Klebsiella pneumoniae (K. pneumoniae)-induced pneumonia poses growing clinical challenges due to the emergence of hypervirulent and carbapenem-resistant strains. Butyrate contributes to antibacterial immunity while its role in pulmonary infections remains poorly understood. Here, we showed that K. pneumoniae infection caused alveolar macrophage depletion and concomitant inflammatory tissue damage, while butyrate administration preserved alveolar macrophage populations and attenuated pulmonary damage. Mechanistically, butyrate upregulated both the expression and phosphorylation of p62, and regulated the Keap1-Nrf2 signaling pathway to counter oxidative stress. Moreover, we demonstrated that K. pneumoniae infection triggered oxidative stress injury in critically ill pneumonia patients. Circulating monocytes exhibited elevated levels of 4-hydroxynonenal (4-HNE), a marker of oxidative stress, along with downregulated mRNA levels of SQSTM1 and NRF2, which were inversely correlated with 4-HNE levels. These findings establish butyrate as a dual modulator of the p62-Nrf2 antioxidant axis, highlighting its therapeutic potential for mitigating oxidative stress in K. pneumoniae-associated pneumonia.

BACKGROUND:Hypervirulent Klebsiella pneumoniae (hvKp) induces severe pneumonia and sepsis. HIF-1α coordinates metabolic and immune responses in myeloid cells, but its role in hvKp-mediated pulmonary defense remains undefined. METHODS:Monocyte HIF-1α expression was assessed in patients with Klebsiella pneumoniae (K. pneumoniae) pneumonia. Myeloid-specific Hif-1α knockout mice and BMDMs were used to examine survival, bacterial burden, and macrophage function. RNA-seq, Seahorse flux analysis, and confocal microscopy were employed to investigate the regulatory effects of HIF-1α on phagocytosis and ROS production. The Hif-1α-NCF2-ROS signaling pathway was substantiated through the application of small interfering RNA (siRNA), JASPAR prediction tools, dual-luciferase reporter assays, chromatin immunoprecipitation followed by quantitative PCR (ChIP-qPCR), metabolic inhibitors, and dimethyloxalylglycine (DMOG), a prolyl hydroxylase inhibitor that stabilizes HIF-1α. RESULTS:Clinical data showed a negative correlation between monocyte HIF-1α levels and serum CRP, procalcitonin, ICU stay duration, and SOFA scores. In vivo, myeloid Hif-1α knockout mice demonstrated heightened susceptibility to hvKp, with markedly reduced survival and widespread bacterial dissemination. Mechanistically, Hif-1α-deficient macrophages displayed impaired phagocytosis, phagolysosomal maturation, and glycolytic reprogramming in response to infection. RNA-seq identified NCF2, encoding p67-phox, as a critical HIF-1α-dependent component of the NADPH oxidase complex. JASPAR prediction, dual-luciferase reporter assays, and ChIP-qPCR further demonstrated that NCF2 is directly transcriptionally regulated by HIF-1α. HIF-1α deficiency impaired both glycolytic ATP production and NCF2-mediated ROS generation, thereby compromising macrophage antibacterial activity. Inhibition of glycolysis or silencing NCF2 abolished HIF-1α-dependent defense, whereas pharmacological stabilization of HIF-1α using DMOG significantly enhanced host resistance. CONCLUSION:HIF-1α serves as a pivotal regulator of host defense in experimental hvKp pneumonia and is clinically associated with disease severity in K. pneumoniae pneumonia, linking glycolytic metabolism to the NCF2-ROS bactericidal pathway. These findings highlight the potential of targeting immunometabolic pathways to improve host defense against severe K. pneumoniae infections.

Nitric oxide (NO) plays a crucial role in bacterial physiology and survival, particularly in relation to antibiotic resistance. The protective role of NO against antibiotics is intricate, and the potential antagonistic interactions between NO donors and polymyxin E remain largely unexplored. This study aimed to evaluate the antagonistic effects of nicorandil, a NO donor, on the bactericidal activity of polymyxin E against Klebsiella pneumoniae. Methods: Thirty clinical strains were identified as multidrug-resistant K. pneumoniae using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The antimicrobial efficacy of polymyxin E combined with nicorandil against K. pneumoniae was evaluated through in vitro rapid killing assays and growth curve analyses, and in vivo using a murine pulmonary infection model and a Galleria mellonella larvae infection model. The release of NO by nicorandil was confirmed via reactive nitrogen species (RNS) assays. The impact of NO on oxidative stress responses induced by polymyxin E was evaluated using reactive oxygen species (ROS) assays and RT-qPCR. Results: Nicorandil counteracted the bactericidal effects of polymyxin E in 16 out of 30 clinical isolates of K. pneumoniae. Notably, the most pronounced effects were observed in the K. pneumoniae strain GN 191035. In this context, the release of NO from nicorandil conferred protection to the bacteria against oxidative stress by reducing ROS, as demonstrated by a murine model of pulmonary infection and a Galleria mellonella larvae infection model. Conclusions: Our study further elucidated that nicorandil treatment mitigates the bactericidal efficacy of polymyxin E against K. pneumoniae. These findings highlight the significant risk of increased bacterial infections associated with the concurrent administration of nicorandil and polymyxin E.

