Integrative multi-omics analysis identifies genetically supported druggable targets and immune cell specificity for myasthenia gravis.

BACKGROUND: Myasthenia gravis (MG) is a chronic autoimmune disorder characterized by fluctuating muscle weakness. Despite the availability of established therapies, the management of MG symptoms remains suboptimal, partially attributed to lack of efficacy or intolerable side-effects. Therefore, new effective drugs are warranted for treatment of MG. METHODS: By employing an analytical framework that combines Mendelian randomization (MR) and colocalization analysis, we estimate the causal effects of blood druggable expression quantitative trait loci (eQTLs) and protein quantitative trait loci (pQTLs) on the susceptibility of MG. We subsequently investigated whether potential genetic effects exhibit cell-type specificity by utilizing genetic colocalization analysis to assess the interplay between immune-cell-specific eQTLs and MG risk. RESULTS: We identified significant MR results for four genes (CDC42BPB, CD226, PRSS36, and TNFSF12) using cis-eQTL genetic instruments and three proteins (CTSH, PRSS8, and CPN2) using cis-pQTL genetic instruments. Six of these loci demonstrated evidence of colocalization with MG susceptibility (posterior probability > 0.80). We next undertook genetic colocalization to investigate cell-type-specific effects at these loci. Notably, we identified robust evidence of colocalization, with a posterior probability of 0.854, linking CTSH expression in TH2 cells and MG risk. CONCLUSIONS: This study provides crucial insights into the genetic and molecular factors associated with MG susceptibility, singling out CTSH as a potential candidate for in-depth investigation and clinical consideration. It additionally sheds light on the immune-cell regulatory mechanisms related to the disease. However, further research is imperative to validate these targets and evaluate their feasibility for drug development.

Integrative transcriptome analysis identifies new oxidosqualene cyclase genes involved in ginsenoside biosynthesis in Jilin ginseng.

BACKGROUND: Jilin ginseng, Panax ginseng, is a valuable medicinal herb whose ginsenosides are its major bioactive components. The ginseng oxidosqualene cyclase (PgOSC) gene family is known to play important roles in ginsenoside biosynthesis, but few members of the gene family have been functionally studied. METHODS: The PgOSC gene family has been studied by an integrated analysis of gene expression-ginsenoside content correlation, gene mutation-ginsenoside content association and gene co-expression network, followed by functional analysis through gene regulation. RESULTS: We found that five of the genes in the PgOSC gene family, including two published ginsenoside biosynthesis genes and three new genes, were involved in ginsenoside biosynthesis. Not only were the expressions of these genes significantly correlated with ginsenoside contents, but also their nucleotide mutations significantly influenced ginsenoside contents. These results were further verified by regulation analysis of the genes by methyl jasmonate (MeJA) in ginseng hairy roots. Four of these five PgOSC genes were mapped to the ginsenoside biosynthesis pathway. These PgOSC genes expressed differently across tissues, but relatively consistent across developmental stages. These PgOSC genes formed a single co-expression network with those published ginsenoside biosynthesis genes, further confirming their roles in ginsenoside biosynthesis. When the network varied, ginsenoside biosynthesis was significantly influenced, thus revealing the molecular mechanism of ginsenoside biosynthesis. CONCLUSION: At least five of the PgOSC genes, including the three newly identified and two published PgOSC genes, are involved in ginsenoside biosynthesis. These results provide gene resources and knowledge essential for enhanced research and applications of ginsenoside biosynthesis in ginseng.

Basic leucine zipper (bZIP) transcription factor genes and their responses to drought stress in ginseng, Panax ginseng C.A. Meyer.

BACKGROUND: Ginseng is an important medicinal herb in Asia and Northern America. The basic leucine zipper (bZIP) transcription factor genes play important roles in many biological processes and plant responses to abiotic and biotic stresses, such as drought stress. Nevertheless, the genes remain unknown in ginseng. RESULTS: Here, we report 91 bZIP genes identified from ginseng, designated PgbZIP genes. These PgbZIP genes were alternatively spliced into 273 transcripts. Phylogenetic analysis grouped the PgbZIP genes into ten groups, including A, B, C, D, E, F, G, H, I and S. Gene Ontology (GO) categorized the PgbZIP genes into five functional subcategories, suggesting that they have diversified in functionality, even though their putative proteins share a number of conserved motifs. These 273 PgbZIP transcripts expressed differentially across 14 tissues, the roots of different ages and the roots of different genotypes. However, the transcripts of the genes expressed coordinately and were more likely to form a co-expression network. Furthermore, we studied the responses of the PgbZIP genes to drought stress in ginseng using a random selection of five PgbZIP genes, including PgbZIP25, PgbZIP38, PgbZIP39, PgbZIP53 and PgbZIP54. The results showed that all five PgbZIP genes responded to drought stress in ginseng, indicating that the PgbZIP genes play important roles in ginseng responses to drought stress. CONCLUSIONS: These results provide knowledge and gene resources for deeper functional analysis of the PgbZIP genes and molecular tools for enhanced drought tolerance breeding in ginseng.

