Expression Of Synthesis-related Genes Research Articles

Functional characterization of transcription factor WIN1 genes associated with lipid biosynthesis and stress tolerance in soybean (Glycine max)

Transcription factor WAX INDUCER1 (WIN1) plays an important role in wax and cutin biosynthesis in plants. In this study, six GmWIN1 genes were identified from soybean ( Glycine max ), with GmWIN1–5 having high expression in flowers and seeds, particularly under cold stress. GmWIN1–5′s functions in lipid/oil biosynthesis and stress tolerance were characterized by its overexpression in soybean hairy roots and tobacco ( Nicotiana benthamiana ) plants. Under cold stress, GmWIN1–5 overexpression ( GmWIN1–5- OE) resulted in large oil enhancement and high level of phospholipids involved in cell membranes formation. Malondialdehyde content and elcetronlyte leakage in GmWIN1–5-OE plants was smaller than that in the wild-type control under cold stress, indicating that GmWIN1–5 promote plant stress tolerance. Moreover, GmWIN1–5-OE also led to upregulated expression of numerous genes involved in de novo fatty acid biosynthesis and triacylglycerol (TAG) production, including genes encoding phospholipase D ( PLD ), biotin carboxyl carrier protein 1 ( BCCP1 ), lysophosphatidic acid acyltransferase 5 ( LPAT5 ), and diacylglycerol acyltransferase 2 ( DGAT2 ). GmWIN1–5 directly bound to the promoter region of PLD gene. Overall, the results revealed that GmWIN1–5 can upregulate the biosynthesis and accumulation of lipids/oils, especially unsaturated fatty acids and phospholipids benefiting membrane integrity, and ultimately confer plants with high stress tolerance. • Six GmWIN1 members with structural integrity are identified in soybean ( Glycine max ). • Of the six GmWIN1s, GmWIN1-5 expression level was the highest in flower and seed tissues. • Overexpression of GmWiN1-5 in soybean hair roots increased total lipids and cold stress tolerance. • Ectopic expression of GmWIN1-5 in tobacco plant boosted oil content and stress tolerance. • GmWIN1-5 promoted expression of several lipid synthesis-related genes, particularly PLD.

Antibiofilm and Antiquorum Sensing Potential of Lactiplantibacillus plantarum Z057 against Vibrio parahaemolyticus.

Vibrio parahaemolyticus is a widespread foodborne pathogen that causes serious seafood-borne gastrointestinal infections. Biofilm and quorum sensing (QS) are critical in regulating these infections. In this study, first, the ability of Lactiplantibacillus plantarum Z057 to compete, exclude, and displace V. parahaemolyticus biofilm was evaluated. Then, the inhibitory effects of L. plantarum Z057 extract (Z057-E) on V. parahaemolyticus biofilm and QS were explored from the aspects of biofilm biomass, metabolic activity, physicochemical properties, extracellular polymer matrix content, QS signal AI-2 activity, biofilm microstructure, and the expression levels of biofilm and QS-related genes. Results showed that L. plantarum Z057 effectively inhibited biofilm formation of V. parahaemolyticus and interfered with the adhesion of V. parahaemolyticus on the carrier surface. In addition, the Z057-E could significantly reduce the biofilm biomass, metabolic activity, hydrophobicity, auto-aggregation ability, swimming and swarming migration diameter, AI-2 activity, extracellular polysaccharide (EPS), and extracellular protein content of V. parahaemolyticus. Fluorescence microscope and scanning electron microscope (SEM) images demonstrated that the Z057-E could efficiently inactivate the living cells, destroy the dense and complete biofilm architectures, and reduce the essential component of the extracellular polymer matrix. Real-time fluorescence quantitative PCR revealed that the Z057-E treatment down-regulated the expression of flagellum synthesis-related genes (flaA, flgM), EPS, and extracellular protein synthesis-related genes (cpsA, cpsQ, cpsR, ompW), QS-related genes (luxS, aphA, opaR), and hemolysin secretion-related genes (toxS, toxR) of V. parahaemolyticus. Thus, our results suggested that L. plantarum Z057 could represent an alternative biocontrol strategy against foodborne pathogens with anti-adhesive, antibiofilm, and antiquorum sensing activities.

Akkermansia muciniphila Enhances Egg Quality and the Lipid Profile of Egg Yolk by Improving Lipid Metabolism.

