Santosh Kumar Yadav

In the present study, an extracellular alkali-thermo-tolerant xylanase from Bacillus paramycoides was produced in the presence of an organic solvent. The enzyme was purified by ammonium sulphate precipitation, gel filtration, and ion exchange chromatography, with an overall recovery of 25.9%. The purified enzyme hada 70 kDa molecular weight (MW) confirmed by SDS-PAGE gel analysis. The maximum enzyme activity was reported at 55 °C and pH 7.0. Xylanase activity and stability were improved in the presence of 30% (v/v) n-dodecane, iso-octane, n-decane, and cyclohexane (7 days). The enzyme activity was improved by Co²⁺, EDTA, and Triton-X-100 while vigorously repressed by Hg²⁺ and Cu²⁺. The purified enzyme showed 1.473 mg/mL K_m and 654.017 µg/mL/min V_max values. The distinctive assets of the isolate verified the potential application in the field of biomass conversion into fuel and other industrial processes. Organic solvent-tolerant xylanases can be used for concurrent saccharification and bioethanol production, the amplification of intoxicating beverages, and the fermenting industry.

Spermatogenesis in most mammals (including human and rat) occurs at ~ 3 °C lower than body temperature in a scrotum and fails rapidly at 37 °C inside the abdomen. The present study investigates the heat-sensitive transcriptome and miRNAs in the most vulnerable germ cells (spermatocytes and round spermatids) that are primarily targeted at elevated temperature in a bid to identify novel targets for contraception and/or infertility treatment. Testes of adult male rats subjected to surgical cryptorchidism were obtained at 0, 24, 72 and 120 h post-surgery, followed by isolation of primary spermatocytes and round spermatids and purification to > 90% purity using a combination of trypsin digestion, centrifugal elutriation and density gradient centrifugation techniques. RNA isolated from these cells was sequenced by massive parallel sequencing technique to identify the most-heat sensitive mRNAs and miRNAs. Heat stress altered the expression of a large number of genes by ≥2.0 fold, out of which 594 genes (286↑; 308↓) showed alterations in spermatocytes and 154 genes (105↑; 49↓) showed alterations in spermatids throughout the duration of experiment. 62 heat-sensitive genes were common to both cell types. Similarly, 66 and 60 heat-sensitive miRNAs in spermatocytes and spermatids, respectively, were affected by ≥1.5 fold, out of which 6 were common to both the cell types. The study has identified Acly, selV, SLC16A7(MCT-2), Txnrd1 and Prkar2B as potential heat sensitive targets in germ cells, which may be tightly regulated by heat sensitive miRNAs rno-miR-22-3P, rno-miR-22-5P, rno-miR-129-5P, rno-miR-3560, rno-miR-3560 and rno-miR-466c-5P.

In the quest for novel scaffolds for the management of androgen sensitive prostatic disorders like prostate cancer and benign prostatic hyperplasia, a series of twenty-six aryl/heteroaryl piperazine derivatives have been described. Three compounds, 8a, 8c and 9a, exhibited good activity profiles against an androgen sensitive prostate cancer cell line (LNCaP) with EC₅₀ values of 9.8, 7.6 and 11.2 μM, respectively. These compounds caused a decrease in luciferase activity and a decline in PSA and Ca²⁺ levels, which are indicative of their anti-androgenic and α_1A-adrenergic receptor blocking activities, respectively. Compound 9a reduced the prostate weight of rats (47%) and in pharmacokinetic analysis at 10 mg kg⁻¹ it demonstrated an MRT of ∼14 h post dose, exhibiting high levels in prostate. Compound 9a docked in a similar orientation to hydroxyflutamide on an androgen receptor and showed strong π–π interactions. These findings reveal that compound 9a is a promising candidate for management of prostatic disorders with anti-androgenic and α_1A-blocking activities.

Quiescent sperm survive in cauda epididymis for long periods of time under extreme crowding conditions and with very limited energy substrate, while after ejaculation motile sperm live for much smaller period with unlimited energy resource and without crowding. Thus the energy metabolism vis-a-vis energy requirement of the two may be quite different. A simple, physiological technique was evolved to collect viable quiescent sperm from rat cauda epididymis to compare its energy metabolism with motile sperm. Quiescent sperm exhibited 40-60% higher activities of mitochondrial electron transport chain complexes I, II, III, IV and ATP synthase in comparison to motile sperm, and accumulated Ca²⁺ in the mid-piece mitochondria to enhance oxidative phosphorylation (OxPhos). In contrast, motile sperm displayed up to 75% higher activities of key glycolytic enzymes and secreted >2-times lactate than quiescent sperm. Quiescent sperm phosphorylated AMPK and MAPK-p38 while motile sperm phosphorylated AKT and MAPK/ERK. Glycolytic inhibitor iodoacetamide prevented motility activation of quiescent rat sperm and inhibited conception in rabbits more effectively than OxPhos uncoupler 2,4-dinitrophenol. Apparently, quiescent sperm employ the most energy efficient OxPhos to survive for extended periods of time under extreme conditions of nutrition and crowding. However, on motility initiation, sperm switch to predominantly glycolysis to cater their high and quick energy requirement of much shorter periods. This study also presents a proof-of-concept for targeting sperm energy metabolism for contraception.