P-glycoprotein (P-gp) functions as a critical membrane transporter that drives tumor resistance by mediating drug efflux, ultimately contributing to multidrug resistance (MDR). Recently potent inhibitors have shown significant potential in countering chemotherapeutic resistance, particularly in breast cancer. However, P-gp's presence in essential organs complicates clinical applications, underscoring the importance of developing tumor-specific targeting strategies. Given the high-level expression of folate receptors (FR) on the surface of breast cancer cells, this study conjugated a previously developed P-gp inhibitor with folic acid, with the goal of harnessing FR-mediated targeting for enhanced tumor cell specificity. In vitro evaluations reveal that the resultant conjugate maintains substantial resistance reversal efficacy against the MCF-7/ADR breast cancer-resistant cell line, comparable to the standalone inhibitor. The conjugate emerges as a highly potent and safe P-gp inhibitor in xenograft mouse, likely attributable to its enhanced tumor-targeting specificity, exhibiting superior in vivo efficacy when administered in combination with doxorubicin, relative to the original P-gp inhibitor.

The rising environmental levels of yttrium have sparked concerns regarding its possible health hazards. Nevertheless, limited toxicological data are available to determine yttrium's toxicity and potential mechanisms on sperm. In our research, the action of oxidative stress and the NF-κB pathway on decreased sperm quality and testicular inflammatory reaction induced by yttrium exposure was analyzed. Yttrium nitrate (YN), N-Acetyl Cysteine (NAC), and JSH-23 were used to intervene in mice and cells in vivo and in vitro experiments. Eosin-nigrosine staining, in vitro fertilization, Annexin V-FITC/PI staining, ICP-MS, Hematoxylin-eosin staining, RT-qPCR, DCFH-DA staining, biochemical methods, ELISA, and western blot were applied to detect sperm motility, fertilizing capacity, apoptosis, Y3+ accumulation, testicular structure, testicular function, and NF-κB gene expression, ROS, MDA, GSH, pro-inflammatory cytokines, and NF-κB protein expression, respectively. The results revealed that YN exposure reduced sperm motility, increased sperm apoptosis, disrupted testicular tissue structure and function in mice. Exposure to YN increased ROS content and NF-κB pathway activation in testicular tissue and cells, resulting in upregulation of pro-inflammatory cytokines in the testis. When NAC scavenged ROS, the YN-induced sperm damage and inflammatory reaction, and NF-κB pathway abnormal activation in the testis of mice were alleviated. In addition, sperm damage and testicular inflammatory reaction caused by YN were alleviated after blocking the NF-κB pathway with JSH-23 treatment. Our present study elucidated that YN could damage sperm quality and induce testicular inflammatory reaction, establishing YN's toxicological impact on the male reproductive system.

Klebsiella pneumoniae (K. pneumoniae), a major hospital-acquired infection, poses a significant threat to life and global public health. Indole compounds have been found to affect bacterial growth through multiple metabolic pathways, but the mechanism is unclear. To investigate the combination of indole-3-carbinol (I3C) and polymyxin B (PMNB) as a new strategy to combat bloodstream infections caused by K. pneumoniae. The antibacterial synergy between I3C and PMNB was comprehensively assessed both in vitro and in vivo through a variety of methods including drug sensitivity tests, checkerboard assays, time-kill curves, growth curves, and a murine bloodstream infection model. Furthermore, the mechanisms underpinning the synergistic antibacterial effects of I3C as an adjuvant to PMNB were explored and substantiated via cell morphology studies, reactive oxygen species (ROS) analysis, efflux pump activity assays, and transcriptomic analyses. When combined with PMNB, I3C exhibited synergistic antibacterial effects in vitro, affecting cell morphology and ROS production. Moreover, this combination significantly enhanced outcomes in a murine model of K. pneumoniae infection, evidenced by increased survival rates, recovery of body weight, reduced bacterial loads, and diminished pathological damage. Additionally, I3C influenced the lipid metabolism pathways of K. pneumoniae and altered the structure of the cellular membrane. This investigation evaluates the synergistic antibacterial properties of I3C and PMNB as adjuvants and offers a detailed analysis of their capacity to augment the bactericidal efficacy of PMNB by modulating bacterial lipid metabolism. This work provides a solid research foundation for managing K. pneumoniae infections in clinical practice.

