Thermostable Bacterial Collagenolytic Proteases: A Review.

Collagenolytic proteases are widely used in the food, medical, pharmaceutical, cosmetic, and textile industries. Mesophilic collagenases exhibit collagenolytic activity under physiological conditions, but have limitations in efficiently degrading collagen-rich wastes, such as collagen from fish scales, at high temperatures due to their poor thermostability. Bacterial collagenolytic proteases are members of various proteinase families, including the bacterial collagenolytic metalloproteinase M9 and the bacterial collagenolytic serine proteinase families S1, S8, and S53. Notably, the C-terminal domains of collagenolytic proteases, such as the pre-peptidase C-terminal domain, the polycystic kidney disease-like domain, the collagen-binding domain, the proprotein convertase domain, and the ß-jelly roll domain, exhibit collagen-binding or -swelling activity. These activities can induce conformational changes in collagen or the enzyme active sites, thereby enhancing the collagen-degrading efficiency. In addition, thermostable bacterial collagenolytic proteases can function at high temperatures, which increases their degradation efficiency since heat-denatured collagen is more susceptible to proteolysis and minimizes the risk of microbial contamination. To date, only a few thermophile-derived collagenolytic proteases have been characterized. TSS, a thermostable and halotolerant subtilisin-like serine collagenolytic protease, exhibits high collagenolytic activity at 60°C. In this review, we present and summarize the current research on A) the classification and nomenclature of thermostable and mesophilic collagenolytic proteases derived from diverse microorganisms, and B) the functional roles of their C-terminal domains. Furthermore, we analyze the cleavage specificity of the thermostable collagenolytic proteases within each family and comprehensively discuss the thermostable collagenolytic protease TSS.

Unveiling the intricate connection between per- and polyfluoroalkyl substances and prostate hyperplasia.

The presence of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in various everyday products has raised concerns about their potential impact on prostate health. This study aimed to investigate the effects of different types of PFAS on prostate health, including PFDeA, PFOA, PFOS, PFHxS, and PFNA. To assess the relationship between PFAS exposure and prostate injury, machine learning algorithms were employed to analyze prostate-specific antigen (PSA) metrics. The analysis revealed a linear and positive dose-dependent association between PFOS and the ratio of free PSA to total PSA (f/tPSA). Non-linear dose-response relationships were observed between the other four types of PFAS and the f/tPSA ratio. Additionally, the analysis showed a positive association between the mixture of PFAS and prostate hyperplasia, with PFNA having the highest impact followed by PFOS. These findings suggest that elevated serum levels of PFDeA, PFOA, PFOS, and PFNA are linked to prostate hyperplasia. Therefore, this study utilized advanced machine learning techniques to uncover potential hazardous effects of PFAS exposure on prostate health, specifically the positive association between PFAS and prostate hyperplasia.

Gestational α-ketoglutarate supplementation ameliorates arsenic-induced hepatic lipid deposition via epigenetic reprogramming of ß-oxidation process in female offspring.

Inorganic trivalent arsenic (iAsⅢ) at environmentally relevant levels has been found to cause developmental toxicity. Maternal exposure to iAsⅢ leads to enduring hepatic lipid deposition in later adult life. However, the exact mechanism in iAsⅢ induced hepatic developmental hazards is still unclear. In this study, we initially found that gestational exposure to iAsⅢ at an environmentally relevant concentration disturbs lipid metabolism and reduces levels of alpha-ketoglutaric acid (α-KG), an important mitochondrial metabolite during the citric acid cycle, in fetal livers. Further, gestational supplementation of α-KG alleviated hepatic lipid deposition caused by early-life exposure to iAsⅢ. This beneficial effect was particularly pronounced in female offspring. α-KG partially restored the ß-oxidation process in hepatic tissues by hydroxymethylation modifications of carnitine palmitoyltransferase 1a (Cpt1a) gene during fetal development. Insufficient ß-oxidation capacities probably play a crucial role in hepatic lipid deposition in adulthood following in utero arsenite exposure, which can be efficiently counterbalanced by replenishing α-KG. These results suggest that gestational administration of α-KG can ameliorate hepatic lipid deposition caused by iAsⅢ in female adult offspring partially through epigenetic reprogramming of the ß-oxidation pathway. Furthermore, α-KG shows potential as an interventive target to mitigate the harmful effects of arsenic-induced hepatic developmental toxicity.

Didactical approaches and insights into environmental processes and cardiovascular hazards of arsenic contaminants.

