The functional role of Ire1 in regulating autophagy and proteasomal degradation under prolonged proteotoxic stress.

Inhibition of endoribonuclease/kinase Ire1 has shown beneficial effects in many proteotoxicity-induced pathology models. The mechanism by which this occurs has not been elucidated completely. Using a proteotoxic yeast model of Huntington's disease, we show that the deletion of Ire1 led to lower protein aggregation at longer time points. The rate of protein degradation was higher in ΔIre1 cells. We monitored the two major protein degradation mechanisms in the cell. The increase in expression of Rpn4, coding for the transcription factor controlling proteasome biogenesis, was higher in ΔIre1 cells. The chymotrypsin-like proteasomal activity was also significantly enhanced in these cells at later time points of aggregation. The gene and protein expression levels of the autophagy gene Atg8 were higher in ΔIre1 than in wild-type cells. Significant increase in autophagy flux was also seen in ΔIre1 cells at later time points of aggregation. The results suggest that the deletion of Ire1 activates UPR-independent arms of the proteostasis network, especially under conditions of aggravated stress. Thus, the inhibition of Ire1 may regulate UPR-independent cellular stress-response pathways under prolonged stress.

Translating Treg Therapy for Inflammatory Bowel Disease in Humanized Mice.

Crohn's disease and ulcerative colitis, two major forms of inflammatory bowel disease (IBD) in humans, afflicted in genetically predisposed individuals due to dysregulated immune response directed against constituents of gut flora. The defective immune responses mounted against the regulatory mechanisms amplify and maintain the IBD-induced mucosal inflammation. Therefore, restoring the balance between inflammatory and anti-inflammatory immunepathways in the gut may contribute to halting the IBD-associated tissue-damaging immune response. Phenotypic and functional characterization of various immune-suppressive T cells (regulatory T cells; Tregs) over the last decade has been used to optimize the procedures for in vitro expansion of these cells for developing therapeutic interventional strategies. In this paper, we review the mechanisms of action and functional importance of Tregs during the pathogenesis of IBD and modulating the disease induced inflammation as well as role of mouse models including humanized mice repopulated with the human immune system (HIS) to study the IBD. "Humanized" mouse models provide new tools to analyze human Treg ontogeny, immunobiology, and therapy and the role of Tregs in developing interventional strategies against IBD. Overall, humanized mouse models replicate the human conditions and prove a viable tool to study molecular functions of human Tregs to harness their therapeutic potential.

Protriptyline improves spatial memory and reduces oxidative damage by regulating NFκB-BDNF/CREB signaling axis in streptozotocin-induced rat model of Alzheimer's disease.

Antidepressants are well known to exert their role via upregulation of brain derived neurotrophic factor (BDNF). BDNF has been reported to exerts its neuroprotective effect in rodent and primate models as well as in patients of Alzheimer's disease (AD). The aim of our study was to evaluate the effect of protriptyline (PRT), a tricyclic antidepressant, in streptozotocin (STZ)- induced rat model of AD. Total 10 µl of STZ was injected into each ventricle (1 mg/kg). PRT (10 mg/kg, i.p.) treatment was started 3-day post STZ administration and continued till 21 days. We found that STZ treatment significantly increased pTau, Aß42 and BACE-1 expression, oxidative stress and neurodegeneration in hippocampus and cortex of adult rats. STZ induced impairment in spatial learning and retention memory was associated with increased NFκB and reduced CREB and BDNF expression in cortex and hippocampus. Interestingly, PRT treatment significantly reduced pTau, Aß42 and BACE-1 levels, neurodegeneration, oxidative stress and glial activation, contributing to the improved spatial learning and retention memory in STZ treated rats. Moreover, PRT treatment significantly improved p-ERK/ERK ratio and enhanced BDNF and CREB levels by reducing NFκB and GFAP expression in STZ treated rats. Our data suggest that impaired NFκB and CREB signaling potentially contribute in AD pathogenesis by elevating oxidative stress and neuroinflammation mediated neurodegeneration. Our study has established protriptyline as a multi target molecule in pre-clinical model of AD and further investigations on PRT like molecules could pave way for further development of effective new treatments in neurodegenerative disorders.

