Engineered nanomicelles inhibit the tumour progression via abrogating the prostaglandin-mediated immunosuppression

Cancer treatment is challenged due to immunosuppressive inflammatory tumour microenvironment (TME) caused by infiltration of tumour-promoting and inhibition of tumour-inhibiting immune cells. Here, we report the engineering of chimeric nanomicelles (NMs) targeting the cell proliferation using docetaxel (DTX) and inflammation using dexamethasone (DEX) that alters the immunosuppressive TME. We show that a combination of phospholipid-DTX conjugate and PEGylated-lipid-DEX conjugate can self-assemble to form sub-100 nm chimeric NMs (DTX-DEX NMs). Anti-cancer activities against syngeneic and xenograft mouse models showed that the DTX-DEX NMs are more effective in tumour regression, enhance the survival of mice over other treatment modes, and alter the tumour stroma. DTX-DEX NMs cause a significant reduction in myeloid-derived suppressor cells, alter the polarization of macrophages, and enhance the accumulation of cytotoxic CD4+ and CD8+ T cells in tumour tissues, along with alterations in cytokine expression. We further demonstrated that these DTX-DEX NMs inhibit the synthesis of prostaglandins, especially PGE2, by targeting the cyclooxygenase 2 that is partly responsible for immunosuppressive TME. Therefore, this study presents, for the first time, the engineering of lithocholic acid-derived chimeric NMs that affect the prostaglandin pathway, alter the TME, and mitigate tumour progression with enhanced mice survival.

A localized hydrogel-mediated chemotherapy causes immunogenic cell death via activation of ceramide-mediated unfolded protein response

Treatment of triple-negative breast cancer (TNBC) is challenging because of its "COLD" tumor immunosuppressive microenvironment (TIME). Here, we present a hydrogel-mediated localized delivery of a combination of docetaxel (DTX) and carboplatin (CPT) (called DTX-CPT-Gel therapy) that ensured enhanced anticancer effect and tumor regression on multiple murine syngeneic and xenograft tumor models. DTX-CPT-Gel therapy modulated the TIME by an increase of antitumorigenic M1 macrophages, attenuation of myeloid-derived suppressor cells, and increase of granzyme B+CD8+ T cells. DTX-CPT-Gel therapy elevated ceramide levels in tumor tissues that activated the protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK)-mediated unfolded protein response (UPR). This UPR-mediated activation of apoptotic cell death led to release of damage-associated molecular patterns, thereby activating the immunogenic cell death that could even clear the metastatic tumors. This study provides a promising hydrogel-mediated platform for DTX-CPT therapy that induces tumor regression and effective immune modulation and, therefore, can be explored further for treatment of TNBC.

Prediction of transcript structure and concentration using RNA-Seq data

Alternative splicing (AS) is a key post-transcriptional modification that helps in increasing protein diversity. Almost 90% of the protein-coding genes in humans are known to undergo AS and code for different transcripts. Some transcripts are associated with diseases such as breast cancer, lung cancer and glioblastoma. Hence, these transcripts can serve as novel therapeutic and prognostic targets for drug discovery. Herein, we have developed a pipeline, Finding Alternative Splicing Events (FASE), as the R package that includes modules to determine the structure and concentration of transcripts using differential AS. To predict the correct structure of expressed transcripts in given conditions, FASE combines the AS events with the information of exons, introns and junctions using graph theory. The estimated concentration of predicted transcripts is reported as the relative expression in terms of log2CPM. Using FASE, we were able to identify several unique transcripts of EMILIN1 and SLK genes in the TCGA-BRCA data, which were validated using RT-PCR. The experimental study demonstrated consistent results, which signify the high accuracy and precision of the developed methods. In conclusion, the developed pipeline, FASE, can efficiently predict novel transcripts that are missed in general transcript-level differential expression analysis. It can be applied selectively from a single gene to simple or complex genome even in multiple experimental conditions for the identification of differential AS-based biomarkers, prognostic targets and novel therapeutics.

Progesterone limits the tumor-promoting effects of the beta-subunit of human chorionic gonadotropin via non-nuclear receptors

The post-menopausal state in women is associated with increased cancer incidence, the reasons for which remain obscure. Curiously, increased circulating levels of beta-hCG (human chorionic gonadotropin) (a hormonal subunit linked with tumors of several lineages) are also often observed post-menopause. This study describes a previously unidentified interplay between beta-hCG and progesterone in tumorigenesis. Progesterone mediated apoptosis in beta-hCG responsive tumor cells via non-nuclear receptors. The transgenic expression of beta-hCG, particularly in the absence of the ovaries (a mimic of the post-menopausal state) constituted a potent pro-tumorigenic signal. Significantly, the administration of progesterone had significant anti-tumor effects. RNA-seq profiling identified molecular signatures associated with these processes. TCGA analysis revealed correlates between the expression of several newly identified genes and poor prognosis in post-menopausal patients of lung adenocarcinoma, colon adenocarcinoma, and glioblastoma. Specifically in these women, the detection of intra-tumoral/extra-tumoral beta-hCG may serve as a useful prognostic indicator, and treatment with progesterone on its detection may prove beneficial.

Computational Insights of Unfolding of N-Terminal Domain of TDP-43 Reveal the Conformational Heterogeneity in the Unfolding Pathway

TDP-43 proteinopathies is a disease hallmark that characterizes amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). The N-terminal domain of TDP-43 (NTD) is important to both TDP-43 physiology and TDP-43 proteinopathy. However, its folding and dimerization process is still poorly characterized. In the present study, we have investigated the folding/unfolding of NTD employing all-atom molecular dynamics (MD) simulations in 8 M dimethylsulfoxide (DMSO) at high temperatures. The MD results showed that the unfolding of the NTD at high temperature evolves through the formation of a number of conformational states differing in their stability and free energy. The presence of structurally heterogeneous population of intermediate ensembles was further characterized by the different extents of solvent exposure of Trp80 during unfolding. We suggest that these non-natives unfolded intermediate ensembles may facilitate NTD oligomerization and subsequently TDP-43 oligomerization, which might lead to the formation of irreversible pathological aggregates, characteristics of disease pathogenesis.

