Downregulation of monocyte miRNAs: implications for immune dysfunction and disease severity in drug-resistant tuberculosis

Monocyte miRNAs govern both protective and pathological responses during tuberculosis (TB) through their differential expression and emerged as potent targets for biomarker discovery and host-directed therapeutics. Thus, this study examined the miRNA profile of sorted monocytes across the TB disease spectrum [drug-resistant TB (DR-TB), drug-sensitive TB (DS-TB), and latent TB] and in healthy individuals (HC) to understand the underlying pathophysiology and their regulatory mechanism

Identification of specific let-7 microRNA binding complexes in Caenorhabditis elegans

Little is known about the protein complexes required for microRNA formation and function. Here we used native gel electrophoresis to identify miRNA ribonucleoprotein complexes (miRNPs) in Caenorhabditis elegans. Our data reveal multiple distinct miRNPs that assemble on the let-7 miRNA in vitro. The formation of these complexes is affected but not abolished by alg-1 or alg-2 null mutations. The largest complex (M*) with an estimated molecular mass of >669 kDa cofractionates with the known RISC factors ALG-1, VIG-1, and TSN-1. The M* complex and two complexes, M3 and M4, with similar molecular weights of ∼500 kDa, also assemble on all other miRNAs used in our experiments. Two smaller complexes, M1 (∼160 kDa) and M2 (∼250 kDa), assemble on the members of the let-7 miRNAs family but not lin-4 or mir-234, and their formation is highly dependent on specific sequences in the 5′ seed region of let-7. Moreover, an unidentified protein, p40, which only appears in the M1 and M2 complexes, was detected by UV triggered cross-linking to let-7 but not to lin-4. The cross-linking of p40 to let-7 is also dependent on the let-7 sequence. Another unidentified protein, p13, is detected in all let-7 binding complexes and lin-4 cross-linked products. Our data suggest that besides being present in certain large miRNPs with sizes similar to reported RISC, the let-7 miRNA also assembles with specific binding proteins and forms distinct small complexes

High-throughput metabolomic and transcriptomic analyses vet the potential route of cerpegin biosynthesis in two varieties of Ceropegia bulbosa Roxb.

Main conclusion: Exploration with high-throughput transcriptomics and metabolomics of two varieties of Ceropegia bulbosa identifies candidate genes, crucial metabolites and a potential cerpegin biosynthetic pathway. Abstract: Ceropegia bulbosa is an important medicinal plant, used in the treatment of various ailments including diarrhea, dysentery, and syphilis. This is primarily attributed to the presence of pharmaceutically active secondary metabolites, especially cerpegin. As this plant belongs to an endemic threatened category, genomic resources are not available hampering exploration on the molecular basis of cerpegin accumulation till now. Therefore, we undertook high-throughput metabolomic and transcriptomic analyses using different tissues from two varieties namely, C. bulbosa var. bulbosa and C. bulbosa var. lushii. Metabolomic analysis revealed spatial and differential accumulation of various metabolites. We chemically synthesized and characterized the cerpegin and its derivatives by liquid chromatography tandem–mass spectrometry (LC–MS/MS). Importantly, these comparisons suggested the presence of cerpegin and 5-allyl cerpegin in all C. bulbosa tissues. Further, de novo transcriptome analysis indicated the presence of significant transcripts for secondary metabolic pathways through the Kyoto encyclopedia of genes and genomes database. Tissue-specific profiling of transcripts and metabolites showed a significant correlation, suggesting the intricate mechanism of cerpegin biosynthesis. The expression of potential candidate genes from the proposed cerpegin biosynthetic pathway was further validated by qRT-PCR and NanoString nCounter. Overall, our findings propose a potential route of cerpegin biosynthesis. Identified transcripts and metabolites have built a foundation as new molecular resources that could facilitate future research on biosynthesis, regulation, and engineering of cerpegin or other important metabolites in such non-model plants