Transdermal Immunization of Elastic Liposome-Laden Recombinant Chimeric Fusion Protein of P. falciparum (PfMSP-Fu24) Mounts Protective Immune Response.

Transdermal immunization exhibits poor immunogenic responses due to poor permeability of antigens through the skin. Elastic liposomes, the ultradeformable nanoscale lipid vesicles, overcome the permeability issues and prove a versatile nanocarrier for transcutaneous delivery of protein, peptide, and nucleic acid antigens. Elastic liposome-mediated subcutaneous delivery of chimeric fusion protein (PfMSP-Fu24) of Plasmodium falciparum exhibited improved immunogenic responses. Elastic liposomes-mediated immunization of PfMSP-Fu24 conferred immunity to the asexual blood-stage infection. Present study is an attempt to compare the protective immune response mounted by the PfMSP-Fu24 upon administered through transdermal and intramuscular routes. Humoral and cell-mediated immune (CMI) response elicited by topical and intramuscularly administered PfMSP-Fu24-laden elastic liposomes (EL-PfMSP-Fu24) were compared and normalized with the vehicle control. Sizeable immune responses were seen with the transcutaneously immunized EL-PfMSP-Fu24 and compared with those elicited with intramuscularly administered antigen. Our results show significant IgG isotype subclass (IgG1and IgG3) response of specific antibody levels as well as cell-mediated immunity (CMI) activating factor (IFN-γ), a crucial player in conferring resistance to blood-stage malaria in mice receiving EL-PfMSP-Fu24 through transdermal route as compared to the intramuscularly administered formulation. Heightened immune response obtained by the vaccination of EL-PfMSP-Fu24 was complemented by the quantification of the transcript (mRNA) levels cell-mediated (IFN-γ, IL-4), and regulatory immune response (IL-10) in the lymph nodes and spleen. Collectively, elastic liposomes prove their immune-adjuvant property as they evoke sizeable and perdurable immune response against PfMSP-Fu24 and justify its potential for the improved vaccine delivery to inducing both humoral and CM immune response.

Viburnum nervosum Leaf Extract Mediated Green Synthesis of Silver Nanoparticles: A Viable Approach to Increase the Efficacy of an Anticancer Drug.

BACKGROUND: There is an urgent need to devise improved alternatives for the efficient delivery of drugs to develop improved therapeutic interventions against cancers. Nanotechnology-based drug delivery vehicles are in-use with obvious issues of toxicity and bio-distribution. Therefore, green synthetic routes are being deployed to replace the conventional nanoparticle formulations for effective drug delivery aiming at developing interventional strategies against cancer. OBJECTIVE: A simple, viable, and fast approach was used for the green synthesis of silver nanoparticles (AgNPs) using aqueous leaf-extract of Viburnum nervosum (VN) and to explore the anti-cancer potential of the crude extract of VN. METHODS: Silver NPs were synthesized by reacting silver nitrate (AgNO3) with leaf extract of VN. Various analytical techniques were used to characterize the AgNPs. Finally, the anti-cancer potential of VN was observed when delivered through AgNPs. RESULTS: The surface plasmon spectra for AgNPs exhibited absorbance peak at 445 nm, and Fourier-Transform Infrared Spectroscopy investigation revealed the presence of biomolecules acting as an effective reducing and capping agent for converting silver nitrate to AgNPs. Further, our results suggest the spherical size of synthesized AgNPs ranging from 12-17 nm. Moreover, in vitro studies conducted for VN extract with breast (MCF-7) and epidermal carcinoma (A431) cells showed biocompatibility. CONCLUSION: Doxorubicin loaded AgNPs documented an increased bioavailability of the drug compared to the free drug, suggesting the use of AgNPs as "novel drug delivery vectors".