Microscopic and Transcriptomic Analyses of Dalbergoid Legume Peanut Reveal a Divergent Evolution Leading to Nod-Factor-Dependent Epidermal Crack-Entry and Terminal Bacteroid Differentiation

Root nodule symbiosis (RNS) is the pillar behind sustainable agriculture and plays a pivotal role in the environmental nitrogen cycle. Most of the genetic, molecular, and cell-biological knowledge on RNS comes from model legumes that exhibit a root-hair mode of bacterial infection, in contrast to the Dalbergoid legumes exhibiting crack-entry of rhizobia. As a step toward understanding this important group of legumes, we have combined microscopic analysis and temporal transcriptome to obtain a dynamic view of plant gene expression during Arachis hypogaea (peanut) nodule development. We generated comprehensive transcriptome data by mapping the reads to A. hypogaea, and two diploid progenitor genomes. Additionally, we performed BLAST searches to identify nodule-induced yet-to-be annotated peanut genes. Comparison between peanut, Medicago truncatula, Lotus japonicus, and Glycine max showed upregulation of 61 peanut orthologs among 111 tested known RNS-related genes, indicating conservation in mechanisms of nodule development among members of the Papilionoid family. Unlike model legumes, recruitment of class 1 phytoglobin-derived symbiotic hemoglobin (SymH) in peanut indicates diversification of oxygen-scavenging mechanisms in the Papilionoid family. Finally, the absence of cysteine-rich motif-1-containing nodule-specific cysteine-rich peptide (NCR) genes but the recruitment of defensin-like NCRs suggest a diverse molecular mechanism of terminal bacteroid differentiation. In summary, our work describes genetic conservation and diversification in legume-rhizobia symbiosis in the Papilionoid family, as well as among members of the Dalbergoid legumes.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Identification of genome-wide alternative splicing events in sequential, isogenic clinical isolates of Candida albicans reveals a mechanism important for drug resistance and tolerance to cellular stress

Alternative gene splicing (AS) is a process by which a single gene can give rise to different protein isoforms, generating proteome diversity. Despite recent advances in our understanding of AS in basic cellular processes, the role of AS in drug resistance and fungal pathogenesis is poorly understood. In Candida albicans, approximately 6% of the genes contain introns. Considering this low and random distribution of introns, we focused our study on alternative splicing (AS) and its impact on the development of drug resistance, an area largely unexplored in this yeast. We performed comparative RNA sequencing of sequential isogenic azole sensitive and resistant isolates of C. albicans. The analysis revealed differential expression of splice junctions/isoforms in 14 genes, between the drug sensitive and resistant isolates. Furthermore, C. albicans WT cells exposed to antifungal drugs, heat stress or metal deficiency also showed differential expression of isoforms for the genes undergoing AS. In this study we present data on the effect of AS on the function of SOD3. The C. albicans SOD3 has a single intron and is important for the removal of superoxide radicals. The overexpression of the two isoforms of SOD3 in its null background highlighted importance of spliced isoform in complementing the susceptibility to menadione. However, the two isoforms did not differ in rescuing the susceptibility of sod3Δ/Δto Amphotericin B. Collectively, these data suggest that AS may be a novel mechanism in C. albicans for stress adaptation and overcoming drug resistance.

Intron distribution and emerging role of alternative splicing in fungi

Spliceosomal introns are noncoding sequences that are spliced from pre-mRNA. They are ubiquitous in eukaryotic genomes, although the average number of introns per gene varies considerably between different eukaryotic species. Fungi are diverse in terms of intron numbers ranging from 4% to 99% genes with introns. Alternative splicing is one of the most common modes of posttranscriptional regulation in eukaryotes, giving rise to multiple transcripts from a single pre-mRNA and is widespread in metazoans and drives extensive proteome diversity. Earlier, alternative splicing was considered to be rare in fungi, but recently, increasing numbers of studies have revealed that alternative splicing is also widespread in fungi and has been implicated in the regulation of fungal growth and development, protein localization and the improvement of survivability, likely underlying their unique capacity to adapt to changing environmental conditions. However, the role of alternative splicing in pathogenicity and development of drug resistance is only recently gaining attention. In this review, we describe the intronic landscape in fungi. We also present in detail the newly discovered functions of alternative splicing in various cellular processes and outline areas particularly in pathogenesis and clinical drug resistance for future studies that could lead to the development of much needed new therapeutics.

Identifying the natural polyphenol catechin as a multi-targeted agent against SARS-CoV-2 for the plausible therapy of COVID-19: an integrated computational approach

The global pandemic crisis, coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has claimed the lives of millions of people across the world. Development and testing of anti-SARS-CoV-2 drugs or vaccines have not turned to be realistic within the timeframe needed to combat this pandemic. Here, we report a comprehensive computational approach to identify the multi-targeted drug molecules against the SARS-CoV-2 proteins, whichare crucially involved in the viral-host interaction, replication of the virus inside the host, disease progression and transmission of coronavirus infection. Virtual screening of 75 FDA-approved potential antiviral drugs against the target proteins, spike (S) glycoprotein, human angiotensin-converting enzyme 2 (hACE2), 3-chymotrypsin-like cysteine protease (3CLpro), cathepsin L (CTSL), nucleocapsid protein, RNA-dependent RNA polymerase (RdRp) and non-structural protein 6 (NSP6), resulted in the selection of seven drugs which preferentially bind to the target proteins. Further, the molecular interactions determined by molecular dynamics simulation revealed that among the 75 drug molecules, catechin can effectively bind to 3CLpro, CTSL, RBD of S protein, NSP6 and nucleocapsid protein. It is more conveniently involved in key molecular interactions, showing binding free energy (ΔGbind) in the range of -5.09 kcal/mol (CTSL) to -26.09 kcal/mol (NSP6). At the binding pocket, catechin is majorly stabilized by the hydrophobic interactions, displays ΔEvdW values: -7.59 to -37.39 kcal/mol. Thus, the structural insights of better binding affinity and favorable molecular interaction of catechin toward multiple target proteins signify that catechin can be potentially explored as a multi-targeted agent against COVID-19.

