RNA sequencing reveals potential interacting networks between the altered transcriptome and ncRNome in the skeletal muscle of diabetic mice

For a global epidemic like Type 2 diabetes mellitus (T2DM), while impaired gene regulation is identified as a primary cause of aberrant cellular physiology; in the past few years, non-coding RNAs (ncRNAs) have emerged as important regulators of cellular metabolism. However, there are no reports of comprehensive in-depth cross-talk between these regulatory elements and the potential consequences in the skeletal muscle during diabetes. Here, using RNA sequencing, we identified 465 mRNAs and 12 long non-coding RNAs (lncRNAs), to be differentially regulated in the skeletal muscle of diabetic mice and pathway enrichment analysis of these altered transcripts revealed pathways of insulin, FOXO and AMP-activated protein kinase (AMPK) signaling to be majorly over-represented. Construction of networks showed that these pathways significantly interact with each other that might underlie aberrant skeletal muscle metabolism during diabetes. Gene-gene interaction network depicted strong interactions among several differentially expressed genes (DEGs) namely, Prkab2, Irs1, Pfkfb3, Socs2 etc. Seven altered lncRNAs depicted multiple interactions with the altered transcripts, suggesting possible regulatory roles of these lncRNAs. Inverse patterns of expression were observed between several of the deregulated microRNAs (miRNAs) and the differentially expressed transcripts in the tissues. Towards validation, overexpression of miR-381-3p and miR-539-5p in skeletal muscle C2C12 cells significantly decreased the transcript levels of their targets, Nfkbia, Pik3r1 and Pi3kr1, Cdkn2d, respectively. Collectively, the findings provide a comprehensive understanding of the interactions and cross-talk between the ncRNome and transcriptome in the skeletal muscle during diabetes and put forth potential therapeutic options for improving insulin sensitivity.

Plateletpheresis donation through donor awareness, motivation, and recruitment drives: A unique concept and experience from a tertiary care oncology centre in India

OBJECTIVES

The majority of blood donor motivational and awareness activities are directed toward whole blood donation and not much emphasis is given to the plateletpheresis. The study was designed to analyze the effectiveness of the unique concept of platelet drives (PD) to increase voluntary plateletpheresis donations.

MATERIALS AND METHODS

The study was a retrospective study conducted at a tertiary care oncology hospital-based blood transfusion services (BTS).

RESULTS

A total of 13 PDs were conducted from January 2016 to December 2020. A total of 559 potential donors came for the donor registration and 125 donors got deferred on medical history. A total of 434 donors gave their samples for the testing of plateletpheresis. The median age of potential male and female donors was 32 and 30 years respectively. A total of 58 males and two females have donated single donor platelets (14.3% vs. 7.4%, P=0.319). The median age of male and female donors was 36 and 42 years, respectively. In male donors, 48 had donated once, seven donated twice, two donated thrice and one donor donated four times. Out of two female donors, one donor donated twice and the other donor donated four times. The female donors were more committed to repeat donations (P=0.004). Since the start of PDs, the number of voluntary donations has increased considerably over the years.

CONCLUSION

PDs have helped in increasing the number of voluntary plateletpheresis donors. All the BTS must have the standard operating procedures in place for these kinds of awareness and motivational drives.

High throughput detection and genetic epidemiology of SARS-CoV-2 using COVIDSeq next-generation sequencing