Akkermansia muciniphila (A. muciniphila) has shown potential as a probiotic for the prevention and treatment of non-alcoholic fatty liver disease in both humans and mice. However, relatively little is known about the effects of A. muciniphila on lipid metabolism, productivity, and product quality in laying hens. In this study, we explored whether A. muciniphila supplementation could improve lipid metabolism and egg quality in laying hens and sought to identify the underlying mechanism. In the first experiment, 80 Hy-Line Brown laying hens were divided into four groups, one of which was fed a normal diet (control group), while the other three groups were administered a high-energy, low-protein diet to induce fatty liver hemorrhagic syndrome (FLHS). Among the three FLHS groups, one was treated with phosphate-buffered saline, one with live A. muciniphila, and one with pasteurized A. muciniphila. In the second experiment, 140 Hy-Line Brown laying hens were divided into two groups and respectively fed a basal diet supplemented or not with A. muciniphila lyophilized powder. The results showed that, in laying hens with FLHS, treatment with either live or pasteurized A. muciniphila efficiently decreased body weight, abdominal fat deposition, and lipid content in both serum and the liver; downregulated the mRNA expression of lipid synthesis-related genes and upregulated that of lipid transport-related genes in the liver; promoted the growth of short-chain fatty acids (SCFAs)-producing microorganisms and increased the cecal SCFAs content; and improved the yolk lipid profile. Additionally, the supplementation of lyophilized powder of A. muciniphila to aged laying hens reduced abdominal fat deposition and total cholesterol (TC) levels in both serum and the liver, suppressed the mRNA expression of cholesterol synthesis-related genes in the liver, reduced TC content in the yolk, increased eggshell thickness, and reshaped the composition of the gut microbiota. Collectively, our findings demonstrated that A. muciniphila can modulate lipid metabolism, thereby, promoting laying hen health as well as egg quality and nutritive value. Live, pasteurized, and lyophilized A. muciniphila preparations all have the potential for use as additives for improving laying hen production.

Dietary resistant starch ameliorating lipopolysaccharide-induced inflammation in meat ducks associated with the alteration in gut microbiome and glucagon-like peptide 1 signaling

BackgroundConsumption of resistant starch (RS) has been associated with various intestinal and systemic health benefits, but knowledge of its effects on intestinal health and inflammatory response in stressed birds is limited. Here, we examined how dietary RS supplementation from 12% raw potato starch (RPS) modulated inflammatory severity induced by lipopolysaccharide (LPS) in meat ducks.ResultsLPS administration at 14, 16, and 18 d (chronic challenge) decreased body weight (BW) and glucagon-like peptide 1 receptor (GLP-1R) level with higher intestinal permeability and inflammation, evident by higher pro-inflammatory cytokine levels. Dietary 12% RPS supplementation enhanced Claudin-1 and GLP-1R expression, along with lower levels of inflammatory factors in both ileum and serum. Microbiome analysis showed that RS treatment shifted microbial structure reflected by enriched the proportion of Firmicutes, Bifidobacterium, Ruminococcus, etc. Dietary RS addition also significantly increased the concentrations of propionate and butyrate during chronic LPS challenge. Furthermore, response to acute challenge, the ducks received 2 mg/kg BW LPS at 14 d had higher concentrations of serum endotoxins and inflammatory cytokines, as well as upregulated transcription of toll like receptor 4 (TLR4) in ileum when compared to control birds. Analogous to GLP-1 agonist liraglutide, dietary RS addition decreased endotoxins and inflammation cytokines, whereas it upregulated the GLP-1 synthesis related genes expression. Meanwhile, dietary RS supplementation suppressed the acute LPS challenge-induced TLR4 transcription.ConclusionsThese data suggest that dietary 12% RPS supplementation could attenuate the LPS-induced inflammation as well as intestinal injury of meat ducks, which might involve in the alteration in gut microbiota, SCFAs production and the signaling pathways of TLR4 and GLP-1/GLP-1R.

Study on the Influencing Mechanism of Human Chorionic Gonadotropin (hCG) on Oocyte Maturation in Patients with Polycystic Ovary Syndrome.

The study was aimed at investigating the influence of human chorionic gonadotropin (hCG) hormone on oocyte maturation in the patients with polycystic ovary syndrome (PCOS). A total of 54 patients with PCOS who received in vitro maturation (IVM) treatment in the Cheeloo College of Medicine, Shandong University, were divided into two groups: one group who underwent hCG injections was the observation group (OG; n = 27) and other was the control group (CG; n = 27) with no hCG injection. The oocyte development and the expression of steroid hormone synthesis-related genes including gonadotropin-releasing hormone receptor (GnRHR), Conexin43, epidermal growth factor-related genes, luteinizing hormone/choriogonadotropin receptor (LHCGR), epiregulin (EREG), and vascular endothelial growth factor (VEGF) were examined. The human ovarian granulosa cell line (SVOG cells) and ovarian epithelial cell line (HOSEpiC cells) were employed to analyze the effect of hCG on the biological behaviour of cells. As a result, OG showed higher normal fertilization, cleavage, and high-qualified embryo rate than CG. Expression levels of GnRHR, Cx43, LHCGR, EREG, and VEGF were significantly elevated in granulosa cells in the OG group. Western blot revealed that phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and rapamycin (mTOR) proteins were decreased in granulosa cells under hCG intervention. A biological behaviour test indicated that the multiplication capacity of hCG-intervened SVOG and HOSEpiC was increased, while the apoptosis was decreased. In conclusion, hCG could accelerate follicular development and oocyte maturation by activating oocyte maturation genes in PCOS patients, which could significantly improve and popularize the application of IVM technology.

