Cell cycle deregulation by methyl isocyanate: Implications in liver carcinogenesis

Liver is often exposed to plethora of chemical toxins. Owing to its profound physiological role and central function in metabolism and homeostasis, pertinent succession of cell cycle in liver epithelial cells is of prime importance to maintain cellular proliferation. Although recent evidence has displayed a strong association between exposures to methyl isocyanate (MIC), one of the most toxic isocyanates, and neoplastic transformation, molecular characterization of the longitudinal effects of MIC on cell cycle regulation has never been performed. Here, we sequentially delineated the status of different proteins arbitrating the deregulation of cell cycle in liver epithelial cells treated with MIC. Our data reaffirms the oncogenic capability of MIC with elevated DNA damage response proteins pATM and γ-H2AX, deregulation of DNA damage check point genes CHK1 and CHK2, altered expression of p53 and p21 proteins involved in cell cycle arrest with perturbation in GADD-45 expression in the treated cells. Further, alterations in cyclin A, cyclin E, CDK2 levels along with overexpression of mitotic spindle checkpoints proteins Aurora A/B, centrosomal pericentrin protein, chromosomal aberrations, and loss of Pot1a was observed. Thus, MIC impacts key proteins involved in cell cycle regulation to trigger genomic instability as a possible mechanism of developmental basis of liver carcinogenesis.

Surface-enhanced Raman scattering biosensors for detection of oncomiRs in breast cancer

Surface-enhanced Raman scattering (SERS) has emerged as one of the most promising platforms for various biosensing applications. These sensing systems encompass the advantages of specificity, ultra-high sensitivity, stability, low cost, repeatability, and easy-to-use methods. Moreover, their ability to offer a molecular fingerprint and identify the target analyte at low levels make SERS a promising technique for detecting circulating cancer biomarkers with greater sensitivity and reliability. Among the various circulating biomolecules, oncomiRs are emerging as prominent biomarkers for the early screening of breast cancers (BCs). In this review, we provide a comprehensive understanding of different SERS-based biosensors and their application to identify BC-specific oncomiRs. We also discuss different SERS-based sensing strategies, nano-analytical frameworks, and challenges to be addressed for effective clinical translation.

Surface structured liposomes for site specific delivery of an antiviral agent-indinavir

The present investigation was aimed at targeting indinavir, a protease inhibitor to cells of mononuclear phagocyte system (MPS) via mannosylated liposomes. β-d-1-thiomannopyranoside residues were covalently coupled with dimyristoyl phosphatidylethanolamine (DMPE) to generate mannosylated-DMPE (Man-DMPE) conjugate which was further incorporated with disteroyl phosphatidyl choline and cholesterol to prepare mannosylated liposomes. The optimized mannosylated liposomes were nanometric in size (142 ± 2.8 nm) with optimum entrapment efficiency (88.7 ± 2.3%). Less than 20% cumulative drug release was observed from the prepared formulations in 24 h in phosphate buffer saline (pH 7.4). Cellular uptake studies performed on J774.A1 macrophage cell line via flow cytometric analysis depicted enhanced uptake of mannosylated liposomes as compared to plain liposomes. Annexin-V-fluorescein isothiocyanate/propidium iodide apoptosis assay delineated marginal cytotoxicity in macrophages from the developed formulation. Plasma and tissue distribution studies performed to assess the drug reach to macrophage rich regions depicted a significant level (P < 0.05) of indinavir in macrophage rich tissues like liver, spleen, and lungs from mannosylated liposomes as compared to plain liposomes and free drug. The conducted studies suggest the potential of indinavir loaded mannosylated liposomes for anti-human immunodeficiency virus therapy.

Nanoengineered strategies to optimize dendritic cells for gastrointestinal tumor immunotherapy: from biology to translational medicine

Nanomedicine may play an important role in improving the clinical efficacy of dendritic cell-based immunotherapy against GI tract malignancies. Dendritic cell-based vaccines have proven their effectiveness against different established GI tract tumors, yet their success is mainly hindered by the strong tumor-induced suppressive microenvironment. The sustained and targeted release of tumor antigens to dendritic cells using different nanoengineered approaches would be an efficient strategy to overcome established immune tolerance. Encapsulation would result in low diffusivity, restricted movement, effective crosspresentation and enhanced T-cell responses. These nanotherapy-based approaches will certainly help with the designing of clinically translatable dendritic cell-based therapeutic vaccines and facilitate the selective removal of residual disease in gastrointestinal cancer patients following standard treatments.

