Peptide-directed interference of PD-1/PD-L1 binding increases B lymphocyte function after infectious bursal disease viral infection.

Programmed cell death protein 1 (PD-1)/PD-1 ligand 1 (PD-L1) binding contributes to immune evasion mechanisms responsible for B lymphocyte exhaustion and apoptosis. This facilitates immunosuppression in chronic viral infections, including infectious bursal disease virus (IBDV). Our previous study showed that PD-1 and PD-L1 expression increases in the peripheral blood mononuclear cells of chickens infected with IBDV. However, due to their high production costs and immune-related adverse events, monoclonal antibodies targeting PD-1 or PD-L1 are unsuitable therapeutic agents. Thus, in the current study, we designed peptides with optimized binding sites for PD-1 and investigated their ability to disrupt PD-1/PD-L1 binding and restore B lymphocyte function in vitro. The peptide gCK-16 exhibited a high affinity for PD-1 (KD: 3.37 nM) and effectively inhibited the PD-1/PD-L1 interaction in vitro. Moreover, gCK-16 significantly enhanced B lymphocyte proliferation. Remarkably, gCK-16 treatment abrogated the IBDV-induced upregulation of PD-1/PD-L1, NF-κB activation, and B lymphocyte apoptosis. Additionally, IBDV infection attenuated PI3K/AKT pathway activation in B lymphocytes, while gCK-16 treatment increased immunoglobulin M (IgM) production in IBDV-infected B lymphocytes. Together, these results demonstrate that gCK-16 treatment can potentially enhance B lymphocyte function against IBDV infection, guiding the development of vaccine adjuvants to effectively prevent IBDV-induced avian immunosuppression.

Effect of Voluntary Wheel Running on Anxiety- and Depression-Like Behaviors in Fluoride-Exposed Mice.

Fluoride, an environmental toxicant, could induce endoplasmic reticulum stress (ERS) in neuronal cells ultimately leading to apoptosis and emotional dysfunction. Meanwhile, voluntary wheel running contributes to mitigate anxiety and depression. Our investigation aimed to study the effect of voluntary wheel running on anxiety- and depression-like behaviors in fluoride-exposure mice. The results showed that exposure to 100 mg/L sodium fluoride (NaF) for 6 months can induce anxiety- and depression-like behavior in mice. Fluorosis mice subjected to voluntary wheel running have less anxiety- and depression-like behaviors. Nissl and TUNEL staining demonstrated that fluoride led to a reduced proportion of Nissl body area in the cerebral cortex and an increased apoptotic ratio of nerve cells in the cerebral cortex. In contrast, these pathologic damages were improved in voluntary wheel running mice exposed to NaF. Moreover, the expressions of mRNA in the cerebral cortex GABA, GAD65, GAD67, DR, vGLU, 5-HT1A, BDNF, NMDAR1, and Bcl2 were downregulated and the levels of c-fos, GRP78, PERK, eIF2α, CHOP, Caspase-12, and Caspase-3 mRNA were upregulated in mice exposed to fluoride. NaF treatment had increased the PERK, ATF6, IRE1, p-eIF2α, and Caspase-3 protein levels and reduced the expressions of proteins, including GAD67, VGAT, BDNF, NMDAR1, PSD95, and SYN. By contrast, fluorosis mice subjected to voluntary wheel running enhanced the expression of GAD65, GAD67, VGAT, and neuroplasticity-related proteins in mice and inhibited the PERK-CHOP pathway. It is worth noting that the correlation between the amount of exercise and the behavioral indicators as well as neurotransmitter levels was found. In conclusion, voluntary wheel running inhibits the fluoride-induced ERS and GRP78 expression through the PERK-CHOP pathway and plays an anti-apoptotic role, ultimately ameliorating emotional dysfunction in NaF-exposed mice.

Zn(II) enhances the antimicrobial effect of chloroxine and structural analogues against drug-resistant ESKAPE pathogens in vitro.

