Biology subjects

Arif, T.

Publications and source records attributed to Arif, T..

3 recordsLinked to original sources

bioRxiv2026

Green Synthesized Zinc Oxide Nanoparticles from Azadirachta indica Exhibit Enhanced Antibacterial, Antioxidant and Cytotoxic Activities

Green synthesis of zinc oxide nanoparticles (ZnO NPs) offers a sustainable strategy for developing multifunctional antimicrobial nanomaterials. In this study, ZnO NPs were synthesized using Azadirachta indica leaf extract and characterized by UV-vis spectroscopy, FTIR, XRD, SEM, and GC-MS. The nanoparticles exhibited a characteristic absorption peak at 352 nm, a direct band gap of 3.07 eV, and hexagonal wurtzite crystallinity with an average crystallite size of approximately 32 nm. The biosynthesized ZnO NPs showed concentration-dependent antibacterial activity against Erwinia carotovora, producing inhibition zones of up to 25.9 mm. Mechanistic studies revealed significant membrane damage, evidenced by 4.77-fold and 5.62-fold increases in extracellular protein and amino acid leakage, respectively, with marked alterations in bacterial protein profiles detected by SDS-PAGE. The nanoparticles also exhibited strong antioxidant activity, achieving 89.4% DPPH radical scavenging, and induced dose-dependent cytotoxicity in HepG2 cells with an estimated IC50 of 124.8 g/mL. These findings demonstrate that neem mediated ZnO nanoparticles possess potent antibacterial activity through membrane disruption while exhibiting promising antioxidant properties, highlighting their potential as eco-friendly nanomaterials for the management of bacterial soft rot and other phytopathogenic diseases.

microbiology↗

bioRxiv2025

STING and VDAC inhibitors attenuate inflammation and ineffective erythropoiesis caused by an altered metabolome in the Nan (EKLF/E339D) mouse model of neonatal anemia

Erythroid Kruppel-like factor (EKLF/KLF1) is an essential transcriptional regulator of all aspects of erythropoiesis. The mouse neonatal anemia (Nan) mutation is driven by a semi-dominant mutation in one allele of the EKLF second Zn-finger at position E339D. RNA-seq analysis of Nan/+ erythroid cells showed that expression of numerous enzymes associated with metabolic pathways are changed as a result. We assessed and analyzed the effects of this dysregulation by mass spectrometry of embryonic and adult material. Our results show that mono-allelic expression of Nan-EKLF has profound impacts on erythroid cell metabolism: levels of amino acids, nucleotides, and metabolites are altered, more energy is needed for survival and proliferation, and glucose is taken up more rapidly. As a result, mitochondrial morphology is distorted, leading to VDAC1 oligomerization and mtDNA release to the cytosol. This activates the cGAS-STING signaling pathway and induces a type-I IFN response that drives inflammation. Use of STING or VDAC inhibitors alleviates these conditions both ex vivo and in vivo. Mechanistically, treatment restores normal erythroid cell divisions and differentiation, and decreases inflammatory pathways in the bone marrow. Our findings are likely directly relevant to the dyserythropoiesis observed in CDA type IV patients that carry a similar mutation.

molecular biology↗

bioRxiv2022

Elevated p21 (CDKN1a) mediates β-thalassemia erythroid apoptosis but its loss does not improve β-thalassemic erythropoiesis

{beta}-thalassemias are common hemoglobinopathies due to mutations in the {beta}-globin gene that lead to hemolytic anemias. Premature death of {beta}-thalassemic erythroid precursors results in ineffective erythroid maturation, increased production of erythropoietin (Epo), expansion of erythroid progenitor compartment, extramedullary erythropoiesis and splenomegaly. However, the molecular mechanism of erythroid apoptosis in {beta}-thalassemia is not well understood. Using a mouse model of {beta}-thalassemia (Hbbth3/+), we show that dysregulated expression of Foxo3 transcription factor and its upstream pro-apoptotic regulator TP53 is implicated in {beta}-thalassemia erythroid apoptosis. In Foxo3-/- /Hbbth3/+ mice, erythroid apoptosis is significantly reduced while erythroid cell maturation, red blood cell and hemoglobin production are substantially improved. However, persistence of elevated reticulocytes and splenomegaly suggests that ineffective erythropoiesis is not resolved in Foxo3-/-/Hbbth3/+. We next focused on cell cycle inhibitor Cdkn1a (p21) and show that p21 that is a target of both Foxo3 and TP53 is markedly upregulated in both mouse and patients-derived {beta}-thalassemic erythroid precursors. To address the contribution of p21 to {beta}-thalassemia pathophysiology, we generated p21-/- /Hbbth3/+ mice. Double mutant p21/Hbbth3/+ mice exhibited embryonic lethality with only a fraction of mice surviving to weaning. Notably, studies in adult mice showed apoptosis and circulating Epo were greatly reduced in erythroid compartments of surviving p21-/- /Hbbth3/+ relative to Hbbth3/+ mice, while ineffective erythroid cell maturation, extramedullary erythropoiesis and splenomegaly were not modified. These combined results indicate that while lack of Foxo3 reduces apoptosis and improves anemia, diminished p21-mediated apoptosis is insufficient to improve red blood cell production in Hbbth3/+ mice. They also suggest that a molecular network constituted by p21, FOXO3 and TP53, control erythroid cell survival and differentiation in {beta}-thalassemia. Overall, these studies provide a new framework for investigating ineffective erythropoiesis in {beta}-thalassemia. Key PointsO_LIElevated p21 mediates {beta}-thalassemia erythroid cell apoptosis C_LIO_LILoss of Foxo3 or p21 reduces {beta}-thalassemia erythroid cell apoptosis but does not improve {beta}-thalassemia ineffective erythropoiesis C_LIO_LIA network of Foxo3, p21 and TP53 controls {beta}-thalassemia erythroid apoptosis C_LIO_LIApoptosis may be uncoupled from ineffective erythropoiesis in {beta}-thalassemia C_LI

developmental biology↗