Biology subjects

Zahoor, M.

Publications and source records attributed to Zahoor, M..

9 recordsLinked to original sources

bioRxiv2026

VEZF1 facilitates pluripotency exit by regulating developmental transcriptional programs and CTCF occupancy

Vascular Endothelial Zinc Finger 1 (VEZF1) is essential for embryonic development, but its role in pluripotency exit remains unclear. Previous work showed that Vezf1-deficient ESCs exhibit impaired differentiation, reduced Dnmt3b expression, and genome-wide hypomethylation. Here, we show that Vezf1-/- ESCs fail to efficiently repress the pluripotency transcriptional program during differentiation, a defect that persists after ectopic Dnmt3b expression. Genome-wide analysis revealed VEZF1 occupancy at regulatory regions of genes involved in several developmental signaling pathways, including MAPK, WNT, and Hippo, as well as at some pluripotency-associated genes. Many VEZF1-bound MAPK genes showed reduced expression in undifferentiated Vezf1-/-ESCs, suggesting that VEZF1 activity contributes to transcriptional competence required for efficient pluripotency exit. VEZF1 loss also led to widespread acquisition of new CTCF sites associated with developmental signaling, a subset of which overlapped VEZF1-bound regulatory regions. CTCF depletion had only limited effects on the expression of the VEZF1-bound MAPK genes examined, indicating that increased CTCF occupancy alone is insufficient to explain their reduced expression in Vezf1-/- ESCs. Together, our findings identify a DNMT3B-independent function of VEZF1 in facilitating the exit from pluripotency and establishing transcriptional competence for differentiation, while revealing a potential role for VEZF1 in regulating CTCF occupancy during developmental state transitions.

developmental biology↗

bioRxiv2025

The glutamine transporter Slc38a1 is widely expressed in the embryonic neurogenic niches and impacts neuronal volume, survival, and morphology

The amino acid glutamine, and its derivatives glutamate and GABA, are pivotal for neurogenesis. However, how glutamine is mechanistically supplied to the cells in the neurogenic niches and its broader impact on neurodevelopment, remain poorly characterized. The Solute carrier family 38 member 1 (Slc38a1) exhibits high affinity for glutamine and accumulates glutamine in select cells. We investigated whether Slc38a1 is essential for neurogenesis and whether it has an impact on brain structure and function. Slc38a1 mRNA transcript and protein are widely expressed in the embryonic brain, including in the dorsal pallium and sub-pallium. At embryonic day 15.5, Slc38a1 localizes in neuronal stem cells in the ventricular zone in the forebrain, while it localizes in mature neurons in the sub-ventricular zone of the hindbrain. In the adult brain, Slc38a1 is not detected in neuronal stem cells in the sub-granular zone, however, it is highly enriched in mature local parvalbumin+ and somatostatin+ interneurons and ependyma. Analyses of single-cell RNA sequencing data further reveal that both the number of Slc38a1-expressing cells and the average transcript level of Slc38a1 are significantly higher in embryo brain cells compared to adults. In the embryo, Slc38a1 transcripts are particularly enriched in immature neuronal lineages and embryonic oligodendrocyte precursor populations, whereas in the adult, expression is more prominent in neural progenitor cells and radial glia. Disruption of Slc38a1 in mice impacts body weight, brain size and glutamatergic neuronal volume, while dendritic arborization is diminished and cellular life span is shortened. Altogether, Slc38a1 is essential for normal neurodevelopment, indirectly regulates adult neurogenesis in the sub-granular zone and influence neuronal morphology and cell viability.

neuroscience↗

bioRxiv2023

Identification of a link between splicing and endoplasmic reticulum proteostasis

The role of general splicing in endoplasmic reticulum (ER)-proteostasis remains poorly understood. Here, we identify SNRPB, a component of the spliceosome, as a novel regulator of export from the ER. Mechanistically, SNRPB regulates the splicing of components of the ER export machinery, including Sec16A, a regulator of ER exit sites. Loss of function of SNRPB is causally linked to cerebro-costo-mandibular syndrome (CCMS), a genetic disease characterized by bone defects. We show that heterozygous deletion of SNRPB in mice resulted in intracellular accumulation of type-1 collagen as well as bone defects reminiscent of CCMS. Silencing SNRPB inhibited osteogenesis in vitro, which could be rescued by overexpression of Sec16A. This indicates that the role of SNRPB in osteogenesis is linked to its effects on ER export. Finally, we show that SNRPB is a target for the unfolded protein response (UPR), which supports a mechanistic link between the spliceosome and ER-proteostasis. Our work highlights SNRPB as a novel node in the proteostasis network, shedding light on CCMS pathophysiology.

cell biology↗

bioRxiv2023

Solvent based fractional biosynthesis, phytochemical analysis and biological activity of silver nanoparticles obtained from extract of Salvia moorcroftiana