Characteristics of RNA alternative splicing and its potential roles in ginsenoside biosynthesis in a single plant of ginseng, Panax ginseng C.A. Meyer.

RNA alternative splicing (AS) is prevalent in higher organisms and plays a paramount role in biology; therefore, it is crucial to have comprehensive knowledge on AS to understand biology. However, knowledge is limited about how AS activates in a single plant and functions in a biological process. Ginseng is one of the most widely used medicinal herbs that is abundant in a number of medicinal bioactive components, especially ginsenosides. In this study, we sequenced the transcripts of 14 organs from a 4-year-old ginseng plant and quantified their ginsenoside contents. We identified AS genes by analyzing their transcripts with the ginseng genome and verified their AS events by PCR. The plant had a total of 13,863 AS genes subjected to 30,801 AS events with five mechanisms: skipped exon, retained intron, alternative 5'splice site, alternative 3' splice site, and mutually exclusive exon. The genes that were more conserved, had more exons, and/or expressed across organs were more likely to be subjected to AS. AS genes were enriched in over 500 GO terms in the plant even though the number of AS gene-enriched GO terms varied across organs. At least 24 AS genes were found to be involved in ginsenoside biosynthesis. These AS genes were significantly up-enriched and more likely to form a co-expression network, thus suggesting the functions of AS and correlations of the AS genes in the process. This study provides comprehensive insights into the molecular characteristics and biological functions of AS in a single plant; thus, helping better understand biology.

Identification and characterization of a novel intronic splicing mutation in CSF1R-related leukoencephalopathy.

AIMS: Colony stimulating factor 1 receptor (CSF1R)-related leukoencephalopathy is a rapidly progressing neurodegenerative disease caused by CSF1R gene mutations. This study aimed to identify and investigate the effect of a novel intronic mutation (c.1754-3C>G) of CSF1R on splicing. METHODS: A novel intronic mutation was identified using whole-exome sequencing. To investigate the impact of this mutation, we employed various bioinformatics tools to analyze the transcription of the CSF1R gene and the three-dimensional structure of its encoded protein. Furthermore, reverse transcription polymerase chain reaction (RT-PCR) was performed to validate the findings. RESULTS: A novel mutation (c.1754-3C>G) in CSF1R was identified, which results in exon 13 skipping due to the disruption of the 3' splice site consensus sequence NYAG/G. This exon skipping event was further validated in the peripheral blood of the mutation carrier through RT-PCR and Sanger sequencing. Protein structure prediction indicated a disruption in the tyrosine kinase domain, with the truncated protein showing significant structural alterations. CONCLUSIONS: Our findings underscore the importance of intronic mis-splicing mutations in the diagnosis and management of CSF1R-related leukoencephalopathy.

Genetic and molecular dissection of ginseng (Panax ginseng Mey.) germplasm using high-density genic SNP markers, secondary metabolites, and gene expressions.

Genetic and molecular knowledge of a species is crucial to its gene discovery and enhanced breeding. Here, we report the genetic and molecular dissection of ginseng, an important herb for healthy food and medicine. A mini-core collection consisting of 344 cultivars and landraces was developed for ginseng that represents the genetic variation of ginseng existing in its origin and diversity center. We sequenced the transcriptomes of all 344 cultivars and landraces; identified over 1.5 million genic SNPs, thereby revealing the genic diversity of ginseng; and analyzed them with 26,600 high-quality genic SNPs or a selection of them. Ginseng had a wide molecular diversity and was clustered into three subpopulations. Analysis of 16 ginsenosides, the major bioactive components for healthy food and medicine, showed that ginseng had a wide variation in the contents of all 16 ginsenosides and an extensive correlation of their contents, suggesting that they are synthesized through a single or multiple correlated pathways. Furthermore, we pair-wisely examined the relationships between the cultivars and landraces, revealing their relationships in gene expression, gene variation, and ginsenoside biosynthesis. These results provide new knowledge and new genetic and genic resources for advanced research and breeding of ginseng and related species.

Genome-wide analysis of the C2H2 zinc finger protein gene family and its response to salt stress in ginseng, Panax ginseng Meyer.

