Biology subjects

Pokharel, A.

Publications and source records attributed to Pokharel, A..

3 recordsLinked to original sources

bioRxiv2023

Computational Assessment of Aromatase: Unmasking Therapeutic Avenues for Female Hormonal Disorders

Women of reproductive age widely experience the physical, mental, and emotional effects of hormonal imbalances. The levels of two hormones, estrogen, and progesterone, were particularly high. When these two hormones are unbalanced, symptoms such as irregular menstrual cycles, pelvic pain, and uterine fibroids can appear. Statistics show that 80 percent of women have hormonal imbalances. The creation of novel disease-containing drug candidates may be facilitated by computer-aided drug design (CADD), as many drugs and surgical treatments have unique adverse effects. Achieving good data coverage requires an optimized process for protein identification and enhanced selection techniques for medicinal compounds, including their metabolic characterization. In this study, aromatase is the prioritized protein that acted as a rate-limiting enzyme in steroidogenesis. To maintain its expression and regulation to control estrogen production, natural compounds were retrieved from the ZINC15 database through ADME/TOX property filtration. Compound B, specifically designated as (1R,3S,6S,7S,10S,11R)-7-[(dimethylamino)methyl]-3,12-dimethyl-2,9-dioxatetracyclo [9.3.0.01,3.06,10] tetradec-12-en-8-one, exhibits remarkable therapeutic potential, as evidenced by its inability to inhibit S-adenosyl methionine (SAM) biosynthesis, the observed stability of molecular interactions based on Density Functional Theory (DFT), and a favorable energy gap between molecular orbital stages. This research can be employed as a utility module for fast screening of drug-like molecules and taking these leads forward to clinical trials, assessing their value as potential suitors for drug repurposing against female hormonal disorders.

bioinformatics↗

bioRxiv2020

Natural Antisense Transcript of Period2, Per2AS, regulates the amplitude of the mouse circadian clock

Circadian transcriptome studies identified a novel transcript at the Period2 (Per2) locus, which we named Per2AS. Per2AS is a long non-coding RNA transcribed from the antisense strand of Per2, and is expressed rhythmically and anti-phasic to Per2 mRNA. Previously, we mathematically tested the hypothesis that Per2AS and Per2 mutually inhibit each others expression by forming a double negative feedback loop, and found that Per2AS expands the oscillatory domain. In this study, we have experimentally tested this prediction by perturbing the expression of Per2AS in mouse fibroblasts. We found that Per2AS represses Per2 pre-transcriptionally in cis and regulates the amplitude of the circadian clock, but not period or phase. Unexpectedly, we also found that Per2 positively regulates Per2AS post-transcriptionally, indicating that Per2AS and Per2 form a single negative feedback loop. Because knock-down of Per2 does not recapitulate the phenotypes of Per2AS perturbation and Per2AS also activates Bmal1 in trans, we propose that Per2AS regulates the amplitude of the circadian clock without producing a protein by rewiring the molecular clock circuit.

molecular biology↗

bioRxiv2020

Connexin 43 hemichannels mediate spatial and temporal disease spread in ALS

Connexin 43 (Cx43) gap junctions and hemichannels mediate astrocyte intercellular communication in the central nervous system under normal conditions and may contribute to astrocyte-mediated neurotoxicity in amyotrophic lateral sclerosis (ALS). Here we show that astrocyte-specific knockout of Cx43 in a mouse model of ALS slows disease progression both spatially and temporally, provides motor neuron (MN) protection, and improves survival. In human ALS tissues and biofluids, we observe that higher levels of Cx43 correlate with accelerated disease progression. Using human iPSC-derived astrocytes (hiPSC-A) from both familial and sporadic ALS, we show that Cx43 is upregulated and that Cx43-hemichannels are enriched at the astrocyte membrane. We then demonstrate that the pharmacological blockade of Cx43-hemichannels in ALS astrocytes, during a specific temporal window, provides neuroprotection of hiPSC-MN and reduces ALS astrocyte-mediated neuronal hyperexcitability. Our data identify Cx43 hemichannels as novel conduits of astrocyte-mediated disease progression and a pharmacological target for disease-modifying ALS therapies.

neuroscience↗