Biology subjects

Nadeem, M.

Publications and source records attributed to Nadeem, M..

5 recordsLinked to original sources

bioRxiv2025

Polystyrene and polyethylene terephthalate nanoplastics differentially impact mouse ovarian follicle function

Exposure to micro- and nanoplastics is unavoidable. Foods and beverages contain plastic particles from environmental contamination and processing and packaging materials, which are frequently made of polyethylene terephthalate (PET). Micro- and nanoplastics have been detected in human tissues such as the brain, liver, and placenta, as well as in ovarian follicular fluid, but little is known about the effects nanoplastics have on the female reproductive system. In addition, few studies on the health impacts of nanoplastics have been performed using environmentally relevant plastic types and concentrations. Thus, this research tested the hypothesis that nanoplastics made of spherical polystyrene (PS), a common model nanoplastic, would have different effects on cultured mouse ovarian follicles compared to secondary PET nanoplastics at environmentally relevant doses. The ovary is a highly sensitive reproductive organ responsible for the development of follicles, which contain the oocyte, and production of steroid hormones. Follicles were harvested from adult mouse ovaries and cultured for 96 h with vehicle, spherical commercially available 200 nm PS nanoplastics (1-100 {micro}g/mL), or lab-generated 240 nm PET nanoplastics (0.1-10 {micro}g/mL). PS and PET nanoplastic exposure inhibited follicle growth and altered expression of genes related to steroid synthesis, cell cycle, and oxidative stress. PET nanoplastics increased levels of pregnenolone and decreased expression of Cyp17a1. Overall, both plastic types altered ovarian function, but they impacted different genes in similar pathways. These findings suggest that nanoplastic exposure at environmentally relevant concentrations may pose a risk to female reproductive health by disrupting hormonal and molecular pathways. In addition, environmentally relevant plastic types and doses are necessary for studying health impacts of nanoplastics. HighlightsO_LINanoplastics disrupted ovarian function in vitro C_LIO_LISecondary PET and virgin PS differently inhibited follicle growth and ovarian gene expression C_LIO_LIPET exposure increased pregnenolone, impacting steroid hormone pathways C_LIO_LIEnvironmentally relevant plastics can harm female reproductive health C_LI

pharmacology and toxicology↗

bioRxiv2025

Rapid detection of G6PD deficiency SNPs using a novel amplicon-based MinION Sequencing Assay

Plasmodium vivax malaria remains a significant global health challenge, complicated by the parasites ability to form dormant liver stages (hypnozoites) that cause relapses. Radical cure of P. vivax malaria requires administration of a hypnozoitocidal drug, such as primaquine or tafenoquine. However, these drugs can cause severe haemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD deficiency is caused by more than 230 different variants at the gene level that confer different degrees of deficiency phenotypically. Understanding the distribution of different G6PD variants in affected populations is essential to inform safer antimalarial treatment strategies. This study aimed to develop a cost-effective sequencing assay targeting key regions of the G6PD gene, suitable for field deployment. A novel assay based on Nanopore technology was designed to amplify two amplicons covering exon 3 to exon 13, focusing on known variants associated with enzyme deficiency. A total of 79 samples from individuals in Cambodia, Vietnam, Afghanistan, and China were sequenced, and a bioinformatics pipeline was created for the targeted variant calling of 192 G6PD SNP mutations. The assay demonstrated reliable detection of known variants, with high concordance between runs, within runs, and with Sanger sequencing. The Nanopore MinION long-amplicon sequencing assay offers a robust and portable solution for large-scale G6PD genotyping in low-resource settings, that will improve malaria control and elimination strategies by enabling safer antimalarial treatment.