Diagnosis of gastrointestinal tuberculosis: Using cytomorphological, microbiological, immunological and molecular techniques - A study from Central India

The present study included three groups: (A) age and gender matched control (n=24) with no previous signs of M. tuberculosis complex (MTBC) infection, (B) patients (n=28) diagnosed with gastro-intestinal TB (GITB), (C) patients (n=50) with clinical and histo-pathological signs of GITB, but were culture and AFB negative. Real time assay performed using fluorescence resonance energy transfer hybridization probes showed a positivity index of 36 % in group C, i.e. 18 were found reactive from the total 50 cases studied. In addition, immune characterization of these 18 cases showed depleted CD(4) (+) count and increased levels of IFN-γ and TNF-α cytokines. No positive case was found in group A, while in group B, out of total 28 cases studied 27 were found positive. A combinatorial diagnostic approach for rapid detection and characterization of GITB might provide specific therapeutic strategies for prevention and treatment of the infection in future.

Molecular surveillance of hepatitis and tuberculosis infections in a cohort exposed to methyl isocyanate

OBJECTIVE

The potential toxic effects on the immune system exerted by occupational and accidental environmental exposures and underlying molecular regulatory mechanisms involved in the etiology and progression of infectious diseases are now being characterized. The Bhopal gas tragedy is undoubtedly one of the worst industrial disasters in the history of mankind. After 25 years of accidental exposure to methyl isocyanate (MIC), severe systemic ailments still continue to pre-occupy the lives of the affected population that survived this tragedy. We have performed a molecular surveillance study to characterize hepatitis and tuberculosis infections amongst the first and the second generation of survivors exposed to MIC.

MATERIALS AND METHODS

Both outdoor and indoor patients referred for molecular diagnosis of hepatitis B virus (HBV), hepatitis C virus (HCV) and Mycobacterium tuberculosis (MTB) were examined. Qualitative analysis for HBsAg, anti-HBc, anti-HCV through ELISA was performed, while BacT/ALERT and Ziehl-Neelson technique were utilized for the assessment of tuberculosis. Detection and quantification of viral and bacterial nucleic acid and characterization of hepatitis genotypes were analyzed using real-time and end-point PCR techniques.

RESULTS

The results suggest that HBV infections are most common among the MIC-exposed cohort, followed by extra-pulmonary and pulmonary MTB and HCV infections. Genotype 3 is the most prevalent HCV genotype among the survivors. Failure to detect HBsAg, anti-HBc and anti-HCV through ELISA, and tuberculosis by culture and Ziehl-Neelson stain, indicates higher prevalence of occult hepatitis and latent tuberculosis in the affected population.

CONCLUSIONS

Our study underscores the importance of hospital-based records used as a data source for monitoring possible environmental health hazards. As the risk of progress of infection is often influenced by conditions and periods of environmental chemical exposure, therefore, insights of interconnected molecular pathways will further illuminate the gene-environment association and might offer valuable information for rational drug design.

Lactobacillus rhamnosus (LR) ameliorates pulmonary and extrapulmonary acute respiratory distress syndrome (ARDS) via targeting neutrophils