Discovery of Novel Iminosugar Compounds Produced by Lactobacillus paragasseri MJM60645 and Their Anti-Biofilm Activity against Streptococcus mutans.

ABSTRACTThe oral cavity contains a number of microbes. They interact with each other and play an important role in human health. Among oral cariogenic microbes, Streptococcus mutans is recognized a major etiological bacteria of dental caries. Lactobacilli strains have been promoted as possible probiotic agents against S. mutans. However, their inhibitory mechanism has not been well elucidated yet. In the present study, two new compounds with strong antibiofilm activities were purified from the culture supernatant of Lactobacillus paragasseri MJM60645, which was isolated from the human oral cavity. These compounds showed strong inhibitory activities against S. mutans biofilm formation, with IC50 (concentration at which 50% biofilm was inhibited) of 30.4 μM for compound 1 and 18.9 μM for compound 2. However, these compounds did not show bactericidal activities against S. mutans. Structure elucidation by nuclear magnetic resonance (NMR) and mass spectrometry showed that compound 1 was composed of two arabinofuranose iminosugars jointed with one glycerol and oleic acid, and compound 2 was composed of two arabinofuranose iminosugars jointed with one glycerol and nervonic acid. To the best of our knowledge, these structures were discovered for the first time in this study. Treatment of S. mutans with compound 1 strongly downregulated expression levels of genes related to biofilm formation, including gtfB, gtfC, gtfD, gbpB, brpA, spaP, ftf, and smu0630 without affecting the expression of comDE or relA. This study provides new insights into novel molecules produced by Lactobacillus to regulate the pathogenesis of S. mutans, facilitating a better understanding of the mechanism for interactions between Lactobacillus and S. mutans.IMPORTANCE In this study, we isolated lactic acid bacteria that inhibit streptococcal biofilm from the oral cavity of infants and identified two novel compounds from the supernatant of their culture broth. The two compounds are structurally similar, and both consist of iminosugars, glycerol, and unsaturated fatty acid. A search of the SciFinder database revealed that these structures are novel and were discovered for the first time in this study. Mechanism studies have shown that these compounds can inhibit the expression of biofilm synthesis-related genes. This is the first report that lactic acid bacteria inhibit streptococcal biofilms by small molecules with new chemical structures. This study not only expands the understanding of natural products derived from lactic acid bacteria but also provides a new paradigm for the understanding of the interaction of bacteria in the oral microbiota.

MdNAC4 Interacts With MdAPRR2 to Regulate Nitrogen Deficiency-Induced Leaf Senescence in Apple (Malus domestica).

Nitrogen (N) is one of the important macronutrients in plants, and N deficiency induces leaf senescence. However, the molecular mechanism underlying how N deficiency affects leaf senescence is unclear. Here, we report an apple NAC TF, MdNAC4, that participates in N deficiency-induced leaf senescence. The senescence phenotype of apple leaves overexpressing MdNAC4 was enhanced after N deficiency. Consistently, the chlorophyll content of transgenic leaves was significantly lower than that in the WT control leaves, the expression of chlorophyll catabolism-related genes (MdNYC1, MdPAO, and MdSGR1) was significantly higher than that in the WT controls, and the expression of chlorophyll synthesis-related genes (MdHEMA, MdCHLI, and MdCHLM) was significantly lower than that in the WT control leaves. Furthermore, MdNAC4 was found to directly activate the transcription of the chlorophyll catabolism-related genes MdNYC1 and MdPAO. Additionally, MdNAC4 was proven to interact with MdAPRR2 proteins both in vitro and in vivo, and overexpression of MdAPRR2 seemed to delay N deficiency-induced leaf senescence. Correspondingly, the chlorophyll loss of MdAPRR2-overexpressing (MdAPRR2-OE) lines was significantly lower than in WT control plants. Although downregulated, the expression of the chlorophyll synthesis-related genes MdHEMA, MdCHLI, and MdCHLM in the transgenic plants was more than twice that in the WT control plants. Taken together, our results enrich the regulatory network of leaf senescence induced by N deficiency through the interaction between MdNAC4 and MdAPRR2.