Arsenic, as a metalloid, has the ability to move and transform in different environmental media. Its widespread contamination has become a significant environmental problem and public concern. Arsenic can jeopardize multiple organs through various pathways, influenced by environmental bioprocesses. This article provides a comprehensive overview of current research on the cardiovascular hazards of arsenic. A bibliometric analysis revealed that there are 376 papers published in 145 journals, involving 40 countries, 631 institutions, and 2093 authors, all focused on arsenic-related concerns regarding cardiovascular health. China and the U.S. have emerged as the central hubs of collaborative relationships and have the highest number of publications. Hypertension and atherosclerosis are the most extensively studied topics, with redox imbalance, apoptosis, and methylation being the primary mechanistic clues. Cardiovascular damage caused by arsenic includes arrhythmia, cardiac remodeling, vascular leakage, and abnormal angiogenesis. However, the current understanding is still inadequate over cardiovascular impairments, underlying mechanisms, and precautionary methods of arsenic, thus calling an urgent need for further studies to bridge the gap between environmental processes and arsenic hazards.

[Detection and Characteristics of Hepatitis C Virus Infection among Blood Donors in Qingyang City].

OBJECTIVE: To deeply understand the epidemic status of hepatitis C virus (HCV) among blood donors in Qingyang City, and prevent the risk of transmission of HCV via blood. METHODS: To compare the application of nucleic acid and enzyme immunoassay adopted in HCV screening of volunteer blood donors in Qingyang City. The characteristics of positive population and the status of co-infection were studied. RESULTS: From 2015 to 2020, the positive rate of HCV detection among blood donors in Qingyang City was 3.2‰. Among the HCV positive co-infections, treponema pallidum (TP) accounted for the largest proportion, followed by alanine aminotransferase (ALT) and HBsAg. Blood donation was mainly based on individual voluntariness, and the main age group was 26-45 years old. The distribution of blood type showed that 31.08% for type B, 28.31% for type O, 27.38% for type A and 13.23% for type AB, the population of type AB was lower than that of type B and type O. The distribution of sex showed that male was more than female. The marital status was concentrated in married population. The regional distribution was concentrated in Xifeng District. Qingcheng County was higher than Huachi County and other places, while Ning County, Heshui County, Zhenyuan County and Huan County were close. The occupation was dominated by unemployed. Their nationalities were all Han. The overall awareness rate of HCV knowledge in young volunteers was 67.2%. CONCLUSION: There are more HCV infected people with TP infection in voluntary blood donors, and the cognitive level of HCV knowledge in young volunteers needs to be improved.

Functional Characterization of the Lysine-Specific Histone Demethylases Family in Soybean.

Histone modifications, such as methylation and demethylation, have crucial roles in regulating chromatin structure and gene expression. Lysine-specific histone demethylases (LSDs) belong to the amine oxidase family, which is an important family of histone lysine demethylases (KDMs), and functions in maintaining homeostasis of histone methylation. Here, we identified six LSD-like (LDL) genes from the important leguminous soybean. Phylogenetic analyses divided the six GmLDLs into four clusters with two highly conserved SWRIM and amine oxidase domains. Indeed, demethylase activity assay using recombinant GmLDL proteins in vitro demonstrated that GmLDLs have demethylase activity toward mono- and dimethylated Lys4 but not trimethylated histone 3, similar to their orthologs previously reported in animals. Using real-time PCR experiments in combination with public transcriptome data, we found that these six GmLDL genes exhibit comparable expressions in multiple tissues or in response to different abiotic stresses. Moreover, our genetic variation investigation of GmLDL genes among 761 resequenced soybean accessions indicates that GmLDLs are well conserved during soybean domestication and improvement. Taken together, these findings demonstrate that GmFLD, GmLDL1a, and GmLDL1b are bona fide H3K4 demethylases towards H4K4me1/2 and GmLDLs exist in various members with likely conserved and divergent roles in soybeans.

Microplastics exposure causes oxidative stress and microbiota dysbiosis in planarian Dugesia japonica.

Planarians are widely used as water quality indicator species to provide early warning of harmful pollution in aquatic ecosystems. However, the impact of microplastics on freshwater planarians remains poorly investigated. Here we simulated waterborne microplastic exposure in the natural environments to examine the effect on the antioxidant defense system and microbiota in Dugesia japonica. The results showed that exposure to microplastics significantly changed the levels of antioxidant enzymes, including superoxide dismutase, catalase, and glutathione S-transferase, indicating that microplastic exposure induces oxidative stress in planarians. High-throughput 16S rRNA gene sequencing results revealed that exposure to microplastics altered the diversity, abundance, and composition of planarian microbiota community. At phylum level, the relative abundance of the dominant phyla Proteobacteria and Bacteroidetes changed significantly after microplastic exposure. At genus level, the abundance of dominant genera also changed significantly, including Curvibacter and unclassified Chitinophagales. Predictive functional analysis showed that the microbiota of microplastic-exposed planarians exhibited an enrichment in genes related to fatty acid metabolism. Overall, these results showed that microplastics can cause oxidative stress and microbiota dysbiosis in planarians, indicating that planarians can serve as an indicator species for microplastic pollution in freshwater systems.