Bile Acid Tethered Docetaxel-Based Nanomicelles Mitigate Tumor Progression through Epigenetic Changes

In this study, we describe the engineering of sub-100 nm nanomicelles (DTX-PC NMs) derived from phosphocholine derivative of docetaxel (DTX)-conjugated lithocholic acid (DTX-PC) and poly(ethylene glycol)-tethered lithocholic acid. Administration of DTX-PC NMs decelerate tumor progression and increase the mice survivability compared to Taxotere (DTX-TS), the FDA-approved formulation of DTX. Unlike DTX-TS, DTX-PC NMs do not cause any systemic toxicity and slow the decay rate of plasma DTX concentration in rodents and non-rodent species including non-human primates. We further demonstrate that DTX-PC NMs target demethylation of CpG islands of Sparcl1 (a tumor suppressor gene) by suppressing DNA methyltransferase activity and increase the expression of Sparcl1 that leads to tumor regression. Therefore, this unique system has the potential to improve the quality of life in cancer patients and can be translated as a next-generation chemotherapeutic.

"Identification of Nafamostat and VR23 as COVID-19 drug candidates by targeting 3CLpro and PLpro."

The sudden increase in the COVID-19 epidemic affected by novel coronavirus 2019 has jeopardized public health worldwide. Hence the necessities of a drug or therapeutic agent that heal SARS-CoV-2 infections are essential requirements. The viral genome encodes a large Polyprotein, further processed by the main protease/ 3C-like protease (3CL^pro) and papain-like proteases (PL^pro) into 16 nonstructural proteins to form a viral replication complex. These essential functions of 3CL^pro and PL^pro in virus duplication make these proteases a promising target for discovering potential therapeutic candidates and possible treatment for SARS-CoV-2 infection.

This study aimed to screen a unique set of protease inhibitors library against 3CL^pro and PL^pro of the SARS-CoV-2. A molecular docking study was performed using PyRx to reveal the binding affinity of the selected ligands and molecular dynamic simulations were executed to assess the three-dimensional stability of protein-ligand complexes. The pharmacodynamics parameters of the inhibitors were predicted using admetSAR. The top two ligands (Nafamostat and VR23) based on docking scores were selected for further studies. Selected ligands showed excellent pharmacokinetic properties with proper absorption, bioavailability and minimal toxicity. Due to the emerging and efficiency of remdesivir and dexamethasone in healing COVID-19 patients, ADMET properties of the selected ligands were thus compared with it. MD Simulation studies up to 100 ns revealed the ligands' stability at the target proteins' binding site residues. Therefore, Nafamostat and VR23 may provide potential treatment options against SARS-CoV-2 infections by potentially inhibiting virus duplication though more research is warranted.

VapBC22 toxin-antitoxin system from Mycobacterium tuberculosis is required for pathogenesis and modulation of host immune response

Virulence-associated protein B and C toxin-antitoxin (TA) systems are widespread in prokaryotes, but their precise role in physiology is poorly understood. We have functionally characterized the VapBC22 TA system from Mycobacterium tuberculosis. Transcriptome analysis revealed that overexpression of VapC22 toxin in M. tuberculosis results in reduced levels of metabolic enzymes and increased levels of ribosomal proteins. Proteomics studies showed reduced expression of virulence-associated proteins and increased levels of cognate antitoxin, VapB22 in the ΔvapC22 mutant strain. Furthermore, both the ΔvapC22 mutant and VapB22 overexpression strains of M. tuberculosis were susceptible to killing upon exposure to oxidative stress and showed attenuated growth in guinea pigs and mice. Host transcriptome analysis suggests upregulation of the transcripts involved in innate immune responses and tissue remodeling in mice infected with the ΔvapC22 mutant strain. Together, we demonstrate that the VapBC22 TA system belongs to a key regulatory network and is essential for M. tuberculosis pathogenesis.

Delineating the conformational dynamics of intermediate structures on the unfolding pathway of β-lactoglobulin in aqueous urea and dimethyl sulfoxide

The funnel shaped energy landscape model of the protein folding suggests that progression of folding proceeds through multiple pathways, having the multiple intermediates which leads to multidimensional free-energy surface. Herein, we applied all-atom MD simulation to conduct a comparative study on the structure of β-lactoglobulin (β-LgA) in aqueous mixture of 8 M urea and 8 M dimethyl sulfoxide (DMSO), at different temperatures. The cumulative results of multiple simulations suggest a common unfolding pathway of β-LgA, occurred through the stable and meta-stable intermediates (I), in both urea and DMSO. However, the free-energy landscape (FEL) analyses show that the structural transitions of I-states are energetically different. In urea, FEL shows distinct ensemble of intermediates, I1 and I2, separated by the energy barrier of ∼3.0 kcal mol^-1. Similarly, we find the population of two distinct I1 and I2 states in DMSO, however, the I1 appeared transiently around ∼30-35 ns and is short-lived. But, the I2 ensemble is observed structurally compact and long-lived (∼50-150 ns) as compared to unfolding in urea. Furthermore, the I1 and I2 are separated through a high energy barrier of ∼6.0 kcal mol^-1. Thus, our results provide the structural insights of intermediates which essentially bear the signature of a different unfolding pathway of β-LgA in urea and DMSO.Abbreviationsβ-LgAβ-lactoglobulinDMSOdimethyl sulfoxideFELfree-energy landscapeGdmClguanidinium chlorideIintermediate stateMGmolten globule statePMEparticle mesh EwaldQfraction of native contactsRMSDroot mean square deviationRMSFroot mean square fluctuationR_gradius of gyrationSASAsolvent Accessible Surface AreascSASAthe side chain SASATrptryptophanCommunicated by Ramaswamy H. Sarma.

