CD4/CD8 Ratio Recovered as a Predictor of Decreased Liver Damage in Adults Infected With HIV: 16-Year Observational Cohort Study.

BACKGROUND: As the life expectancy of individuals infected with HIV continues to increase, vigilant monitoring of non-AIDS-related events becomes imperative, particularly those pertaining to liver diseases. In comparison to the general population, patients infected with HIV experience a higher frequency of liver-related deaths. The CD4/CD8 ratio is emerging as a potential biomarker for non-AIDS-related events. However, few existing studies have been specially designed to explore the relationship between the CD4/CD8 ratio and specific types of non-AIDS-related events, notably liver damage. OBJECTIVE: This study aimed to investigate the potential association between the CD4/CD8 ratio and the development of liver damage in a sizable cohort of patients infected with HIV receiving antiretroviral treatment (ART). Additionally, the study sought to assess the effectiveness of 3 antiretroviral drugs in recovering the CD4/CD8 ratio and reducing the occurrence of liver damage in this population. METHODS: We conducted an observational cohort study among adults infected with HIV receiving ART from 2004 to 2020 in Guangxi, China. Propensity score matching, multivariable Cox proportional hazard, and Fine-Gray competing risk regression models were used to determine the relationship between the CD4/CD8 ratio recovered and liver damage. RESULTS: The incidence of liver damage was 20.12% among 2440 eligible individuals during a median follow-up period of 4 person-years. Patients whose CD4/CD8 ratio did not recover to 1.0 exhibited a higher incidence of liver damage compared to patients with a CD4/CD8 ratio recovered (adjusted hazard ratio 7.90, 95% CI 4.39-14.21; P<.001; subdistribution hazard ratio 6.80, 95% CI 3.83-12.11; P<.001), findings consistent with the propensity score matching analysis (adjusted hazard ratio 6.94, 95% CI 3.41-14.12; P<.001; subdistribution hazard ratio 5.67, 95% CI 2.74-11.73; P<.001). The Efavirenz-based regimen exhibited the shortest time for CD4/CD8 ratio recovery (median 71, IQR 49-88 months) and demonstrated a lower prevalence of liver damage (4.18/100 person-years). CONCLUSIONS: Recovery of the CD4/CD8 ratio was associated with a decreased risk of liver damage in patients infected with HIV receiving ART, adding evidence for considering the CD4/CD8 ratio as a potential marker for identifying individuals at risk of non-AIDS-related diseases. An efavirenz-based regimen emerged as a recommended choice for recovering the CD4/CD8 ratio and mitigating the risk of liver damage.

Prevalence, Trends and Correlates of HIV, Syphilis and HCV Infection Among Chinese Local and Cross-border Migrant Female Sex Workers in the Sino-Vietnam Border Area of Guangxi, 2016-2021.

Female sex workers (FSWs) are considered a high-risk group for sexually transmitted infections (STIs). However, limited data exist on the prevalence and trends of HIV, syphilis and HCV among FSWs in the Sino-Vietnam border area. To determine the prevalence, trends and correlates of STIs among Chinese local FSWs (CL-FSWs) and cross-border migrant FSWs (CM-FSWs), we conducted consecutive cross-sectional surveys from 2016 to 2021, recruiting 7747 CL-FSWs and 932 CM-FSWs. The overall HIV, syphilis and HCV prevalence declined from 1.0%, 8.8% and 1.7% to 0.1%, 0.9% and 0.3%, respectively. There was no significant downward trend in the overall HIV and syphilis prevalence. However, HCV prevalence showed a decreasing trend among CL-FSWs. CM-FSWs had higher HIV prevalence (2.5% vs. 0.6%). Similarities and differences in STIs-related factors existed between CM-FSWs and CL-FSWs. For instance, receiving HIV-related services in the last year reduced the risk of HIV infection (for CM-FSWs: aOR = 0.234, 95% CI: 0.055-0.993; for CL-FSWs: aOR = 0.182, 95% CI: 0.058-0.567). Serving male clients at least 50 years old increased the risk of syphilis infection (for CM-FSWs: aOR = 4.277, 95% CI: 1.535-11.917; for CL-FSWs: aOR = 1.404, 95% CI: 1.087-1.815). Moreover, CM-FSWs with past-year STIs history had a higher risk of HIV (aOR = 34.976, 95% CI: 5.338-229.176) and HCV infection (aOR = 17.649, 95% CI: 1.846-168.846), both of which were associated with multiple factors in CL-FSWs. It is therefore necessary to develop effective, accessible, high-quality and targeted interventions for CM-FSWs and CL-FSWs.