Modulation of evening complex activity enables north-to-south adaptation of soybean.

Soybean, a typical short-day crop, is sensitive to photoperiod, which is a major limiting factor defining its north-to-south cultivation range. The long-juvenile (LJ) trait is controlled primarily by the J locus which has been used for decades by soybean breeders to delay flowering and improve grain yield in tropical regions. The J gene encodes an ortholog of the Arabidopsis Evening Complex (EC) component EARLY FLOWERING 3 (ELF3). To identify modifiers of J, we conducted a forward genetic screen and isolated a mutant (eoj57) that in combination with j has longer flowering delay compared with j single mutant plants. Map-based cloning and genome re-sequencing identified eoj57 (designated as GmLUX2) as an ortholog of the Arabidopsis EC component LUX ARRHYTHMO (LUX). To validate that GmLUX2 is a modifier of J, we used trans-complementation and identified a natural variant allele with a similar phenotype. We also show that GmLUX2 physically interacts with GmELF3a/b and binds DNA, whereas the mutant and natural variant are attenuated in both activities. Transcriptome analysis shows that the GmLUX2-GmELF3a complex co-regulates the expression of several circadian clock-associated genes and directly represses E1 expression. These results provide mechanistic insight into how GmLUX2-GmELF3 controls flowering time via synergistic regulation of gene expression. These novel insights expand our understanding of the regulation of the EC complex, and facilitate the development of soybean varieties adapted for growth at lower latitudes.

The Largest Subunit of DNA Polymerase Delta Is Required for Normal Formation of Meiotic Type I Crossovers.

Meiotic recombination contributes to the maintenance of the association between homologous chromosomes (homologs) and ensures the accurate segregation of homologs during anaphase I, thus facilitating the redistribution of alleles among progeny. Meiotic recombination is initiated by the programmed formation of DNA double strand breaks, the repair of which requires DNA synthesis, but the role of DNA synthesis proteins during meiosis is largely unknown. Here, we hypothesized that the lagging strand-specific DNA Polymerase δ (POL δ) might be required for meiotic recombination, based on a previous analysis of DNA Replication Factor1 that suggested a role for lagging strand synthesis in meiotic recombination. In Arabidopsis (Arabidopsis thaliana), complete mutation of the catalytic subunit of POL δ, encoded by AtPOLD1, leads to embryo lethality. Therefore, we used a meiocyte-specific knockdown strategy to test this hypothesis. Reduced expression of AtPOLD1 in meiocytes caused decreased fertility and meiotic defects, including incomplete synapsis, the formation of multivalents, chromosome fragmentation, and improper segregation. Analysis of meiotic crossover (CO) frequencies showed that AtPOLD1RNAi plants had significantly fewer interference-sensitive COs than the wild type, indicating that AtPOL δ participates in type I CO formation. AtPOLD1RNAi atpol2a double mutant meiocytes displayed more severe meiotic phenotypes than those of either single mutant, suggesting that the function of AtPOLD1 and AtPOL2A is not identical in meiotic recombination. Given that POL δ is highly conserved among eukaryotes, we hypothesize that the described role of POL δ here in meiotic recombination likely exists widely in eukaryotes.

[Screening of HBV and Positive Population Distribution Characteristics of Voluntary Blood Donors in Qingyang].

OBJECTIVE: To study and analyse the application of ELISA and nucleic acid test (NAT) to HBV detection of voluntary blood donors in Qingyang city and the characteristics and social attributes of HBV positive population. METHODS: The HBV of 70 659 blood donors in Qingyang city from January 2013 to December 2016 was detected by using ELISA and NAT, and the statistical analysis of results was performed by means of X2 detection and FIsher' s Exact test. RESULTS: The HBV positive rate detected by ELISA was 0.47% in 70 659 blood samples, and the HBV positive rate detected by NAT was 0.05% in 47 913 HBV negative samples detected by ELISA, moreover, the number of HBV negative by ELISA detection yet HBV positive by NAT detection increased year by year. The statistical analysis of positive population characteristics showed that the age distoibution was mainly between 26-45 years old, however the difference of detected rate between 26-45 years old and 18-25 years old gradually decreased on near 2 years, showing that the positive population tended to be younger. The distribution of blood type was B>O>A>AB, while the sex distribution was male> female, but this difference showed gradually nairowing trend due to increment of female voluntary donors with HBV positive; for marital status, HBV positive concentrated in married population. The regional distribution of HBV positive mainly concentrated in Xifeng region, mainly in jobless population; the HBV positive comparison betwwen anationalities showed Han natienatity was > minoring nationalitie. CONCLUSION: The application of ELISA combined with NAT for the HBV screaning of blood voluntary donors in Qiangyang city can prevent the detection failed and occult HBV, and reduce the potential risk of blood transfution. The characteristis analysis of HBV positive population provides practical basis for the safe use and transfution of blood.