Carbapenemase-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) is a common pathogen that can cause severe pneumonia. The innate immune response, especially the response of macrophages, plays a crucial role in the host's defense against bacterial infections. Glycolysis is implicated in the modulation of immune functions in macrophages. Here, we provide evidence supporting the role of GPR35 in decreasing glycolysis and reducing the secretion of IL-1β in macrophages by inhibiting the transcription of HK2 during K. pneumoniae-induced pneumonia. Mice with GPR35 knock-out exhibit higher mortality and increased lung bacterial burdens. Mechanistically, GPR35 activation by kynurenic acid inhibits caspase-1 cleavage and reduces IL-1β secretion in macrophages by specifically suppressing activation of the NLRP3 inflammasome. These findings underscore the role of GPR35 in regulating inflammation during K. pneumoniae-induced pneumonia and suggest that GPR35 is a potential therapeutic target for clinical treatment.

Bacterial cystitis, caused by Escherichia coli (E. coli), is a common urinary tract infection that frequently recurs and seriously affects patient health. Although it is known that gut dysbiosis increases susceptibility to recurrent urinary tract infections, its impact on non-complicated bacterial cystitis—the most common and primary form of urinary tract infection—remains uncertain. This study found that bacterial infection can cause long-term alterations in gut microbiota structure and affect the production of metabolites. Depletion of the gut microbiota worsens the inflammatory response to bacterial infection, disrupts the epithelial barrier of the bladder, and increases E. coli retention in the bladder and bloodstream. Fecal microbiota transplantation was found to significantly alleviate these excessive inflammatory responses. The study also identified that several tryptophan derivatives derived from the gut microbiota were significantly altered during bacterial microbiota depletion and bacterial infection, with indole-3-propionic acid (IPA) exhibiting the most significant alleviating effect on the excessive inflammatory response during infection. Additionally, the study demonstrated that transcriptional activation of the immune-inhibitory protein Prg4 is regulated by the IPA receptor AhR, which is expressed in bladder urothelial cells. Knockout of AhR in bladder urothelial reduced Prg4 expression and overactivated NF-κB signaling, resulting in the loss of the IPA-alleviating effect. This study suggests that the normal gut microbiota can activate AhR in bladder urothelial cells through its metabolite IPA, regulating the transcription of Prg4 and subsequently modulating the inflammatory response to bacterial cystitis caused by E. coli infection. These findings provide a theoretical foundation for the clinical diagnosis and treatment of bacterial cystitis by leveraging the gut microbiota and their metabolites as promising therapeutic targets.

[This corrects the article DOI: 10.1021/acsmedchemlett.4c00127.].

BackgroundDiabetic retinopathy (DR) stands as a prominent complication of diabetes. Berberine (BBR) has reported to be effective to ameliorate the retinal damage of DR. Studying the potential immunological mechanisms of BBR on the streptozotocin (STZ) induced DR mouse model will explain the therapeutic mechanisms of BBR and provide theoretical basis for the clinical application of this drug.MethodsC57BL/6J mice were induced into a diabetic state using a 50 mg/(kg·d) dose of STZ over a 5-day period. Subsequently, they were subjected to a high-fat diet (HFD) for one month. Following a 5-week treatment with 100 mg/(kg·d) BBR, the concentrations of inflammatory factors in the mice's peripheral blood were determined using an enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin staining was employed to scrutinize pathological changes in the mice's retinas, while flow cytometry assessed the proportions of T-lymphocyte subsets and the activation status of dendritic cells (DCs) in the spleen and lymph nodes. CD4+T cells and DC2.4 cell lines were utilized to investigate the direct and indirect effects of BBR on T cells under high glucose conditions in vitro.ResultsFollowing 5 weeks of BBR treatment in the streptozotocin (STZ) mouse model of DR, we observed alleviation of retinal lesions and a down-regulation in the secretion of inflammatory cytokines, namely TNF-α, IL-1β, and IL-6, in the serum of these mice. And in the spleen and lymph nodes of these mice, BBR inhibited the proportion of Th17 cells and promoted the proportion of Treg cells, thereby down-regulating the Th17/Treg ratio. Additionally, in vitro experiments, BBR directly inhibited the expression of the transcription factor RORγt and promoted the expression of the transcription factor Foxp3 in T cells, resulting in a down-regulation of the Th17/Treg ratio. Furthermore, BBR indirectly modulated the Th17/Treg ratio by suppressing the secretion of TNF-α, IL-1β, and IL-6 by DCs and enhancing the secretion of indoleamine 2,3-dioxygenase (IDO) and transforming growth factor-beta (TGF-β) by DCs. This dual action inhibited Th17 cell differentiation while promoting Treg cells.ConclusionOur findings indicate that BBR regulate T cell subpopulation differentiation, reducing the Th17/Treg ratio by directly or indirectly pathway. This represents a potential therapeutic avenue of BBR for improving diabetic retinopathy.