Hexadecanamide alleviates Staphylococcus aureus-induced mastitis in mice by inhibiting inflammatory responses and restoring blood-milk barrier integrity.

Subacute ruminal acidosis (SARA) has been demonstrated to promote the development of mastitis, one of the most serious diseases in dairy farming worldwide, but the underlying mechanism is unclear. Using untargeted metabolomics, we found hexadecanamide (HEX) was significantly reduced in rumen fluid and milk from cows with SARA-associated mastitis. Herein, we aimed to assess the protective role of HEX in Staphylococcus aureus (S. aureus)- and SARA-induced mastitis and the underlying mechanism. We showed that HEX ameliorated S. aureus-induced mastitis in mice, which was related to the suppression of mammary inflammatory responses and repair of the blood-milk barrier. In vitro, HEX depressed S. aureus-induced activation of the NF-κB pathway and improved barrier integrity in mouse mammary epithelial cells (MMECs). In detail, HEX activated PPARα, which upregulated SIRT1 and subsequently inhibited NF-κB activation and inflammatory responses. In addition, ruminal microbiota transplantation from SARA cows (S-RMT) caused mastitis and aggravated S. aureus-induced mastitis, while these changes were reversed by HEX. Our findings indicate that HEX effectively attenuates S. aureus- and SARA-induced mastitis by limiting inflammation and repairing barrier integrity, ultimately highlighting the important role of host or microbiota metabolism in the pathogenesis of mastitis and providing a potential strategy for mastitis prevention.

Retinoic acid ameliorates low-grade endotoxemia-induced mastitis by limiting inflammatory responses in mice.

Mastitis is a serious disease for humans and animals, which causes huge economic losses in the dairy industry and is hard to prevent due to the complex and unclear pathogenesis. Subacute ruminal acidosis (SARA) has contributed to the development of mastitis by inducing ruminal dysbiosis and subsequent low-grade endotoxemia (LGE), however, how ruminal metabolic changes regulate this progress is still unclear. Our previous study revealed that cows with SARA had increased ruminal retinoic acid (RA) levels, a metabolic intermediate of vitamin A that plays an essential role in mucosal immune responses. Hence, the aim of this study was to investigate the protective effect of RA on LGE-induced mastitis and the underlying mechanisms in mice. The results showed that RA alleviated LGE-induced mastitis, as evidenced by RA significantly reduced the increase in mammary proinflammatory cytokines and improved blood-milk barrier injury caused by LGE. In addition, RA increased the expression of tight junction proteins, including ZO-1, occludin and claudin-3. Furthermore, we found that RA limited the mammary inflammatory responses by inhibiting the activation of NF-κB and NLRP3 signaling pathways. These findings suggest that RA effectively alleviates LGE-induced mastitis and implies a potential strategy for the treatment and prevention of mastitis and other diseases.

Trends and associated factors of HIV, HCV and syphilis infection among different drug users in the China-Vietnam border area: an 11-year cross-sectional study (2010-2020).

BACKGROUND: Data on recent human immunodeficiency virus (HIV), hepatitis C virus (HCV) and syphilis prevalence among drug users in the Southwest China are sparse despite the high burden of drug use. This study aims at assessing the prevalence trends and related factors of HIV, HCV and syphilis infection among different drug users in the China-Vietnam border area. METHODS: A continuous cross-sectional survey was conducted among drug users from 2010 to 2020 in the China-Vietnam border area. Chi-square trend tests were used to assess the trend of HIV, HCV and syphilis prevalence and the proportion for drug type used by drug users. Multivariate logistic regression was used to identify associated factors of HIV, HCV and syphilis infection in different drug users. RESULTS: In this study, a total of 28,951 drug users were included, of which 27,893 (96.45%) male, 15,660 (54.09%) aged 13-34 years, 24,543 (84.77%) heroin-only users, 2062 (7.12%) synthetic drug-only (SD-only) users and 2346 (8.10%) poly-drug users. From 2010 to 2020, the proportion of heroin-only users decreased from 87.79% to 75.46%, whereas SD-only users and poly-drug users increased from 5.16% to 16.03%, and from 7.05% to 8.52%, respectively. The prevalence of HIV, HCV, and syphilis during the study period declined from 12.76%, 60.37% and 5.72% to 4.35%, 53.29% and 4.53%, respectively, among heroin-only users and declined from 18.30%, 66.67% and 15.69% to 6.95%, 27.81% and 5.35%, respectively, among poly-drug users; however, the prevalence of HIV and HCV among SD-only users increased from 0.89% and 8.93% to 2.84% and 18.75%, respectively. Having ever injected drugs and needle sharing were common associated factors for both HIV and HCV infection among poly-drug users and heroin-only users. Aged ≥ 35 years old was an associated factor for HIV, HCV and syphilis infection among the SD-only users. Female drug users were at high risk of contracting syphilis among three different drug users. CONCLUSIONS: The prevalence of HIV, HCV and syphilis among heroin-only users and poly-drug users decreased during the study period. However, the prevalence of HIV and HCV among SD-only users increased. Comprehensive intervention strategies, particularly focusing on the SD-only users are needed in order to bring down the disease burden in this population in the China-Vietnam border areas.

