ALTERATION OF AKT1-GSK3Β SIGNALING PATHWAY IN TRAUMA HEMORRHAGIC SHOCK PATIENTS.

ABSTRACT: Trauma hemorrhagic shock (THS) is a major cause of death and disability worldwide. It is the leading cause of death with or without sepsis in approximately 50% of patients. In THS, there is an incidence of cellular apoptosis, which contributes majorly to cellular dysfunction, organ failure, and mortality. The Akt (protein kinase B) isoform, Akt1, and glycogen synthase kinase 3ß (Akt1-GSK3ß) signaling pathway controls cell survival and apoptosis. Deleterious consequences of alteration of this signaling system might lead to inflammation, cytokine storm, and other diseases. Hence, in the present study, we investigated the role of this signaling system by measuring the phosphorylation levels of Akt1-GSK3ß. Here, we demonstrated that the downregulation of pAkt1 and upregulation of pGSK3ß in THS were significantly associated with the severity of the shock, apoptosis of immune cells, altered glucose metabolism, inflammation, cytokine storm, hemostasis, and acidosis, causing mortality with or without sepsis. For the first time, this study shows that a dysregulated pAkt1-GSK3ß pathway causes contrasting cell fates in THS, leading to trauma pathology. Hence, the delineation and the implications of this signaling system may provide a new important target for the treatment of THS. In addition, Akt activation may become a potential strategy for increasing the survival rate following THS.

In silico and experimental studies of bovine serum albumin-encapsulated carbenoxolone nanoparticles with reduced cytotoxicity.

Carbenoxolone (CBX) is a semi-synthetic plant derivative with pleiotropic pharmacological properties like anti-microbial and anti-inflammatory activities. Though approved for treatment of gastric ulcers, its use is limited due to adverse effects such as cytotoxicity. Bovine serum albumin (BSA) is a natural, non-toxic protein with high water-solubility and low immunogenicity, and is widely used as a nanocarrier for targeted drug delivery. In the present study, controlled release BSA-CBX nanoparticles (NPs) were synthesized by desolvation method to reduce drug cytotoxicity. These NPs showed desirable physicochemical properties such as particle size (∼240 nm), polydispersity index (0.08), zeta potential (-7.12 mV), drug encapsulation efficiency (72 %), and were stable for at least 3 months at room temperature. The drug was released from the BSA-CBX NPs in a biphasic manner in vitro following non-fickian diffusion. Computational analysis determined that the binding between BSA and CBX occurred through van der Waals forces, hydrophobic interactions, and hydrogen bonds with 93 % steric stability. Further, the cytotoxic assays demonstrated ∼1.8-4.9-fold reduction in cytotoxicity using three human cell lines (A549, MCF-7, and U-87). Subsequently, this novel CBX formulation with BSA as an efficient carrier can potentially be used for diverse biomedical applications.

Controlled release and enhanced biological activity of chitosan-fabricated carbenoxolone nanoparticles.

Nanotechnology based antimicrobial drugs are developed to enhance their properties to combat multidrug resistant microbes. Carbenoxolone (CBX) is a semi-synthetic derivate of a natural substance from the licorice plant, with anti- (inflammatory, fungal, viral, microbial, fibrotic and cancer) properties. Though used to treat gastric ulcers, its low aqueous stability, low bioavailability and toxicity limited the drug's utility. To enhance its antimicrobial activity and reduce cytotoxicity, a controlled release nanoformulation was developed using natural biodegradable polymer chitosan (CS) as a carrier which is biocompatible, nontoxic with placid antimicrobial property. UV-visible spectroscopy, electron microscopy, and Fourier transform infrared spectroscopy were used for characterization of the resultant CS-CBX nanoparticles (NPs). They were spherical with uniform dispersion, ~200 nm in size with surface charge of +18.6 mV and drug encapsulation of >80%. Drug release kinetics exhibited a controlled release of 86% over 36 h following zero order kinetics. The anti-microbial activity against common pathogenic Gram -ve and +ve bacteria and yeast increased ~2-fold with a concomitant 4-fold reduction in cytotoxicity assessed using human lung adeno carcinoma (A549) cells. This study demonstrates the affirmative aspects of CS-CBX NPs as a promising antibacterial agent and may facilitate repositioning of the drug for diverse applications.

Spatial expression of components of a calcitonin receptor-like receptor (CRL) signalling system (CRL, calcitonin gene-related peptide, adrenomedullin, adrenomedullin-2/intermedin) in mouse and human heart valves.

Heart valves are highly organized structures determining the direction of blood flow through the heart. Smooth muscle cells within the valve are thought to play an active role during the heart cycle, rather than being just passive flaps. The mature heart valve is composed of extracellular matrix (ECM), various differentiations of valvular interstitial cells (VIC), smooth muscle cells and overlying endothelium. VIC are important for maintaining the structural integrity of the valve, thereby affecting valve function and ECM remodelling. Accumulating evidence suggests an important role of calcitonin receptor-like receptor (CRL) signalling in preventing heart damage under several pathological conditions. Thus we investigate the existence of a putative CRL signalling system in mouse and human heart valves by real-time RT-PCR, laser-assisted microdissection, immunofluorescence and NADPH-diaphorase histochemistry. Mouse and human heart valves expressed mRNAs for the CRL ligands adrenomedullin (AM), adrenomedullin-2 (AM-2) and calcitonin gene-related peptide (CGRP) and for their receptor components, i.e., CRL and receptor-activity-modifying proteins 1-3. Immunofluorescence analysis revealed AM-, AM-2- and CRL-immunolabelling in endothelial cells and VIC, whereas CGRP immunoreactivity was restricted to nerve fibres and some endothelial cells. Nitric oxide synthase activity, as demonstrated by NADPH-diaphorase histochemistry, was shown mainly in valvular endothelial cells in mice, whereas in human aortic valves, VIC and smooth muscle cells were positive. Our results showed the presence of an intrinsic AM/AM-2/CGRP signalling system in murine and human heart valves with distinct cellular localization, suggesting its involvement in the regulation of valve stiffness and ECM production and turnover.