Molecular Evidence of Chemical Disguise by the Socially Parasitic Spiny Ant Polyrhachis lamellidens (Hymenoptera: Formicidae) When Invading a Host Colony

While most ant species establish a colony independently, some socially parasitic ants build the foundation of their colony by invading other ant (host) colonies and utilizing their labor forces. Many socially parasitic ants disguise their cuticular hydrocarbon (CHC) profile, which is also known as signature mixture for nestmate discrimination, when invading the host colony. Since the strategy of chemical disguise is widespread in socially parasitic ants, elucidating the mechanism of chemical disguise will promote knowledge on the evolutionary history of social parasitism. However, detailed knowledge is still lacking, as the relevant information has only originated from circumstantial evidence, which was obtained from ecological observations. In this study, we investigated the mechanism of chemical disguise in a new queen of a temporary socially parasitic spiny ant (Polyrhachis lamellidens) by measuring its CHC profile, performing a tracing assay with labeled substances, and analyzing gene expression levels. First, after rubbing behavior was observed against the host workers, the CHC profile in P. lamellidens shifted to pronounced peaks that closely resembling that of the host workers. We also observed a reduction in aggressive behaviors by the host ant against P. lamellidens after rubbing behavior was performed. In addition, P. lamellidens acquired artificially-applied labeling substances from host workers through their rubbing behaviors, while gene expression profiling showed the expression of CHC synthesis-related genes did not change during this behavior. These results suggest that P. lamellidens directly obtains host CHCs through rubbing behavior, and these host CHCs enables P. lamellidens to remain disguised during colony invasion.

Arabidopsis SUMO E3 ligase SIZ1 enhances cadmium tolerance via the glutathione-dependent phytochelatin synthesis pathway

Sumoylation is a posttranslational modification (PTM) in which SUMO (small ubiquitin-like modifier) is covalently conjugated to protein substrates via a range of enzymes. SUMO E3 ligase SIZ1 is involved in mediating several essential or nonessential element-responsive SUMO conjugations in Arabidopsis. However, whether SIZ1 is involved in the cadmium (Cd) response remains to be identified. In this study, we found that SIZ1 positively regulates plant Cd tolerance. The loss-of-function siz1–2 mutant exhibited impaired resistance to Cd exposure and accumulated more reactive oxygen species (ROS). Moreover, the transcription of GSH1, GSH2, PCS1, and PCS2 was suppressed while the accumulation of Cd was enhanced in the siz1–2 mutant under Cd exposure. Further analysis revealed that the higher Cd sensitivity of the siz1–2 mutant was partially rescued by the overexpression of GSH1. Consistently, Cd stress stimulated the accumulation of SUMO1 conjugates in wild-type plants but not in the siz1–2 mutant. Together, our results demonstrate that Cd-induced SIZ1 activates GSH- and PC synthesis-related gene expression to increase the synthesis of GSH- and PCs, thereby leading to higher Cd tolerance in plants.

Effect of Heat Stress on Egg Production, Steroid Hormone Synthesis, and Related Gene Expression in Chicken Preovulatory Follicular Granulosa Cells.

Simple SummaryThe debilitating effects of heat stress on poultry production have been well documented. Heat stress already results in severe economic loss worldwide. Regarding the decline in the reproductive performance of heat-stressed hens, the exact mechanisms involved are still unknown. The present study was conducted to elucidate the molecular mechanisms underlying heat-stress-induced abnormal egg production in laying hens. Our results confirmed that laying hens reared under heat stress had impaired laying performance. Follicular granulosa cells cultured in vitro are sensitive to the effects of heat stress, showing an increase in apoptosis and cellular ultrastructural changes. These effects appeared in the form of heat-stress-elevated progesterone, with the increased expression of steroidogenic acute regulatory protein, cytochrome P450 family 11 subfamily A member 1, and 3b-hydroxysteroid dehydrogenase, along with inhibited estradiol synthesis through the decreased expression of follicle-stimulating hormone receptor and the cytochrome P450 family 19 subfamily A member 1. Collectively, laying hens exposed to high temperatures showed damage to granulosa cells that brought about a decline in egg production. This study provides a molecular mechanism for the abnormal laying performance of hens subjected to heat stress, which may help when developing novel strategies to reverse the adverse impact.This study was conducted to elucidate the molecular mechanisms underlying heat stress (HS)-induced abnormal egg-laying in laying hens. Hy-Line brown laying hens were exposed to HS at 32 °C or maintained at 22 °C (control) for 14 days. In addition, granulosa cells (GCs) from preovulatory follicles were subjected to normal (37 °C) or high (41 °C or 43 °C) temperatures in vitro. Proliferation, apoptosis, and steroidogenesis were investigated, and the expression of estrogen and progesterone synthesis-related genes was detected. The results confirmed that laying hens reared under HS had impaired laying performance. HS inhibited proliferation, increased apoptosis, and altered the GC ultrastructure. HS also elevated progesterone secretion by increasing the expression of steroidogenic acute regulatory protein (StAR), cytochrome P450 family 11 subfamily A member 1 (CYP11A1), and 3b-hydroxysteroid dehydrogenase (3β-HSD). In addition, HS inhibited estrogen synthesis in GCs by decreasing the expression of the follicle-stimulating hormone receptor (FSHR) and cytochrome P450 family 19 subfamily A member 1 (CYP19A1). The upregulation of heat shock 70 kDa protein (HSP70) under HS was also observed. Collectively, laying hens exposed to high temperatures experienced damage to follicular GCs and steroidogenesis dysfunction, which reduced their laying performance. This study provides a molecular mechanism for the abnormal laying performance of hens subjected to HS.