The emerging antibiotic-resistant bacteria, especially the "ESKAPE" pathogens, pose a continuous threat to global health. In this study, we explored metalloantibiotics as promising therapeutics and innovative antimicrobial agents. The role of metal in the antimicrobial activity of chloroxine (5,7-dichloro-8-hydroxyquinoline), as a metalloantibiotic, was investigated by minimal inhibit concentration (MIC) assay and a series of assays, including growth curve, time-killing, and UV-visible spectroscopy and PAR (4-(2-pyridylazo)-resorcinol) competition assays. Both chloroxine and its structural analogues exhibited increased antibacterial potency against Gram-positive bacteria compared to Gram-negative bacteria. The introduction of exogenous manganese or zinc ions significantly boosted chloroxine's antibacterial efficacy against Gram-negative bacteria, including the notorious ESKAPE pathogens. However, the enhanced antibacterial activity induced by zinc ions could be negated in the presence of copper or ferrous iron ions, as well as changes in oxygen availability, highlighting the involvement of proton motive force, oxidative and antioxidative systems. Notably, chloroxine effectively inhibited the enzymatic activity of superoxide dismutase (SOD). In addition, chloroxine could reverse polymyxin and carbapenem resistance in E. coli in vitro. Therefore, these results suggested that chloroxine with zinc ions are promising therapeutics and antibiotics potentiator to combat multidrug-resistant ESKAPE pathogens.

Integrating network pharmacology with pharmacological research to elucidate the mechanism of modified Gegen Qinlian Decoction in treating porcine epidemic diarrhea.

Porcine Epidemic Diarrhea Virus (PEDV) poses a significant threat to neonatal piglets, particularly due to the limited efficacy of existing vaccines and the scarcity of efficacious therapeutic drugs. Gegen Qinlian Decoction (GQD) has been employed for over two millennia in treating infectious diarrhea. Nonetheless, further scrutiny is required to improve the drug's efficacy and elucidate its underlying mechanisms of action. In this study, a modified GQD (MGQD) was developed and demonstrated its capacity to inhibit the replication of PEDV. Animal trials indicated that MGQD effectively alleviated pathological damage in immune tissues and modulated T-lymphocyte subsets. The integration of network analysis with UHPLC-MS/MS facilitated the identification of active ingredients within MGQD and elucidated the molecular mechanisms underlying its therapeutic effects against PEDV infections. In vitro studies revealed that MGQD significantly impeded PEDV proliferation in IPEC-J2 cells, promoting cellular growth via virucidal activity, inhibition of viral attachment, and disruption of viral biosynthesis. Furthermore, MGQD treatment led to increased expression levels of IFN-α, IFN-ß, and IFN-λ3, while concurrently decreasing the expression of TNF-α, thereby enhancing resistance to PEDV infection in IPEC-J2 cells. In conclusion, our findings suggest that MGQD holds promise as a novel antiviral agent for the treatment of PEDV infections.

Screening and characterization of a novel linear B-cell epitope on orf virus F1L protein.

Background: Orf, also known as contagious ecthyma (CE), is an acute, contagious zoonotic disease caused by the orf virus (ORFV). The F1L protein is a major immunodominant protein on the surface of ORFV and can induce the production of neutralizing antibodies. Methods: The prokaryotic expression system was used to produce the recombinant F1L protein of ORFV, which was subsequently purified and used to immunize mice. Positive hybridoma clones were screened using an indirect enzyme-linked immunosorbent assay (ELISA). The reactivity and specificity of the monoclonal antibody (mAb) were verified through Western blot and indirect immunofluorescence (IFA). The linear antigenic epitope specific to the mAb was identified through Western blot, using truncated F1L proteins expressed in eukaryotic cells. A multiple sequence alignment of the ORFV reference strains was performed to evaluate the degree of conservation of the identified epitope. Results: After three rounds of subcloning, a mAb named Ba-F1L was produced. Ba-F1L was found to react with both the exogenously expressed F1L protein and the native F1L protein from ORFV-infected cells, as confirmed by Western blot and IFA. The mAb recognized the core epitope 103CKSTCPKEM111, which is highly conserved among various ORFV strains, as shown by homologous sequence alignment. Conclusion: The mAb produced in the present study can be used as a diagnostic reagent for detecting ORFV and as a basic tool for exploring the mechanisms of orf pathogenesis. In addition, the identified linear epitope may be valuable for the development of epitope-based vaccines.

