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A new prenylated indole alkaloid—Penicimutamide C N-oxide (1), a new alkaloid penicimutamine A (2), along with six known alkaloids were isolated from an endophytic fungus Pallidocercospora crystallina. A simple and accurate method was used to determine the N-O bond in the N-oxide group of 1. By using a β-cell ablation diabetic zebrafish model, compounds 1, 3, 5, 6 and 8 showed significantly hypoglycemic activities under the concentration of 10 μM. Further studies revealed that compounds 1 and 8 lowered the glucose level through promoting glucose uptake in zebrafish. In addition, all eight compounds showed no acute toxicity, teratogenicity, nor vascular toxicity in zebrafish under the concentrations range from 2.5 μΜ to 40 μM. Importantly, these results provide new lead compounds for the development of antidiabetes strategies.

Protein kinases of the MAPK cascade family (MAPKKK–MAPKK–MAPK) play an essential role in plant stress response and hormone signal transduction. However, their role in the cold hardiness of Prunus mume (Mei), a class of ornamental woody plant, remains unclear. In this study, we use bioinformatic approaches to assess and analyze two related protein kinase families, namely, MAP kinases (MPKs) and MAPK kinases (MKKs), in wild P. mume and its variety P. mume var. tortuosa. We identify 11 PmMPK and 7 PmMKK genes in the former species and 12 PmvMPK and 7 PmvMKK genes in the latter species, and we investigate whether and how these gene families contribute to cold stress responses. Members of the MPK and MKK gene families located on seven and four chromosomes of both species are free of tandem duplication. Four, three, and one segment duplication events are exhibited in PmMPK, PmvMPK, and PmMKK, respectively, suggesting that segment duplications play an essential role in the expansion and evolution of P. mume and its gene variety. Moreover, synteny analysis suggests that most MPK and MKK genes have similar origins and involved similar evolutionary processes in P. mume and its variety. A cis-acting regulatory element analysis shows that MPK and MKK genes may function in P. mume and its variety’s development, modulating processes such as light response, anaerobic induction, and abscisic acid response as well as responses to a variety of stresses, such as low temperature and drought. Most PmMPKs and PmMKKs exhibited tissue-specifific expression patterns, as well as time-specific expression patterns that protect them through cold. In a low-temperature treatment experiment with the cold-tolerant cultivar P. mume ‘Songchun’ and the cold-sensitive cultivar ‘Lve’, we find that almost all PmMPK and PmMKK genes, especially PmMPK3/5/6/20 and PmMKK2/3/6, dramatically respond to cold stress as treatment duration increases. This study introduces the possibility that these family members contribute to P. mume’s cold stress response. Further investigation is warranted to understand the mechanistic functions of MAPK and MAPKK proteins in P. mume development and response to cold stress.

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Obesity, along with type 2 diabetes mellitus (T2DM), is a major contributor to hypertension. The renin-angiotensin-aldosterone system is involved in the occurrence of diabetes and hypertension. However, the mechanism by which obesity is related to T2DM induced hypertension is unclear. In this study, we observed that blood pressure and serum renin content were increased in patients with diabetes and hypertension. Hydrogen sulfide (H2S), as an endogenous bioactive molecule, has been shown to be a vasodilator. Db/db mice, characterized by obesity and T2DM, and juxtaglomerular (JG) cells, which line the afferent arterioles at the entrance of the glomeruli to produce renin, treated with glucose, palmitic acid (PA) and oleic acid (OA), were used as animal and cellular models. NaHS, the H2S donor, was administered to db/db mice through intraperitoneal injection. NaHS significantly alleviated blood pressure in db/db mice, decreased the renin content in the serum of db/db mice and reduced renin secretion from JG cells. NaHS modulated renin release via cAMP and soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), including synaptosome-associated protein 23 (SNAP23) and vesicle-associated membrane protein 2 (VAMP2), which mediate renin exocytosis. Furthermore, NaHS increased the levels of autophagy-related proteins and colocalization with EGFP-LC3 puncta with renin-containing granules and VAMP2 to consume excessive renin to maintain intracellular homeostasis. Therefore, exogenous H2S attenuates renin release and promotes renin-vesicular autophagy to relieve diabetes-induced hypertension.

Heterozygous variants in the hepatocyte nuclear factor 1a (HNF1a) cause MODY3 (maturity-onset diabetes of the young, type 3). In this study, we found a case of novel HNF1a p.Gln125* (HNF1a-Q125ter) variant clinically. However, the molecular mechanism linking the new HNF1a variant to impaired islet β-cell function remains unclear. Firstly, a similar HNF1a-Q125ter variant in zebrafish (hnf1a+/−) was generated by CRISPR/Cas9. We further crossed hnf1a+/− with several zebrafish reporter lines to investigate pancreatic β-cell function. Next, we introduced HNF1a-Q125ter and HNF1a shRNA plasmids into the Ins-1 cell line and elucidated the molecular mechanism. hnf1a+/− zebrafish significantly decreased the β-cell number, insulin expression, and secretion. Moreover, β cells in hnf1a+/− dilated ER lumen and increased the levels of ER stress markers. Similar ER-stress phenomena were observed in an HNF1a-Q125ter-transfected Ins-1 cell. Follow-up investigations demonstrated that HNF1a-Q125ter induced ER stress through activating the PERK/eIF2a/ATF4 signaling pathway. Our study found a novel loss-of-function HNF1a-Q125ter variant which induced β-cell dysfunction by activating ER stress via the PERK/eIF2a/ATF4 signaling pathway.

