Helicobacter pylori and Epstein-Barr virus infection in cell polarity alterations

The asymmetrical distribution of the cellular organelles inside the cell is maintained by a group of cell polarity proteins. The maintenance of polarity is one of the vital host defense mechanisms against pathogens, and the loss of it contributes to infection facilitation and cancer progression. Studies have suggested that infection of viruses and bacteria alters cell polarity. Helicobacter pylori and Epstein-Barr virus are group I carcinogens involved in the progression of multiple clinical conditions besides gastric cancer (GC) and Burkitt's lymphoma, respectively. Moreover, the coinfection of both these pathogens contributes to a highly aggressive form of GC. H. pylori and EBV target the host cell polarity complexes for their pathogenesis. H. pylori-associated proteins like CagA, VacA OipA, and urease were shown to imbalance the cellular homeostasis by altering the cell polarity. Similarly, EBV-associated genes LMP1, LMP2A, LMP2B, EBNA3C, and EBNA1 also contribute to altered cell asymmetry. This review summarized all the possible mechanisms involved in cell polarity deformation in H. pylori and EBV-infected epithelial cells. We have also discussed deregulated molecular pathways like NF-κB, TGF-β/SMAD, and β-catenin in H. pylori, EBV, and their coinfection that further modulate PAR, SCRIB, or CRB polarity complexes in epithelial cells.

De-glutathionylases: The resilient underdogs to keep neurodegeneration at bay

Proteins become S-glutathionylated as a result of the derivatization of their cysteine thiols with the thiolate anion derivative of glutathione; this process is frequently linked to diseases and protein misbehavior. Along with the other well-known oxidative modifications like S-nitrosylation, S-glutathionylation has quickly emerged as a major contributor to a number of diseases, with a focus on neurodegeneration. The immense clinical significance of S-glutathionylation in cell signaling and the genesis of diseases are progressively coming to light with advanced research, which is also creating new opportunities for prompt diagnostics that utilize this phenomenon. In-depth investigation in recent years has revealed other significant deglutathionylases in addition to glutaredoxin, necessitating the hunt for their specific substrates. The precise catalytic mechanisms of these enzymes must also be understood, along with how the intracellular environment affects their impact on protein conformation and function. These insights must then be extrapolated to the understanding of neurodegeneration and the introduction of novel and clever therapeutic approaches to clinics. Clarifying the importance of the functional overlap of glutaredoxin and other deglutathionylases and examining their complementary functions as defense systems in the face of stress are essential prerequisites for predicting and promoting cell survival under high oxidative/nitrosative stress.

S-Denitrosylation: A Crosstalk between Glutathione and Redoxin Systems

S-nitrosylation of proteins occurs as a consequence of the derivatization of cysteine thiols with nitric oxide (NO) and is often associated with diseases and protein malfunction. Aberrant S-nitrosylation, in addition to other genetic and epigenetic factors, has gained rapid importance as a prime cause of various metabolic, respiratory, and cardiac disorders, with a major emphasis on cancer and neurodegeneration. The S-nitrosoproteome, a term used to collectively refer to the diverse and dynamic repertoire of S-nitrosylated proteins, is relatively less explored in the field of redox biochemistry, in contrast to other covalently modified versions of the same set of proteins. Advancing research is gradually unveiling the enormous clinical importance of S-nitrosylation in the etiology of diseases and is opening up new avenues of prompt diagnosis that harness this phenomenon. Ever since the discovery of the two robust and highly conserved S-nitrosoglutathione reductase and thioredoxin systems as candidate denitrosylases, years of rampant speculation centered around the identification of specific substrates and other candidate denitrosylases, subcellular localization of both substrates and denitrosylases, the position of susceptible thiols, mechanisms of S-denitrosylation under basal and stimulus-dependent conditions, impact on protein conformation and function, and extrapolating these findings towards the understanding of diseases, aging and the development of novel therapeutic strategies. However, newer insights in the ever-expanding field of redox biology reveal distinct gaps in exploring the crucial crosstalk between the redoxins/major denitrosylase systems. Clarifying the importance of the functional overlap of the glutaredoxin, glutathione, and thioredoxin systems and examining their complementary functions as denitrosylases and antioxidant enzymatic defense systems are essential prerequisites for devising a rationale that could aid in predicting the extent of cell survival under high oxidative/nitrosative stress while taking into account the existence of the alternative and compensatory regulatory mechanisms. This review thus attempts to highlight major gaps in our understanding of the robust cellular redox regulation system, which is upheld by the concerted efforts of various denitrosylases and antioxidants.