Phytosphingosine alleviates Staphylococcus aureus-induced mastitis by inhibiting inflammatory responses and improving the blood-milk barrier in mice.

Mastitis is one of the common diseases in dairy cows which threatens the health of cows and impacts on economic benefits seriously. Recent studies have been showed that Subacute Ruminal Acidosis (SARA) increased the susceptibility of cow mastitis. SARA leads the disturbance of the rumen microbiota, and the rumen bacterial disordered community is an important endogenous factor of cow mastitis. That is to say, cows which suffer from SARA have a disordered rumen microbiota, a prolonged decline in ruminal PH and a high level of lipopolysaccharide (LPS) in the rumen, blood. Therefore, ruminal metabolism is closely related to the rumen microbiota. However, the specific mechanism of SARA and mastitis still not clear. We found an intestinal metabolite according to the metabonomics, which is correlated to inflammation. Phytophingosine (PS), a product from rumen fluid and milk of the cows which suffer from SARA and mastitis. It has the effect of killing bacteria and anti-inflammatory. Emerging evidences indicate that PS can alleviate inflammatory diseases. However, how PS affects mastitis is largely unknown. In this study, we explored the concrete role of PS on Staphylococcus aureus (S. aureus) -induced mastitis in mice. We found that PS obviously decreased the level of the proinflammatory cytokines. Meanwhile, PS also significantly relieved the mammary gland inflammation caused by S. aureus and restored the function of the blood-milk barrier. Here, we showed that PS increased the expression of the classic Tight-junctions (TJs) proteins including ZO-1, Occludin and Claudin-3. Moreover, PS improves S. aureus-induced mastitis by inhibiting the activation of the NF-κB and NLRP3 signaling pathways. These data indicated that PS relieved S. aureus-induced mastitis effectively. This also provides a reference for exploring the correlation between the intestinal metabolism and inflammation.

Metabolomics Reveals Gut Microbiota Contribute to PPARα Deficiency-Induced Alcoholic Liver Injury.

Incidence and mortality rates of alcoholic liver disease (ALD) is one of the highest in the world. In the present study, we found that the genetic knockout nuclear receptor the peroxisome proliferator-activated receptor α (PPARα) exacerbated ALD. Lipidomics of the liver revealed changed levels of lipid species encompassing phospholipids, ceramides (CM), and long-chain fatty acids in Ppara-null mice induced by ethanol. Moreover, 4-hydroxyphenylacetic acid (4-HPA) was changed as induced by ethanol in the metabolome of urine. Moreover, the phylum level analysis showed a decrease in the level of Bacteroidetes and an increase in the level of Firmicutes after alcohol feeding in Ppara-null mice, while there was no change in wild-type mice. In Ppara-null mice, the level of Clostridium_sensu_stricto_1 and Romboutsia were upregulated after alcohol feeding. These data revealed that PPARα deficiency potentiated alcohol-induced liver injury through promotion of lipid accumulation, changing the metabolome of urine, and increasing the level of Clostridium_sensu_stricto_1 and Romboutsia. 4-HPA could improve ALD in mice by regulating inflammation and lipid metabolism. Therefore, our findings suggest a novel approach to the treatment of ALD: focusing on the gut microbiota and its metabolites. Data are available via ProteomeXchange (PXD 041465).

Sialic acid exacerbates gut dysbiosis-associated mastitis through the microbiota-gut-mammary axis by fueling gut microbiota disruption.

