Eco-friendly reduced graphene oxide for the determination of mycophenolate mofetil in pharmaceutical formulations.

Graphene oxide (GO) was synthesized and characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). GO was then electrochemically reduced and used for electrochemical study of mycophenolate mofetil (MMF). The electrochemically reduced graphene oxide (ERGO) film on glassy carbon electrode (GCE) showed enhanced peak current for electrooxidation of MMF. MMF exhibited two irreversible oxidation peaks at 0.84 V (peak a1) and 1.1 V (peak a2). Effects of accumulation time, pH and scan rate were studied and various electrochemical parameters were calculated. A differential pulse voltammetric method was developed for the determination of MMF in bulk samples and pharmaceutical formulations. Linear relationship was observed between the peak current and concentration of MMF in the range of 40 nM-15 µM with a limit of detection of 11.3 nM. The proposed method is simple, sensitive and inexpensive and, hence, could be readily adopted in clinical and quality control laboratories.

Silencing of dedicator of cytokinesis (DOCK180) obliterates pregnancy by interfering with decidualization due to blockage of nuclear entry of autoimmune regulator (AIRE).

PROBLEM: Dedicator of cytokinesis (DOCK 180) involved in cytoskeletal reorganization is primarily a cytosolic molecule. It is recently shown to be nuclear in HeLa cells but its nuclear function is not known. METHOD OF STUDY: The spatiotemporal distribution of DOCK180 in uterus was studied in uterine cytoplasmic and nuclear compartments during the "window of implantation." The functional significance of nuclear DOCK180 was explored by homology modeling, co-immunoprecipitation assays, and mass spectrometric analysis. Dock180's role in early pregnancy was ascertained by Dock 180 silencing and subsequent quantitative real-time PCR and Western blotting analysis. RESULTS: Our study shows a nuclear DOCK180 in the uterus during "window of implantation." Estrogen and progesterone mediate expression and nuclear translocation of DOCK180. The nuclear function of DOCK180 is attributed to its ability to import autoimmune regulator (AIRE) into the nucleus. Silencing of Dock180 inhibited AIRE nuclear shuttling which influenced its downstream targets, thereby affecting decidualization with AIRE and HOXA-10 as the major players as well as lack of implantation site formation due to impact on angiogenesis-associated genes. CONCLUSION: DOCK180 has an indispensable role in pregnancy establishment as knocking down Dock180 abrogates pregnancy by a consolidated impact on decidualization and angiogenesis by regulating AIRE nuclear entry.

STAT3 and MCL-1 associate to cause a mesenchymal epithelial transition.

Embryo implantation is effected by a myriad of signaling cascades acting on the embryo-endometrium axis. Here we show, by using MALDI TOF analysis, far-western analysis and colocalization and co-transfection studies, that STAT3 and MCL-1 are interacting partners during embryo implantation. We show in vitro that the interaction between the two endogenous proteins is strongly regulated by estrogen and progesterone. Implantation, pregnancy and embryogenesis are distinct from any other process in the body, with extensive, but controlled, proliferation, cell migration, apoptosis, cell invasion and differentiation. Cellular plasticity is vital during the early stages of development for morphogenesis and organ homeostasis, effecting the epithelial to mesenchymal transition (EMT) and, the reverse process, mesenchymal to epithelial transition (MET). STAT3 functionally associates with MCL-1 in the mammalian breast cancer cell line MCF7 that overexpresses STAT3 and MCL-1, which leads to an increased rate of apoptosis and decreased cellular invasion, disrupting the EMT. Association of MCL-1 with STAT3 modulates the normal, anti-apoptotic, activity of MCL-1, resulting in pro-apoptotic effects. Studying the impact of the association of STAT3 with MCL-1 on MET could lead to an enhanced understanding of pregnancy and infertility, and also metastatic tumors.

Interactions of polyphenols with plasma proteins: insights from analytical techniques.

Phenolic compounds are commonly found in natural sources like plant-based foods and beverages. These compounds have received much attention due to their unique biological properties. Polyphenols possess a significant binding affinity for serum albumins which are known to be principal extracellular proteins with a high concentration in blood plasma. They act as carriers of several drugs to different molecular targets. This review summarizes the salient features of the reported work on polyphenol-protein interactions by analytical methods viz., chromatography, circular dichroism, fluorescence spectroscopy (steady state and time resolved), light scattering, equilibrium dialysis, differential scanning calorimetry, UV-vis spectroscopy, isothermal calorimetry, MALDI-TOF mass spectrometry, size exclusion chromatography, capillary electrophoresis, electrospray ionization mass spectrometry, FT-IR, molecular modelling, HPLC, NMR, cyclic voltammetry etc. Polyphenol-serum albumin interaction studies assume significance from the view point of pharmacokinetics and pharmacodynamics.