MiRNA-seq and mRNA-seq revealed the mechanism of fluoride-induced cauda epididymal injury.

The widespread presence of fluoride in water, food, and the environment continues to exacerbate the impact of fluoride on the male reproductive health. However, as a critical component of the male reproductive system, the intrinsic mechanism of fluoride-induced cauda epididymis damage and the role of miRNAs in this process are still unclear. This study established a mouse fluorosis model and employed miRNA and mRNA sequencing; Evans blue staining, Oil Red O staining, TEM, immunofluorescence, western blotting, and other technologies to investigate the mechanism of miRNA in fluoride-induced cauda epididymal damage. The results showed that fluoride exposure increased the fluoride concentration in the hard tissue and cauda epididymis, altered the morphology and ultrastructure of the cauda epididymis, and reduced the motility rate, normal morphology rate, and hypo-osmotic swelling index of the sperm in the cauda epididymis. Furthermore, sequencing results revealed that fluoride exposure resulted in differential expression of 17 miRNAs and 4725 mRNAs, which were primarily enriched in the biological processes of tight junctions, inflammatory response, and lipid metabolism, with miR-742-3p, miR-141-5p, miR-878-3p, and miR-143-5p serving as key regulators. Further verification found that fluoride damaged tight junctions, raised oxidative stress, induced an inflammatory response, increased lipid synthesis, and reduced lipid decomposition and transport in the cauda epididymis. This study provided a theoretical basis for developing miRNA as potential diagnostic markers and therapeutic target drugs for this injury.

Exercise Alleviates Fluoride-Induced Learning and Memory Impairment in Mice: Role of miR-206-3p and PREG.

Fluorosis decreases the learning and memory ability in humans and animals, while exercise can reduce the risk of cognitive decline. However, the effect of exercise on learning and memory in fluoride-exposed mice is unclear. For this purpose, in this study, mice were randomly allotted into four groups (16 mice per group, half male and half female): control group (group C), fluoride group (group F, 100 mg/L sodium fluoride (NaF)), exercise group (group E, treadmill exercise), and E plus F group (group EF, treadmill exercise, and 100 mg/L NaF). During 6 months of exposure, exercise alleviated the NaF-induced decline in memory and learning. In addition, NaF induced injuries in mitochondria and myelin sheath ultrastructure and reduced the neurons number, while exercise restored them. Metabolomics results showed that phosphatidylethanolamine, pregnenolone (PREG), and lysophosphatidic acid (LysoPA) were altered among groups C, F, and EF. Combined with previous studies, it can be suggested that PREG might be a biomarker in response to exercise-relieving fluorine neurotoxicity. The miRNA sequencing results indicated that in the differently expressed miRNAs (DEmiRNAs), miR-206-3p, miR-96-5p, and miR-144-3p were shared in groups C, F, and EF. After the QRT-PCR validation and in vitro experiments, it was proved that miR-206-3p could reduce cell death and regulate AP-1 transcription factor subunit (JunD) and histone deacetylase 4 (HDAC4) to alleviate fluoride neurotoxicity. To sum up, the current study reveals that exercise could alleviate NaF-induced neurotoxicity by targeting miR-206-3p or PREG, which will contribute to revealing the pathogenesis and therapeutic method of fluoride neurotoxicity.

Inactivation of Mst/Nrf2/Keap1 signaling flexibly mitigates MAPK/NQO-HO1 activation in the reproductive axis of experimental fluorosis.