Glutathione-dependent thioredoxin reduction and lipoamide system support in-vitro mammalian ribonucleotide reductase catalysis: a possible antioxidant redundancy

BACKGROUND

The thioredoxin system (Trx), comprising of Trx, Thioredoxin reductase (TrxR) and NADPH aids in donating hydrogen group to support Ribonucleotide reductase (RNR) catalysis during de-novo DNA biosynthesis. However, it has been observed that inhibiting TrxR does not affect the viability of cancer cells that are susceptible to pharmacological glutathione (GSH) depletion. This prompted us to study the potential antioxidant redundancies that might prolong RNR activity.

METHODS

To study the RNR activity assay, the RNR complex was reconstituted by mixing purified mouse recombinant RNR subunits and the conversion of [³ H] CDP into [³ H] dCDP was monitored. In the assay system, either purified Trx and GSH or Lipoamide system was supplemented as reducing agents to support RNR catalysis.

RESULTS

Herein, we have found that GSH-dependent Trx reduction supports mammalian class I RNR catalysis in absence of TrxR in the system. Our data also presents the first report that the LAM system is capable of supporting in-vitro RNR activity in the complete absence of either Trx or Grx systems.

CONCLUSIONS

We conclude that GSH-mediated Trx reduction and LAM systems support basal level RNR activity in vitro; in absence of TrxR and complete redoxin systems respectively and hypothesize that potential redundancy between the various antioxidant systems might synergize in sustaining RNR activity.

Two new species of Platensina Enderlein (Diptera, Tephritidae, Tephritinae, Dithrycini) from India

Two new species of Platensina Enderlein, P.rabbanii David & Hancock, sp. nov., and P.flavistigma David & Hancock, sp. nov., are described from Meghalaya and southern India, respectively. Platensinarabbanii can be differentiated from P.alboapicalis Hering by the presence of a single hyaline indentation in cell r₁ and the apical hyaline band in cell r₂₊₃ restricted to the apex; P.flavistigma differs from P.quadrula Hardy by the presence of a yellow/fulvous pterostigma and shape of the epandrium. DNA barcode sequences of P.acrostacta (Wiedemann), P.flavistigma and P.platyptera Hendel were obtained and reported. Postabdominal descriptions and illustrations of P.acrostacta, P.platyptera and P.zodiacalis (Bezzi) are also provided along with keys to all 23 species and the 7 known from India.

A new species, new postabdominal descriptions and a new synonymy in Euphranta Loew (Diptera: Tephritidae: Trypetinae: Adramini)

A new species of Euphranta, E. flavothoracica David, Hancock Sachin, sp. n. is described from India and placed in the zeylanica group of species. Postabdominal structures of E. cassiae (Munro), E. crux (Fabricius) and E. klugii (Wiedemann) are described. A revised key to the 16 species of Euphranta known from India is provided. A new generic and specific synonymy is established: Euphranta Loew, 1862 = Ichneumonomacula Chen, 2020, syn. n. and Dacus figuratus Walker, 1856 (=Euphranta figurata (Walker, 1856))= Ichneumonomacula wangyongi Chen, 2020, syn. n.

