen-poor (hypoxic) environments due to disorganized blood vessels, which limits oxygen supply and affects cell behavior through hypoxia-induced transcription factor 1.
  • - Hypoxic conditions can decrease the effectiveness of chemotherapy by reducing the production of harmful free radicals, making it harder to treat cancer effectively.
  • - The article discusses various reliable cell-based assays designed to measure hypoxia in cancer cells, highlighting their potential to enhance cancer treatment outcomes based on the knowledge gained from these assays.
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Several studies have been reported linking the role of polyglutamine (polyQ) disease-associated proteins with altered gene regulation induced by an unstable trinucleotide (CAG) repeat. Owing to their dynamic nature of expansion, these DNA repeats form secondary structures interfering with the normal cellular mechanisms like replication and transcription and, thereby, have become the underlying cause of numerous neurodegenerative disorders involving mental retardation and/or muscular or neuronal degeneration. Despite the widespread expression of the disease-causing protein, specific subsets of neurons are susceptible to specific patterns of inheritance and clinical symptoms.

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Bone marrow (BM)-mediated trained innate immunity (TII) is a state of heightened immune responsiveness of hematopoietic stem and progenitor cells (HSPC) and their myeloid progeny. We show here that maladaptive BM-mediated TII underlies inflammatory comorbidities, as exemplified by the periodontitis-arthritis axis. Experimental-periodontitis-related systemic inflammation in mice induced epigenetic rewiring of HSPC and led to sustained enhancement of production of myeloid cells with increased inflammatory preparedness.

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Precise regulation of inflammasome is critical during any pathogenic encounter. The whole innate immune system comprising of pattern recognition receptors (PRRs) relies on its ability to sense microbes. The fate of cellular death in infected cells depends mostly on the activation of these inflammasome, the dysregulation of which, due to functional manipulation by various pathogens, leads to be the cause of many human diseases.

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We report biochemical studies on two Cys residues mutation (Cys15Thr, Cys38Gly) nearest to the active site and three other amino acid substitution mutations expected to be the part of active site of LdDLDH_Variant1. Our biochemical studies show that the replacement of Cys15 increases the K for dihydrolipoamide (DLD) substrate by five folds and NAD by three fold indicating that this mutation affects the binding of DLD and NAD significantly. Cys38 was also mutated to 'Gly' which resulted in nine fold greater K for NAD without affecting K for DLD.

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Protozoan parasites of the Leishmania genus have evolved unique signaling pathways that can sense various environmental changes and trigger stage differentiation for survival and host infectivity. MAP kinase (MAPK) plays a critical role in various cellular activities like cell differentiation, proliferation, stress regulation, and apoptosis. The Leishmania donovani MAPK3 (LdMAPK3) is involved in the regulation of flagella length and hence plays an important role in disease transmission.

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Article Synopsis
  • - Visceral leishmaniasis, a severe and fatal disease, is caused by a parasite that evades the immune system by manipulating immune responses, particularly through a protein called BLIMP-1.
  • - The study reveals that BLIMP-1 suppresses the death of immune cells (macrophage pyroptosis) during infection, impacting the NFκβ-NLRP3 signaling pathway, which is essential for an effective immune response.
  • - Experiments demonstrate an inverse relationship between BLIMP-1 and NFκβ, suggesting that the parasite exploits this mechanism to hinder cell death and promote its survival in the host.
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Significant advances have been made in understanding the regulation of inflammasomes and its involvement in innate immunity during pathogenic infections. Inflammasome activation is a tightly regulated process that provides defense against pathogenic infection and important for inflammatory response. Very few studies on the involvement of NLRP3 inflammasome protein complex have been reported in leishmanial infections with contradictory results and without much mechanistic insights.

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The presence of dye, including azo functional group (NN) containing dyes, in industrial waste water is one of the major causes of water pollution. This report showcases the functional role of azoreductase from Chromobacterium violaceum (MTCC No: 2656) as a valuable enzyme for degradation of azo dyes. The enzyme was cloned, expressed, purified and biochemically characterized and further tested for degradation efficiency of azo group containing dyes like methyl red, amaranth and methyl orange.

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Trypanothione based redox metabolism is unique to the Trypanosomatida family. Despite extensive studies on redox metabolism of Leishmania parasites, a prominent question of why Leishmania adopt this unique redox pathway remains elusive. We have episomally expressed human glutathione reductase (HuGR) in Leishmania donovani (LdGR) and investigated its effect.

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Apoptosis, a form of programmed cell death, plays a very crucial role in various physiological processes for maintaining cell homeostasis. This process has several characteristic features like membrane blebbing, nuclear condensation, DNA fragmentation and cell shrinkage. Any defect in this highly regulated process eventually leads to extended cell survival and could result in neoplastic cell expansion followed by genetic instability.

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Visceral leishmaniasis is a deadly endemic disease. Unresponsiveness to the only available oral drug miltefosine poses a big challenge for the chemotherapy of the disease. We report a novel molecule, PS-203 {4-(4,4,8-trimethyl-7-oxo-3-oxabicyclo[3.

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