Fluoride induced reprotoxicity through oxidative stress-mediated reproductive cell death. Hence, the current study evaluated the importance of the MST/Nrf2/MAPK/NQO-HO1 signaling pathway in fluorosis-induced reproductive toxicity. For this purpose, the reproductive toxicity of sodium fluoride (NaF) at physiological, biochemical, and intracellular levels was evaluated. In-vivo, NaF at 100 mg/L instigated physiological dysfunction, morphological, stereological, and structural injuries in the gut-gonadal axis of fluorosis mice through weakening the antioxidant signaling, Nrf2/HO-1/NQO1signaling pathway, causing the gut-gonadal barrier disintegrated via oxidative stress-induced inflammation, mitochondrial damage, apoptosis, and autophagy. Similar trends were also observed in-vitro in the isolated Leydig cells (LCs) challenging with 20 mg/L NaF. Henceforth, activating the cellular antioxidant signaling pathway, Nrf2/HO-1/NQO1, inactivating autophagy and apoptosis, or attenuating lipopolysaccharide (LPS) can be the theoretical basis and valuable therapeutic targets for coping with NaF-induced reproductive toxicity.

α-Lipoic acid improves mitochondrial biogenesis and dynamics by enhancing antioxidant and inhibiting Wnt/Ca2+ pathway to relieve fluoride-induced hepatotoxic injury.

Fluoride (F), widely present in water and food, poses a serious threat to liver health, and oxidative damage and mitochondrial damage are its main causes. As a natural mitochondrial protector and antioxidant, α-lipoic acid (ALA)'s alleviating effect on fluorosis liver injury and its underlying mechanism are still unclear. Therefore, this study established a fluorosis ALA intervention mice model to explore the mechanism of mitochondrial biogenesis, mitochondrial dynamics, and Wnt/Ca2+ pathway in ALA attenuating fluorosis liver injury. The results showed that ALA mitigated F-induced weight loss, hepatic structural and functional damage, hepatocytes mitochondrial damage, and decreased antioxidant levels. However, ALA did not reduce F accumulation in the femur. Further mRNA and protein detection results showed that F increased the expression levels of key genes in the mitochondrial fission (Drp1, Mff, and Fis1), mitophagy (Parkin, Pink1, and Prdx3), Wnt/Ca2+ pathway (Wnt5a and CaMK2), and rised the number and intensity of fluorescent spots of Drp1, but decreased the expression levels of key genes in the mitochondrial biogenesis (Sirt1, Sirt3, and PGC-1α) and fusion (OPA1, Mfn2, and Mfn1), and reduced the number and intensity of fluorescent spots of PGC-1α in the liver. However, the intervention of ALA relieved the F-induced changes in the expressions of the above genes. In conclusion, ALA mitigated F-induced hepatic injury through enhancing antioxidant capacity and inhibiting Wnt/Ca2+ pathway to improve mitochondrial biogenesis and dynamics disturbance. This study further reveals the hepatotoxic mechanism of F and the protective mechanism of ALA, and provides a theoretical basis for ALA as a potential preventive and palliative agent for F-induced hepatotoxic injury.

Intestinal microbiota regulates colonic inflammation in fluorosis mice by TLR/NF-κB pathway through short-chain fatty acids.

Intestinal inflammation and microbial dysbiosis are found simultaneously in patients with fluorosis. However, whether the inflammation derived from fluoride exposure only or intestinal microbial disorders has not been clarified. In this study, 100 mg/L NaF exposure for 90 days significantly elevated the expressions of inflammatory factors (TNF-α, IL-1ß, IL-6, IFN-γ, TGF-ß, and IL-10), and the levels of TLR4, TRAF6, Myd88, IKKß, and NF-κB P65 in mouse colon, while the above factors were reduced in pseudo germ-free mice with fluorosis, hinting that disordered microbiota might play a more direct role in the development of colonic inflammation than fluoride. Fecal microbiota transplantation (FMT) lowered the levels of inflammatory factors and inactivated the TLR/NF-κB pathway in fluoride-exposed mice. In addition, supplementing short-chain fatty acids (SCFAs) exhibited the identical effects to the model of FMT. In summary, intestinal microbiota may alleviate the colonic inflammatory of mice with fluorosis by regulating TLR/NF-κB pathway through SCFAs.

Interleukin-17A knockout or self-recovery alleviated autoimmune reaction induced by fluoride in mouse testis.

