Exosomes in immunoregulation of chronic lung diseases

Exosomes are nano-sized, membrane-bound vesicles released from cells that transport cargo including DNA, RNA, and proteins, between cells as a form of intercellular communication. In addition to their role in intercellular communication, exosomes are beginning to be appreciated as agents of immunoregulation that can modulate antigen presentation, immune activation, suppression, and surveillance. This article summarizes how these multifaceted functions of exosomes may promote development and/or progression of chronic inflammatory lung diseases including asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. The potential of exosomes as a novel therapeutic is also discussed.

2-(3′,4′-Dimethoxybenzylidene)tetralone induces anti-breast cancer activity through microtubule stabilization and activation of reactive oxygen species

2-Benzylidene tetralone derivatives are exhibited as potent anti-breast cancer agents through microtubule stabilization and induction of apoptosis through reactive oxygen species.

Synthesis of combretastatin A4 analogues on steroidal framework and their anti-breast cancer activity

Combretastatin A4 analogues were synthesized on steroidal framework from gallic acid with a possibility of anti-breast cancer agents. Twenty two analogues were synthesized and evaluated for cytotoxicity against human breast cancer cell lines (MCF-7 & MDA-MB 231). The best analogue 22 showed potent antitubulin effect. Docking experiments also supported strong binding affinity of 22 to microtubule polymerase. In cell cycle analysis, 22 induced apoptosis in MCF-7 cells significantly. It was found to be non-toxic up to 300 mg/kg dose in Swiss albino mice in acute oral toxicity. This article is part of a Special Issue entitled "Synthesis and biological testing of steroid derivatives as inhibitors".

Metformin ameliorates IL-6-induced hepatic insulin resistance via induction of orphan nuclear receptor small heterodimer partner (SHP) in mouse models

AIMS/HYPOTHESIS

IL-6 is a proinflammatory cytokine associated with the pathogenesis of hepatic diseases. Metformin is an anti-diabetic drug used for the treatment of type 2 diabetes, and orphan nuclear receptor small heterodimer partner (SHP, also known as NR0B2), a transcriptional co-repressor, plays an important role in maintaining metabolic homeostasis. Here, we demonstrate that metformin-mediated activation of AMP-activated protein kinase (AMPK) increases SHP protein production and regulates IL-6-induced hepatic insulin resistance.

METHODS

We investigated metformin-mediated SHP production improved insulin resistance through the regulation of an IL-6-dependent pathway (involving signal transducer and activator of transcription 3 [STAT3] and suppressor of cytokine signalling 3 [SOCS3]) in both Shp knockdown and Shp null mice.

RESULTS

IL-6-induced STAT3 transactivation and SOCS3 production were significantly repressed by metformin, adenoviral constitutively active AMPK (Ad-CA-AMPK), and adenoviral SHP (Ad-SHP), but not in Shp knockdown, or with the adenoviral dominant negative form of AMPK (Ad-DN-AMPK). Chromatin immunoprecipitation (ChIP), co-immunoprecipitation (Co-IP) and protein localisation studies showed that SHP inhibits DNA binding of STAT3 on the Socs3 gene promoter via interaction and colocalisation within the nucleus. Upregulation of inflammatory genes and downregulation of hepatic insulin signalling by acute IL-6 treatment were observed in wild-type mice but not in Shp null mice. Finally, chronic IL-6 exposure caused hepatic insulin resistance, leading to impaired insulin tolerance and elevated gluconeogenesis, and these phenomena were aggravated in Shp null mice.

CONCLUSIONS/INTERPRETATION

Our results demonstrate that SHP upregulation by metformin may prevent hepatic disorders by regulating the IL-6-dependent pathway, and that this pathway can help to ameliorate the pathogenesis of cytokine-mediated metabolic dysfunction.

Hepatoprotective Effects and Safety Evaluation of Coumarinolignoids Isolated from Cleome viscosa Seeds

The aim of the present work was to investigate the in vivo hepatoprotective potential of coumarinolignoids (cleomiscosins A, B, and C) isolated from the seeds of C. viscosa. The study was performed against CCl(4)-induced hepatotoxicity in albino rats. Rats were divided into four groups. The animals of group I served as normal and was given only vehicle. Group II served as toxin control and administered with CCl(4) (50% solution liquid paraffin, 2 ml/kg intraperitoneally). The animals of group III received coumarinolignoids (50 mg/kg) for six days orally as well as CCl(4) (2 ml/kg) on 4(th) day i.p. Similarly animals of group IV received silymarin (50 mg/kg) for six days orally as well as CCl(4) on 4(th) day i.p. On 7(th) day various parameters viz. serum glutamyl oxaloacetic transaminase, serum glutamyl pyruvate transaminase, serum alkaline phosphatase, serum bilirubin, liver glycogen were estimated and histopathology was performed. Additionally, acute oral toxicity of the said coumarinolignoids was carried out in swiss albino mice. The coumarinolignoids were found to be effective as hepatoprotective against CCl(4)-induced hepatotoxicity as evidenced by in vivo and histopathological studies in small animals. Safety evaluation studies also exhibit that coumarinolignoids are well tolerated by small animals in acute oral toxicity study except minor changes in red blood cell count and hepatic protein content at 5000 mg/kg body weight as a single oral dose. Coumarinolignoids which is the mixture of three compounds (cleomiscosin A, B and C) is showing the significant protective effects against CCl(4)-induced hepatotoxicity in small animals and also coumarinolignoids are well tolerated by small animals in acute oral study.