Taxonomic notes on the genus Elaphromyia Bigot (Diptera: Tephritidae: Tephritinae: Pliomelaenini) in India, with description of a new species

A new species of Elaphromyia, E. juncta David, Hancock Sachin, sp. n. is described from India. It can be differentiated from the morphologically similar E. siva Frey and E. pterocallaeformis (Bezzi) by the wing pattern, epandrial characters, morphology of spicules on the eversible membrane and spermathecal shape. Elaphromyia siva Frey and E. yunnanensis Wang are recorded for the first time from India. Records of E. pterocallaeformis (Bezzi) from southern India are regarded as misidentifications. A key to the 7 known non-African species is included.

Microbial Fabricated Nanosystems: Applications in Drug Delivery and Targeting

The emergence of nanosystems for different biomedical and drug delivery applications has drawn the attention of researchers worldwide. The likeness of microorganisms including bacteria, yeast, algae, fungi, and even viruses toward metals is well-known. Higher tolerance to toxic metals has opened up new avenues of designing microbial fabricated nanomaterials. Their synthesis, characterization and applications in bioremediation, biomineralization, and as a chelating agent has been well-documented and reviewed. Further, these materials, due to their ability to get functionalized, can also be used as theranostics i.e., both therapeutic as well as diagnostic agents in a single unit. Current article attempts to focus particularly on the application of such microbially derived nanoformulations as a drug delivery and targeting agent. Besides metal-based nanoparticles, there is enough evidence wherein nanoparticles have been formulated using only the organic component of microorganisms. Enzymes, peptides, polysaccharides, polyhydroxyalkanoate (PHA), poly-(amino acids) are amongst the most used biomolecules for guiding crystal growth and as a capping/reducing agent in the fabrication of nanoparticles. This has promulgated the idea of complete green chemistry biosynthesis of nano-organics that are most sought after in terms of their biocompatibility and bioavailability.

A new species of Hemilea Loew and two new records of Trypetini (Diptera: Tephritidae: Trypetinae) from India

A new species of Hemilea Loew, H. totu David, Hancock Sachin, sp. n., is described from India. Paratrypeta appendiculata (Hendel) and Vidalia thailandica Hancock Drew are recorded for the first time from India and a key to species of Hemilea from India and Myanmar is provided.

A Network Biology Approach for Assessing the Role of Pathologic Adipose Tissues in Insulin Resistance Using Meta-analysis of Microarray Datasets

Background

The role of adipose tissue in Insulin resistance (IR) and Type 2 Diabetes (T2D) has well been received in the biomedical community; being a precursor of T2D, identification of the molecular basis of IR is therefore, vital to elucidate T2D- pathogenesis and meta-analysis of previously conducted microarray studies provides an inexpensive approach to achieve this end.

Methods

In this study, we have carried out a statistical meta-analysis of 157 microarray datasets from five independent studies and identified a meta-signature of 1,511 genes; their functional meaning was elucidated by integrated pathways-analysis. Further, a protein-protein interaction network was constructed and key genes along with their high confidence transcriptional- and epigenetic-mediators were identified using a network biology approach.

Results

Various inflammation- and immune system-related pathways such as TGF-β signaling, IL7 signaling, Neutrophil degranulation, and Chemokine signaling etc. were enriched in sick adipose tissues; identified transcription factors, and microRNAs were also found to regulate processes relevant to IR/T2D pathophysiology.

Conclusion

This study endorses the development of effective bioinformatics workflow and further grants an indication for the acceptance of adiposopathy as the root mechanistic pathology that poses risk for development of type 2 diabetes; concept of adipospathy in place of metabolic syndrome will open the possibility to design drugs, those will ameliorate adipose functions and hence proved to be more effective against Type 2 Diabetes.