Fluoride (F) is usually treated as a hazardous material, and F-caused public health problem has attracted global attention. Previous studies demonstrate that interleukin-17A (IL-17A) plays a crucial role in F-elicited autoimmune orchitis and self-recovery reverses F-induced testicular toxicity to some extent, but these basic mechanisms remain unclear. Thus, we established a 180 d F exposure model of wild type (WT) mice and IL-17A knockout mice (C57BL/6 J background), and 60 d & 120 d self-recovery model based on F exposure model of WT mice, and used various techniques like qRT-PCR, western blot, immunohistochemistry and ELISA to further explore the mechanism of F-induced autoimmune reaction, the role of IL-17A in it and the reversibility of F-caused toxicity in testis. The results indicated that F exposure for 180 d caused the decreased sperm quality, the damaged testis histopathology, the enhanced mRNA and protein expression levels of inflammatory cytokines, the changes of autoantibody such as the appearance and increased content of anti-testicular autoantibodies in sera and the autoantibody deposition in testis, the alterations of autoimmune related genes containing the decreased mRNA and protein expressions of AIRE and FOXP3 with an increase of MHCII, and the reduced protein expressions of CTLA4, and the activation of IL-17A signaling cascade like the elevated mRNA and protein expressions of IL-17A, Act1, NF-κB, AP-1 and CEBPß, and the increased protein expressions of IL-17RC, with a decrease of IκBα. After IL-17A knockout, 29 of 35 F-induced changes were alleviated. In two self-recovery models, all F-caused differences except fluorine concentration in femur were gradually restored in a time-dependent manner. This study concluded that IL-17A knockout or self-recovery attenuated F-induced testicular injury and decrease of sperm quality through alleviating autoimmune reaction which was involved with the activation of IL-17A pathway, the damage of self-tolerance and the enhancement of antigen presentation.

Effects of Treadmill Exercise on Liver Apoptosis in Fluoride-Exposed Mice.

Hepatotoxicity induced by excessive fluoride (F) exposure has been extensively studied in both humans and animals. Chronic fluorosis can result in liver apoptosis. Meanwhile, moderate exercise alleviates apoptosis caused by pathological factors. However, the effect of moderate exercise on F-induced liver apoptosis remains unclear. In this research, sixty-four three-week-old Institute of Cancer Research (ICR) mice, half male and half female, were randomly divided into four groups: control group (distilled water); exercise group (distilled water and treadmill exercise); F group [100 mg/L sodium fluoride (NaF)]; and exercise plus F group (100 mg/L NaF and treadmill exercise). The liver tissues of mice were taken at 3 months and 6 months, respectively. Hematoxylin-eosin (HE) staining and situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) results showed that nuclear condensation and apoptotic hepatocytes occurred in the F group. However, this phenomenon could be reversed with the intervention of treadmill exercise. The results of QRT-PCR and western blot displayed NaF- induced apoptosis via tumor necrosis factor recpter 1 (TNFR1) signaling pathway, while treadmill exercise could restore the molecular changes caused by excessive NaF exposure.

Identifying Serum Metabolites and Gut Bacterial Species Associated with Nephrotoxicity Caused by Arsenic and Fluoride Exposure.

Co-contamination of arsenic (As) and fluoride (F) is widely distributed in groundwater, which are known risk factors for the nephrotoxicity. Emerging evidence has linked environmentally associated nephrotoxicity with the disturbance of gut microbiota and blood metabolites. In this study, we generated gut microbiota and blood metabolomic profile and identified multiple serum metabolites and gut bacteria species, which were associated with kidney injury on rat model exposed to As and F alone or combined. Combined As and F exposure significantly increased creatinine level. Abnormal autophagosomes and lysosome were observed, and the autophagic genes were enhanced in kidney tissue after single and combined As and F exposure. The metabolome data showed that single and combined As and F exposure remarkably altered the serum metabolites associated with the proximal tubule reabsorption function pathway, with glutamine and alpha-ketoglutarate level decreased in all exposed group. Furthermore, phosphatidylethanolamine (PE), the key contributor of autophagosomes, was decreased significantly in As and F + As exposed groups during the screen of autophagy-animal pathway. Multiple altered gut bacterial microbiota at phylum and species levels post As and F exposure were associated with targeted kidney injury, including p_Bacteroidetes, s_Chromohalobacter_unclassified, s_Halomonas_unclassified, s_Ignatzschineria_unclassified, s_Bacillus_subtilis, and s_Brevundimonas_sp._NA6. Meanwhile, our analysis indicated that As and F co-exposure possessed an interactive influence on gut microbiota. In conclusion, single or combined As and F exposure leads to the disruption of serum metabolic and gut microbiota profiles. Multiple metabolites and bacterial species are identified and associated with nephrotoxicity, which have potential to be developed as biomarkers of As and/or F-induced kidney damage.