Development of QSAR model for immunomodulatory activity of natural coumarinolignoids

Immunomodulation is the process of alteration in immune response due to foreign intrusion of molecules inside the body. Along with the available drugs, a large number of herbal drugs are promoted in traditional Indian treatments, for their immunomodulating activity. Natural coumarinolignoids isolated from the seeds of Cleome viscose have been recognized as having hepatoprotective action and have recently been tested preclinically for their immunomodulatory activity affecting both cell-mediated and humoral immune response. To explore the immunomodulatory compound from derivatives of coumarinolignoids, a quantitative structure activity relationship (QSAR) and molecular docking studies were performed. Theoretical results are in accord with the in vivo experimental data studied on Swiss albino mice. Immunostimulatory activity was predicted through QSAR model, developed by forward feed multiple linear regression method with leave-one-out approach. Relationship correlating measure of QSAR model was 99% (R² = 0.99) and predictive accuracy was 96% (RCV² = 0.96). QSAR studies indicate that dipole moment, steric energy, amide group count, lambda max (UV-visible), and molar refractivity correlates well with biological activity, while decrease in dipole moment, steric energy, and molar refractivity has negative correlation. Docking studies also showed strong binding affinity to immunomodulatory receptors.

Outcomes of respiratory diphtheria in a tertiary referral infectious disease hospital

BACKGROUND

Diphtheria is a fatal disease and may cause serious complications if not recognized early and treated properly.

OBJECTIVES

To study the epidemiology, clinical features, complications, and outcomes in respiratory diphtheria.

MATERIALS AND METHODS

Diphtheria cases admitted in the infectious disease hospital, Beliaghata, Kolkata, India between January 2009 to January 2011 were evaluated in respect to demographic profile, immunization status, clinical features, complications, and outcomes.

RESULTS

200 diphtheria cases were studied. 150 (75%) patients had history of an adequate immunization, and 100 (50%) patients were from lower socio-economic groups. Common clinical features observed were throat pain in 148 (74%) cases and fever in 112 (56%) cases. Complications observed were myocarditis in 136 (68%) cases, neuropathy in 30 (15%) cases, and respiratory compromise in 14 (7%) cases. Death occurred in 5 (2.5%) patients.

CONCLUSIONS

diphtheria is still a public health problem in many developing countries. Strict public health measures like an increased immunization coverage, improvement of socio-economic status, easy availability of anti-diphtheritic serum (ADS), early recognition and effective treatment-all may reduce the incidence and mortality.

Pattern of ovarian protein synthesis and secretion during the reproductive cycle ofScotophilus heathi: synthesis of an albumin-like protein

Ovarian proteins synthesized de novo and secreted in vitro were investigated during different stages of the reproductive cycle of Scotophilus heathi. We found increased ovarian protein synthesis and secretion during the recrudescence and the preovulatory periods, coinciding with two peaks of follicular development and steroidogenesis. The ovaries synthesized protein at a low rate during quiescence and the late phase of delayed ovulation. In vitro analysis using 35 S-methionine incorporation showed increased synthesis of 66 kDa protein during delayed ovulation, but secretion of this protein declined markedly during the preovulatory period. N-terminal sequencing of the 66 kDa protein showed that it shares 70% homology with human serum albumin. Immunocytochemistry indicated that this protein is found primarily in the granulosa cells of the follicles. Whether the increase in albumin production by the ovaries during delayed ovulation is associated with a hyperinsulinemic and hyperandrogenic condition requires further investigation.

Changes in circulating insulin and corticosterone concentrations during different reproductive phases and their relationships to body weight and androstenedione concentration of male Scotophilus heathi

The aim of the present study was to determine the serum levels of insulin and corticosterone during different reproductive stages in a natural population of the male bat, Scotophilus heathi and their relationship to body weight and androstenedione level. Changes in body weight were marked by weight gain before winter dormancy and weight loss during winter dormancy. Circulating insulin level varied significantly over the season and correlated positively with changes in body weight and androstenedione level. Circulating corticosterone level also varied significantly over the season but correlated negatively with changes in body weight and androstenedione level. High corticosterone level during August coincided with a period of increased feeding activity in this species. The results suggest that insulin may act as an anabolic agent to promote fat deposition and corticosterone exerts a predominantly fat-mobilizing influence. A high insulin level prior to winter dormancy may be an important factor responsible for inducing high androstenedione concentration shown in Scotophilus heathi.