Multiple transcription factors co-regulate the Mycobacterium tuberculosis adaptation response to vitamin C

Background

Latent tuberculosis infection is attributed in part to the existence of Mycobacterium tuberculosis in a persistent non-replicating dormant state that is associated with tolerance to host defence mechanisms and antibiotics. We have recently reported that vitamin C treatment of M. tuberculosis triggers the rapid development of bacterial dormancy. Temporal genome-wide transcriptome analysis has revealed that vitamin C-induced dormancy is associated with a large-scale modulation of gene expression in M. tuberculosis.

Results

An updated transcriptional regulatory network of M.tuberculosis (Mtb-TRN) consisting of 178 regulators and 3432 target genes was constructed. The temporal transcriptome data generated in response to vitamin C was overlaid on the Mtb-TRN (vitamin C Mtb-TRN) to derive insights into the transcriptional regulatory features in vitamin C-adapted bacteria. Statistical analysis using Fisher’s exact test predicted that 56 regulators play a central role in modulating genes which are involved in growth, respiration, metabolism and repair functions. Rv0348, DevR, MprA and RegX3 participate in a core temporal regulatory response during 0.25 h to 8 h of vitamin C treatment. Temporal network analysis further revealed Rv0348 to be the most prominent hub regulator with maximum interactions in the vitamin C Mtb-TRN. Experimental analysis revealed that Rv0348 and DevR proteins interact with each other, and this interaction results in an enhanced binding of DevR to its target promoter. These findings, together with the enhanced expression of devR and Rv0348 transcriptional regulators, indicate a second-level regulation of target genes through transcription factor- transcription factor interactions.

Conclusions

Temporal regulatory analysis of the vitamin C Mtb-TRN revealed that there is involvement of multiple regulators during bacterial adaptation to dormancy. Our findings suggest that Rv0348 is a prominent hub regulator in the vitamin C model and large-scale modulation of gene expression is achieved through interactions of Rv0348 with other transcriptional regulators.

A Localized Chimeric Hydrogel Therapy Combats Tumor Progression through Alteration of Sphingolipid Metabolism

Rapid proliferation of cancer cells assisted by endothelial cell-mediated angiogenesis and acquired inflammation at the tumor microenvironment (TME) lowers the success rate of chemotherapeutic regimens. Therefore, targeting these processes using localized delivery of a minimally toxic drug combination may be a promising strategy. Here, we present engineering of a biocompatible self-assembled lithocholic acid-dipeptide derived hydrogel (TRI-Gel) that can maintain sustained delivery of antiproliferating doxorubicin, antiangiogenic combretastatin-A4 and anti-inflammatory dexamethasone. Application of TRI-Gel therapy to a murine tumor model promotes enhanced apoptosis with a concurrent reduction in angiogenesis and inflammation, leading to effective abrogation of tumor proliferation and increased median survival with reduced drug resistance. In-depth RNA-sequencing analysis showed that TRI-Gel therapy induced transcriptome-wide alternative splicing of many genes responsible for oncogenic transformation including sphingolipid genes. We demonstrate that TRI-Gel therapy targets the reversal of a unique intron retention event in β-glucocerebrosidase 1 (Gba1), thereby increasing the availability of functional Gba1 protein. An enhanced Gba1 activity elevates ceramide levels responsible for apoptosis and decreases glucosylceramides to overcome drug resistance. Therefore, TRI-Gel therapy provides a unique system that affects the TME via post-transcriptional modulations of sphingolipid metabolic genes, thereby opening a new and rational approach to cancer therapy.

Understanding the molecular basis of stability in Kunitz (STI) family of inhibitors in terms of a conserved core tryptophan residue: A theoretical investigation

β-trefoil is one of the superfolds among proteins. Important classes of proteins like Interleukins (ILs), FibroblastGrowth Factors (FGFs), Kunitz (STI) family of inhibitors etc. belong to this fold. Kunitz (STI) family of inhibitors of proteins possess a highly conserved and structurally important Trytophan 91 (W91) residue, which stitches the top layer of the barrel with the lid. In this article we have investigated the molecular insights of the involvement of this W91 residue in the stability and folding pathway of Kunitz (STI) family. Winged bean Chymotrypsin inhibitor (WCI), a member of Kunitz (STI) family was chosen as a model system for carrying out the work. Molecular dynamics (MD) simulations were run with a set of total six proteins, including wild type WCI (WT) & five mutants namely W91F, W91M, W91A, W91H and W91I. Among all of them the coordinates of four proteins were taken from their crystal structures deposited in the Protein Data Bank (PDB), where as the coordinates for the rest two was generated using in-silico modelling. Our results suggest that truly this W91 residue plays a determining role in stability and folding pathway of Kunitz (STI) family. The mutants are less stable and more susceptible to quicker unfolding at higher temperatures compared to the wild type WCI. These effects are most pronounced for the smallest mutants namely W91H and W91A, indicating more is the cavity created by mutation at W91 position more the proteins becomes unstable.