BACKGROUND: Mastitis is one of the most severe diseases in humans and animals, especially on dairy farms. Mounting evidence indicates that gastrointestinal dysbiosis caused by induction of subacute ruminal acidosis (SARA) by high-grain diet consumption and low in dietary fiber is associated with mastitis initiation and development, however, the underlying mechanism remains unknown. RESULTS: In the present study, we found that cows with SARA-associated mastitis have altered metabolic profiles in the rumen, with increased sialic acids level in particular. Consumption of sialic acid (SA) in antibiotic-treated mice, but not healthy mice, induced marked mastitis. SA treatment of antibiotic-treated mice also induced mucosal and systemic inflammatory responses, as evidenced by increased colon and liver injuries and several inflammatory markers. In addition, gut dysbiosis caused by antibiotic impaired gut barrier integrity, which was aggravated by SA treatment. SA potentiated serum LPS level caused by antibiotic treatment, leading to increased activation of the TLR4-NF-κB/NLRP3 pathways in the mammary gland and colon. Moreover, SA facilitated gut dysbiosis caused by antibiotic, and especially enhanced Enterobacteriaceae and Akkermansiaceae, which correlated with mastitis parameters. Fecal microbiota transplantation from SA-antibiotic-treated mice mimicked mastitis in recipient mice. In vitro experiments showed that SA prompted Escherichia coli growth and virulence gene expression, leading to higher proinflammatory cytokine production in macrophages. Targeting the inhibition of Enterobacteriaceae by sodium tungstate or treating with the commensal Lactobacillus reuteri alleviated SA-facilitated mastitis. In addition, SARA cows had distinct ruminal microbial structure by the enrichment of SA-utilizing opportunistic pathogenic Moraxellaceae and the depletion of SA-utilizing commensal Prevotellaceae. Treating mice with the specific sialidase inhibitor zanamivir reduced SA production and Moraxellaceae abundance, and improved mastitis in mice caused by ruminal microbiota transplantation from cows with SARA-associated mastitis. CONCLUSIONS: This study, for the first time, indicates that SA aggravates gut dysbiosis-induced mastitis by promoting gut microbiota disturbance and is regulated by commensal bacteria, indicating the important role of the microbiota-gut-mammary axis in mastitis pathogenesis and suggesting a potential strategy for mastitis intervention based on gut metabolism regulation. Video Abstract.

Gut microbiota-mediated secondary bile acid alleviates Staphylococcus aureus-induced mastitis through the TGR5-cAMP-PKA-NF-κB/NLRP3 pathways in mice.

Although emerging evidence shows that gut microbiota-mediated metabolic changes regulate intestinal pathogen invasions, little is known about whether and how gut microbiota-mediated metabolites affect pathogen infection in the distal organs. In this study, untargeted metabolomics was performed to identify the metabolic changes in a subacute ruminal acidosis (SARA)-associated mastitis model, a mastitis model with increased susceptibility to Staphylococcus aureus (S. aureus). The results showed that cows with SARA had reduced cholic acid (CA) and deoxycholic acid (DCA) levels compared to healthy cows. Treatment of mice with DCA, but not CA, alleviated S. aureus-induced mastitis by improving inflammation and the blood-milk barrier integrity in mice. DCA inhibited the activation of NF-κB and NLRP3 signatures caused by S. aureus in the mouse mammary epithelial cells, which was involved in the activation of TGR5. DCA-mediated TGR5 activation inhibited the NF-κB and NLRP3 pathways and mastitis caused by S. aureus via activating cAMP and PKA. Moreover, gut-dysbiotic mice had impaired TGR5 activation and aggravated S. aureus-induced mastitis, while restoring TGR5 activation by spore-forming bacteria reversed these changes. Furthermore, supplementation of mice with secondary bile acids producer Clostridium scindens also activated TGR5 and alleviated S. aureus-induced mastitis in mice. These results suggest that impaired secondary bile acid production by gut dysbiosis facilitates the development of S. aureus-induced mastitis and highlight a potential strategy for the intervention of distal infection by regulating gut microbial metabolism.

A fiber-enriched diet alleviates Staphylococcus aureus-induced mastitis by activating the HDAC3-mediated antimicrobial program in macrophages via butyrate production in mice.