Multi-drug resistant bacteria sometimes known as "superbugs" developed through overuse and misuse of antibiotics are determined to be sensitive to small concentrations of silver nanoparticles. Various methods and sources are under investigation for the safe and efficient synthesis of silver nanoparticles having effective antibacterial activity even at low concentrations. We used a medicinal plant named Salvia moorcroftiana to extract phytochemicals with antibacterial, antioxidant, and reducing properties. Three types of solvents; from polar to nonpolar, i.e., water, dimethyl sulfoxide (DMSO), and hexane, were used to extract the plant as a whole and as well as in fractions. The biosynthesized silver nanoparticles in all extracts (except hexane-based extract) were spherical, smaller than 20 nm, polydispersed (PDI ranging between 0.2 and 0.5), and stable with repulsive force of action (average zeta value = -18.55{+/-}1.17). The tested bacterial strains i.e., Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis were found to be sensitive to even small concentrations of AgNPs, especially P. aeruginosa. The antibacterial effect of these AgNPs was associated with their ability to generate reactive oxygen species. DMSO (in fraction) could efficiently extract antibacterial phytochemicals and showed activity against MDR bacteria (inhibition zone = 11-12 mm). Thus, the antibacterial activity of fractionated DMSO extract was comparable to that of AgNPs because it contained phytochemicals having solid antibacterial potential. Furthermore, AgNPs synthesized from this extract owned superior antibacterial activity. However, whole aqueous extract based AgNPs MIC was least (7-32 {micro}g/mL) as compared to others.

microbiology↗

bioRxiv2022

Genotypic variation in tolerance to salinity in Pakistani okra (Abelmoschus esculentus L.) varieties as assessed at seed germination, seedling growth and biochemical characters

Salt stress is one of the major abiotic stresses that causes reduction in crops yield. Okra (Abelmoschus esculentus L.) is a high-value nutraceutical vegetable because its various parts are used for different purposes. This study was conducted to calculate the salt tolerance among thirteen okra varieties. Different salt (NaCl) levels: 0, 50, 75 and 100 mM were selected to measure the response of the okra varieties to stress. The experimental data showed that all varieties were affected by salt level with a differential variation in their stress response, demonstrating the presence of genetic variability. Five varieties: "NAYAB-F1", "Arka anamika", "MALAV-27", "Sarhad Green" and 051-F1 showed germination at all stress levels (0, 50, 75 and 100 mM), six varieties: "Feveeri Green", "Punjab Selection", "Local Multani", "Shehzadi", "Green Star" and "Hunza" showed germination at (0, 50 and 75 mM) and two: "Anmol" and "Sabz Pari" showed germination at (0 and 50 mM). As a result of salt stress, germination percentage (PG), leaf fresh and dry weight (LFW and LDW), shoot fresh and dry weight (SFW and SDW), root fresh and dry weight (RFW and RDW) were significantly reduced with increasing stress level. Based on the performance of variety to salt stress, five varieties were selected for biochemical analysis, concentrating on the determination of osmolytes. The values of sugar and proline were affected both by the varieties and salt levels. Variety "NAYAB-F1" showed higher sugar and proline content at all stress levels compared to varieties "Arka anamika", "MALAV-27", "051-F1" and Sarhad Green. Correspondingly, in the stressed seedling a decreasing trend in chlorophyll "a" and "b" were noted depending on the varieties and stress concentrations. After a series of experiment, it has been concluded that varieties "NAYAB-F1", "Arka anamika", "MALAV-27", "Sarhad Green" and "051-F1" were recommended as salt tolerant varieties and could be utilized in the breeding program of salt tolerant okra.

developmental biology↗

bioRxiv2022

A combined experimental-computational approach uncovers a role for the Golgi matrix protein Giantin in breast cancer progression

Few studies so far have investigated the impact of different cell migration traits on tumor progression. To address this, we developed a mathematical model wherein cells migrate in two-dimensional space, divide, die or intravasate into the vasculature. Exploring a wide range of speed and persistence combinations, we find that tumor growth positively correlates with increasing speed and higher persistence. As a biologically relevant example, we focused on Golgi fragmentation induced by depletion of Giantin, a Golgi matrix protein, the downregulation of which correlates with poor patient survival. Applying the migration and invasion traits of Giantin depleted cells to our mathematical model, we predict that loss of Giantin increases the number of intravasating cells. This prediction was validated, by showing that circulating tumor cells express significantly less Giantin than primary tumor cells. Altogether, our computational model identifies cell migration traits that regulate tumor progression and uncovers a role of Giantin in breast cancer progression.

cancer biology↗

bioRxiv2021

IL-32 is a metabolic regulator promoting survival and proliferation of malignant plasma cells