Exposure to Fluoride From in Utero to Puberty Alters Gonadal Structure and Steroid Hormone Expression in Offspring Rats.

The reproductive toxicity of fluoride has been proven by a large number of studies. While the underlying mechanism of reproductive toxicity during pregnancy is still unclear. Hence, in this study, we investigated the effects of fluoride exposure on ovarian and testicular steroid hormone synthesis in young and adult rat offspring. We established a model of fluoride-exposed rat pups from in utero to puberty to explore the mechanisms of fluoride impacts on reproductive toxicity in the offspring. The results showed that NaF exposure did not affect the 3 weeks of age offspring. Whereas the body weight in both sexes significantly decreased, and the ovarian and testicular tissue structures were damaged at 11 weeks of age. In females, the total number of secondary follicles and mature follicles were significantly reduced after NaF exposure. Moreover, estradiol (E2) and follicle-stimulating hormone (FSH) levels in the females were significantly reduced in the 100 mg/L NaF exposure group. In males, the sperm viability and testosterone (T) were significantly decreased in the NaF exposure groups. Additionally, during steroidogenesis in ovaries and testes, fluoride remarkably decreased the expression levels of genes and proteins, including acute regulatory protein (StAR), 3ß-hydroxysteroid dehydrogenase (3ß-HSD), cytochrome P450 17a-hydroxylase (CYP17A1), and cholesterol side-chain cleavage enzyme (CYP11A1), while the mRNA levels of 17ß-hydroxysteroid dehydrogenase (17ß-HSD) decreased only in the testes. These results indicated that fluoride exposure disrupted the steroid hormone balance by changing several important steroidogenic-related genes associated with the development of the gonads, and damage the normal structure of the gonads in rat offspring.

Fecal microbiota transplantation and short-chain fatty acids improve learning and memory in fluorosis mice by BDNF-PI3K/AKT pathway.

Fluoride, an environmental toxicant, not only arouses intestinal microbiota dysbiosis, but also causes neuronal apoptosis and a decline in learning and memory ability. The purpose of this study was to explore whether fecal microbiota transplantation (FMT) from healthy mice and bacteria-derived metabolites short-chain fatty acids (SCFAs) supplement protect against fluoride-induced learning and memory impairment. Results showed that FMT reversed the elevated percentage of working memory errors (WME) and reference memory errors (RME) in fluorosis mice during the eight-arm maze test. Nissl and TUNEL staining presented that fluoride led to a decreased proportion of Nissl bodies area in the hippocampal CA3 region and an increased apoptotic ratio of nerve cells in CA1, CA3 and DG areas, whereas FMT alleviated those pathological damages. Moreover, the expressions of mRNA in hippocampal BDNF, PDK1, AKT, Bcl-2, and Bcl-xL were downregulated in mice exposed to fluoride, but the levels of PI3K, Bax, Bak, and Caspase-7 mRNA were upregulated. NaF treatment had an increase in PI3K and Caspase-3 protein levels and reduced the expressions of these four proteins, including BDNF, p-PI3K, AKT and p-AKT. By contrast, FMT enhanced the expression of BDNF and thus activated the PI3K/AKT pathway. Besides, the 16S rRNA sequencing revealed that fluoride caused a reduction in certain SCFA producers in the colon as evidenced by a decline in Erysipelatoclostridiaceae, and a downward trend in Akkermansia, Blautia and Alistipes. However, the disordered gut microbiome was restored via frequent FMT. Of note, SCFAs administration also increased BDNF levels and regulated its downstream pathways, which contributed to cell survival and learning and memory function recovery. In conclusion, FMT and SCFAs may activate the BDNF-PI3K/AKT pathway to play an anti-apoptotic role and ultimately improve learning and memory deficits in fluorosis mice.