Pulmonary and extrapulmonary acute respiratory distress syndrome (ARDS) is a life-threatening respiratory failure associated with high mortality. Despite progress in our understanding of the pathological mechanism causing the crippling illness, there are currently no targeted pharmaceutical treatments available for it. Recent discoveries have emphasized the existence of a potential nexus between gut and lung health fueling novel approaches including probiotics for the treatment of ARDS. We thus investigated the prophylactic-potential of Lactobacillus rhamnosus-(LR) in lipopolysaccharide (LPS)-induced pulmonary and cecal ligation puncture (CLP) induced extrapulmonary ARDS mice. Our in-vivo findings revealed that pretreatment with LR significantly ameliorated vascular-permeability (edema) of the lungs via modulating the neutrophils along with significantly reducing the expression of inflammatory-cytokines in the BALF, lungs and serum in both pulmonary and extrapulmonary mice-models. Interestingly, our ex-vivo immunofluorescence and flow cytometric data suggested that mechanistically LR via short chain fatty acids (butyrate being the most potent and efficient in ameliorating the pathophysiology of both pulmonary and extra-pulmonary ARDS) targets the phagocytic and neutrophils extracellular traps (NETs) releasing potential of neutrophils. Moreover, our in-vivo data further corroborated our ex-vivo findings and suggested that butyrate exhibits enhanced potential in ameliorating the pathophysiology of ARDS via reducing the infiltration of neutrophils into the lungs. Altogether, our study establishes the prophylactic role of LR and its associated metabolites in the prevention and management of both pulmonary and extrapulmonary ARDS via targeting neutrophils.

Biochemical characterization of unusual cysteine protease of P. falciparum, metacaspase-2 (MCA-2)

Earlier studies on Plasmodium apoptosis revealed the presence of proteases with caspases like- activity, which are known as "metacaspases". Although this family of cysteine proteases is structurally similar to caspases with Cys-His dyad but their evolutionary significance and functional relevance remains largely unknown. These proteases are considered to be an important target against malaria due to their absence in humans. In this report, we have biochemically characterized metacaspase-2 (PfMCA-2) of P.falciparum. Enzymatic assay showed that PfMCA-2 efficiently cleaved arginine/lysine specific peptide, but not caspase-specific substrate. Consistently, PfMCA-2 activity was sensitive to effector caspases inhibitor, Z-FA-FMK, and mildly inhibited by aprotinin and E-64. However, general caspase inhibitors such as Z-VAD-FMK and Z-DEVD-FMK had no effect on PfMCA-2 activity. Z-FA-FMK inhibits parasite growth with an IC50 value of 2.7 μM along with the notable morphological changes. PfMCA-2 specifically expressed in schizonts and gametocyte stages and there was a notable depletion of PfMCA-2 expression in Z-FA-FMK treated schizonts and gametocytes stages of parasite. Notably, PfMCA-2 cleaves a phylogenetically conserved protein, TSN (Tudor staphylococcal nuclease) and the proteolysis of PfTSN did not occur after treatment with the Z-FA-FMK. The production of large amount of reactive oxygen species in presence of Z-FA-FMK caused oxidative stress which in turn leads to loss of cell viability. The oxidative stress further generates positive feedback for the occurrence of cell death in term of phosphatidylserine externalization and DNA fragmentation in vitro.

Point-of-care diagnostics approaches for detection of lung cancer-associated circulating miRNAs

Circulating cell-free miRNAs (ccf-miRs) have gained significant interest as biomarkers for lung cancer (LC) diagnosis. However, the clinical application of ccf-miRs is mainly limited by time, cost, and expertise-related problems of existing detection strategies. Recently, the development of different point-of-care (POC) approaches offers useful on-site platforms, because these technologies have important features such as portability, rapid turnaround time, minimal sample requirement, and cost-effectiveness. In this review, we discuss different POC approaches for detecting ccf-miRs and highlight the utility of incorporating nanomaterials for enhanced biorecognition and signal transduction, further improving their diagnostic applicability in LC settings.

Clostridium perfringens phospholipase C impairs innate immune response by inducing integrated stress response and mitochondrial-induced epigenetic modifications