BACKGROUND:The current investigation sought to conduct a real-world analysis of adverse events (AEs) associated with selexipag by utilizing data from the Food and Drug Administration Adverse Event Reporting System (FAERS). METHODS:The Reporting Odds Ratios (ROR) and the Medicines Healthcare Products Regulatory Agency (MHRA) method were employed to assess the potential associations between selexipag and AEs. Case reports of adverse drug reaction (ADR) related to selexipag were systematically sourced from PubMed, Embase, and Web of Science databases. RESULTS:Our analysis identified 281 Preferred Terms (PTs) signals across 20 System Organ Classes (SOCs) were found to meet the screening threshold. The most common AEs were consistent with instructions, randomized controlled trials (RCTs), and case reports. Of significant note, unexpected AEs principally target SOCs of infections and infestations, blood and lymphatic system, renal and urinary disorders, hepatobiliary disorders, including pneumonia, metapneumovirus, decreased hemoglobin. transfusion, iron-deficiency anemia, dialysis hypotension, abnormal creatinine renal clearance, liver function test increased, hepatic function abnormal, hepatic enzyme increased. Within the pediatric population, unexpected signals such as pyrexia, pneumonia, and intussusception necessitate special precautionary measures. CONCLUSIONS:The findings contribute valuable insights to clinical practice, reinforcing the importance of vigilant monitoring, and can be instrumental in guiding both therapeutic applications and safety assessments of this particular medication.

Rapid diagnosis of pulmonary tuberculosis (PTB) is urgently needed. We aimed to improve diagnosis rates by combining tuberculosis-interferon (IFN)-γ release assays (TB-IGRA) with metagenomic next-generation sequencing (mNGS) for PTB diagnosis. A retrospective study of 29 PTB and 32 non-TB patients from our hospital was conducted between October 2022 and June 2023. Samples were processed for TB-IGRA and mNGS tests according to the manufacturer’s protocol. The levels of IFN-γ release in PTB patients were significantly higher than those in non-TB patients (604.15 ± 112.18 pg/mL, and 1.04 ± 0.38 pg/mL, respectively; p < 0.0001). Regarding presenting symptoms or signs, cough and thoracalgia were less common in PTB patients than in non-TB patients (p = 0.001 and p = 0.024, respectively). Total protein and albumin levels in the sera of PTB patients were significantly elevated compared to non-TB patients (p = 0.039 and p = 0.004, respectively). The area under the ROC curve (AUC) for TB-IGRA in PTB diagnosis was 0.939. With an optimal IFN-γ cut-off value of 14.3 pg/mL (Youden’s index 0.831), sensitivity was 86.2

Osteoporosis, a global bone disease, results in decreased bone density, mass, and microarchitecture deterioration, increasing fracture risk. In previous research, FRATtide, a peptide derived from a glycogen synthase kinase-3 binding protein, effectively hindered osteoclast differentiation to yield therapeutically potent derivatives via single and double stapling. However, FRATtide's structure-activity relationship remains unclear. This study synthesized 25 FRATtide-derived peptides through systematic alanine scanning and evaluated their activities. Substitutions in Pro2, Leu5, Leu9, Val10, Leu11, Ser12, Asn14, Leu15, Ile16, Glu18, Arg22, Ser25, and Arg26 showed reduced activity, while FRT13 and FRT20 with Gly13 and Arg21 substitutions, respectively, displayed enhanced activities. F-actin binding and bone resorption assays on FRT13 and FRT20 showed better inhibition of osteoclast differentiation and bone resorption compared with FRATtide. This study elucidated FRATtide's structure-activity relationship, thereby facilitating future structural optimization for osteoporosis treatment.