Response of Phytic Acid to Nitrogen Application and Its Relation to Protein Content in Rice Grain

Nitrogen (N) fertilization has been recognized as improving the grain beneficial micronutrients, including Zn and Fe, in rice. However, only a few studies have explicitly focused on N-induced variation in anti-nutritional components such as phytic acid (PA), PA synthesis-related gene expression, and variation in grain protein fractions. Therefore, in this study, two culture systems (hydroponic and detached panicle culture systems) were used to elucidate the influence of N application on PA concentration and its relation to the grain protein fractions, such as albumin, globulin, prolamin, and glutelin, and total protein in rice. Results showed that N application generally decreased the grain PA concentration in brown rice and down-regulated the PA synthesis-related genes in the lipid-independent pathway. In contrast, total grain protein and its fractions concentrations increased significantly. For grain positional distribution, PA and protein concentration were generally higher in the aleurone fraction than in the milled rice, regardless of N application. However, higher N application decreased the PA in both aleurone fraction and milled rice, while increased the grain protein fractions mainly in milled rice. These findings imply that N application could substantially improve the rice nutrition by reducing the PA while increasing the protein concentration. Hence, these findings may provide critical bases for rice nutritional improvement through optimal N management.

All-trans retinoic acid inhibits the malignant behaviors of hepatocarcinoma cells by regulating ferroptosis

All-trans retinoic acid (ATRA) can reverse the malignant behaviors of hepatocellular carcinoma (HCC) cells, thereby exerting anti-HCC effect; however, the underlying mechanism is yet to be understood. This study aimed to demonstrate that ATRA is vital to ferroptosis in HCC. Ferroptosis-related genes exhibit different expression in patients with HCC compared to that in healthy individuals. A total of 20 amino acid products were detected in HepG2 cells, the expression level of 5 was decreased after ATRA treatment. ATRA improved the levels of lipid ROS, MDA, and NAPD+/NADPH, and reduced the mt-DNA copy number and changed the structure of mitochondria, in HepG2 and Hep3B cells. We found the expression of genes positively correlated with ferroptosis to increase and those negatively correlated to decrease with ATRA treatment. Inhibition of ferroptosis by Ferrostatin-1 reversed ATRA-inhibited proliferation of HCC cells, along with cell migration and invasion. GSH synthesis was blocked by ATRA, accompanied by decreased cystine content and increased glutamate content, and downregulation of the expression of GSH synthesis-related genes. Our findings suggested that ATRA inhibited the malignancy of HCC cells by improving ferroptosis, and that inhibition of GSH synthesis contributed to ATRA-induced ferroptosis.

Sucrose-free hawthorn leathers formulated with fructooligosaccharides and xylooligosaccharides ameliorate high-fat diet induced inflammation, glucose and lipid metabolism in liver of mice

