Design, synthesis, in vitro inhibition and toxicological evaluation of human carbonic anhydrases I, II and IX inhibitors in 5-nitroimidazole series

With the aim to obtain novel compounds possessing both strong affinity against human carbonic anhydrases and low toxicity, we synthesised novel thiourea and sulphonamide derivatives 3, 4 and 10, and studied their in vitro inhibitory properties against human CA I, CA II and CA IX. We also evaluated the toxicity of these compounds using zebrafish larvae. Among the three compounds, derivative 4 showed efficient inhibition against hCA II (KI = 58.6 nM). Compound 10 showed moderate inhibition against hCA II (KI = 199.2 nM) and hCA IX (KI = 147.3 nM), whereas it inhibited hCA I less weakly at micromolar concentrations (KI = 6428.4 nM). All other inhibition constants for these compounds were in the submicromolar range. The toxicity evaluation studies showed no adverse effects on the zebrafish larvae. Our study suggests that these compounds are suitable for further preclinical characterisation as potential inhibitors of hCA I, II and IX

Catalytically inactive carbonic anhydrase-related proteins enhance transport of lactate by MCT1

Carbonic anhydrases (CA) catalyze the reversible hydration of CO2 to protons and bicarbonate and thereby play a fundamental role in the epithelial acid/base transport mechanisms serving fluid secretion and absorption for whole-body acid/base regulation. The three carbonic anhydrase-related proteins (CARPs) VIII, X, and XI, however, are catalytically inactive. Previous work has shown that some CA isoforms noncatalytically enhance lactate transport through various monocarboxylate transporters (MCT). Therefore, we examined whether the catalytically inactive CARPs play a role in lactate transport. Here, we report that CARP VIII, X, and XI enhance transport activity of the MCT MCT1 when coexpressed in Xenopus oocytes, as evidenced by the rate of rise in intracellular H+ concentration detected using ion-sensitive microelectrodes. Based on previous studies, we suggest that CARPs may function as a 'proton antenna' for MCT1, to drive proton-coupled lactate transport across the cell membrane

PD-1 and PD-L1: architects of immune symphony and immunotherapy breakthroughs in cancer treatment

PD-1 (Programmed Cell Death Protein-1) and PD-L1 (Programmed Cell Death Ligand-1) play a crucial role in regulating the immune system and preventing autoimmunity. Cancer cells can manipulate this system, allowing them to escape immune detection and promote tumor growth. Therapies targeting the PD-1/PD-L1 pathway have transformed cancer treatment and have demonstrated significant effectiveness against various cancer types. This study delves into the structure and signaling dynamics of PD-1 and its ligands PD-L1/PD-L2, the diverse PD-1/PD-L1 inhibitors and their efficacy, and the resistance observed in some patients. Furthermore, this study explored the challenges associated with the PD-1/PD-L1 inhibitor treatment approach. Recent advancements in the combination of immunotherapy with chemotherapy, radiation, and surgical procedures to enhance patient outcomes have also been highlighted. Overall, this study offers an in-depth overview of the significance of PD-1/PD-L1 in cancer immunotherapy and its future implications in oncology

Navigating bioactivity space in anti-tubercular drug discovery through the deployment of advanced machine learning models and cheminformatics tools : a molecular modeling based retrospective study

Mycobacterium tuberculosis is the bacterial strain that causes tuberculosis (TB). However, multidrug-resistant and extensively drug-resistant tuberculosis are significant obstacles to effective treatment. As a result, novel therapies against various strains of M. tuberculosis have been developed. Drug development is a lengthy procedure that includes identifying target protein and isolation, preclinical testing of the drug, and various phases of a clinical trial, etc., can take decades for a molecule to reach the market. Computational approaches such as QSAR, molecular docking techniques, and pharmacophore modeling have aided drug development. In this review article, we have discussed the various techniques in tuberculosis drug discovery by briefly introducing them and their importance. Also, the different databases, methods, approaches, and software used in conducting QSAR, pharmacophore modeling, and molecular docking have been discussed. The other targets targeted by these techniques in tuberculosis drug discovery have also been discussed, with important molecules discovered using these computational approaches. This review article also presents the list of drugs in a clinical trial for tuberculosis found drugs. Finally, we concluded with the challenges and future perspectives of these techniques in drug discovery.Peer reviewe

Inactivation of ca10a and ca10b Genes Leads to Abnormal Embryonic Development and Alters Movement Pattern in Zebrafish

Carbonic anhydrase related proteins (CARPs) X and XI are highly conserved across species and are predominantly expressed in neural tissues. The biological role of these proteins is still an enigma. Ray-finned fish have lost the CA11 gene, but instead possess two co-orthologs of CA10. We analyzed the expression pattern of zebrafish ca10a and ca10b genes during embryonic development and in different adult tissues, and studied 61 CARP X/XI-like sequences to evaluate their phylogenetic relationship. Sequence analysis of zebrafish ca10a and ca10b reveals strongly predicted signal peptides, N-glycosylation sites, and a potential disulfide, all of which are conserved, suggesting that all of CARP X and XI are secretory proteins and potentially dimeric. RT-qPCR showed that zebrafish ca10a and ca10b genes are expressed in the brain and several other tissues throughout the development of zebrafish. Antisense morpholino mediated knockdown of ca10a and ca10b showed developmental delay with a high rate of mortality in larvae. Zebrafish morphants showed curved body, pericardial edema, and abnormalities in the head and eye, and there was increased apoptotic cell death in the brain region. Swim pattern showed abnormal movement in morphant zebrafish larvae compared to the wild type larvae. The developmental phenotypes of the ca10a and ca10b morphants were confirmed by inactivating these genes with the CRISPR/Cas9 system. In conclusion, we introduce a novel zebrafish model to investigate the mechanisms of CARP Xa and CARP Xb functions. Our data indicate that CARP Xa and CARP Xb have important roles in zebrafish development and suppression of ca10a and ca10b expression in zebrafish larvae leads to a movement disorder.</p

