Cronobacter sakazakii lysozyme inhibitor LprI mediated by HmsP and c-di-GMP is essential for biofilm formation and virulence.

Cronobacter sakazakii poses a significant threat, particularly to neonates and infants. Despite its strong pathogenicity, understanding of C. sakazakii biofilms and their role in infections remains limited. This study investigates the roles of HmsP and c-di-GMP in biofilm formation and identifies key genetic and proteomic elements involved. Gene knockout experiments reveal that HmsP and c-di-GMP are linked to biofilm formation in C. sakazakii. Comparative proteomic profiling identifies the lysozyme inhibitor protein LprI, which is downregulated in hmsP knockouts and upregulated in c-di-GMP knockouts, as a potential biofilm formation factor. Further investigation of the lprI knockout strain shows significantly reduced biofilm formation and decreased virulence in a rat infection model. Additionally, LprI is demonstrated to bind extracellular DNA, suggesting a role in anchoring C. sakazakii within the biofilm matrix. These findings enhance our understanding of the molecular mechanisms underlying biofilm formation and virulence in C. sakazakii, offering potential targets for therapeutic intervention and food production settings.IMPORTANCECronobacter sakazakii is a bacterium that poses a severe threat to neonates and infants. This research elucidates the role of the lysozyme inhibitor LprI, modulated by HmsP and c-di-GMP, and uncovers a key factor in biofilm formation and virulence. The findings offer crucial insights into the molecular interactions that enable C. sakazakii to form resilient biofilms and persist in hostile environments, such as those found in food production facilities. These insights not only enhance our understanding of C. sakazakii pathogenesis but also identify potential targets for novel therapeutic interventions to prevent or mitigate infections. This work is particularly relevant to public health and the food industry, where controlling C. sakazakii contamination in powdered infant formula is vital for safeguarding vulnerable populations.

Long-term exposure to advanced lipid peroxidation end products impairs cognitive function through microbiota-gut-brain axis.

The frequent intake of ultra-processed, heat-processed, and fat-enriched foods rich in dietary advanced lipoxidation end-products (ALEs) has been correlated with cognitive decline; however, the underlying mechanisms of action remain unexplored. This study investigated the impact of a 12-month dietary exposure to ALEs on learning, memory, and Aß1-42 accumulation in mice, with a focus on the AMPK/SIRT1 signaling pathway and ADAM10 expression. The gut microbiota and metabolomic profiles revealed ALEs-induced gut dysbiosis and cognitive impairment, highlighting modulation through the microbiota-gut-brain axis. Key findings include increased pathogenic bacteria and decreased beneficial bacteria, linked to metabolite profile changes that affect neurotoxic Aß1-42 peptide accumulation. This long-term comprehensive study underscores the need for dietary guidelines to reduce ALE intake and mitigate neurodegenerative disease risk, highlighting the intricate interplay between diet, gut microbiota, and cognitive health.

Lactobacillus rhamnosus NKU FL1-8 Isolated from Infant Feces Ameliorates the Alcoholic Liver Damage by Regulating the Gut Microbiota and Intestinal Barrier in C57BL/6J Mice.