Clostridium perfringens, a rod-shaped, gram-positive, anaerobic, spore-forming bacterium is one of the most widely occurring bacterial pathogens, associated with a spectrum of diseases in humans. A major virulence factor during its infection is the enzyme phospholipase C encoded by the plc gene, known as Clostridium perfringens phospholipase C (CpPLC). The present study was designed to understand the role of CpPLC in inducing survival mechanisms and mitochondrial-induced epigenetic changes in a human lymphocyte cell culture model. Following exposure to CpPLC, a significant generation of mitochondrial reactive oxygen species was observed, which coincided with the changes in the expression of vital components of MAP/ERK/RTK signaling cascade that regulates the downstream cellular functions. These disturbances further led to alterations in the mitochondrial genome and functioning. This was supported by the observed upregulation in the expression of mitochondrial fission genes Drp1, Fis1, and Mff, and mitochondrial fusion genes MFN1, MFN2, and OPA1 following CpPLC exposure. CpPLC exposed cells showed upregulation of OMA1, DELE1, and HRI genes involved in the integrated stress response (ISR), which suggests that it may induce the ISR that provides a pro-survival mechanism to the host cell. CpPLC also initiated immune patho-physiologic mechanisms including mitochondrial-induced epigenetic modifications through a mitochondrial-ROS driven signaling pathway. Interestingly, epigenetic machinery not only play a pivotal role in lymphocyte homeostasis by contributing to cell-fate decisions but thought to be one of the mechanisms by which intracellular pathogens survive within the host cells. Importantly, the impairment of mtDNA repair among the CpPLC exposed cells, induced alterations within mtDNA methylation, and led to the deregulation of MT-CO1, MT-ND6, MT-ATPase 6, and MT-ATPase8 gene expression profiles that are important for mitochondrial bioenergetics and subsequent metabolic pathways. This was further confirmed by the changes in the activity of mitochondrial electron chain complexes (complex I, II, III, IV and V). The altered mtDNA methylation profile was also found to be closely associated with the varied expression of mitomiRs and their targets. CpPLC exposed cells showed up-regulation of miR24 expression and down-regulation of miR34a, miR150, and miR155, while the increased expression of mitomiR target genes i.e. of K-Ras, MYC, EGFR, and NF-kβ was also observed in these cells. Altogether, our findings provide novel insights into the derailment of redox signaling machinery in CpPLC treated lymphocytes and its role in the induction of survival mechanisms and mitochondrial-induced epigenetic modifications.

Fetal nucleic acids in maternal plasma: from biology to clinical translation

Exposure to environmental contaminants during the critical window of pregnancy results in deregulation of highly coordinated genetic and epigenetic mechanisms involved in prenatal growth. Such disturbances significantly alter the fetal programming, and lead to various developmental disorders immediately, over the lifetime, or transgenerationally. During the process of placental development, fetal nucleic acids enter maternal plasma as a result of necrotic, apoptotic, and inflammatory mechanisms. These nucleic acids reflect normal or abnormal ongoing cellular changes during prenatal fetal development. Here, we critically review the utility of maternally circulating cell free fetal nucleic acids towards developing reliable biomarkers for widespread screening of environmentally-associated fetal abnormalities. We further discuss the most recent developments in the fetal nucleic acid analysis, quantification methodologies, challenges involved in their accurate detection and their potential applications in fetomaternal medicine.

Impairment of mitochondrial-nuclear cross talk in neutrophils of patients with type 2 diabetes mellitus

Increased leukocyte apoptosis is intrinsically linked to disease patho-physiology, susceptibility to and severity of infections in type 2 diabetes mellitus (T2DM) patients. A consistent defect in neutrophil function is considered central to this increased risk for infections. Although redox imbalance is considered a potential mediator of these associated complications, detailed molecular evidence in clinical samples remains largely undetected. The study consisted of three groups (n = 50 each) of Asian Indians: early diagnosed diabetic patients, cases with late-onset diabetic complications and age and gender-matched healthy controls. We evaluated mitochondrial oxidative stress, levels of nuclear DNA damage and apoptosis in peripheral blood neutrophils isolated from T2DM patients. We observed that in both early and late diabetic subjects, the HbA1c levels in neutrophils were altered considerably with respect to healthy controls. Increased oxidative stress observed in both early and late diabetics imply the disentanglement of fine equilibrium of mitochondria-nuclear cross talk which eventually effected the augmentation of downstream nuclear γH2AX activation and caspase-3 expression. It would be overly naïve to refute the fact that mitochondrial deregulation in neutrophils perturbs immunological balance in type 2 diabetic conditions. By virtue of our data, we posit that maneuvering mitochondrial function might offer a prospective and viable method to modulate neutrophil function in T2DM. Nevertheless, similar investigations from other ethnic groups in conjunction with experimental evidences would be a preeminent need. Obviously, our study might aid to comprehend this complex interplay between mitochondrial dysfunction and neutrophil homeostasis in T2DM.