Multiomics Analysis Revealed the Molecular Mechanism of miRNAs in Fluoride-Induced Hepatic Glucose and Lipid Metabolism Disorders.

Fluoride-induced liver injury seriously endangers human and animal health and animal food safety, but the underlying mechanism remains unclear. This study aims to explore the mechanism of miRNAs in fluoride-induced hepatic glycolipid metabolism disorders. C57 male mice were used to establish the fluorosis model (22.62 mg/L F-, 12 weeks). The results indicated that fluoride increased fluoride levels, impaired the structure and function, and disrupted the glycolipid metabolism in the liver. Furthermore, the sequencing results showed that fluoride exposure resulted in the differential expression of 35 miRNAs and 480 mRNAs, of which 23 miRNAs were related to glycolipid metabolism. miRNA-mRNA network analyses and RT-PCR revealed that miRNAs mediated fluoride-induced disturbances in the hepatic glycolipid metabolism. Its possible mechanism was to regulate the insulin pathway, PPAR pathway, and FOXO pathway, which in turn affected the bile secretion, the metabolic processes of glucose, the decomposition of lipids, and the synthesis of unsaturated fatty acids in the liver. This study provides a theoretical basis for miRNAs as diagnostic indicators and target drugs for the treatment of fluoride-induced liver injury.

Efficient production of ε-poly-L-lysine from cassava bagasse hydrolysate used as carbon source by Streptomyces albulus US3-18.

The production of ε-poly-L-lysine (ε-PL) from cassava bagasse hydrolysate (CBH) by Streptomyces albulus US3-18 was investigated in this study. With 30 g/L glucose from CBH, 1.30 g/L ε-PL and 10.68 g/L biomass were obtained in shake flask fermentation. Interestingly, the two values were increased by 14.0% and 21.5%, respectively, compared to the control (1.14 g/L and 8.79 g/L). Simultaneously, the activities of four key enzymes of ε-PL synthesis during CBH fermentation were enhanced to varying degrees. In batch fermentation of 5-L bioreactor, 3.39 g/L ε-PL and 10.17 g/L DCW were harvested with 40 g/L glucose from CBH. The combination of fed-batch fermentation with two-stage pH strategy significantly increased ε-PL titer and biomass to 37.41 g/L and 41.0 g/L, respectively. Moreover, eleven volatile components were detected in CBH by GC-MS, and 6-pentyl-α-pyrone (6PP) was first identified as the most abundant volatile ingredient. The results in CBH fermentation demonstrated that S. albulus US3-18 exhibited high tolerance to these volatile byproducts. Using ICP-MS, the calcium concentration in CBH was determined as 195.0 mg/(kg hydrolyzate), and cobalt, copper, lead, chromium, mercury and arsenic were not detected. By adding 0.05 g/L CaCl2 to M3G medium, ε-PL yield was improved by 28.0%, indicating calcium was one of the factors for the enhanced ε-PL production. The study provides a reference for the efficient production of ε-PL from low-cost agricultural residues.

Moderate exercise relieves fluoride-induced liver and kidney inflammatory responses through the IKKß/NFκB pathway.

With the intensification of environmental pollution, the content of fluoride is increasing in human and animal living environments. Long-term fluoride exposure can cause damage to the liver and kidney, which are the main sites for fluoride metabolism, storage and removal. Moreover, exercise often accompanies the entire process of fluoride exposure in humans and animals. However, the mechanism of exercise on fluoride-induced liver and kidney injury remains unclear. Hence, we established a fluoride exposure and/or exercise mouse model to explore the influence of exercise on fluoride-induced liver and kidney inflammation and the potential mechanism. The results showed that fluoride caused obvious structural and functional damage and the notable recruitment of immunocytes in the liver and kidney. In addition, fluoride increased the levels of IL-1ß, IL-2, IL-4, IL-6, IL-10, IL-12, IL-13, IL-21, TNF-α, and TGF-ß but decreased the ratio of IFN-γ/IL-4 and IL-2/IL-10, which indicated that fluoride disturbed the inflammatory balance and caused hepatonephritis. In addition, the expression levels of IKKß and NFκB were increased, and the expression of IκBα was decreased after fluoride exposure, indicating that fluoride activated the IKKß/NFκB pathway. In summary, long-term moderate treadmill exercise relieved fluoride-induced liver and kidney inflammatory responses through the IKKß/NFκB pathway, and exercise can be used to prevent fluoride-induced liver and kidney damage.

