👤 Saumyaranjan Mallick

Multidrug-resistant tuberculosis continues to be a major threat to mankind and is a major social and economic burden to society. Line probe assay (LPA) is a method for detecting Mycobacterium tuberculosis (MTb) in combination with resistance to rifampicin and isoniazid by first-line LPA, resistance to fluoroquinolones (FQ) and second-line injectable drugs (SLID) by second-line LPA in sputum smear-positive specimens (direct testing) and cultured isolates (indirect testing). LPA uses a DNA-based reverse hybridization method, which determines the drug resistance profile through the pattern of binding of DNA amplicons to probes that target specific areas of the MTb genome for MTb detection and to most common mutations conferring resistance to various drugs and/or the corresponding wild-type DNA sequence. LPA is endorsed by the National Tuberculosis Elimination Programme (NTEP), but very limited data are available, especially from high-burden areas such as Bihar, where a rapid, accurate, cost-effective technique like LPA can play a crucial role in early diagnosis and initiation of treatment and ultimately contribute to the effective elimination of the disease. This cross-sectional study was performed at Indira Gandhi Institute of Medical Sciences, Patna, a tertiary care centre, and aimed at the molecular characterization of Rifampicin resistant tuberculosis (RR-TB) isolates using the line probe assay method. The study was conducted between November 2022 and May 2024 with 116 samples obtained from both pulmonary tuberculosis(PTB) and extrapulmonary tuberculosis(EPTB) cases that were found to be rifampicin-resistant on CBNAAT (Cartridge based nucleic acid amplification test-Gene Xpert Mtb/RIF). In this study, 116 patients were enrolled, of whom 80(68.9 %) were pre-XDR-TB cases and 36(31 %) were MDR-TB cases. The most common pattern of mutation associated with rifampicin rpoB gene was WT8 MUT3 S531L and, Isoniazid inhA gene was WT1 MUT1 c-15 t. High-level isoniazid resistance involving KatG mutation was present in 111 (95.7 %) cases and the most common mutation associated was MUT1 -S315T1. Overall prevalence of fluoroquinolone resistance in this study was 68.9 %. There is a wide prevalence of high-level isoniazid resistance and fluoroquinolone resistance among RR-TB patients, indicating the rapid emergence and transmission of resistant strains in the community. This underscores the need for enforced interventions, such as screening for MDR-TB before starting therapy and surveillance of fluoroquinolone susceptibility. Molecular characterization of RR-TB strains by Line probe assay method can play a critical role in the rapid determination of pattern of resistance in the circulating strains and hence guide tailored therapy at the earliest opportunity especially in high burden setting with limited infrastructure. Show less

The interaction between stromal and tumor cells in tumor microenvironment is a crucial factor in Mantle cell lymphoma (MCL) progression and therapy resistance. We have identified a long non-coding RNA, CERS6-AS1, upregulated in MCL and associated with poor overall survival. CERS6-AS1 expression was elevated in primary MCL within stromal microenvironment and in a subset of MCL cells adhered to stromal layer. These stromal-adhered MCL-subsets exhibited cancer stem cell signatures than suspension counterparts. Mechanistically, we found that downregulating CERS6-AS1 in MCL reduced Fibroblast Growth Factor Receptor-1 (FGFR1), expression attributed to loss of its interaction with RNA-binding protein nucleolin. In addition, using in-silico approach, we have discovered a direct interaction between nucleolin and 5'UTR of FGFR1, thereby regulating FGFR1 transcript stability. We discovered a positive association of CERS6-AS1 with cancer stem cell signatures, and Wnt signaling. Building on these, we explored potential therapeutic strategies where combining nucleolin-targeting agent with FGFR1 inhibition significantly contributed to reversing cancer stem cell signatures and abrogated primary MCL cell growth on stromal layer. These findings provide mechanistic insights into regulatory network involving CERS6-AS1, nucleolin, and FGFR1 axis-associated crosstalk between tumor cells and stromal cell interaction and highlights therapeutic potential of targeting a non-coding RNA in MCL. Show less