Design and Fabrication of a Nanobiosensor for the Detection of Cell-Free Circulating miRNAS-LncRNAS-mRNAS Triad Grid

The increased understanding of the competitive endogenous RNA (ceRNA) network in the onset and development of breast cancers has suggested their use as promising disease biomarkers. Keeping these RNAs as molecular targets, we designed and developed an optical nanobiosensor for specific detection of the miRNAs-LncRNAs-mRNAs triad grid in circulation. The sensor was formulated using three quantum dots (QDs), i.e., QD-705, QD-525, and GQDs. These QDs were surface-activated and modified with a target-specific probe. The results suggested the significant ability of the developed nanobiosensor to identify target RNAs in both isolated and plasma samples. Apart from the higher specificity and applicability, the assessment of the detection limit showed that the sensor could detect the target up to 1 fg concentration. After appropriate validation, the developed nanobiosensor might prove beneficial to characterizing and detecting aberrant disease-specific cell-free circulating miRNAs-lncRNAs-mRNAs.

"Osteomicrobiology": The Nexus Between Bone and Bugs

A growing body of scientific evidence supports the notion that gut microbiota plays a key role in the regulation of various physiological and pathological processes related to human health. Recent findings have now established that gut microbiota also contributes to the regulation of bone homeostasis. Studies on animal models have unraveled various underlying mechanisms responsible for gut microbiota-mediated bone regulation. Normal gut microbiota is thus required for the maintenance of bone homeostasis. However, dysbiosis of gut microbiota communities is reported to be associated with several bone-related ailments such as osteoporosis, rheumatoid arthritis, osteoarthritis, and periodontitis. Dietary interventions in the form of probiotics, prebiotics, synbiotics, and postbiotics have been reported in restoring the dysbiotic gut microbiota composition and thus could provide various health benefits to the host including bone health. These dietary interventions prevent bone loss through several mechanisms and thus could act as potential therapies for the treatment of bone pathologies. In the present review, we summarize the current knowledge of how gut microbiota and its derived microbial compounds are associated with bone metabolism and their roles in ameliorating bone health. In addition to this, we also highlight the role of various dietary supplements like probiotics, prebiotics, synbiotics, and postbiotics as promising microbiota targeted interventions with the clinical application for leveraging treatment modalities in various inflammatory bone pathologies.

Medicinal chemistry aspects and synthetic strategies of coumarin as aromatase inhibitors: an overview

Coumarin is a bicyclic oxygen bearing heterocyclic scaffold formed by fusion of benzene with the pyrone ring. Because of its unique physicochemical characteristics and the ease with which it may be transformed into a wide range of functionalized coumarins during synthesis, coumarin provides a privileged scaffold for medicinal chemists. As a result, many coumarin derivatives have been developed, synthesized, and evaluated to target a variety of therapeutic domains, thereby making it an attractive template for designing novel anti-breast cancer compounds. The main culprit in estrogen overproduction in the estrogen-dependent breast cancer (EDBC), is the enzyme aromatase (AR), and it is thought to be a significant target for the effective treatment of EDBC. Considering coumarins versatility, this review presents a detailed overview of diverse study of aromatase as a target for coumarins. An overview of structure-activity relationship analysis of coumarin core is also included so as to summarize the desired pharmacophoric features essential for design and development of aromatase inhibitors (AIs) using coumarin core. Identification of key synthesis techniques that could aid researchers in designing and developing novel analogues with significant anti-breast cancer properties along with their mechanism of action have also been covered in the current review.