A study of median nerve entrapment neuropathy at wrist in uremic patients

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy seen in uremic patients. The study was undertaken to estimate the frequency of CTS in uremic patients and to identify the most sensitive electrodiagnostic test. Study was conducted on 80 subjects of age 30–60 years. End-stage kidney disease patients were recruited for the clinical evaluation, motor nerve conduction studies (NCS), sensory NCS, F wave study and median-versus-ulnar comparison studies (palm-to-wrist mixed comparison study, digit 4 sensory latencies study and lumbrical-interossei comparison study). Among three different diagnostic modalities, frequency of CTS was found to be 17.5% with clinical evaluation, 15% with routine NCS studies and 25% with median-versus-ulnar comparison studies. Among the median-versus-ulnar comparison studies, lumbrical-interossei comparison study was found to be most sensitive (90%). The comparative tests for CTS are more sensitive compared to routine NCS and clinical examination. Among the comparative tests, lumbrical-interossei comparison study is the most sensitive. Early diagnosis of CTS may help patients of uremia to seek proper treatment at an appropriate time.

High temperature unfolding of a truncated hemoglobin by molecular dynamics simulation

Heme containing proteins are associated with peroxidase activity. The proteins like hemoglobin, myoglobins, cytochrome c and micro-peroxidase other than peroxidases have been shown to exhibit weak peroxidase-like activity. This weak peroxidase-like activity in hemoglobin-like molecules is due to heme moiety. We conducted molecular dynamics (MD) studies to decipher the unfolding path of Ba-Glb (a truncated hemoglobin from Bacillus anthracis) and the role of heme moiety to its unfolding path. The similar unfolding path is also observed in vitro by UV/VIS spectroscopy. The data confirmed that the unfolding of Ba-Glb follows a three state process with a meta-stable (intermediate) state between the native and unfolded conformations. The present study is supported by several unfolding parameters like root-mean-square-deviation (RMSD), dictionary of protein secondary structure (DSSP), and free energy landscape. Understanding the structure of hemoglobin like proteins in unicellular dreaded pathogens like B. anthracis will pave way for newer drug discovery targets and in the disease management of anthrax.

Possible implication of oxidative stress in anti filarial effect of certain traditionally used medicinal plants in vitro against Brugia malayi microfilariae

Introduction:

Tropical disease research scheme of World Health Organization has duly recognized traditional medicine as alternative for antifilarial drug development. Polyphenolic compounds present in traditionally used herbal medicines are natural antioxidants; however, paradoxically they may exert pro-oxidant effect. Popular drug diethyl carbamazine citrate harnesses the innate inflammatory response and the consequent oxidative assault to combat invading microbes.

Methods:

With this perspective, extracts of Vitex negundo L. (roots), Butea monosperma L. (leaves), Aegle marmelos Corr. (leaves), and Ricinus communis L. (leaves) were selected to explore the possible role of oxidative rationale in the antifilarial effect in vitro.

Results:

Apart from the last, other three plant extracts were reported to have polyphenolic compounds. Dose-dependent increase was found in the levels of lipid peroxidation and protein carbonylation for all the three plant extracts except Ricinus communis L. (leaves). Such increase in oxidative parameters also showed some degree of plant-specific predilection in terms of relatively higher level of particular oxidative parameter. High degree of correlation was observed between the antifilarial effect and the levels of corresponding oxidative stress parameters for these three plants. However, extracts of Ricinus communis L. (leaves) which is relatively deficient in polyphenolic ingredients recorded maximum 30% loss of motility and also did not show any significant difference in various stress parameters from corresponding control levels.

Conclusion:

These results reveal that targeted oxidative stress might be crucial in the pharmacodynamics.

A modeled structure for amidase-03 from Bacillus anthracis

Homology models of amidase-03 from Bacillus anthracis were constructed using Modeller (9v2). Modeller constructs protein models using an automated approach for comparative protein structure modeling by the satisfaction of spatial restraints. A template structure of Listeria monocytogenes bacteriophage PSA endolysin PlyPSA (PDB ID: 1XOV) was selected from protein databank (PDB) using BLASTp with BLOSUM62 sequence alignment scoring matrix. We generated five models using the Modeller default routine in which initial coordinates are randomized and evaluated by pseudo-energy parameters. The protein models were validated using PROCHECK and energy minimized using the steepest descent method in GROMACS 3.2 (flexible SPC water model in cubic box of size 1 Å instead of rigid SPC model). We used G43a1 force field in GROMACS for energy calculations and the generated structure was subsequently analyzed using the VMD software for stereo-chemistry, atomic clash and misfolding. A detailed analysis of the amidase-03 model structure from Bacillus anthracis will provide insight to the molecular design of suitable inhibitors as drug candidates.

High temperature unfolding of Bacillus anthracis amidase-03 by molecular dynamics simulations

The stability of amidase-03 structure (a cell wall hydrolase protein) from Bacillus anthracis was studied using classical molecular dynamics (MD) simulation. This protein (GenBank accession number: NP_844822) contains an amidase-03 domain which is known to exhibit the catalytic activity of N-acetylmuramoyl-L-alanine amidase (digesting MurNAc-Lalanine linkage of bacterial cell wall). The amidase-03 enzyme has stability at high temperature due to the core formed by the combination of several secondary structure elements made of beta-sheets. We used root-mean-square-displacement (RMSD) of the simulated structure from its initial state to demonstrate the unfolding of the enzyme using its secondary structural elements. Results show that amidase-03 unfolds in transition state ensemble (TSE). The data suggests that alpha-helices unfold before beta-sheets from the core during simulation.