Histone deacetylases (HDACs) play important roles in plant growth, development, and stress response. However, the pattern of how they are expressed in response to cold stress in the ornamental woody plant Prunus mume is poorly understood. Here, we identify 121 RoHDACs from eight Rosaceae plants of which 13 PmHDACs genes are from P. mume. A phylogenetic analysis suggests that the RoHDACs family is classified into three subfamilies, HDA1/RPD3, HD2, and SIR2. We identify 11 segmental duplication gene pairs of RoHDACs and find, via a sequence alignment, that the HDACs gene family, especially the plant-specific HD2 family, has experienced gene expansion and contraction at a recent genome evolution history. Each of the three HDACs subfamilies has its own conserved domains. The expression of PmHDACs in mei is found to be tissue-specific or tissue-wide. RNA-seq data and qRT-PCR experiments in cold treatments suggest that almost all PmHDACs genes—especially PmHDA1/6/14, PmHDT1, and PmSRT1/2—significantly respond to cold stress. Our analysis provides a fundamental insight into the phylogenetic relationship of the HDACs family in Rosaceae plants. Expression profiles of PmHDACs in response to cold stress could provide an important clue to improve the cold hardiness of mei.

The common vetch (Vicia sativa L.) seed is an ideal plant-based protein food for humans, but its edible value is mainly limited by the presence of cyanogenic glycosides that hydrolyze to produce toxic hydrogen cyanide (HCN), and the genes that regulate HCN synthesis in common vetch are unknown. In this study, seeds from common vetch at 5, 10, 15, 20, 25, 30, and 35 days after anthesis were sampled, and the seven stages were further divided into five developmental stages, S1, S2, S3, S4, and S5, based on morphological and transcriptome analyses. A total of 16,403 differentially expressed genes were identified in the five developmental stages. The HCN contents of seeds in these five stages were determined by alkaline titration, and weighted gene coexpression network analysis was used to explain the molecular regulatory mechanism of HCN synthesis in common vetch seeds. Eighteen key regulatory genes for HCN synthesis were identified, including the VsGT2, VsGT17 and CYP71A genes, as well as the VsGT1 gene family. VsGT1, VsGT2, VsGT17 and CYP71A jointly promoted HCN synthesis, from 5 to 25 days after anthesis, with VsGT1-1, VsGT1-4, VsGT1-11 and VsGT1-14 playing major roles. The HCN synthesis was mainly regulated by VsGT1, from 25 to 35 days after anthesis. As the expression level of VsGT1 decreased, the HCN content no longer increased. In-depth elucidation of seed HCN synthesis lays the foundations for breeding common vetch with low HCN content.

The glucagon receptor (GCGR) is a G-protein-coupled receptor (GPCR) that mediates the activity of glucagon. Disruption of GCGR results in many metabolic alterations, including increased glucose tolerance, decreased adiposity, hypoglycemia, and pancreatic α-cell hyperplasia. To better understand the global transcriptomic changes resulting from GCGR deficiency, we performed whole-organism RNA sequencing analysis in wild type and gcgr-deficient zebrafish. We found that the expression of 1645 genes changes more than two-fold among mutants. Most of these genes are related to metabolism of carbohydrates, lipids, and amino acids. Genes related to fatty acid β-oxidation, amino acid catabolism, and ureagenesis are often downregulated. Among gcrgr-deficient zebrafish, we experimentally confirmed increases in lipid accumulation in the liver and whole-body glucose uptake, as well as a modest decrease in total amino acid content. These results provide new information about the global metabolic network that GCGR signaling regulates in addition to a better understanding of the receptor’s physiological functions.

Spikelet number per panicle (SNP) is one of the most important yield components in rice. Rice ENHANCING BIOMASS AND SPIKELET NUMBER (OsEBS), a gene involved in improved SNP and yield, has been cloned from an accession of Dongxiang wild rice. However, the mechanism of OsEBS increasing rice SNP is poorly understood. In this study, the RNA-Seq technology was used to analyze the transcriptome of wildtype Guichao 2 and OsEBS over-expression line B102 at the heading stage, and analysis of the evolution of OsEBS was also conducted. A total of 5369 differentially expressed genes (DEGs) were identified between Guichao2 and B102, most of which were down-regulated in B102. Analysis of the expression of endogenous hormone-related genes revealed that 63 auxin-related genes were significantly down-regulated in B102. Gene Ontogeny (GO) enrichment analysis showed that the 63 DEGs were mainly enriched in eight GO terms, including auxin-activated signaling pathway, auxin polar transport, auxin transport, basipetal auxin transport, and amino acid transmembrane transport, most of which were directly or indirectly related to polar auxin transport. Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis further verified that the down-regulated genes related to polar auxin transport had important effects on increased SNP. Analysis of the evolution of OsEBS found that OsEBS was involved in the differentiation of indica and japonica, and the differentiation of OsEBS supported the multi-origin model of rice domestication. Indica (XI) subspecies harbored higher nucleotide diversity than japonica (GJ) subspecies in the OsEBS region, and XI experienced strong balancing selection during evolution, while selection in GJ was neutral. The degree of genetic differentiation between GJ and Bas subspecies was the smallest, while it was the highest between GJ and Aus. Phylogenetic analysis of the Hsp70 family in O. sativa, Brachypodium distachyon, and Arabidopsis thaliana indicated that changes in the sequences of OsEBS were accelerated during evolution. Accelerated evolution and domain loss in OsEBS resulted in neofunctionalization. The results obtained from this study provide an important theoretical basis for high-yield rice breeding.