Alcoholic liver damage is caused by long-term or heavy drinking, and it may further progress into alcoholic liver diseases (ALD). Probiotic supplements have been suggested for the prevention or improvement of liver damage. This study was designed to consider the ameliorative effects of Lactobacillus rhamnosus NKU FL1-8 isolated from infant feces against alcoholic liver damage. The mice were gavaged with a 50% ethanol solution and treated with 109 CFU of L. rhamnosus NKU FL1-8 suspension. The factors for liver function, oxidative stress, inflammation, gut microbiota composition, and intestinal barrier integrity were measured. The results showed that L. rhamnosus NKU FL1-8 could decrease the levels of aspartate aminotransferase (AST) to 61% and alanine aminotransferase (ALT) to 50% compared with ethanol given by gavage. It could inhibit the expression level of malondialdehyde (MDA), increase superoxide dismutase (SOD), glutathione (GSH) to relieve oxidative stress, and down-regulate the cytokines to decrease hepatic inflammation. After treatment, the level of triglycerides was reduced, and the expression levels of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and the peroxisome proliferators-activated receptor-α (PPAR-α) pathway were up-regulated. Additionally, the 16S rRNA sequencing analysis showed that L. rhamnosus NKU FL1-8 increased the relative abundance of Lactobacillus, Ruminococcaceae, etc. At the same time, L. rhamnosus NKU FL1-8 could significantly reduce lipopolysaccharides (LPS) and enhance intestinal tight junction proteins. These results demonstrated that L. rhamnosus NKU FL1-8 could reduce the level of oxidative stress, fat accumulation, and liver inflammation caused by alcohol in the host. The underlying mechanism could be that L. rhamnosus NKU FL1-8 inhibits LPS by regulating the gut microbiota and repairing the intestinal barrier. Thereby, these findings support L. rhamnosus NKU FL1-8 as a potential functional food for the relief of ALD.

Inhibitory Potential of Bifidobacterium longum FB1-1 Cell-Free Supernatant against Carbapenem-Resistant Klebsiella pneumoniae Drug Resistance Spread.

The widespread dissemination of carbapenem-resistant Klebsiella pneumoniae (CRKP) and its drug resistance transfer poses a global public health threat. While previous studies outlined CRKP's drug resistance mechanism, there is limited research on strategies inhibiting CRKP drug resistance spread. This study investigates the potential of Bifidobacterium longum (B. longum) FB1-1, a probiotic, in curbing the spread of drug resistance among CRKP by evaluating its cell-free supernatant (CFS) for antibacterial activity. Evaluating the inhibitory effect of FB1-1 CFS on CRKP drug resistance spread involved analyzing its impact on drug resistance and virulence gene expression; drug resistance plasmid transfer FB1-1 CFS exhibited an MIC range of 125 µL/mL against CRKP. After eight hours of co-culture, CFS achieved a 96% and 100% sterilization rate at two and four times the MIC, respectively. At sub-inhibitory concentrations (1/2× MIC), FB1-1 CFS reduced the expression of the bla_KPC gene, which is pivotal for carbapenem resistance, by up to 62.13% across different CRKP strains. Additionally, it markedly suppressed the expression of the uge gene, a key virulence factor, by up to 91%, and the fim_H gene, essential for bacterial adhesion, by up to 53.4%. Our study primarily focuses on determining the inhibitory effect of FB1-1 CFS on CRKP strains harboring the bla_KPC gene, which is a critical resistance determinant in CRKP. Furthermore, FB1-1 CFS demonstrated the ability to inhibit the transfer of drug resistance plasmids among CRKP strains, thus limiting the horizontal spread of resistance genes. This study highlights FB1-1 CFS's inhibitory effect on CRKP drug resistance spread, particularly in strains carrying the bla_KPC gene, thus offering a novel idea and theoretical foundation for developing antibacterial drugs targeting CRKP resistance.

Immunomodulation of nutritional formula containing epigallocatechin-3-gallate, ginseng extract, and polydextrose on inflammation and macrophage polarization.

Single nutrient likes polyphenol or dietary fiber have been exhaustively investigated to validate their positive intervention in health or disease. Meanwhile, the common interaction of inner systems with the nutrient complex has not been well elucidated, which raises the scientific issue of the modulatory effect of the nutrient complex on immunity. The representative prebiotics of epigallocatechin-3-gallate (EGCG), ginseng extract, and polydextrose (PDX) were selected on behalf of the classification of polyphenol, flavone or polysaccharides, and dietary fiber to generally cover the daily food intake in this study to explore their intervention in inflammation and macrophage polarization. The intervention of selected nutrients on inflammation and macrophage polarization has been evaluated against macrophages to unveil their comprehensive effects. The synergistic effect of selected nutrients was demonstrated by inhibiting M1 macrophage polarization and the promotion of M2 macrophage polarization. Then, the nutrient formula was set up to verify the intervention effect, and the results revealed the significant inhibition of cell inflammation and the effect on cell proliferation through promoting the cell cycle in the G2 phase. The nutrient complex could inhibit M1 macrophage polarization to inhibit M1-mediated inflammation and promote M2 macrophages for anti-inflammatory effect and enhance cell phagocytosis. Moreover, the varied intervention effects of the nutrient complex with different formulas could be summarized. In general, the formula containing EGCG, ginseng extract, and PDX was demonstrated to possess an enhanced immunomodulatory effect on cell inflammation and macrophage polarization, which could potentially inspire the investigation of complex nutrients in health and diseases.