Genome-Wide Analysis of Soybean JmjC Domain-Containing Proteins Suggests Evolutionary Conservation Following Whole-Genome Duplication.

Histone modifications, such as methylation and demethylation, play an important role in regulating chromatin structure and gene expression. The JmjC domain-containing proteins, an important family of histone lysine demethylases (KDMs), play a key role in maintaining homeostasis of histone methylation in vivo. In this study, we performed a comprehensive analysis of the jumonji C (JmjC) gene family in the soybean genome and identified 48 JmjC genes (GmJMJs) distributed unevenly across 18 chromosomes. Phylogenetic analysis showed that these JmjC domain-containing genes can be divided into eight groups. GmJMJs within the same phylogenetic group share similar exon/intron organization and domain composition. In addition, 16 duplicated gene pairs were formed by a Glycine-specific whole-genome duplication (WGD) event approximately 13 million years ago (Mya). By investigating the expression profiles of these gene pairs in various tissues, we showed that the expression pattern is conserved in the polyploidy-derived JmjC duplicates, demonstrating that the majority of GmJMJs were preferentially retained after the most recent WGD event and suggesting important roles for demethylase duplications in soybean evolution. These results shed light on the evolutionary history of this family in soybean and provide insights into the JmjCs which will be helpful to reveal their functions in controlling soybean development.

ROP6 is involved in root hair deformation induced by Nod factors in Lotus japonicus.

Roots of leguminous plants perceive Nod factor signals, and then root hair deformation responses such as swelling and curling are activated. However, very little is known about the molecular mechanisms of such root hair deformation. We have previously shown that LjROP6, a member of the Rho family of small GTPases, was identified as an NFR5 (Nod Factor Receptor 5)-interacting protein and participated in symbiotic nodulation in Lotus japonicus. In this study, we identified ten LjROP GTPases including LjROP6, and they were distributed into groups II, III, IV but not group I by phylogenetic analysis. The expression profiles of ten LjROP genes during nodulation were examined. LjROP6 belonged to group IV and interacted with NFR5 in a GTP-dependent manner. Overexpression of either wild-type ROP6 or a constitutively active mutant (ROP6-CA) generated root hair tip growth depolarization, while overexpression of a dominant negative mutant (ROP6-DN) exhibited normal root hair growth. After inoculating with Mesorhizobium loti or adding Nod factors to hairy roots, overexpression of ROP6 and ROP6-CA exhibited extensive root hair deformation, while overexpression of ROP6-DN inhibited root hair deformation. The infection event and nodule number were increased in ROP6 and ROP6-CA overexpressing transgenic plants; but decreased in ROP6-DN overexpressing transgenic plants. These studies provide strong evidence that ROP6 GTPase, which binds NFR5 in a GTP-dependent manner, is involved in root hair development as well as root hair deformation responses induced by NFs in the early stage of symbiotic interaction in L. japonicus.

Genome-Wide Identification, Classification, and Expression Analysis of Amino Acid Transporter Gene Family in Glycine Max.

Amino acid transporters (AATs) play important roles in transporting amino acid across cellular membranes and are essential for plant growth and development. To date, the AAT gene family in soybean (Glycine max L.) has not been characterized. In this study, we identified 189 AAT genes from the entire soybean genomic sequence, and classified them into 12 distinct subfamilies based upon their sequence composition and phylogenetic positions. To further investigate the functions of these genes, we analyzed the chromosome distributions, gene structures, duplication patterns, phylogenetic tree, tissue expression patterns of the 189 AAT genes in soybean. We found that a large number of AAT genes in soybean were expanded via gene duplication, 46 and 36 GmAAT genes were WGD/segmental and tandemly duplicated, respectively. Further comprehensive analyses of the expression profiles of GmAAT genes in various stages of vegetative and reproductive development showed that soybean AAT genes exhibited preferential or distinct expression patterns among different tissues. Overall, our study provides a framework for further analysis of the biological functions of AAT genes in either soybean or other crops.

[Tissue distribution on methyl nonyl ketone of the volatile oil from Houttyunia cordata in mice].

OBJECTIVE: To study the tissue distribution on methyl nonyl ketone of the volatile oil from Houttuynia cordata in mice in order to provide a guidance for the clinical trial. METHODS: The concentrations of the volatile oil from Houttuynia cordata in biological samples were determined by GC method. RESULTS: After a single oral dose of 5.0 g/kg volatile oil from Houttuynia cordata in mice, parent drug was mainly distributed in windpipe, intesting, liver, kidney, heart, blood, spleen, lung, brain, muscle; after 7 hours, parent drug of every tissue decreased over 90%. CONCLUSION: Parent drug mianly distributes in windpipe, intestine, liver, kidney. The experiment provides pharmacokinetic evidence for the rational administration and the further development of Houttuynia cordata.