microbiology↗

bioRxiv2024

A common phthalate replacement disrupts ovarian function in young adult mice

Di-2-ethylhexyl terephthalate (DEHTP) is a replacement for its structural isomer di-2-ethylhexyl phthalate (DEHP), a known endocrine disrupting chemical and ovarian toxicant. DEHTP is used as a plasticizer in polyvinyl chloride products and its metabolites are increasingly found in biomonitoring studies at levels similar to phthalates. However, little is known about the effects of DEHTP on the ovary. In this research, we tested the hypothesis that DEHTP is an ovarian toxicant and likely endocrine disrupting chemical like its isomer DEHP. The impact of environmentally relevant exposure to DEHTP and/or its metabolite mono-2-ethylhexyl terephthalate (MEHTP) on the mouse ovary was investigated in vivo and in vitro. For the in vivo studies, young adult CD-1 mice were orally dosed with vehicle, 10 {micro}g/kg, 100 {micro}g/kg, or 100 mg/kg of DEHTP for 10 days. For the in vitro studies, isolated untreated ovarian follicles were exposed to vehicle, 0.1, 1, 10, or 100 {micro}g/mL of DEHTP or MEHTP. Follicle counts, hormone levels, and gene expression of steroidogenic enzymes, cell cycle regulators, and apoptosis factors were analyzed. In vivo, DEHTP exposure increased primordial follicle counts at 100 {micro}g/kg and 100 mg/kg and decreased primary follicle counts at 100 mg/kg compared to control. DEHTP exposure also decreased expression of cell cycle regulators and apoptotic factors compared to control. In vitro, follicle growth was reduced by 1 {micro}g/mL DEHTP and 1, 10, and 100 {micro}g/mL MEHTP compared to controls, and expression of the cell cycle regulator Cdkn2b was increased. Steroid hormone levels and steroidogenic enzyme gene expression trended toward decreases in vivo, whereas progesterone was significantly increased by exposure to 100 {micro}g/mL MEHTP in vitro. Overall, these results suggest that DEHTP and MEHTP may be ovarian toxicants at low doses and should be subjected to further scrutiny for reproductive toxicity due to their similar structures to phthalates.

pharmacology and toxicology↗

bioRxiv2021

Plant lipid metabolism in susceptible and tolerant soybean (Glycine max) cultivars in response to Phytophthora sojae colonization and infection

Soybean is one of the most cultivated crops globally and a staple food for much of the worlds population. The annual global crop losses due to infection by the Phytophthora sojae are currently estimated at approximately $2B USD, yet we have limited understanding of the role of lipid metabolism in the adaptative strategies used to limit infection and crop loss. We employed a multi-modal lipidomics approach to investigate how soybean cultivars remodel their lipid metabolism to successfully limit infection by Phytophthora sojae. Both the tolerant and susceptible soybean cultivars showed alterations in lipid metabolism in response to Phytophthora sojae infection. Relative to non-inoculated controls, induced accumulation of stigmasterol was observed in the susceptible cultivar whereas, induced accumulation of phospholipids and glycerolipids occurred in tolerant soybean cultivar. We have generated a comprehensive metabolic map of susceptible and tolerant soybean root and stem lipid metabolism to identify lipid modulators of host immune or tolerance response to Phytophthora sojae infection and identified potential pathways and unique lipid biomarkers like TG(15:0/22:0/22:5), TG(10:0/10:0/10:0), TG(10:0/10:0/14:0), DG(18:3/18:3), DG(16:0/18:3) and DG(24:0/18:2) as possible targets for the development of future plant protection solutions.

pathology↗

bioRxiv2019

Characterization of the workplace chemical exposome using untargeted LC-MS/MS: a case study

Western people now spend close to 90% of their time indoors, one-quarter of which occurs at their place of employment. As such, interactions between employees and the workplace built environment have significant potential impact on employee health and safety. However, the range of workers daily chemical exposures is still poorly understood. Likewise, the influence of workers themselves and of worker behavior on the chemical composition of the workplace is still unknown. In this case study, we used untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) to compare the chemical signatures of three different types of workplaces: scientific research buildings, office buildings, and one mixed-purpose building. Our results identified differential signatures of public building surfaces based on building purpose, sampling location and surface materials. Overall, these results are helping define the influence of human behavior on the workplace chemical environment and identify the chemical hazards to which people are exposed throughout their workday. HighlightsO_LIImplementation of untargeted liquid chromatography-tandem mass spectrometry to study workplace chemical exposures. C_LIO_LIShared chemical signatures were identified based on building purpose. C_LIO_LIDifferential chemical signatures were identified based on surface material and sampling location. C_LIO_LIAnnotated molecules include pharmaceuticals, illicit drugs, food chemicals, constituents of paints and stains, and cleaning products. C_LI

biochemistry↗