High sucrose content in traditional hawthorn leathers limits the potential consumption, particularly for elders and diabetics. In this study, sucrose-free hawthorn leathers were formulated with 75% fructooligosaccharides (FOS) and 25% xylooligosaccharides (XOS) (HLF75), which exhibited comparable morphology and sensory properties to the traditional ones. Then, the anti-obesity activity of HLF75 was investigated using high-fat diet (HFD) fed C57BL/6J mice. Comparing with traditional hawthorn leathers, HLF75 supplementation in HFD significantly decreased the levels of blood glucose and serum lipid. The histomorphologies of liver and subcutaneous fat tissues were ameliorated by HLF75, as well as the down-regulated mRNA expression levels of IL-1β, Nos2 and Cox-2 in the liver. Moreover, the protein levels of MyD88 and NF-κB in the liver were suppressed by HLF75 treatment with decreased F4/80-positive macrophage number. However, the expression levels of PI3K, phosphorylated-AKT (Thr308), and phosphorylated-mTOR (Ser2448) proteins related to glucose metabolism were increased in the liver. Moreover, fat synthesis-related gene expression in HLF75-fed mice was suppressed while expressions of lipolysis genes were improved. Thus, HLF75 supplementation alleviated HFD-induced obesity through the alleviation of inflammation and restoration of the disturbed glucose and lipid metabolism. Functional oligosaccharides could be effective sucrose substitutes in hawthorn leathers and enable their potential utilization as functional foods.

Leucine alters blood parameters and regulates hepatic protein synthesis via mammalian/mechanistic target of rapamycin activation in intrauterine growth-restricted piglets.

Neonatal piglets often suffer low birth weights and poor growth performance accompanied by the disruption of protein metabolism, when intrauterine growth restriction (IUGR) takes place during pregnancy, leading to a higher mortality and bigger economic loss than expected. Leucine has been proposed to function as a nutritional signal-regulating protein synthesis in numerous studies. The aim of this study was to determine the effect of dietary leucine supplementation on the blood parameters and hepatic protein metabolism in IUGR piglets. Weaned piglets were assigned to one of four treatments in a 2 × 2 factorial arrangement: 1) piglets fed a basal diet with normal birth weight, 2) piglets fed a basal diet plus 0.35% l-leucine with normal birth weight, 3) IUGR piglets fed a basal diet with low birth weight, and 4) IUGR piglets fed a basal diet plus 0.35% l-leucine with low birth weight. The results showed that IUGR decreased serum aspartate aminotransferase and alkaline phosphatase activities and increased serum cortisol and prostaglandin E2 levels at 35 d of age (P < 0.05), suggesting the occurrence of liver dysfunction and stress response. Leucine supplementation increased serum alkaline phosphatase activity and decreased serum cortisol levels at 35 d of age (P < 0.05). IUGR decreased the lysozyme activity and complement 3 level in serum (P < 0.05), which were prevented by dietary leucine supplementation. IUGR piglets showed increased hepatic DNA contents while showing a reduced RNA/DNA ratio (P < 0.05). Piglets supplied with leucine had decreased RNA/DNA ratio in the liver (P < 0.05). Leucine supplementation stimulated hepatic protein anabolism through upregulating protein synthesis-related genes expression and activating the phosphorylation of mammalian/mechanistic target of rapamycin (mTOR) (P < 0.05). Moreover, IUGR inhibited the mRNA expression of hepatic protein degradation-related genes, indicating a compensatory mechanism for the metabolic response. Dietary leucine supplementation attenuated the suppression of the protein catabolism induced by IUGR in the liver. These results demonstrate that dietary leucine supplementation could alter the blood parameters and alleviated the disrupted protein metabolism induced by IUGR via enhanced mTOR phosphorylation to promote protein synthesis in weaned piglets.

Hydroxy Selenomethionine Alleviates Hepatic Lipid Metabolism Disorder of Pigs Induced by Dietary Oxidative Stress via Relieving the Endoplasmic Reticulum Stress.

This study used 40 castrated male pigs to determine the protective effects of a new selenium molecule (hydroxy selenomethionine, OH-SeMet) on dietary oxidative stress (DOS) induced hepatic lipid metabolism disorder, and corresponding response of selenotranscriptome. The pigs were randomly grouped into 5 dietary treatments and fed a basal diet formulated with either normal corn and oils or oxidized diet in which the normal corn and oils were replaced by aged corn and oxidized oils, and supplemented with OH-SeMet at 0.0, 0.3, 0.6 and 0.9 mg Se/kg for a period of 16 weeks (n = 8). The results showed that DOS induced liver damage, increased serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels, decreased serum triacylglycerol (TG) level, suppressed antioxidant capacity in the liver, and changed lipid metabolism enzyme activity, thus causing lipid metabolism disorder in the liver. The DOS-induced lipid metabolism disorder was accompanied with endoplasmic reticulum (ER) stress, changes in lipid metabolism-related genes and selenotranscriptome in the liver. Dietary Se supplementation partially alleviated the negative impact of DOS on the lipid metabolism. These improvements were accompanied by increases in Se concentration, liver index, anti-oxidative capacity, selenotranscriptome especially 11 selenoprotein-encoding genes, and protein abundance of GPX1, GPX4 and SelS in the liver, as well as the decrease in SelF abundance. The Se supplementation also alleviated ER stress, restored liver lipid metabolism enzyme activity, increased the mRNA expression of lipid synthesis-related genes, and decreased the mRNA levels of lipidolysis-related genes. In conclusion, the dietary Se supplementation restored antioxidant capacity and mitigated ER stress induced by DOS, thus resisting hepatic lipid metabolism disorders that are associated with regulation of selenotranscriptome.