Novel approach for quantification of hepatitis C virus in liver cirrhosis using real-time reverse transcriptase PCR

BACKGROUND

Hepatitis C virus (HCV) infects nearly 3% of the population worldwide and is a major cause of acute and chronic infections leading to fibrosis, cirrhosis, and hepatocellular carcinoma. Current laboratory diagnosis of HCV is based on specific antibody detection (anti-hepatitis C virus (anti-HCV)) in serum. As HCV replicates in the liver cells, detection and localization of HCV RNA in liver tissue are vital for diagnosis.

METHODS

Ten biopsy samples diagnosed for cryptogenic liver cirrhosis, negative for the presence of anti-HCV and serum HCV RNA, were studied for analyzing presence of viral nucleic acid in liver tissues. Qualitative screening for HCV was done through ELISA while the nucleic acid analysis was performed through COBAS Amplicor. Detection of HCV RNA in liver tissue biopsies was performed following standard protocol of HCV detection kit (Shenzhen PG Biotech) with modifications using Light Cycler 2.0 (minimum detection limit 10 copies/ml).

RESULT

Quantitative detection in liver biopsies following the modified method showed the presence of HCV RNA in three samples out of the ten studied.

CONCLUSION

The results indicate that using Light Cycler 2.0, following the modified technique described, constitutes a reliable method of quantitative detection and localization of HCV in tissue in "serosilent" HCV infection.

Pre-clinical Validation of Mito-targeted Nano-engineered Flavonoids Isolated From Selaginella bryopteris (Sanjeevani) As A Novel Cancer Prevention Strategy

BACKGROUND

Novel bioactive plant secondary metabolites, including flavonoids, offer a spectrum of chemo-protective responses against a range of human tumor models. However, the clinical translation of these promising anti-cancer agents has been hindered largely by their poor solubility, rapid metabolism, or a combination of both, ultimately resulting in poor bioavailability upon oral administration.

OBJECTIVE

To circumvent the challenges associated with herbal drug development and for effective integration into clinical setting, nano-engineering is one of the emerging pragmatic strategies which has promise to deliver therapeutic concentrations of bio-actives upon oral administration.

METHOD

We assessed the nano-encapsulated flavonoid-rich fraction isolated from a traditional Indian herb Selaginella bryopteris (Sanjeevani) (NP.SB). Both in vitro and in vivo studies were performed to evidence the epigenetic protection mechanisms of NP.SB through a mitochondrial-targeted pre-clinical validation strategy.

RESULTS

The mito-protective activity of NP.SB revealed a dose-dependent effect when tested in GC-1 spg (mouse spermatogonial epithelial) and B/CMBA.Ov (mouse ovarian epithelial) following exposure to Nsuccinimidyl N-methylcarbamate, a potential human carcinogen. Smaller size, rapid internalization, faster mobility and site specific delivery conferred significant cancer protection in cultured cells. Notably, this encapsulated flavonoid supplementation; prevented emergence of neoplastic daughter clones from senescent mother phenotypes in pro-oxidant treated GC-1 spg and B/CMBA.Ov cells by selective abrogation of mitochondrial oxidative stress-induced aberrant epigenetic modifications. In vivo studies using a diethylnitrosamine and 2- acetylaminofluorene mouse model demonstrated that NP.SB has a significant inhibitory effect on tumor growth which clearly substantiated our in vitro findings.

CONCLUSION

Anti-carcinogenic property in conjunction with low toxicity of NP.SB, underscores the translational significance of dietary flavonoids as cancer-protective agents for preferential application in clinical settings.

Immune cell engineering: opportunities in lung cancer therapeutics

Engineered immune cells offer a prime therapeutic alternate for some aggressive and frequently occurring malignancies like lung cancer. These therapies were reported to result in tumor regression and overall improvement in patient survival. However, studies also suggest that the presence of cancer cell-induced immune-suppressive microenvironment, off-target toxicity, and difficulty in concurrent imaging are some prime impendent in the success of these approaches. The present article reviews the need and significance of the currently available immune cell-based strategies for lung cancer therapeutics. It also showcases the utility of incorporating nanoengineered strategies and details the available formulations of nanocarriers. In last, it briefly discussed the existing methods for nanoparticle fuctionalization and challenges in translating basic research to the clinics. Graphical Abstract.