Progesterone interacts with the mutational hot-spot of TRPV4 and acts as a ligand relevant for fast Ca2+-signalling.

Steroids are also known to induce immediate physiological and cellular response which occurs within minutes to seconds, or even faster. Such non-genomic actions of steroids are rapid and are proposed to be mediated by different ion channels. Transient receptor potential vanilloid sub-type 4 (TRPV4), is a non-specific polymodal ion channel which is involved in several physiological and cellular processes. In this work, we explored the possibilities of Progesterone (P4) as an endogenous ligand for TRPV4. We demonstrate that P4 docks as well as physically interacts with the TM4-loop-TM5 region of TRPV4, a region which is a mutational hotspot for different diseases. Live cell imaging experiments with a genetically encoded Ca2+-sensor suggests that P4 causes quick influx of Ca2+ specifically in the TRPV4 expressing cells, which can be partially blocked by TRPV4-specific inhibitor, suggesting that P4 can act as a ligand for TRPV4. Such P4-mediated Ca2+-influx is altered in cells expressing disease causing TRPV4 mutants, namely in L596P, R616Q, and also in embryonic lethal mutant L618P. P4 dampens, both in terms of "extent" as well as the "pattern" of the Ca2+-influx by other stimulus too in cells expressing TRPV4-Wt, suggesting that P4 crosstalk with the TRPV4-mediated Ca2+-signalling, both in quick and long-term manner. We propose that P4 crosstalk with TRPV4 might be relevant for both acute and chronic pain as well as for other health-related functions.

A review on antimicrobial mechanism and applications of graphene-based materials.

In recent years, graphene and its derivatives, owing to their phenomenal surface, and mechanical, electrical, and chemical properties, have emerged as advantageous materials, especially in terms of their potential for antimicrobial applications. Particularly important among graphene's derivatives is graphene oxide (GO) due to the ease with which its surface can be modified, as well as the oxidative and membrane stress that it exerts on microbes. This review encapsulates all aspects regarding the functionalization of graphene-based materials (GBMs) into composites that are highly potent against bacterial, viral, and fungal activities. Governing factors, such as lateral size (LS), number of graphene layers, solvent and GBMs' concentration, microbial shape and size, aggregation ability of GBMs, and especially the mechanisms of interaction between composites and microbes are discussed in detail. The current and potential applications of these antimicrobial materials, especially in dentistry, osseointegration, and food packaging, have been described. This knowledge can further drive research that aims to look for the most suitable components for antimicrobial composites. The need for antimicrobial materials has seldom been more felt than during the COVID-19 pandemic, which has also been highlighted here. Possible future research areas include the exploration of GBMs' ability against algae.