Limited treatment options and multidrug-resistant (MDR) Klebsiella pneumoniae present a significant therapeutic challenge, underscoring the need for novel approaches. Drug repurposing is a promising tool for augmenting the activity of many antibiotics. This study aimed to identify novel synergistic drug combinations against K. pneumoniae based on drug repurposing. We used the clinically isolated GN 172867 MDR strain of K. pneumoniae to determine the reversal resistance activity of zidovudine (AZT). The combined effects of AZT and various antibiotics, including nitrofurantoin (NIT) and omadacycline (OMC), were examined using the checkerboard method, growth curves, and crystal violet assays to assess biofilms. An in vitro combination activity testing was carried out in 12 isolates of K. pneumoniae. In vivo murine urinary tract and lung infection models were used to evaluate the therapeutic effects of AZT + NIT and AZT + OMC, respectively. The fractional inhibitory concentration index and growth curve demonstrated that AZT synergized with NIT or OMC against K. pneumoniae strains. In addition, AZT + NIT inhibited biofilm formation and cleared mature biofilms. In vivo, compared with untreated GN 172867-infected mice, AZT + NIT and AZT + OMC treatment decreased colony counts in multiple tissues (P < 0.05) and pathological scores in the bladder and kidneys (P < 0.05) and increased the survival rate by 60% (P < 0.05). This study evaluated the combination of AZT and antibiotics to treat drug-resistant K. pneumoniae infections and found novel drug combinations for the treatment of acute urinary tract infections. These findings suggest that AZT may exert significant anti-resistance activity.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen that causes various diseases. Extensive researches highlight the significant role of gut microbiota and its metabolites, particularly spermidine, in infectious diseases. However, the immunomodulatory mechanisms of spermidine in MRSA-induced bloodstream infection remain unclear. Here, we confirmed the protective effects of spermidine in bloodstream infection in mice. Spermidine reduced the bacterial load and expression of inflammatory factors by shifting the macrophage phenotype to an anti-inflammatory phenotype, ultimately prolonging the survival of the infected mice. The protective effect against MRSA infection may rely on the elevated expression of protein tyrosine phosphatase nonreceptor 2 (PTPN2). Collectively, these findings confirm the immunoprotective effects of spermidine via binding to PTPN2 in MRSA bloodstream infection, providing new ideas for the treatment of related infectious diseases.

Self-powered hydrogels have gained attention for addressing energy needs of small flexible devices, but creating ones with high voltage and current remains challenging. Here, we report a novel polyacrylamide hydrogel loaded with copper sulfate and ammonium chloride (PAC), which not only exhibits good mechanical properties (maximum strain of 390 %), high conductivity (conductivity of 2.37 S/m), but also possesses excellent antibacterial and antifreeze properties. PAC demonstrates remarkable stimulus responsiveness. When using resistance variation as the output signal, its GF value reaches as high as 5.3 within the strain range of 35 % to 280 %. Additionally, PAC can utilize current variation as an output signal, providing options for various sensor applications. On the other hand, PAC hydrogels can achieve self-powering capabilities through zinc electrodes, with an open-circuit voltage of 0.92 V. By connecting PAC hydrogels in parallel or series, higher output voltage and current can be achieved, providing a strong guarantee for powering small devices. In a stacked series configuration, 8 sets of PACs can generate an output voltage of 7.16 V and an output current of 52.6 mA. In sum, PAC is a high-performance self-powered hydrogel with tremendous potential in the fields of flexible sensing and energy supply.