IL-32 is a non-classical cytokine expressed in cancers, inflammatory diseases and infections. IL-32 can have both extracellular and intracellular functions, and its receptor is not identified. We here demonstrate that endogenously expressed, intracellular IL-32 binds to components of the mitochondrial respiratory chain and promotes oxidative phosphorylation. Knocking out IL-32 in malignant plasma cells significantly reduced survival and proliferation in vitro and in vivo. High throughput transcriptomic and MS-metabolomic profiling of IL-32 KO cells revealed that loss of IL-32 leads to profound perturbations in metabolic pathways, with accumulation of lipids, pyruvate precursors and citrate, indicative of reduced mitochondrial function. IL-32 is expressed in a subgroup of multiple myeloma patients with an inferior prognosis. Primary myeloma cells expressing IL-32 were characterized by a plasma cell gene signature associated with immune activation, proliferation and oxidative phosphorylation. We propose a novel concept for regulation of metabolism by an intracellular cytokine and identify IL-32 as an endogenous growth and survival factor for malignant plasma cells. IL-32 is a potential prognostic biomarker and a treatment target in multiple myeloma.

cancer biology↗

bioRxiv2020

Comprehensive studies of Head Maralla, Punjab, Pakistan vegetation for ethnopharmacological and ethnobotanical uses and their elaboration through quantitative indices

Head Maralla is a non-recognized wetland with diversified flora that becomes focus of current studies. Whole plant or their parts are being used for treating various maladies and they are the integral part of livelihood in the area. Unique species including Osmunda regalis is used for blood and renal diseases purifier. Wild plant resources are key to traditional ethnobotanical knowledge based practices and industrial applications. Current study reports Head Marala inhabitants interaction with these resources and identify priorities at species and habitat level for conservation. Four sites viz., River Tavi, Upstream Chenab, River Manawarwala Tavi and Bhalolpur were designated to record traditional knowledge through questionnaire and interviews during field trips. One hundred nineteen (119) plant species were identified belonging to 54 families, of which 87 species were of dicot, 12monocots, 05ferns, and 4 species of bryophytes. Fifty percent of the plant species were utilized as a whole for therapeutic purposes, followed by leaves which had more than 20% usage of total consumption. Ailments viz., urination (14%) followed by cough (8%), cold (7%), stomach (6%), asthma (6%), constipation (5%), laxative (5%), diarrhea (4%) etc., were associated with vegetation. Bronchial disorders, pneumonia, dyspepsia, anthelmintic and kidney stones, etc., were also among other diseases commonly cured by traditional knowledge. Fifteen percent of vegetation contributes as fodder species consumed by local community for livestock while almost 17% of local plants were utilized for industrial purposes like timber, fuel, furniture, wooden pots and sports goods. In conclusion the ecosystem of Head Maralla is a complex of aquatic, terrestrial and agricultural land that is located on climatic and geographical divides, which further add to botanical interest as included many wetland habitats with unique diversity of plants. It is suggested to devise comprehensive conservation strategies to safe indigenous knowledge in systematic way for comprehending ecological services.

plant biology↗

bioRxiv2019

Bone morphogenetic protein 4 gene therapy in mice inhibits myeloma tumor growth, but has a negative impact on bone

Multiple myeloma is characterized by accumulation of malignant plasma cells in the bone marrow. Most patients suffer from an osteolytic bone disease, caused by increased bone degradation and reduced bone formation. Bone morphogenetic protein 4 (BMP4) is important for both pre- and postnatal bone formation and induces growth arrest and apoptosis of myeloma cells. BMP4-treatment of myeloma patients could have the potential to reduce tumor growth and restore bone formation. We therefore explored BMP4 gene therapy in a human-mouse model of multiple myeloma where humanized bone scaffolds were implanted subcutaneously in RAG2-/- {gamma}C-/-mice. Mice were treated with adeno-associated virus serotype 8 BMP4 vectors (AAV8-BMP4) to express BMP4 in the liver. When mature BMP4 was detectable in the circulation, myeloma cells were injected into the scaffolds and tumor growth was examined by weekly imaging. Strikingly, the tumor burden was reduced in AAV8-BMP4 mice compared with the AAV8-CTRL mice, suggesting that increased circulating BMP4 reduced tumor growth. BMP4-treatment also prevented bone loss in the scaffolds, most likely due to reduced tumor load. To delineate the effects of BMP4 overexpression on bone per se, without direct influence from cancer cells, we examined the unaffected, non-myeloma femurs by CT. Surprisingly, the AAV8-BMP4 mice had significantly reduced trabecular bone volume, trabecular numbers, as well as significantly increased trabecular separation compared with the AAV8-CTRL mice. There was no difference in cortical bone parameters between the two groups. Taken together, BMP4 gene therapy inhibited myeloma tumor growth, but also reduced the amount of trabecular bone in mice. Our data suggest that care should be taken when considering using BMP4 as a therapeutic agent.

cancer biology↗