2'-Fucosyllactose alleviates OVA-induced food allergy in mice by ameliorating intestinal microecology and regulating the imbalance of Th2/Th1 proportion.

Food allergy (FA) has become a prominent problem in public health. 2'-Fucosyllactose (2'-FL) was reported to alleviate FA symptoms; however, the regulatory mechanism is still unclear. This study evaluated the 2'-FL antiallergic potential in an ovalbumin (OVA)-sensitized mouse model and explored the systemic effects of 2'-FL on gut microecology and the intestinal immune barrier. The results showed that 2'-FL alleviated allergy symptoms, decreased serum allergic indicator levels, enhanced the intestinal barrier, and attenuated low-grade inflammation. The up-regulation of G protein-coupled receptors (GPRs) was associated with higher levels of short-chain fatty acids (SCFAs) in 2'-FL intervention mice. 2'-FL also improved the intestinal microbiota diversity and increased the abundance of Akkermansia, Lachnospiraceae UCG-006, and Ruminococcaceae while suppressing Muribaculaceae, Desulfovibrionaceae, and Erysipelotrichaceae. Additionally, 2'-FL ameliorated the imbalance of Th2/Th1, mainly by decreasing Th2-type immune response and enhanced CD4 + Foxp3 + Treg immunoreaction. These results suggest that 2'-FL restores intestinal barrier defects, gut microbiota disorder, and immune impairment while alleviating ovalbumin-induced allergic symptoms in FA mice.

Detection of ß-lactoglobulin under different thermal-processing conditions by immunoassay based on nanobody and monoclonal antibody.

The problems of inaccurate detection values of thermal-processed ß-lactoglobulin (ß-LG) content seriously affect the screening of allergens. A monoclonal antibody (mAb) against ß-LG was successfully prepared and a highly sensitive sandwich ELISA (sELISA) was constructed with specific nanobody (Nb) as the capture antibody with detection limit of 0.24 ng/mL. Based on this sELISA, the ability of Nb and mAb to recognize ß-LG and ß-LG interacting with milk components was explored. Combined with protein structure analysis to elaborate the mechanism of shielding ß-LG antigen epitopes during thermal-processing, thus enabling the differentiation between pasteurized and ultra-high temperature sterilized milk, the detection of milk content in milk-containing beverages, and the highly sensitive detection and analysis of ß-LG allergens in dairy-free products. The method provides methodological support for identifying the quality of dairy products and reducing the risk of ß-LG contamination in dairy-free products.

Protective Effect of Foxtail Millet Protein Hydrolysate on Ethanol and Pyloric Ligation-Induced Gastric Ulcers in Mice.