Mounting evidence suggests that the gut microbiota plays an important role in the pathogenesis of mastitis, an important disease affecting the health of lactating women and the development of the dairy industry. However, the effect of the regulation of the gut microbiota by dietary components on mastitis development remains unknown. In this study, we found that a fiber-enriched diet alleviated Staphylococcus aureus (S. au)-induced mastitis in mice, which was dependent on the gut microbiota as depletion of the gut microbiota by antibiotics abolished this protective effect. Likewise, fecal microbiota transplantation (FMT) from high-inulin (HI)-treated mice (HIF) to recipient mice improved S. au-induced mastitis in mice. Consumption of an HI diet and HIF increased fecal short-chain fatty acid (SCFA) levels compared with the control group. Moreover, treatment with SCFAs, especially butyrate, alleviated S. au-induced mastitis in mice. Mechanistically, consumption of an HI diet enhanced the host antimicrobial program in macrophages through inhibiting histone deacetylase 3 by the production of butyrate. Collectively, our results suggest that modulation of the gut microbiota and its metabolism by dietary components is a potential strategy for mastitis intervention and serve as a basis for other infectious diseases.

Gut dysbiosis induces the development of mastitis through a reduction in host anti-inflammatory enzyme activity by endotoxemia.

BACKGROUND: Mounting experimental evidence has shown that the gut microbiota plays a significant role in the pathogenesis of mastitis, and clinical investigations have found that the occurrence of mastitis is correlated with ruminal dysbiosis. However, the underlying mechanism by which the ruminal microbiota participates in the development of mastitis remains unknown. RESULTS: In the present study, we found that cows with clinical mastitis had marked systemic inflammation, which was associated with significant ruminal dysbiosis, especially enriched Proteobacteria in the rumen. Ruminal microbiota transplantation from mastitis cows (M-RMT) to mice induced mastitis symptoms in recipient mice along with increased mammary proinflammatory signature activation of the TLR4-cGAS-STING-NF-κB/NLRP3 pathways. M-RMT also induced mucosal inflammation and impaired intestinal barrier integrity, leading to increased endotoxemia and systemic inflammation. Moreover, we showed that M-RMT mirrored ruminal microbiota disruption in the gut of recipient mice, as evidenced by enriched Proteobacteria and similar bacterial functions, which were correlated with most proinflammatory parameters and serum lipopolysaccharide (LPS) levels in mice. Recurrent low-grade LPS treatment mirrored gut dysbiosis-induced endotoxemia and caused severe mastitis in mice. Furthermore, we found that gut dysbiosis-derived LPS reduced host alkaline phosphatase activity by activating neuraminidase (Neu), which facilitates low-grade LPS exposure and E. coli-induced mastitis in mice. Conversely, treatment with calf intestinal alkaline phosphatase or the Neu inhibitor zanamivir alleviated low-grade LPS exposure and E. coli-induced mastitis in mice. CONCLUSIONS: Our results suggest that ruminal dysbiosis-derived low-grade endotoxemia can cause mastitis and aggravate pathogen-induced mastitis by impairing host anti-inflammatory enzymes, which implies that regulating the ruminal or gut microbiota to prevent low-grade systemic inflammation is a potential strategy for mastitis intervention. Video Abstract.

Commensal cow Roseburia reduces gut-dysbiosis-induced mastitis through inhibiting bacterial translocation by producing butyrate in mice.

The precise mechanism by which gut dysbiosis contributes to the pathogenesis of extraintestinal diseases and how commensal microbes mediate these processes remain unclear. Here, we show that cows with mastitis had marked gut dysbiosis, characterized by the enrichment of opportunistic pathogenic Escherichia_Shigella and the depletion of commensal Roseburia. Fecal microbiota transplantation from donor cows with mastitis (M-FMT) to recipient mice significantly caused mastitis and changed the gut and mammary microbiota in mice. Notably, M-FMT facilitated the translocation of pathobiont from the gut into the mammary gland, and the depletion of Enterobacteriaceae alleviated M-FMT-induced mastitis in mice. In contrast, commensal Roseburia intestinalis improved M-FMT-induced mastitis and microbial dysbiosis in the gut and mammary gland and limited bacterial translocation by producing butyrate, which was associated with inflammatory signaling inhibition and barrier repair. Our research suggests that commensal Roseburia alleviates gut-dysbiosis-induced mastitis, although further studies in dairy cows and humans are needed.

Commensal Bacillus subtilis from cow milk inhibits Staphylococcus aureus biofilm formation and mastitis in mice.