ABSTRACT Background emergence of multidrug-resistant (MDR) bacterial strains is a public health concern that threatens global and regional security. Efflux pump-overexpressing MDR strains from clinical isolates are the best subjects for studying the mechanisms of MDR caused by bacterial efflux pumps. A Klebsiella pneumoniae strain overexpressing the OqxB-only efflux pump was screened from a clinical strain library to explore reverse OqxB-mediated bacterial resistance strategies. We identified non-repetitive clinical isolated K. pneumoniae strains using a matrix-assisted laser desorption/ionization time-of-flight (TOF) mass spectrometry clinical TOF-II (Clin-TOF-II) and susceptibility test screening against levofloxacin and ciprofloxacin. And the polymorphism analysis was conducted using pulsed-field gel electrophoresis. Efflux pump function of resistant strains is obtained by combined drug sensitivity test of phenylalanine-arginine beta-naphthylamide (PaβN, an efflux pump inhibitor) and detection with ethidium bromide as an indicator. The quantitative reverse transcription PCR was performed to assess whether the oqxB gene was overexpressed in K. pneumoniae isolates. Additional analyses assessed whether the oqxB gene was overexpressed in K. pneumoniae isolates and gene knockout and complementation strains were constructed. The binding mode of PaβN with OqxB was determined using molecular docking modeling. Among the clinical quinolone-resistant K. pneumoniae strains, one mediates resistance almost exclusively through the overexpression of the resistance–nodulation–division efflux pump, OqxB. Crystal structure of OqxB has been reported recently by N. Bharatham, P. Bhowmik, M. Aoki, U. Okada et al. (Nat Commun 12:5400, 2021, https://doi.org/10.1038/s41467-021-25679-0 ). The discovery of this strain will contribute to a better understanding of the role of the OqxB transporter in K. pneumoniae and builds on the foundation for addressing the threat posed by quinolone resistance. IMPORTANCE The emergence of antimicrobial resistance is a growing and significant health concern, particularly in the context of K. pneumoniae infections. The upregulation of efflux pump systems is a key factor that contributes to this resistance. Our results indicated that the K. pneumoniae strain GN 172867 exhibited a higher oqxB gene expression compared to the reference strain ATCC 43816. Deletion of oqxB led a decrease in the minimum inhibitory concentration of levofloxacin. Complementation with oqxB rescued antibiotic resistance in the oqxB mutant strain. We demonstrated that the overexpression of the OqxB efflux pump plays an important role in quinolone resistance. The discovery of strain GN 172867 will contribute to a better understanding of the role of the OqxB transporter in K. pneumoniae and promotes further study of antimicrobial resistance.

To prepare and characterize the mouse polyclonal antibody against the dense granule protein 24 (GRA24) of

Bacterial cystitis, a commonly occurring urinary tract infection (UTI), is renowned for its extensive prevalence and tendency to recur. Despite the extensive utilization of levofloxacin as a conventional therapeutic approach for bacterial cystitis, its effectiveness is impeded by adverse toxic effects, drug resistance concerns, and its influence on the gut microbiota. This study introduces Lev@PADM, a hydrogel with antibacterial properties that demonstrates efficacy in the treatment of bacterial cystitis. Lev@PADM is produced by combining levofloxacin with decellularized porcine acellular dermal matrix hydrogel and exhibits remarkable biocompatibility. Lev@PADM demonstrates excellent stability as a hydrogel at body temperature, enabling direct administration to the site of infection through intravesical injection. This localized delivery route circumvents the systemic circulation of levofloxacin, resulting in a swift and substantial elevation of the antimicrobial agent’s concentration specifically at the site of infection. The in vivo experimental findings provide evidence that Lev@PADM effectively prolongs the duration of levofloxacin’s action, impedes the retention and invasion of E.coli in the urinary tract, diminishes the infiltration of innate immune cells into infected tissues, and simultaneously preserves the composition of the intestinal microbiota. These results indicate that, in comparison to the exclusive administration of levofloxacin, Lev@PADM offers notable benefits in terms of preserving the integrity of the bladder epithelial barrier and suppressing the recurrence of urinary tract infections.

The mesencephalic astrocyte-derived neurotrophic factor (MANF) has been recently identified as a neurotrophic factor, but its role in hepatic fibrosis is unknown. Here, we found that MANF was upregulated in the fibrotic liver tissues of the patients with chronic liver diseases and of mice treated with CCl4. MANF deficiency in either hepatocytes or hepatic mono-macrophages, particularly in hepatic mono-macrophages, clearly exacerbated hepatic fibrosis. Myeloid-specific MANF knockout increased the population of hepatic Ly6Chigh macrophages and promoted HSCs activation. Furthermore, MANF-sufficient macrophages (from WT mice) transfusion ameliorated CCl4-induced hepatic fibrosis in myeloid cells-specific MANF knockout (MKO) mice. Mechanistically, MANF interacted with S100A8 to competitively block S100A8/A9 heterodimer formation and inhibited S100A8/A9-mediated TLR4–NF-κB signal activation. Pharmacologically, systemic administration of recombinant human MANF significantly alleviated CCl4-induced hepatic fibrosis in both WT and hepatocytes-specific MANF knockout (HKO) mice. This study reveals a mechanism by which MANF targets S100A8/A9-TLR4 as a “brake” on the upstream of NF-κB pathway, which exerts an impact on macrophage differentiation and shed light on hepatic fibrosis treatment.