Foxtail millet has been traditionally considered to possess gastroprotective effects, but studies evaluating its use as a treatment for gastric ulcers are lacking. Here, we assessed the antiulcer effects of foxtail millet protein hydrolysate (FPH) and explored its mechanism by using blocking agents. In a mouse model of ethanol-induced gastric ulcers, pretreatment with FPH reduced the ulcerative lesion index, downregulated the expression of inflammatory cytokines in the gastric tissue, increased the activity of antioxidant enzymes, and improved the oxidative status. FPH increased constitutive the activity of nitric oxide synthase (cNOS), NO levels, and mucin expression in gastric mucosa, and inhibited the activation of the ET-1/PI3K/Akt pathway. In a mouse model of pyloric ligation-induced gastric ulcers, FPH inhibited gastric acid secretion and decreased the activity of gastric protease. Pretreatment of mice with the sulfhydryl blocker NEM and the NO synthesis inhibitor L-NAME abolished the gastroprotective effect of FPH, but not the KATP channel blocker glibenclamide and the PGE2 synthesis blocker indomethacin. Among the peptides identified in FPH, 10 peptides were predicted to have regulatory effects on the gastric mucosa, and the key sequences were GP and PG. The results confirmed the gastroprotective effect of FPH and revealed that its mechanism was through the regulation of gastric mucosal mucus and NO synthesis. This study supports the health effects of a millet-enriched diet and provides a basis for millet protein as a functional food to improve gastric ulcers and its related oxidative stress.

Roles of Resolvins in Chronic Inflammatory Response.

An inflammatory response is beneficial to the organism, while an excessive uncontrolled inflammatory response can lead to the nonspecific killing of tissue cells. Therefore, promoting the resolution of inflammation is an important mechanism for protecting an organism suffering from chronic inflammatory diseases. Resolvins are a series of endogenous lipid mediums and have the functions of inhibiting a leukocyte infiltration, increasing macrophagocyte phagocytosis, regulating cytokines, and alleviating inflammatory pain. By promoting the inflammation resolution, resolvins play an irreplaceable role throughout the pathological process of some joint inflammation, neuroinflammation, vascular inflammation, and tissue inflammation. Although a large number of experiments have been conducted to study different subtypes of resolvins in different directions, the differences in the action targets between the different subtypes are rarely compared. Hence, this paper reviews the generation of resolvins, the characteristics of resolvins, and the actions of resolvins under a chronic inflammatory response and clinical translation of resolvins for the treatment of chronic inflammatory diseases.

Analysis of Hepatic Lipid Metabolism and Immune Function During the Development of Collagen-Induced Arthritis.

The liver is essential for metabolic and immune functions and has been linked to systemic inflammatory diseases. However, the role of the liver is still elusive during the development of rheumatoid arthritis (RA), although there have been indeed some reports. We used label-free quantitative proteomics and experimental verification in this study to reveal the hepatic lipid metabolism and immune function during collagen-induced arthritis (CIA) development. The proteomics results revealed that the role of the liver differs in different phases of CIA rats. In terms of specific performance, hepatic lipid metabolism, which is primarily concerned with cholesterol, triacylglycerol, and phospholipid, was significantly influenced in the CIA induction phase, whereas the immune function, which includes binding of granulocytes, adhesion of immune cells, etc., was affected considerably at the peak phase of CIA rats compared to normal rats. Finally, the hepatic dynamic changes in CIA rats were further confirmed using targeted metabolomics and ELISA. We found that most fatty acids of the liver in the CIA induction phase were significantly decreased, and proteins related to complement activation and migration or adhesion of immune cells including C3, MMP-8, CTSZ, and S100A9 were significantly increased in the liver of CIA rats in the peak phase. Our findings indicated that the lipid metabolism and immune function of the liver were influenced in CIA rats. Thus, the conditions of the liver during RA development should be considered in therapeutic and nutritional interventions.

Ozone-Microbubble-Washing with Domestic Equipment: Effects on the Microstructure, and Lipid and Protein Oxidation of Muscle Foods.

This study aimed to compare ozone-microbubble-washing (OM) performed by domestic equipment with conventional water-washing (CW) regarding resultant quality attributes of muscle foods. For this purpose, muscle microstructure and lipid and protein oxidation were evaluated in pork and fish samples after OM and CW treatments. The assessment of muscle microstructure showed that OM treatment did not damage the microstructure of muscle fibers in both pork and fish samples. Thiobarbituric acid reactive substances (TBARS) values were not detected in both treatment groups, and they were substantially below the generally acceptable threshold (1 mg MDA/kg). The methylglyoxal (MGO) level of OM-treated fish samples was significantly higher than that of CW-treated fish samples. However, glyoxal (GO) and MGO levels of OM-treated pork samples were significantly lower than that of CW-treated pork samples. Similar types and sites of oxidative modification and similar numbers of modified peptides, as well as no significant difference in the concentration of total and most of the free amino acids (FAA) between treatment groups, indicated that OM treatment did not accelerate protein oxidation.