Exogenous Melatonin Alleviates Alkaline Stress by Removing Reactive Oxygen Species and Promoting Antioxidant Defence in Rice Seedlings.

Saline-alkali stress seriously restricts rice growth, development, and production in northern China. The damage of alkaline stress on rice is much greater than that of salt due to ion toxicity, osmotic stress, and especially high pH. As a signal molecule, melatonin (N-acetyl-5-methoxytryptamine, MT) mediates many physiological processes in rice and participates in protecting rice from abiotic stress. The potential mechanism of exogenous melatonin-mediated alkaline stress tolerance is still largely unknown. In this study, the effects of melatonin on the morphological change, physiological property, and corresponding genes expression in rice seedlings were analyzed under alkaline stress (20 mmol L−1, pH 9.55). The results showed that the expression levels of MT synthesis genes (TDC2, T5H, SNAT, ASMT1, and ASMT2) were induced by both exogenous MT and alkaline stress treatment. The cell membrane was protected by MT, and the MT furtherly play role in scavenging reactive oxygen species (ROS), reducing lipoxygenase (LOX) activity, and malondialdehyde (MDA) content. The scavenging of ROS by melatonin is attributed to the coupling of the improvement of redox homeostasis and the enhancement of antioxidant enzyme activity and antioxidant content by upregulating the transcriptional levels of antioxidase genes. In the meantime, MT pretreatment promoted the accumulation of free proline, sucrose, and fructose by regulating the OsP5CS, OsSUS7, and OsSPS1 gene expression level and increased chlorophyll content upregulating the expression of chlorophyll synthesis-related genes. Ultimately, the alleviating effect of exogenous melatonin on alkaline stress was reflected in increasing the leaf relative water content (RWC) and root-shoot ratio and reducing the leaf tip wilt index (TWI) through a series of physiological and biochemical changes. Melatonin pretreatment changed the expression level of MT synthesis genes which might contribute to MT synthesis in rice, consequently, activated the ROS scavenging system and alleviating the damage of alkaline stress on rice seedlings. Our study comprehensively understands the alleviating effect of exogenous melatonin on rice under alkaline stress.

Effect of metal ions on lipopeptide secretion from Bacillus subtilis strain FJAT-4: Negative regulation by Ca2.

This study aimed to investigate the effect of metal ions on lipopeptide production by Bacillus subtilis strain FJAT-4 and the mechanism of negative regulation by Ca2+ . The quantitative measurement of lipopeptides in response to K+ , Na+ , Mg2+ and Ca2+ addition was carried out by LC-MS. The contents of fengycin and surfactin varied within the range of 116.24-129.80 mg/L and 34.03-63.11 mg/L in the culture media containing K+ , Na+ and Mg2+ , while the levels were 0.86 and 0.63 mg/L in the media containing Ca2+ . Ca2+ at a high concentration (45 mM) did not adversely affect the growth of strain FJAT-4, but caused significant downregulation of lipopeptide synthesis-related gene expression, corresponding to a decrease in lipopeptide production. This inhibition by Ca2+ was further investigated by proteomic analysis. In total, 112 proteins were upregulated and 524 proteins were downregulated in the presence of additional Ca2+ (45 mM). Among these differentially expressed proteins (DEPs), 28 were related to phosphotransferase activity, and 42 were related to kinase activity. The proteomics results suggested that altered levels of three two-component signal-transduction systems (ResD/ResE, PhoP/PhoR and DegU/DegS) might be involved in the control of expression of the fen and srfA operons of FJAT-4 under high calcium stress. The Ca2+ at the high concentration (45 mM) triggers a decrease in lipopeptide production, which might be attributed to the regulation of three two-component signal-transduction systems ResD/ResE, PhoP/PhoR and DegU/DegS. The regulatory effect of calcium on the expression of genes encoding lipopeptide synthetases can be applied to optimize the production of lipopeptides.