The rapid emergence of coronavirus disease 2019 (COVID-19) as a global pandemic affecting millions of individuals globally has necessitated sensitive and high-throughput approaches for the diagnosis, surveillance, and determining the genetic epidemiology of SARS-CoV-2. In the present study, we used the COVIDSeq protocol, which involves multiplex-PCR, barcoding, and sequencing of samples for high-throughput detection and deciphering the genetic epidemiology of SARS-CoV-2. We used the approach on 752 clinical samples in duplicates, amounting to a total of 1536 samples which could be sequenced on a single S4 sequencing flow cell on NovaSeq 6000. Our analysis suggests a high concordance between technical duplicates and a high concordance of detection of SARS-CoV-2 between the COVIDSeq as well as RT-PCR approaches. An in-depth analysis revealed a total of six samples in which COVIDSeq detected SARS-CoV-2 in high confidence which were negative in RT-PCR. Additionally, the assay could detect SARS-CoV-2 in 21 samples and 16 samples which were classified inconclusive and pan-sarbeco positive respectively suggesting that COVIDSeq could be used as a confirmatory test. The sequencing approach also enabled insights into the evolution and genetic epidemiology of the SARS-CoV-2 samples. The samples were classified into a total of 3 clades. This study reports two lineages B.1.112 and B.1.99 for the first time in India. This study also revealed 1,143 unique single nucleotide variants and added a total of 73 novel variants identified for the first time. To the best of our knowledge, this is the first report of the COVIDSeq approach for detection and genetic epidemiology of SARS-CoV-2. Our analysis suggests that COVIDSeq could be a potential high sensitivity assay for the detection of SARS-CoV-2, with an additional advantage of enabling the genetic epidemiology of SARS-CoV-2.

Circad: a comprehensive manually curated resource of circular RNA associated with diseases

Circular RNAs (circRNAs) are unique transcript isoforms characterized by back splicing of exon ends to form a covalently closed loop or circular conformation. These transcript isoforms are now known to be expressed in a variety of organisms across the kingdoms of life. Recent studies have shown the role of circRNAs in a number of diseases and increasing evidence points to their potential application as biomarkers in these diseases. We have created a comprehensive manually curated database of circular RNAs associated with diseases. This database is available at URL http://clingen.igib.res.in/circad/. The Database lists more than 1300 circRNAs associated with 150 diseases and mapping to 113 International Statistical Classification of Diseases (ICD) codes with evidence of association linked to published literature. The database is unique in many ways. Firstly, it provides ready-to-use primers to work with, in order to use circRNAs as biomarkers or to perform functional studies. It additionally lists the assay and PCR primer details including experimentally validated ones as a ready reference to researchers along with fold change and statistical significance. It also provides standard disease nomenclature as per the ICD codes. To the best of our knowledge, circad is the most comprehensive and updated database of disease associated circular RNAs.

Availability: http://clingen.igib.res.in/circad/

ATP7A Clinical Genetics Resource - A comprehensive clinically annotated database and resource for genetic variants in ATP7A gene

ATP7A is a critical copper transporter involved in Menkes Disease, Occipital horn Syndrome and X-linked distal spinal muscular atrophy type 3 which are X linked genetic disorders. These are rare diseases and their genetic epidemiology of the diseases is unknown. A number of genetic variants in the genes have been reported in published literature as well as databases, however, understanding the pathogenicity of variants and genetic epidemiology requires the data to be compiled in a unified format. To this end, we systematically compiled genetic variants from published literature and datasets. Each of the variants were systematically evaluated for evidences with respect to their pathogenicity and classified as per the American College of Medical Genetics and the Association of Molecular Pathologists (ACMG-AMP) guidelines into Pathogenic, Likely Pathogenic, Benign, Likely Benign and Variants of Uncertain Significance. Additional integrative analysis of population genomic datasets provides insights into the genetic epidemiology of the disease through estimation of carrier frequencies in global populations. To deliver a mechanistic explanation for the pathogenicity of selected variants, we also performed molecular modeling studies. Our modeling studies concluded that the small structural distortions observed in the local structures of the protein may lead to the destabilization of the global structure. To the best of our knowledge, ATP7A Clinical Genetics Resource is one of the most comprehensive compendium of variants in the gene providing clinically relevant annotations in gene.

WilsonGen a comprehensive clinically annotated genomic variant resource for Wilson's Disease