Metastatic sweat gland adenocarcinoma: A clinico-pathological dilemma

BACKGROUND: Sweat gland adenocarcinoma is a rare malignancy with high metastatic potential seen more commonly in later years of life. Scalp is the most common site of occurrence and it usually spreads to lymph nodes. Liver, lung and bones are the distant sites of metastasis with fatal results. The differentiation between apocrine and eccrine metastatic sweat gland carcinoma is often difficult. The criteria's are inadequate to be of any practical utility. CASE REPORT: Two cases of metastatic sweat gland adenocarcinoma (one of eccrine and the other one of apocrine origin) are being reported on account of the rarity and different outcome. CONCLUSION: Sweat gland carcinomas are rare cancers with a poor prognosis often presenting as histological surprises. Surgery in the form of wide local excision and lymph node dissection is the mainstay of treatment. Chemotherapy and/or radiotherapy has limited role.

Impact of field vaccination with a Theileria annulata schizont cell culture vaccine on the epidemiology of tropical theileriosis

Tropical theileriosis, caused by Theileria annulata, is an important tick-borne disease of cattle. A cell culture attenuated vaccine has been developed in our laboratory by long-term in vitro propagation of the schizont stage of the parasite. A longitudinal study was conducted at selected farms housing indigenous, cross-bred and exotic animals to investigate the effect of vaccination on the epidemiology of the disease. A total of 120 animals in 4 age groups were vaccinated with the vaccine before the onset of disease season. An equal number of age-matched animals were kept as controls at the same sites. Animals were monitored for 14 months at monthly intervals. The 97.5% vaccinated animals showed a rise in antibody titres 1 month post-vaccination, as determined by single dilution ELISA. The 78.3% of non-vaccinated animals became sero-positive over the period of observation. Mean antibody titres were significantly higher in vaccinated than non-vaccinated animals. Cross-bred animals showed higher antibody titres followed by exotic and indigenous animals in both the vaccinated and non-vaccinated groups. However, the antibody titres in animals of different ages were similar. The 36.7% vaccinated and 64.2% non-vaccinated animals became carriers (<0.5% piroplasms in erythrocytes) during the observation period. Clinical cases of theileriosis were recorded only in the non-vaccinated group suggesting that vaccinated animals were sufficiently immune to withstand field tick challenge for at least 14 months.

Effect of vaccination in the field with the Theileria annulata (Hisar) cell culture vaccine on young calves born during the winter season

The responses were monitored of young crossbred calves vaccinated against tropical theileriosis during the winter against a field tick challenge in the disease season. Thirty-eight calves below 2 months of age, born after the end of the disease season, were selected at an organized farm. Twenty-five animals were vaccinated with Theileria annulata (Hisar) cell culture vaccine (developed at CCS HAU Hisar laboratory) after the end of the disease season and 13 calves were kept as non-vaccinated controls. These calves were observed for their susceptibility to theileriosis in the new disease season. There was an increase in antibody titre in 18 of the 25 vaccinated animals one month after vaccination. The antibody titre then declined gradually, but remained higher than those of the non-vaccinated animals at month 0. No fever or other clinical signs of tropical theileriosis were observed in any of the vaccinated animals. Nine out of 25 (36%) vaccinated calves showed occasional piroplasms (<0.5%) in blood smears. All the vaccinated animals withstood the field tick challenge. On the other hand, 9 of the 13 (69%) unvaccinated calves exhibited occasional piroplasms, and included three clinical cases of tropical theileriosis. These observations suggest that young crossbred calves vaccinated with the T. annulata (Hisar) cell culture vaccine at the end of the disease season were relatively resistant during the next disease season.

Single dilution ELISAs using soluble piroplasm, cellular schizont and soluble schizont antigens for the detection of antibodies against Theileria annulata

Single dilution ELISAs were standardised for the determination of antibody titres against Theileria annulata using three antigens namely soluble piroplasm, cellular schizont or soluble schizont antigens. Antibody titres of 20 cattle serum samples of known identity were determined by multi-dilution ELISA using the three antigens. The ratio of the optical density (OD) of known positive and known negative sera at different serum dilutions were calculated and termed as positive/negative (P/N) ratios. Coefficients of correlation (r) were calculated between the P/N ratios at different dilutions of known sera and their log10 antibody titres by multi-dilution ELISA. The value of "r" was the highest at the dilution of 1:400. From the log10 antibody titres of known sera and their P/N ratios at the dilution of 1:400, regression equations (Y = a + bX, where Y = predicted log10 titre, X = the P/N ratio at 1:400 dilution) were calculated separately for the three antigens. Thus, the equations Y = 1.63 + 1.35X for soluble piroplasm, Y = 2.67 + 0.547X for cellular schizont and Y = 1.817 + 0.663X for soluble schizont antigens were derived. Test sera were diluted to 1:400 and their OD were read in duplicate wells and converted to P/N ratios. The antibody titres were predicted from the P/N ratios using the above mentioned regression equations. Twenty randomly selected sera tested by single and multidilution ELISAs showed non-significant differences (P < 0.01) between antibody titres. Antibody titres of 90 unknown field sera of cattle were determined by single dilution ELISA. The piroplasm antigen detected higher antibody titres followed by cellular schizont and soluble schizont antigens. The study revealed that a single dilution ELISA could be successfully used for field epidemiological studies of tropical theileriosis.

Determination of duration of immunity of calves vaccinated with the Theileria annulata schizont cell culture vaccine

Bovine tropical theileriosis caused by Theileria annulata is a serious haemoprotozoan disease of cattle affecting exotic cattle, their crossbreeds and young indigenous calves. Cell culture vaccines have been developed and used effectively in various countries for the control of this disease. However, the duration of immunity provided by these vaccines is poorly understood. The present experiments were planned to study the duration of immunity in animals after vaccination with the T. annulata (Hisar) schizont cell culture vaccine. Two groups of calves were vaccinated and challenged after a period of 3 and 6 months, respectively. There was no fever in any of the vaccinated calves after challenge. However, the vaccinated animals exhibited mild to moderate enlargement of lymph nodes and parasitological reactions. The parasitological reactions were very mild in calves challenged after 3 months and moderate in calves challenged after 6 months. There was a mild but significant decrease in the haematological values of calves after challenge. A significant rise in the anti-theilerial antibody titres was observed in all calves after vaccination, which increased further, by many folds after challenge. On the other hand, all the challenge control calves showed symptoms of acute theileriosis and died. The observations suggested that the T. annulata (Hisar) schizont cell culture vaccine provided immunity in vaccinated animals for at least 6 months in the absence of field tick challenge. However, there was some decline in immunity after 6 months, if the animals are not exposed to ticks during this period.