The colonization and virulence production of Staphylococcus aureus (S. aureus), a known pathogen that induces mastitis, depend on its quorum-sensing (QS) system and biofilm formation. It has been reported that Bacillus can inhibit the QS system of S. aureus, thereby reducing S. aureus colonization in the intestine. However, whether Bacillus affects S. aureus biofilm formation and consequent colonization during mastitis is still unknown. In this study, the differences in the colonization of S. aureus and Bacillus were first analyzed by isolating and culturing bacteria from milk samples. It was found that the colonization of Bacillus and S. aureus in cow mammary glands was negatively correlated. Secondly, we found that although Bacillus did not affect S. aureus growth, it inhibited the biofilm formation of S. aureus by interfering its QS signaling. The most significant anti-biofilm effect was found in Bacillus subtilis H28 (B. subtilis H28). Finally, we found that B. subtilis H28 treatment alleviated S. aureus-induced mastitis in a mice model. Our results rerealed that bovine milk derived commensal Bacillus inhibited S. aureus colonization and alleviated S. aureus-induced mastitis by influencing biofilm formation, suggesting a potential targeted strategy to limit the colonization of S. aureus in vivo.

Dietary Tryptophan-Mediated Aryl Hydrocarbon Receptor Activation by the Gut Microbiota Alleviates Escherichia coli-Induced Endometritis in Mice.

Intestinal microbiota-mediated aryl hydrocarbon receptor (AhR) activation plays an important role in host-microbiota interactions and disease development. However, whether AhR activation mediates infection-induced inflammation in remote organs is not clear. The purpose of this study is to assess the effects and underlying mechanism of AhR activation and gut microbiota-mediated dietary tryptophan (Trp) metabolism on infection-induced inflammation using an Escherichia coli (E. coli)-induced endometritis model in mice. We found that AhR activation by 6-formylindolo (3,2-b) carbazole (Ficz), which is an AhR agonist derived from the photooxidation of Trp, alleviated E. coli-induced endometritis by repairing barrier function and inhibiting inflammatory responses, while inhibition of AhR by CH223191, which is a synthetic AhR antagonist, aggravated E. coli-induced endometritis. Gut dysbiosis damaged AhR activation and exacerbated E. coli-induced endometritis in mice, which responded to the reduced abundance of AhR ligand producers, such as Lactobacillus spp. Supplementation with dietary Trp ameliorated E. coli-induced endometritis in a microbiota-dependent manner, which was associated with the production of AhR ligands. Administration of AhR ligands, including indole and indole aldehyde, but not indole-3-propionic acid, rescued the protective effect of Trp on E. coli-induced endometritis in dysbiotic mice. Moreover, consumption of Lactobacillus reuteri (L. reuteri) containing AhR ligand-producing capability also alleviated E. coli-induced endometritis in mice in an AhR-dependent manner. Our results demonstrate that microbiota-mediated AhR activation is a key factor in fighting pathogen-caused inflammation, which leads to a potential strategy to regulate the gut microbiota and metabolism by dietary Trp or probiotics for the intervention of infectious diseases and reproductive health. IMPORTANCE Infection-induced endometritis is a common and frequently occurring disease in humans and animals. Accumulating evidence suggests an important role of the gut microbiota in the development of infection-induced inflammation. Whether and how gut microbiota-mediated AhR activation regulates the pathogenesis of pathogen-induced endometritis remains unknown. The current study found that AhR activation ameliorated E. coli-induced endometritis, and inhibition of AhR produced negative results. Gut dysbiosis reduced the abundance of AhR ligand producers including Lactobacillus spp., damaged AhR activation, and exacerbated E. coli-induced endometritis. Supplementation with dietary Trp, AhR ligands, and L. reuteri containing AhR ligand-producing capability alleviated E. coli-induced endometritis in mice. Our results suggest an important role of microbiota-mediated AhR activation in the pathogenesis of endometritis and provide potential strategies for the intervention of infectious diseases and reproductive health by regulating the gut microbiota and metabolism.

Dysregulated Serum Cytokine Production in Pediatric Patients with ß-Thalassemia Major.