Functional analysis of hot pepper ethylene responsive factor 1A in plant defense

ABSTRACT Ethylene-responsive factors play important roles in the biotic and abiotic stresses. Only some ERF genes from Capsicum annuum have been characterized. In the study, the CaERF1A gene is characterized in response to biotic stress. CaERF1A transcripts were induced by various plant defense-related hormone treatments. Knockdown of CaERF1A in hot pepper plants are negatively affected Tobacco mosaic virus-P0-mediated hypersensitive response cell death, resulting in reduced gene expression of pathogenesis-related genes and ethylene and jasmonic acid synthesis-related gene. Overexpressing CaERF1A transgenic plants show enhanced resistance to fungal pathogen via regulating ethylene and jasmonic acid synthesis-related gene expression. Thus, CaERF1A is a positive regulator of plant defense by modulating ethylene and jasmonic acid synthesis-related gene expressions.

SH2 Domain-Containing Phosphatase 2 Inhibition Attenuates Osteoarthritis by Maintaining Homeostasis of Cartilage Metabolism via the Docking Protein 1/Uridine Phosphorylase 1/Uridine Cascade.

Protein tyrosine kinases regulate osteoarthritis (OA) progression by activating a series of signal transduction pathways. However, the roles of protein tyrosine phosphatases (PTPs) in OA remain obscure. This study was undertaken to identify specific PTPs involved in OA and investigate their underlying mechanisms. The expression of 107 PTP genes in human OA cartilage was analyzed based on a single-cell sequencing data set. The enzyme activity of the PTP SH2 domain-containing phosphatase 2 (SHP-2) was detected in primary chondrocytes after interleukin-1β (IL-1β) treatment and in human OA cartilage. Mice subjected to destabilization of the medial meniscus (DMM) and IL-1β-stimulated mouse primary chondrocytes were treated with an SHP-2 inhibitor or celecoxib (a drug used for the clinical treatment of OA). The function of SHP-2 in OA pathogenesis was further verified in Aggrecan-CreERT ;SHP2flox/flox mice. The downstream protein expression profile and dephosphorylated substrate of SHP-2 were examined by tandem mass tag labeling-based global proteomic analysis and stable isotope labeling with amino acids in cell culture-labeled tyrosine phosphoproteomic analysis, respectively. SHP-2 enzyme activity significantly increased in human OA samples with serious articular cartilage injury and in IL-1β-stimulated mouse chondrocytes. Pharmacologic inhibition or genetic deletion of SHP-2 ameliorated OA progression. SHP-2 inhibitors dramatically reduced the expression of cartilage degradation-related genes and simultaneously promoted the expression of cartilage synthesis-related genes. Mechanistically, SHP-2 inhibition suppressed the dephosphorylation of docking protein 1 and subsequently reduced the expression of uridine phosphorylase 1 and increased the uridine level, thereby contributing to the homeostasis of cartilage metabolism. SHP-2 is a novel accelerator of the imbalance in cartilage homeostasis. Specific inhibition of SHP-2 may ameliorate OA by maintaining the anabolic-catabolic balance.

Receptor-like cytoplasmic kinase OsRLCK241 functions as an important regulator of abscisic acid synthesis and response in rice

As an important receptor-like kinase subfamily in plants, receptor-like cytoplasmic kinases (RLCKs), such as Oryza sativa L. ( Os ) RLCK241 , are critical in the response to abiotic stress conditions. However, the involvement of OsRLCK241 in the abscisic acid (ABA) signal response remains unknown. In this study, we found that OsRLCK241 participates in the ABA response in rice. The results showed that OsRLCK241 transcription was notably induced by ABA in the rice shoot and root in time- and dose-dependent manners. Additionally, β-glucuronidase staining and analysis of subcellular localization demonstrated that O sRLCK241 directly responded to both ABA and salt treatments. Moreover, phenotypic and physiological analyses showed that OsRLCK241 overexpression decreased ABA sensitivity and ABA content relative to the wild-type variant (Kitaake) under salt stress, and OsRLCK241 loss-of-function variants consistently displayed the opposite ABA-sensitivity phenotype and effects on ABA content. Furthermore, OsRLCK241 overexpression or loss of function modified stomatal patterning under salt stress. Quantitative real-time PCR indicated that the expression of most ABA synthesis-related marker genes, as well as that of genes involved in ABA signal transduction, was altered in both OsRLCK241- overexpressing rice lines and loss-of-function mutants under salt stress. These results suggest that Os RLCK241 is an important regulator of ABA synthesis and response in rice and expand the understanding of plant RLCKs. • Receptor-like cytoplasmic kinases (RLCKs) play key roles in rice abiotic stress responses. • The rice RLCK gene OsRLCK241 was notably induced by ABA in a time and dosage-dependent fashion. • OsRLCK241 altered ABA sensitivity and endogenous ABA content in response to salt stress in rice.