Comparison of cellular schizont, soluble schizont and soluble piroplasm antigens in ELISA for detecting antibodies against Theileria annulata

The efficacy and suitability of cellular schizont, soluble schizont and soluble piroplasm antigens was compared for detecting antibodies against Theileria annulata. Fifty bovine sera of known identity were evaluated in ELISA using the above mentioned antigens. Antibody titres of 1:100 to 1:51,200 were detected while using soluble piroplasm and cellular schizont antigen in ELISA. The titres ranged between 1:100 to 1:25,600 with the soluble schizont antigen. Soluble piroplasm antigen exhibited the highest antibody titres followed by cellular schizont and soluble schizont antigens. Cellular schizont antigen proved to be better than soluble schizont antigen for detecting anti-schizontal antibodies. Antibody titres obtained by the three antigens exhibited a good linear correlation amongst each other. The study showed that soluble piroplasm and cellular schizont antigens can be used successfully for detecting antibodies against piroplasm and schizont stages of T. annulata, respectively in bovine sera.

Susceptibility to tropical theileriosis of calves born to dams immunized with Theileria annulata (Hisar) cell culture vaccine

The susceptibility/immune status to tropical theileriosis of calves born of immunized dams was evaluated. Six cows were vaccinated with the Theileria annulata cell culture vaccine in the eighth month of pregnancy. Sera from the immunized dams exhibited very high post-vaccination antibody titres as determined by the indirect fluorescent antibody (IFA) test. The calves born to these dams did not show antibodies against T. annulata at the time of birth (IFA titres of < 1:20). The new-born calves were fed colostrum from their mothers and were challenged with T. annulata-infected ground tick supernate at 5-7 days of age. All the calves developed fever (from day 5-6 onwards) and parasitological reactions (from day 8-9 onwards) after challenge. There was a significant decrease in the haemoglobin and packed cell volume of the calves after challenge. All the calves showed signs of acute theileriosis by day 9-10 after challenge and had to be treated with buparvaquone in order to save their lives. The study indicated that detectable levels of anti-theilerial antibodies were not transferred from immune dams to their offspring. All the calves born to immunized dams were fully susceptible to theileriosis and thus themselves needed vaccination.

Successful long-term in vitro cultivation of Theileria annulata schizonts in media supplemented with homologous and heterologous sera

The efficacy of medium RPMI-1640 supplemented with either foetal bovine, normal bovine, goat or sheep sera was compared for prolonged in vitro propagation of Theileria annulata (Hisar) schizonts. Medium RPMI-1640 supplemented with 20% foetal bovine serum (standard growth medium) resulted in optimum growth of T. annulata (Hisar) schizonts in vitro. Comparable viability and non-viability counts were observed in growth media supplemented with normal bovine or goat sera. However, viability counts in medium supplemented with sheep serum were significantly lower than that of the standard medium. Mitotic indices of cultures of T. annulata (Hisar) schizonts were directly related to the extent of cell growth and were lower in various growth media supplemented with normal bovine, goat or sheep sera than in that of the standard medium. The results suggested that normal bovine and goat sera could be successfully used in place of foetal bovine serum in the growth medium for long-term in vitro propagation of T. annulata schizonts. The study will help in reducing the cost of large-scale in vitro propagation of T. annulata aimed at mass production of the cell culture vaccine.

Monoclonal antibodies against conformationally dependent epitopes on porcine reproductive and respiratory syndrome virus

Monoclonal antibodies (MAbs) against porcine reproductive and respiratory syndrome virus (PRRSV) were prepared and characterized. Four MAbs were developed from the mice immunized with the recombinant GP4 protein expressed in insect cells, and six MAbs were derived from the immunization with recombinant GP5 protein. All of the MAbs showed strong perinuclear fluorescence in PRRSV VR2385 infected cells by immunofluorescence staining. Among the MAbs to GP5 protein, one showed strong reactivity in ELISA and recognized a 26 kDa band of PRRSV in a western blot assay, while another showed neutralizing activity against the VR2385 isolate. Out of the four MAbs to GP4 protein, one showed mild reactivity in ELISA with detergent extracted antigen, but had no reactivity in a western-blot assay. The failure of MAb binding to detergent extracted antigen in ELISA or in western-blot analysis indicated that the MAbs were against conformationally dependent epitopes. Reactivity patterns of the MAbs with PRRSV field isolates tested by fixed-cell ELISA showed that there are antigenic variations in PRRSV GP4 and GP5 proteins. Development of these MAbs will benefit further studies on PRRSV structural proteins as well as in understanding their roles in PRRSV pathogenesis.