ß-Thalassemia major (ß-TM) is an inherited disorder of hemoglobin (Hb) production, which can cause severe anemia. A compromised immune system has been observed in patients with ß-TM, whereas cytokines have a major role in immune modulation. Interleukin-4 (IL-4), IL-8, IL-13 and transforming growth factor-ß (TGF-ß) are critical in initiating pro-inflammatory responses, and the serum levels of those cytokines may be involved in the pathophysiology of ß-thalassemia (ß-thal). To assess this hypothesis, we studied 23 pediatric patients with ß-TM by measuring serum levels of IL-4, IL-8, IL-13 and TGF-ß, as well as evaluating infection frequency per year, total number of transfusions and serum ferritin (SF) levels, together with age-matched healthy controls. We found that patients with ß-thal had higher IL-8, IL-13 and TGF-ß concentrations than normal controls, whereas markedly decreased serum IL-4 level was documented in patients with ß-TM. Serum IL-4 level of ß-thal patients showed a negative significant correlation with infection frequency, total number of transfusions and SF levels. On the contrary, serum levels of IL-8, IL-13 and TGF-ß exerted a positive relationship with those clinical parameters. Taken together, our study implies that dysregulated cytokine profile might contribute to iron overloads and impair immune cell functions, thus serving as useful biomarkers for diagnosis and evaluation of ß-TM in the future. Our study sheds new light on the pathogenesis of ß-TM.

Ferritinophagy is involved in Bisphenol A-induced ferroptosis of renal tubular epithelial cells through the activation of the AMPK-mTOR-ULK1 pathway.

Bisphenol A (BPA) is a common environmental contaminant, whose exposure is associated with the progression of various kidney diseases. BPA exposure has turned out to be associated with cytotoxicity to renal tubular epithelial cells, but its underlying mechanism remains unknown. Herein, we found that BPA induced ferroptosis in kidney and renal tubular epithelial cells, as showed by increased intracellular iron accumulation, lipid peroxidation and cells death upon BPA exposure. Additionally, utilization of ferrostatin-1 and desferrioxamine, typical ferroptosis inhibitors, can fundamentally diminish cells death. Intriguingly, we discovered that autophagy inhibitor chloroquine can shield renal tubular epithelial cells from BPA-caused ferroptosis. Furthermore, we found that ferritinophagy, a phenomenon that degradation of ferritin and inducing subsequent iron overload, occurred after BPA exposure and excessive iron promoted ferroptosis through Fenton reaction. We next demonstrated that BPA activated the AMPK-mTOR-ULK1 signaling pathway. In turn, AMPK, mTOR, and ULK1 knockdown dramatically mitigated BPA-induced TCMK-1 cells death, and decreased MDA and LC3 levels, but increased FTH protein content. These results indicate that activation of the AMPK-mTOR-ULK1 signaling is involved in BPA-induced ferritinophagy. In conclusion, renal dysfunction and renal tubular epithelial damage induced by BPA are linked to ferroptosis, which depends on the activation of ferritinophagy through AMPK-mTOR-ULK1 axis.

Probiotic Enterococcus mundtii H81 inhibits the NF-κB signaling pathway to ameliorate Staphylococcus aureus-induced mastitis in mice.

Mastitis is part of the aggressive diseases that affecting the development of dairy farming. Lactic acid bacteria (LAB), an important microbiological agent of gastrointestinal flora, can effectively promote the development of the immune system. Herein, the objectives of this study is to explore the protective role of LAB on Staphylococcus aureus(S. aureus)-induced mastitis in mice. 88 strains of suspected LAB were isolated from the milk of healthy dairy cows. Antibacterial activity was screened, and the 16S rRNA sequence analysis showed that the bacteria were Enterococcus mundtii H81 (E. mundtii H81). Furthermore, the model of mastitis has been established by nipple duct injection of S. aureus in mice, while E. mundtii H81 was treated 2 h before S. aureus injection. Twenty-four hours later of S. aureus infection, the mammary gland tissues were collected. The pathological changes of the mammary gland were observed by H&E staining. The levels of TNF-α and IL-1ß were measured by ELISA and the myeloperoxidase (MPO) activity was measured by the MPO assay kit. We also observed the changes of nuclear transcription factor kappa B (NF-κB) by using western blotting. The results showed that E. mundtii H81 pretreatment reduced neutrophil infiltration, and significantly reduce the secretion of TNF-α and IL-1ß, down-regulate the phosphorylation of p65 NF-κB and IκB, and the expression of tight junction protein Claudin 3 and ZO-1 was up-regulated. Collectively, our findings showed that E. mundtii H81 protects mammary gland from S. aureus-induced mastitis, which may be a candidate of treatment for mastitis infected by S. aureus.

Endoplasmic reticulum stress-mediated autophagy activation is involved in cadmium-induced ferroptosis of renal tubular epithelial cells.