Wilson disease (WD) is one of the most prevalent genetic diseases with an estimated global carrier frequency of 1 in 90 and a prevalence of 1 in 30,000. The disease owes its genesis to Kinnier Wilson who described the disease, and is caused by accumulation of Copper (Cu) in various organs including the liver, central nervous system, cornea, kidney, joints and cardiac muscle which contribute to the characteristic clinical features of WD. A number of studies have reported genetic variants in the ATP7B gene from diverse ethnic and geographical origins. The recent advent of next-generation sequencing approaches has also enabled the discovery of a large number of novel variants in the gene associated with the disease. Previous attempts have been made to compile the knowledgebase and spectrum of genetic variants from across the multitude of publications, but have been limited by the utility due to the significant differences in approaches used to qualify pathogenicity of variants in each of the publications. The recent formulation of guidelines and algorithms for assessment of the pathogenicity of variants jointly put forward by the American College of Medical Genetics and the Association of Molecular Pathologists (ACMG &AMP) has provided a framework for evidence based and systematic assessment of pathogenicity of variants. In this paper, we describe a comprehensive resource of genetic variants in ATP7B gene manually curated from literature and data resources and systematically annotated using the ACMG & AMP guidelines for assessing pathogenicity. The resource therefore serves as a central point for clinicians and geneticists working on WD and to the best of our knowledge is the most comprehensive and only clinically annotated resource for WD. The resource is available at URL http://clingen.igib.res.in/WilsonGen/. We compiled a total of 3662 genetic variants from publications and databases associated with WD. Of these variants compiled, a total of 1458 were found to be unique entries. This is the largest WD database comprising 656 pathogenic/likely pathogenic variants reported classified according to ACMG & AMP guidelines. We also mapped all the pathogenic variants corresponding to ATP7B protein from literature and other databases. In addition, geographical origin and distribution of ATP7B pathogenic variants reported are also mapped in the database.

Insights into physiological roles of unique metabolites released from Plasmodium-infected RBCs and their potential as clinical biomarkers for malaria

Plasmodium sp. are obligate intracellular parasites that derive most of their nutrients from their host meaning the metabolic circuitry of both are intricately linked. We employed untargeted, global mass spectrometry to identify metabolites present in the culture supernatants of P. falciparum-infected red blood cells synchronized at ring, trophozoite and schizont developmental stages. This revealed a temporal regulation in release of a distinct set of metabolites compared with supernatants of non-infected red blood cells. Of the distinct metabolites we identified pipecolic acid to be abundantly present in parasite lysate, infected red blood cells and infected culture supernatant. Further, we performed targeted metabolomics to quantify pipecolic acid concentrations in both the supernatants of red blood cells infected with P. falciparum, as well as in the plasma and infected RBCs of P. berghei-infected mice. Measurable and significant hyperpipecolatemia suggest that pipecolic acid has the potential to be a diagnostic marker for malaria.

A secreted Heat shock protein 90 of Trichomonas vaginalis

Trichomonas vaginalis is a causative agent of Trichomoniasis, a leading non-viral sexually transmitted disease worldwide. In the current study, we show Heat shock protein 90 is essential for its growth. Upon genomic analysis of the parasite, it was found to possess seven ORFs which could potentially encode Hsp90 isoforms. We identified a cytosolic Hsp90 homolog, four homologs which can align to truncated cytosolic Hsp90 gene products along with two Grp94 homologs (ER isoform of Hsp90). However, both Grp94 orthologs lacked an ER retention motif. In cancer cells, it is very well established that Hsp90 is secreted and regulates key clients involved in metastases, migration, and invasion. Since Trichomonas Grp94 lacks ER retention motif, we examined the possibility of its secretion. By using cell biology and biochemical approaches we show that the Grp94 isoform of Hsp90 is secreted by the parasite by the classical ER-Golgi pathway. This is the first report of a genome encoded secreted Hsp90 in a clinically important parasitic protozoan.

Hsp90 is an essential chaperone in eukaryotes and it is often described as a master regulator of cellular homeostasis. In addition to its well-known functions inside the cell, extracellular Hsp90 has also been implicated in migration and invasion of tumor cells. We have, for the first time, identified the presence of an extracellular Hsp90 in a parasitic protozoan, Trichomonas vaginalis. The extracellular Hsp90 is a Grp94 homolog that lacks a canonical ER retention signal. Our analysis of Grp94 sequences from protozoa shows that it is uncommon for a Grp94 to lack ER retention signal. In the current study, we characterized the biochemical parameters and established the extracellular localization of this Hsp90 paralog. This secreted Hsp90 in Trichomonas can potentially modulate host-pathogen interaction.