System Level Meta-analysis of Microarray Datasets for Elucidation of Diabetes Mellitus Pathobiology

BACKGROUND

Type 2 diabetes (T2D) is a common multi-factorial disease that is primarily ac-counted to ineffective insulin action in lowering blood glucose level and later escalates to impaired insu-lin secretion by pancreatic β cells. Deregulation in insulin signaling to its target organs is attributed to this disease phenotype. Various genome-wide microarray studies from multiple insulin responsive tis-sues have been conducted in past but due to inherent noise in microarray data and heterogeneity in dis-ease etiology; reproduction of prioritized pathways/genes is very low across various studies.

OBJECTIVE

In this study, we aim to identify consensus signaling and metabolic pathways through system level meta-analysis of multiple expression-sets to elucidate T2D pathobiology.

METHOD

We used 'R', an open source statistical environment, which is routinely used for Microarray data analysis particularly using special sets of packages available at Bioconductor. We primarily focused on gene-set analysis methods to elucidate various aspects of T2D.

RESULT

Literature-based evidences have shown the success of our approach in exploring various known aspects of diabetes pathophysiology.

CONCLUSION

Our study stressed the need to develop novel bioinformatics workflows to advance our understanding further in insulin signaling.

Pattern of care in operable endometrial cancer treated at a rural-based tertiary care cancer center

PURPOSE

An audit was planned to study the demographics, staging, treatment details, and outcomes of operable endometrial cancers.

METHODOLOGY

All operable endometrial cancers treated between January 2009 and October 2014 were included in the study. The details regarding demographics, staging, surgical procedure, pathological staging, adjuvant treatment, and outcomes were extracted from the case records. Descriptive statistics was performed. The time-to-event analysis was done by Kaplan-Meier method. Univariate and multivariate analyses were done for disease-free survival (DFS) and overall survival (OS).

RESULTS

There were 55 patients with a median age of 59 years (35-73 years). The Eastern Cooperative Oncology Group performance status was 1 in 52 patients (94.5%) and 2 in 3 patients (5.5%). Forty-nine patients (89.1%) had disease restricted to endometrium while 6 patients (10.9%) had cervical involvement. The surgery done was Type I hysterectomy in 49 patients (89.1%), Type II in 5 patients (9.1%), and Type III in 1 patient (1.8%). Pelvic lymph node dissection was done in all patients while para-aortic (infrahilar) dissection was done in 48 patients (87.3%). The pathological stages were Stage IA in 19 patients, Stage IB in 15 patients, Stage II in 4 patients, Stage IIIA in 3 patients, Stage IIIB in 2 patients, Stage IIIC1 in 5 patients, Stage IIIC2 in 4 patients, and Stage IV in 3 patients. Grade 1 tumors were seen in 23 patients, Grade 2 in 13 patients, and Grade 3 in 19 patients. The histology was endometrioid in 44 patients, serous in 6 patients, clear cell in 3 patients, and others in 2 patients. Adjuvant treatment was received by 40 patients. With a median follow-up of 2.5 years, the 3-year DFS and OS were 78% and 82%, respectively. Age >59 years, Stage III or greater, and Grade 3 tumors were independent prognostic factors adversely affecting both DFS and OS.

CONCLUSION

The outcomes in our study are comparable to that seen in Western literature. Elderly status, higher stage, and a poorly differentiated tumor are associated with poor outcomes.

Novel hydrophilic drug polymer nano-conjugates of Cisplatin showing long blood retention profile: its release kinetics, cellular uptake and bio-distribution