Medicinal Plants as Therapeutic Alternatives to Combat Mycobacterium tuberculosis : A Comprehensive Review

Tuberculosis (TB) is a serious infectious disease caused by Mycobacterium tuberculosis (MTB) and a significant health concern worldwide. The main threat to the elimination of TB is the development of resistance by MTB to the currently used antibiotics and more extended treatment methods, which is a massive burden on the health care system. As a result, there is an urgent need to identify new, effective therapeutic strategies with fewer adverse effects. The traditional medicines found in South Asia and Africa have a reservoir of medicinal plants and plant-based compounds that are considered another reliable option for human beings to treat various diseases. Abundant research is available for the biotherapeutic potential of naturally occurring compounds in various diseases but has been lagging in the area of TB. Plant-based compounds, or phytoproducts, are being investigated as potential anti-mycobacterial agents by reducing bacterial burden or modulating the immune system, thereby minimizing adverse effects. The efficacy of these phytochemicals has been evaluated through drug delivery using nanoformulations. This review aims to emphasize the value of anti-TB compounds derived from plants and provide a summary of current research on phytochemicals with potential anti-mycobacterial activity against MTB. This article aims to inform readers about the numerous potential herbal treatment options available for combatting TB.publishedVersionPeer reviewe

Identification and characterization of a novel zebrafish (Danio rerio) pentraxin-carbonic anhydrase

Background: Carbonic anhydrases (CAs) are ubiquitous, essential enzymes which catalyze the conversion of carbon dioxide and water to bicarbonate and H + ions. Vertebrate genomes generally contain gene loci for 15-21 different CA isoforms, three of which are enzymatically inactive. CAVI is the only secretory protein of the enzymatically active isoforms. We discovered that non-mammalian CA VI contains a C-terminal pentraxin (PTX) domain, a novel combination for both CAs and PTXs.Methods: We isolated and sequenced zebrafish (Danio rerio) CA VI cDNA, complete with the sequence coding for the PTX domain, and produced the recombinant CA VI-PTX protein. Enzymatic activity and kinetic parameters were measured with a stopped-flow instrument. Mass spectrometry, analytical gel filtration and dynamic light scattering were used for biophysical characterization. Sequence analyses and Bayesian phylogenetics were used in generating hypotheses of protein structure and CAVI gene evolution. A CAVI-PTX antiserum was produced, and the expression of CA VI protein was studied by immunohistochemistry. A knock-down zebrafish model was constructed, and larvae were observed up to five days post-fertilization (dpf). The expression of ca6 mRNA was quantitated by qRT-PCR in different developmental times in morphant and wild-type larvae and in different adult fish tissues. Finally, the swimming behavior of the morphant fish was compared to that of wild-type fish.Results: The recombinant enzyme has a very high carbonate dehydratase activity. Sequencing confirms a 530-residue protein identical to one of the predicted proteins in the Ensembl database (ensembl. org). The protein is pentameric in solution, as studied by gel filtration and light scattering, presumably joined by the PTX domains.Mass spectrometry confirms the predicted signal peptide cleavage and disulfides, and N-glycosylation in two of the four observed glycosylation motifs. Molecular modeling of the pentamer is consistent with the modifications observed in mass spectrometry. Phylogenetics and sequence analyses provide a consistent hypothesis of the evolutionary history of domains associated with CAVI in mammals and nonmammals. Briefly, the evidence suggests that ancestral CA VI was a transmembrane protein, the exon coding for the cytoplasmic domain was replaced by one coding for PTX domain, and finally, in the therian lineage, the PTX-coding exon was lost. We knocked down CA VI expression in zebrafish embryos with antisense morpholino oligonucleotides, resulting in phenotype features of decreased buoyancy and swim bladder deflation in 4 dpf larvae.Discussion: These findings provide novel insights into the evolution, structure, and function of this unique CA form

Genetic diversity analysis of Blastocystis subtypes and their distribution among the domestic animals and pigeons in northwest of Iran

Blastocystis is a unicellular, anaerobic, eukaryotic protist, a common parasite found in the intestinal tracts of animals and humans. During the last few years, the host fecal DNA analysis by nucleic acid-based method has led to significant advances in Blastocystis diagnostics and enabled subtypes (STs). The zoonotic transmission of Blastocystis to humans is not well understood, therefore the present study was conducted to identify Blastocystis subtypes in Iran from different animal hosts from northwest of Iran. A total of 427 fresh fecal specimens were collected from cattle, sheep, poultry and pigeon (40,150,132,105 respectively). To detect the Blastocystis sp., each fecal specimen was examined microscopically. Total DNA from the samples that were positive for Blastocystis sp. was isolated, and the barcoding region of the small subunit of ribosomal rRNA (18S rRNA) was amplified and sequenced. Subsequently, sequence analyses, genetic diversity indices and evolutionary relationships of Blastocystis subtype populations were carried out. In total, 14.98 of the analyzed samples were positive for Blastocystis sp. and the subtypes detected were ST3,7,10 and 14. Among these, the ST10 was the main subtype that was found only in the cattle, sheep and poultry and the zoonotic subtype ST3 was present only from cattle. Our study shows the presence of Blastocystis subtypes in the sheep in north west of Iran and also demonstrated that the genetic approaches are crucial to understand the host specify of subtypes and the mode of infection. The study suggests that the genetic approaches will help us to understand the host specificity of subtypes and their role in infection if they are obtained from human and animals from the same geographical locations. Therefore, it is important to study the zoonotic aspects of this parasite with large number of samples from different groups of animals and from different geographical locations. © 202