Responses in animals vaccinated with the Theileria annulata (Hisar) cell culture vaccine

Bovine tropical theileriosis caused by Theileria annulata is an economically important disease of cattle in India. The disease has assumed paramount importance with the intensification of cross-breeding programmes aimed at enhancing milk production in the country. To control this disease, a cell culture vaccine was developed in this department by continuous passaging of T. annulata (Hisar) schizonts in vitro. Current work in this department has concentrated on the epidemiology of theileriosis: development of the cell culture vaccine for very young calves and pregnant cows; evaluation of serological responses using immunofluorescent antibody (IFA) tests and Enzyme-linked immunosorbent antibody assays (ELISA); studies on the duration of immunity stimulated by the cell culture vaccine; the immune/susceptible status of calves born to vaccinated dams. Results have shown the following. Clinical cases of theileriosis were mainly observed in young calves below two months of age followed by adults in exotic and cross-bred animals. Amongst indigenous animals, only young calves below two months of age suffered from clinical disease. Clinical cases of theileriosis mainly occurred between the months of April to October. The T. annulata schizont cell culture vaccine developed in the department was extensively used in the susceptible calves and pregnant/lactating cows in the field. Sufficiently high antibody titres were detected by both schizont as well as piroplasm antigen using both ELISA and IFAT. The results indicated that the vaccine was safe, potent and effective for all breeds and age groups of cattle under field conditions. ELISA was standardised for T. annulata using three antigens, viz.: soluble piroplasm, soluble schizont and cellular schizont antigens. Comparison of results with IFAT showed that ELISA is more sensitive, objective, reliable and specific as well as less cumbersome than IFAT. Piroplasm, cellular schizont and soluble schizont antigens were found to be suitable for the detection of antitheilerial antibodies as per their order in ELISA. Studies on the duration of immunity stimulated by the T. annulata schizont cell culture vaccine indicated that immunity started waning after six months. Calves born of dams immunised against T. annulata with the cell culture vaccine were found to be fully susceptible to theileriosis soon after birth. This indicated that there was no passive transfer of immunity from dams to their offspring through colostrum.

In vitro propagation of Theileria annulata infected schizonts in different media supplemented with heterologous sera

Efficacy of medium RPMI-1640 (supplied by Gibco USA, Centron and Hi-media) supplemented with horse, donkey, sheep and goat sera was evaluated for in vitro propagation of Theileria annulata (Hisar) infected bovine mononuclear cells. The results were compared with the growth rate in RPMI-1640 supplemented with foetal bovine serum (Gibco). RPMI-1640 (Gibco) proved to be the best medium for in vitro cultivation of the parasite infected cells. Foetal bovine serum could be easily, safely and reliably substituted with goat and sheep sera in the growth medium. Horse and donkey sera also gave comparable growth of T. annulata infected cells in vitro. Successful use of heterologous sera greatly helped in reducing the cost of in vitro cultivation of T. annulata schizonts. These findings have important implications on mass production of an attenuated cell culture vaccine for the control of bovine tropical theileriosis.

An immunisation trial with in vitro produced Babesia bigemina exoantigens

Bovine babesiosis, caused by Babesia bigemina, is an important tick-transmitted haemoprotozoan disease in the tropics. This study evaluated the immunoprotective efficacy of in vitro produced B. bigemina exoantigens in bovine calves. The calves inoculated with B. bigemina exoantigens did not show any clinical, parasitological or hypersensitivity reactions after inoculation. They withstood challenge without showing any clinical symptoms except a transient thermal reaction. In contrast, two out of four control calves exhibited clinical symptoms of babesiosis and one died. On challenge, there was a significant reduction in the haematological values of both groups. However, this was more pronounced in the control animals. Challenge resulted into a normocytic hypochromic anaemia. The vaccinated animals revealed a significant rise in antibody titres after vaccination as well as after challenge as detected by a single dilution ELISA. The rise in antibody titres of control animals was only moderate. Inoculation of B. bigemina exoantigens induced a protective immune response in the vaccinated animals which could protect them from infected blood challenge.

Efficacy and safety of unguided percutaneous fine needle aspiration cytology in peripheral lung lesions

The efficacy and safety of unguided percutaneous fine needle aspiration cytology in peripheral lung lesions were studied in 42 patients. The diagnostic yield of unguided aspiration was 83.3%. The yield in malignant lesion was 85.7% while in benign lesion it was 78.6%. There was no false positive report. Complications seen were asymptomatic pneumothorax and blood tinged sputum in a few cases following aspiration. The procedure was well accepted by the patients. Unguided FNAC is a simple, quick, economical, safe and reliable procedure for the diagnosis of peripheral lung lesions.

Endometrial glycogen, protein, nucleic acids and phosphatases during oestrous cycle in buffaloes (Bubalus bubalis)

Distinct cyclic variations were observed in the concentrations of endometrial glycogen, protein, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) and activities of acid phosphatase (ACP) and alkaline phosphatase (AKP) during the follicular and luteal phases of the oestrous cycle in buffaloes. Glycogen, protein, DNA and RNA concentrations were significantly (P less than 0.01) higher in buffalo endometrium during the follicular phase than the luteal phase of the oestrous cycle whereas ACP and AKP activities were significantly (P less than 0.01) elevated during the luteal phase compared with the follicular phase. These results are discussed in relation to the nourishment of the blastocyst during the pre-implantation period.

Studies on lactic dehydrogenase and sorbitol dehydrogenase release in relation to deep freezing of buffalo semen in certain extenders

Forty seminal ejaculates from five mature buffalo bulls (n=8 from each bull), exhibiting more than 70% initial sperm motility, were frozen in the following three extenders: egg-yolk sodium citrate glycerol (EYCG); tris-egg yolk glycerol (TYG); and citric acid whey glycerol (CAWG). The extenders were evaluated for the release of intracellular enzymes, lactic dehydrogenase (LDH) and sorbitol dehydrogenase (SODH) from the spermatozoa during freezing (in fresh semen, after dilution and after equilibration) and post freezing (24 h and 7 d after freezing. It was found that the release of LDH and SODH enzymes was significantly lower in TYG than in EYCG and CAWG extenders. The most critical stage, at which the enzyme release was maximal, was between equilibration and 24 h post freezing in all three extenders.