Deciphering Antitumor Mechanism of Pien Tze Huang in Mice of Hepatocellular Carcinoma Based on Proteomics.

The Chinese formula Pien Tze Huang (PZH) has been used to treat hepatocellular carcinoma (HCC) and showed positive clinical effects. However, the antitumor mechanism of PZH in HCC remains unclear. In this study, HCC xenograft Balb/c mice were treated with PZH; then, proteomics detection and Ingenuity Pathway Analysis (IPA) were used to analyze the differentiated phosphorylated proteins in tumor tissues. The results indicated that PZH could inhibit tumor weight by 50.76%. Eighty-four upregulated and 11 downregulated phosphorylated proteins were identified in PZH-treated mice. Twenty signaling pathways were associated with inflammation (including the IL-6 and TNFR1/2 pathways), cancer growth (including the p53 and FAK pathways), and the cell cycle (including the G2/M and G1/S checkpoint regulation pathways). Moreover, TNF-α, IL-6, and several typical differentially expressed phosphorylated proteins (such as p-CCNB1, p-FOXO3, and p-STAT3) in tumor tissues, tumor cell viability, and cell cycle arrest assay in vitro further verify the results of IPA. These results revealed that PZH achieved antitumor activity in HCC; the underlying mechanisms of which were mainly through regulating the inflammation-associated cytokine secretion, cancer growth pathways, and induction of G2/M arrest. These data provided the potential molecular basis for PZH to act as a therapeutic drug or a supplement to chemotherapy drugs for human HCC in the future.

Wang-Bi Capsule Alleviates the Joint Inflammation and Bone Destruction in Mice with Collagen-Induced Arthritis.

Wang-Bi Capsule (WB), a traditional Chinese medicine- (TCM-) based herbal formula, is currently used in clinic for the treatment of rheumatoid arthritis (RA) with positive clinical effects. However, its pharmacological mechanism of action in RA is still obscure. Therefore, this study established a collagen-induced arthritis (CIA) mice model to examine the efficacy of WB by using arthritis score, histological analysis, and micro-CT examination. Proinflammatory cytokines expression, osteoclast number, OPG/RANKL system, and NF-κB activation were then detected to further investigate the mechanism of WB in RA treatment. The results indicated that WB could alleviate the erythema and swelling of paws in CIA mice. It also inhibited the infiltration of inflammatory cells and bone destruction and increased bone density in joints of CIA mice. Mechanistic studies showed that WB treatment decreased the production of IL-1ß, IL-6, and TNF-α in serum and joints of CIA mice. Moreover, it reduced the osteoclast number, increased OPG level, decreased RANKL level, and inhibited the activation of NF-κB in joints of CIA mice. In conclusion, this study demonstrated that WB could effectively alleviate disease progression of CIA mice by decreasing the IL-1ß, IL-6, and TNF-α levels, modulating the OPG/RANKL system, and inhibiting the activation of NF-κB.