Effect of traditional chinese medicine (TCM) and its fermentation using Lactobacillus plantarum on ceftriaxone sodium-induced dysbacteriotic diarrhea in mice.

BACKGROUND: Buzhongyiqi decoction (BD), Sijunzi decoction (SD), and Shenlingbaizhu decoction (SHD) have been extensively used clinically for the treatment of diseases caused by spleen-Qi deficiency and microbial fermentation has historically been utilized in traditional Chinese medicine (TCM). This study aimed to investigate the mitigative effect of TCM and fermented TCM (FTCM) with Lactobacillus plantarum (LP) on antibiotic-associated diarrhea, and to select an optimal formula and then identify its compounds. METHODS: Dysbacteriosis in mice was induced by ceftriaxone sodium (CS). The mice were then treated with LP, BD, SD, SHD, fermented BD, fermented SD (FSD), and fermented SHD. Diarrhea indexes, the abundances of gut bacteria, intestinal morphometrics, and mRNA expressions of genes related to intestinal barrier function were assessed. Then, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) were employed to identify and relatively quantify the compounds in the selected decoctions. RESULTS: CS significantly increased the fecal output weight, the total number of fecal output, and fecal water content, indicating the occurrence of diarrhea. Bacterial culture tests showed that the above symptoms were accompanied by the disruption of specific intestinal flora. TCM, LP, and FTCM alleviated the diarrhea index and recovered the intestinal microbiota. FTCM showed more advantageous than TCM or LP alone. The mRNA expressions of aquaporins (AQPs) and tight junctions (TJs) decreased by CS were enhanced by TCM, LP, and FTCM. In addition, through UHPLC-Q-TOF/MS, (S)-(-)-2-hydroxyisocaproic acid, L-methionine, 4-guanidinobutyric acid (4GBA), and phenyllactate (PLA) in SD and FSD were identified and relatively quantified. CONCLUSIONS: TCM, LP, and TCM fermented with LP alleviated CS-induced diarrhea symptoms, and improved the intestinal flora and barrier function. Four compounds including (S)-(-)-2-hydroxyisocaproic acid, L-methionine, 4GBA, and PLA in FSD, which were identified by UHPLC-Q-TOF/MS, might function in modulating intestinal flora and improving villi structure.

Selenium Alleviates Chromium(VI)-Induced Ileum Damage and Cecal Microbial Disturbances in Mice.

Hexavalent chromium [Cr(VI)] is one of the most common environmental contaminants caused by its broad industrial applications. Importantly, exposure to Cr(VI) induces oxidative damage and apoptosis in animal cells. Studies have shown that selenium (Se) can alleviate the toxic effects of Cr(VI) by functioning as an antioxidant and/or by chelating Cr(VI) into biologically inert complexes, but the underlying mechanism remains unknown. Here, we evaluated whether Se can ameliorate ileum damage and cecal microbial disturbances induced by Cr(VI) in vivo. Mice administered Cr(VI) for 30 days presented histopathological damage, reduced responses to oxidative stress, and increased expression of apoptosis-related genes in the ileum compared with those in the control (non-exposed) group. Se alleviated the histopathological damage and decreased the oxidative stress and apoptosis induced by Cr(VI) in the ileum. In addition, Cr(VI) disturbed cecal microflora, and it was partially reversed by Se treatment. These findings demonstrate that the damaging and potentially pathological effects of Cr(VI) on the ileum and cecal microflora can be effectively alleviated with Se treatment.