The present study evaluates the efficacy of drug polymer self folding nano-conjugates of pectin-cisplatin to enhance blood circulating levels of cisplatin. The binding of nano-conjugate was confirmed by a peak-shift in UV-spectra. Physical characterization was done by DLS and TEM. Pharmacokinetics and bio-distribution of the nano-conjugates were performed at various time points in normal, Balb-c mice. Zeta Potential showed the shielding effect on the negative potential of pectin that was approximately 7 times more than the pectin chains when conjugated with cisplatin. TEM confirmed the formation of a hydrophilic, easily re-dispersible nano-conjugate in the size range of 100 nm. Release kinetics in plasma showed that the pectin-cisplatin conjugate is a stable, slow and sustained system with no burst effect. Immuno-fluorescence analysis of J-774, a mouse macrophage cell line, was assessed after incubating the cells with pectin chains tagged with FITC as well as Pectin-Cisplatin-FITC conjugates. With the cellular uptake of these particles in J-774, 40% of the cells showed an uptake post 30 min of incubation. However, Pectin chains were clearly eliminated. The plasma proteins facilitate the release of cisplatin with 85-89% of the drug being released in 17 days, and only 57% of drug was released in approximately 30 days without plasma. The reduced negative charge on the conjugate helps in adhesion to the cell surface and subsequent uptake by cells as evidenced by cell uptake studies on J-774 cell line. Nano-conjugates showed long blood retention profile in mice and the cisplatin was found in circulation even after 24 hrs. Pharmacokinetic study clearly indicates that it can form a novel anticancer drug that possesses good efficacy and has a safer profile than cisplatin.

Effect of molecular weight heterogeneity on drug encapsulation efficiency of gelatin nano-particles

Influence of molecular weight heterogeneity and drug solubility, drug loading and hydrodynamic conditions on drug release kinetics from gelatin nanoparticles were investigated. Also to assess the ability of gelatin nanoparticles as a potential intravascular probe for diagnostic purposes and in improving the biodelivery of cycloheximide (CHX), which is being used as a representative drug. Comparative characterization of 75 Bloom (type B, bovine), 175 and 300 Bloom (type A, porcine) gelatin nanoparticles was done to understand the phase behavior and hydrodynamic properties of gelatin chains and its nanoparticles. Gelatin nanoparticles were prepared by two-step desolvation method. Dynamic light scattering studies were performed to estimate hydrodynamic radii as well as intermolecular interaction. Effects of parameters like pH, temperature and molecular weight on the size and stability of the nanoparticles were studied. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) measurements were done for size and stability analysis. Enhanced visco-elastic properties of nanoparticles were observed as compared to normal solutions of gelatin.

Release kinetics from bio-polymeric nanoparticles encapsulating protein synthesis inhibitor- cycloheximide, for possible therapeutic applications

Cycloheximide, a protein synthesis inhibitor, was encapsulated in cross-linked gelatin nanoparticles (Type B, Bovine skin, 75 Bloom) of 168 nm diameter with 26% entrapment efficiency. In-vitro release kinetics of the drug from the nanoparticles was done in phosphate buffer saline (PBS) at pH 7.4 and pH 5.8. The release kinetics showed a bi-phasic curve. Interestingly, the release of drug is approx 90% in acidic pH as compared to 50% release in neutral pH. The particle size was determined by Dynamic Light Scattering (DLS) technique, and size distribution spectra at different pH were observed to vary inversely with increase in pH. These drug loaded nanoparticles were found to be stable in whole blood showing negligible haemolysis. Cytotoxicity in HBL-100 and MCF-7, breast cancer cell lines was done in a 24-72 hrs assay, showing increased anti-tumour activity over a period of time indicating slow release. Dose dependent cytotoxicity was observed after 24 hours upto 72 hours of incubation of nanoparticles while the drug per se (<4 microg) showed 93% toxicity within 24 hours. Phase contrast microscopy of nanoparticle-cell interaction, clearly indicated aggregation along the lipid cell-membrane. Electron Microscopy (TEM, SEM) studies revealed its size and spherical shape. The stability of the particle, the slow and controlled release of drug from the gelatin nanoparticles indicate that it is a good candidate to deliver bio-pharmaceuticals. These behave as "intelligent" carriers for drug delivery, and can be exploited to empty their drug load in acidic medium. The paper focuses on the release kinetics of the gelatin nanoparticles that can be successfully exploited to treat solid tumors.