Acute cadmium (Cd) exposure is a significant risk factor for renal injury and lacks effective treatment strategies. Ferroptosis is a recently identified iron-dependent form of nonapoptotic cell death mediated by membrane damage resulting from lipid peroxidation, and it is implicated in many diseases. However, whether ferroptosis is involved in Cd-induced renal injury and, if so, how it operates. Here, we show that Cd can induce ferroptosis in kidney and renal tubular epithelial cells, as demonstrated by elevation of intracellular iron levels and lipid peroxidation, as well as impaired antioxidant production. Treatment with a ferroptosis inhibitor alleviated Cd-induced cell death. Intriguingly, we established that Cd-induced ferroptosis depended on endoplasmic reticulum (ER) stress, by demonstrating that Cd activated the PERK-eIF2α-ATF4-CHOP pathway and that inhibition of ER stress reduced ferroptosis caused by Cd. We further found that autophagy was required for Cd-induced ferroptosis because the inhibition of autophagy by chloroquine mitigated Cd-induced ferroptosis. Furthermore, we showed that iron dysregulation by ferritinophagy contributed to Cd-induced ferroptosis, by showing that the iron chelator desferrioxamine alleviated Cd-induced cell death and lipid peroxidation. In addition, ER stress is likely activated by MitoROS which trigger autophagy and ferroptosis. Collectively, our results indicate that ferroptosis is involved in Cd-induced renal toxicity and regulated by the MitoROS-ER stress-ferritinophagy axis.

Kynurenic acid protects against mastitis in mice by ameliorating inflammatory responses and enhancing blood-milk barrier integrity.

Mastitis is one of the most serious diseases in humans and animals, especially in the modern dairy industry. Seeking safe and effective mastitis prevention strategies is urgent since food safety and drug residues in milk remain an enormous concern, despite the contribution of antibiotics to control mastitis. Kynurenic acid (KYNA), derived from the kynurenine pathway of tryptophan metabolism, has been shown to exhibit anti-inflammatory and immunomodulatory effects in many diseases. Recently, it was reported that impaired KYNA levels were associated with mastitis. However, the physiological role of KYNA in mastitis has not yet been elucidated. Therefore, the aim of this study was to investigate the protective role of KYNA in pathogen-induced mastitis in mice, as well as the underlying mechanism of this effect. We first evaluated the effects of KYNA on LPS-induced mastitis in mice. Additionally, the underlying anti-inflammatory mechanism of KYNA was investigated in mammary epithelial cells (MMECs). Furthermore, we examined the effects of KYNA on S. aureus and E. coli induced mastitis in mice. Our results demonstrated that KYNA alleviated LPS-induced mastitis by reducing inflammatory responses and enhancing blood-milk barrier integrity. The fundamental mechanisms involved the inhibition of NF-κB and activation of Nrf2/Ho-1, which is probably mediated by G protein-coupled receptor 35 but not aryl hydrocarbon receptor. Notably, KYNA also protected against S. aureus and E. coli induced mastitis in mice. In conclusion, our results highlight the role of KYNA in mastitis and serve as a basis for using endogenous metabolite as a novel preventative or therapeutic strategy for disease intervention.

Aryl hydrocarbon receptor activation by Lactobacillus reuteri tryptophan metabolism alleviates Escherichia coli-induced mastitis in mice.

The intestinal microbiota has been associated with the occurrence and development of mastitis, which is one of the most serious diseases of lactating women and female animals, but the underlying mechanism has not yet been elucidated. Aryl hydrocarbon receptor (AhR) activation by microbiota tryptophan metabolism-derived ligands is involved in maintaining host homeostasis and resisting diseases. We investigated whether AhR activation by microbiota-metabolic ligands could influence mastitis development in mice. In this study, we found that AhR activation using Ficz ameliorated mastitis symptoms, which were related to limiting NF-κB activation and enhancing barrier function. Impaired AhR activation by disturbing the intestinal microbiota initiated mastitis, and processed Escherichia coli (E. coli)-induced mastitis in mice. Supplementation with dietary tryptophan attenuated the mastitis, but attenuation was inhibited by the intestinal microbiota abrogation, while administering tryptophan metabolites including IAld and indole but not IPA, rescued the tryptophan effects in dysbiotic mice. Supplementation with a Lactobacillus reuteri (L. reuteri) strain with the capacity to produce AhR ligands also improved E. coli-induced mastitis in an AhR-dependent manner. These findings provide evidence for novel therapeutic strategies for treating mastitis, and support the role of metabolites derived from the intestinal microbiota in improving distal disease.