The C2H2 zinc finger protein (C2H2-ZFP) gene family plays important roles in response to environmental stresses and several other biological processes in plants. Ginseng is a precious medicinal herb cultivated in Asia and North America. However, little is known about the C2H2-ZFP gene family and its functions in ginseng. Here, we identified 115 C2H2-ZFP genes from ginseng, defined as the PgZFP gene family. It was clustered into five groups and featured with eight conserved motifs, with each gene containing one to six of them. The family genes are categorized into 17 gene ontology subcategories and have numerous regulatory elements responsive to a variety of biological process, suggesting their functional differentiation. The 115 PgZFP genes were spliced into 228 transcripts at seed setting stage and varied dramatically in expression across tissues, developmental stages, and genotypes, but they form a co-expression network, suggesting their functional correlation. Furthermore, four genes, PgZFP31, PgZFP78-01, PgZFP38, and PgZFP39-01, were identified from the gene family that were actively involved in plant response to salt stress. These results provide new knowledge on origin, differentiation, evolution, and function of the PgZFP gene family and new gene resources for C2H2-ZFP gene research and application in ginseng and other plant species.

Structural variation, functional differentiation and expression characteristics of the AP2/ERF gene family and its response to cold stress and methyl jasmonate in Panax ginseng C.A. Meyer.

The APETALA2/Ethylene Responsive Factor (AP2/ERF) gene family has been shown to play a crucial role in plant growth and development, stress responses and secondary metabolite biosynthesis. Nevertheless, little is known about the gene family in ginseng (Panax ginseng C.A. Meyer), an important medicinal herb in Asia and North America. Here, we report the systematic analysis of the gene family in ginseng using several transcriptomic databases. A total of 189 putative AP2/ERF genes, defined as PgERF001 through PgERF189, were identified and these PgERF genes were spliced into 397 transcripts. The 93 PgERF genes that have complete AP2 domains in open reading frame were classified into five subfamilies, DREB, ERF, AP2, RAV and Soloist. The DREB subfamily and ERF subfamily were further clustered into four and six groups, respectively, compared to the 12 groups of these subfamilies found in Arabidopsis thaliana. Gene ontology categorized these 397 transcripts of the 189 PgERF genes into eight functional subcategories, suggesting their functional differentiation, and they have been especially enriched for the subcategory of nucleic acid binding transcription factor activity. The expression activity and networks of the 397 PgERF transcripts have substantially diversified across tissues, developmental stages and genotypes. The expressions of the PgERF genes also significantly varied, when ginseng was subjected to cold stress, as tested using six PgERF genes, PgERF073, PgERF079, PgERF110, PgERF115, PgERF120 and PgERF128, randomly selected from the DREB subfamily. This result suggests that the DREB subfamily genes play an important role in plant response to cold stress. Finally, we studied the responses of the PgERF genes to methyl jasmonate (MeJA). We found that 288 (72.5%) of the 397 PgERF gene transcripts responded to the MeJA treatment, with 136 up-regulated and 152 down-regulated, indicating that most members of the PgERF gene family are responsive to MeJA. These results, therefore, provide new resources and knowledge necessary for family-wide functional analysis of the PgERF genes in ginseng and related species.

Transcriptome analysis identifies strong candidate genes for ginsenoside biosynthesis and reveals its underlying molecular mechanism in Panax ginseng C.A. Meyer.

Ginseng, Panax ginseng C.A. Meyer, is one of the most important medicinal herbs for human health and medicine in which ginsenosides are known to play critical roles. The genes from the cytochrome P450 (CYP) gene superfamily have been shown to play important roles in ginsenoside biosynthesis. Here we report genome-wide identification of the candidate PgCYP genes for ginsenoside biosynthesis, development of functional SNP markers for its manipulation and systems analysis of its underlying molecular mechanism. Correlation analysis identified 100 PgCYP genes, including all three published ginsenoside biosynthesis PgCYP genes, whose expressions were significantly correlated with the ginsenoside contents. Mutation association analysis identified that six of these 100 PgCYP genes contained SNPs/InDels that were significantly associated with ginsenosides biosynthesis (P ≤ 1.0e-04). These six PgCYP genes, along with all ten published ginsenoside biosynthesis genes from the PgCYP and other gene families, formed a strong co-expression network, even though they varied greatly in spatio-temporal expressions. Therefore, this study has identified six new ginsenoside biosynthesis candidate genes, provided a genome-wide insight into how they are involved in ginsenoside biosynthesis and developed a set of functional SNP markers useful for enhanced ginsenoside biosynthesis research and breeding in ginseng and related species.