A major goal of biomedicine is to understand the function of every gene in the human genome. Loss-of-function mutations can disrupt both copies of a given gene in humans and phenotypic analysis of such 'human knockouts' can provide insight into gene function. Consanguineous unions are more likely to result in offspring carrying homozygous loss-of-function mutations. In Pakistan, consanguinity rates are notably high. Here we sequence the protein-coding regions of 10,503 adult participants in the Pakistan Risk of Myocardial Infarction Study (PROMIS), designed to understand the determinants of cardiometabolic diseases in individuals from South Asia. We identified individuals carrying homozygous predicted loss-of-function (pLoF) mutations, and performed phenotypic analysis involving more than 200 biochemical and disease traits. We enumerated 49,138 rare (<1% minor allele frequency) pLoF mutations. These pLoF mutations are estimated to knock out 1,317 genes, each in at least one participant. Homozygosity for pLoF mutations at PLA2G7 was associated with absent enzymatic activity of soluble lipoprotein-associated phospholipase A2; at CYP2F1, with higher plasma interleukin-8 concentrations; at TREH, with lower concentrations of apoB-containing lipoprotein subfractions; at either A3GALT2 or NRG4, with markedly reduced plasma insulin C-peptide concentrations; and at SLC9A3R1, with mediators of calcium and phosphate signalling. Heterozygous deficiency of APOC3 has been shown to protect against coronary heart disease; we identified APOC3 homozygous pLoF carriers in our cohort. We recruited these human knockouts and challenged them with an oral fat load. Compared with family members lacking the mutation, individuals with APOC3 knocked out displayed marked blunting of the usual post-prandial rise in plasma triglycerides. Overall, these observations provide a roadmap for a 'human knockout project', a systematic effort to understand the phenotypic consequences of complete disruption of genes in humans. Show less

Evidence is sparse about the genetic determinants of major lipids in Pakistanis. Variants (n=45 000) across 2000 genes were assessed in 3200 Pakistanis and compared with 2450 Germans using the same gene array and similar lipid assays. We also did a meta-analysis of selected lipid-related variants in Europeans. Pakistani genetic architecture was distinct from that of several ethnic groups represented in international reference samples. Forty-one variants at 14 loci were significantly associated with levels of HDL-C, triglyceride, or LDL-C. The most significant lipid-related variants identified among Pakistanis corresponded to genes previously shown to be relevant to Europeans, such as CETP associated with HDL-C levels (rs711752; P<10(-13)), APOA5/ZNF259 (rs651821; P<10(-13)) and GCKR (rs1260326; P<10(-13)) with triglyceride levels; and CELSR2 variants with LDL-C levels (rs646776; P<10(-9)). For Pakistanis, these 41 variants explained 6.2%, 7.1%, and 0.9% of the variation in HDL-C, triglyceride, and LDL-C, respectively. Compared with Europeans, the allele frequency of rs662799 in APOA5 among Pakistanis was higher and its impact on triglyceride concentration was greater (P-value for difference <10(-4)). Several lipid-related genetic variants are common to Pakistanis and Europeans, though they explain only a modest proportion of population variation in lipid concentration. Allelic frequencies and effect sizes of lipid-related variants can differ between Pakistanis and Europeans. Show less

The liver X receptors (LXRs) have been known as sterol sensors that impact cholesterol and lipid homeostasis, as well as inflammation. Although the hepatic functions of LXRs are well documented, whether and how LXRs play a pathophysiological role in the lung remain largely unknown. Here we show that LXRalpha and LXRbeta are expressed in both type I and type II mouse lung epithelial cells, as well as in human lung cancer cells. To study the role of LXRalpha in vivo including the pulmonary function of this LXR isoform, we created LXRalpha knock-in (LXR-KI) mice in which a constitutively activated LXRalpha (VP-LXRalpha) was inserted into the mouse LXRalpha locus. We show that activation of LXR in LXR-KI mice or LXR agonist-treated wild type mice induced pulmonary expression of genes encoding multiple antioxidant enzymes. Consistent with the induction of antioxidant enzymes, LXR-KI mice and LXR ligand-treated wild type mice showed a substantial resistance to lipopolysaccharide-induced lung injury and decreased production of reactive oxygen species. In summary, we have uncovered a novel role of LXR in regulating antioxidant enzymes in the lung and the implication of this regulation in pulmonary tissue protection. Show less