Songling Xuemaikang Capsule inhibits isoproterenol-induced cardiac hypertrophy via CaMKIIδ and ERK1/2 pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Cardiac hypertrophy is a key pathologic process in heart failure. Songling Xuemaikang Capsule (SXC), is a formulae of Chinese Medicine commonly used in China to treat hypertension and heart failure. However, its mechanism of effects on cardiac hypertrophy is still unclear. AIM OF THE STUDY: The aims of the present study were to investigate the cardio-protection roles and detailed mechanisms of SXC on cardiac hypertrophy in vivo and in vitro. MATERIALS AND METHODS: A rat model of cardiac hypertrophy was constructed by isoproterenol (ISO) intraperitoneal injection (i.p), 10 mg/kg/day for 3 days, and 4 groups were compared: CON (n = 8), ISO (n = 8), MET (metoprolol, positive drug treatment, n = 7), and SXC (SXC treatment, n = 6). Cardiac structure and function were evaluated with echocardiography in vivo. Dose-dependent curve was obtained with SXC different concentrations. In addition, H9C2 rat cardiomyocytes were cultured in vitro and the phosphorylation of ERK1/2, p38, JNK, AKT, and protein expression of CaN, CaMKIIδ, GATA4 were detected with Western blot test. RESULTS: The results showed that SXC reduced diastolic thickness of left ventricular posterior wall, while did not change ejection fraction and fraction shortening significantly (P > 0.05). SXC inhibit ISO-induced cardiac hypertrophy dose-dependently with 50% inhibiting concentration (IC50) is 0.504 g/kg/day. Moreover, SXC inhibited the protein expression of CaMKIIδ, and the phosphorylation of ERK1/2, so inhibiting protein expression of GATA4 in nucleus, and brain natriuretic peptide in serum (P < 0.001). CONCLUSION: The mechanism of SXC in the treatment of heart diseases involves SXC dose-dependently inhibited the ISO-induced cardiac hypertrophy via inhibiting CaMKIIδ and ERK1/2/GATA4 signaling pathway.

Insights of Chinese medicine on ventricular remodeling: Multiple-targets, individualized-treatment.

Ventricular remodeling (VR) can be induced by myocardial injury, leading to progressive cardiac dysfunction and heart failure, and is associated with high morbidity and mortality. Despite being studied for more than 3 decades, current therapeutic strategies still remain unsatisfactory in effificacy, expensive, and with side effects and drug resistances. Chinese medicine (CM) has been used to treat heart diseases for thousands of years. This article reviews the published studies on the mechanisms and therapeutic applications of CM in VR. The major aspects include: mechanistic studies of VR, molecular biology and myocardial functional studies of CM therapies on VR, and mechanism of CM therapies on VR.

Shexiang Tongxin dropping pill protects against isoproterenol-induced myocardial ischemia in vivo and in vitro.

Shexiang Tongxin dropping pill (STDP) is a formulae of Chinese Medicine commonly used to treating angina pectoris in China. However, its mechanism of action is still yet unclear. This study investigated the roles of STDP on myocardial ischemia injury. We constructed a rat model of myocardial injury (isoproterenol subcutaneous injection, i.h, 85 mg/kg/day for 2 days), and compared among 4 groups: CON (control), ISO (ischemic injury model), MET (metoprolol), and STDP. Serum contents of Troponin I (cTnI), creatine kinase (CK), CK-MB, lactate dehydrogenase (LDH), alpha-hydroxybutyric dehydrogenase (α-HBD), and Aspartate Aminotransferase were detected and five STDP doses (1, 10, 100, 1000 and 10000 mg/kg/day) were chosen to obtain a dose-response curve. Western-blot was used to detect phosphorylations of extracellular signal-regulated kinase 1/2 (ERK1/2), protein kinase B (AKT), and camodulin kinase II (CamkII). Furthermore, an ERK1/2 inhibitor PD98059, a phosphatidylinositol-3-kinase inhibitor, LY294002, and a CamKII inhibitor, KN-93 were administered i.h. RESULTS: cTnI, CK, CK-MB, α-HBD, and LDH were significantly lower in STDP than ISO (P<0.05). STDP exhibited a dose-dependent effect with a half maximal inhibitory concentration of 42 mg/kg/day. Phosphorylation of ERK1/2 was enhanced in the STDP group (vs. ISO, P<0.05), while AKT and CamkII were not changed. Further, the protective effects of STDP were offset by PD98059 administration i.h. In conclusion, STDP protected against the ISO-induced myocardial ischemic injury via an ERK1/2 signaling pathway, which provided a mechanism to support clinical applications of STDP as treatment for ischemic heart disease.