Inhibition of insulin degrading enzyme suppresses osteoclast hyperactivity via enhancing Nrf2-dependent antioxidant response in glucocorticoid-induced osteonecrosis of the femoral head.

BACKGROUND: Osteoclast hyperactivation due to the pathological overproduction of reactive oxygen species (ROS) stimulated by glucocorticoids (GCs) is one of the key drivers behind glucocorticoid-induced osteonecrosis of the femoral head (GIONFH). The insulin degrading enzyme (IDE), a conserved Zn2+ metallo-endopeptidase, facilitates the DNA binding of glucocorticoid receptor and plays a substantial role in steroid hormone-related signaling pathways. However, the potential role of IDE in the pathogenesis of GIONFH is yet undefined. METHODS: In this study, we employed network pharmacology and bioinformatics analysis to explore the impact of IDE inhibition on GIONFH with 6bK as an inhibitory agent. Further evidence was collected through in vitro osteoclastogenesis experiments and in vivo evaluations involving methylprednisolone (MPS)-induced GIONFH mouse model. RESULTS: Enrichment analysis indicated a potential role of 6bK in redox regulation amid GIONFH development. In vitro findings revealed that 6bK could attenuate GCs-stimulated overactivation of osteoclast differentiation by interfering with the transcription and expression of key osteoclastic genes (Traf6, Nfatc1, and Ctsk). The use of an H2DCFDA probe and subsequent WB assays introduced the inhibitory effects of 6bK on osteoclastogenesis, linked with the activation of the nuclear factor erythroid-derived 2-like 2 (Nrf2)-mediated antioxidant system. Furthermore, Micro-CT scans validated that 6bK could alleviate GIONFH in MPS-induced mouse models. CONCLUSIONS: Our findings suggest that 6bK suppresses osteoclast hyperactivity in GCs-rich environment. This is achieved by reducing the accumulation of intracellular ROS via promoting the Nrf2-mediated antioxidant system, thus implying that IDE could be a promising therapeutic target for GIONFH.

The Role of Neuromodulation and Potential Mechanism in Regulating Heterotopic Ossification.

Heterotopic ossification (HO) is a pathological process characterized by the aberrant formation of bone in muscles and soft tissues. It is commonly triggered by traumatic brain injury, spinal cord injury, and burns. Despite a wide range of evidence underscoring the significance of neurogenic signals in proper bone remodeling, a clear understanding of HO induced by nerve injury remains rudimentary. Recent studies suggest that injury to the nervous system can activate various signaling pathways, such as TGF-ß, leading to neurogenic HO through the release of neurotrophins. These pathophysiological changes lay a robust groundwork for the prevention and treatment of HO. In this review, we collected evidence to elucidate the mechanisms underlying the pathogenesis of HO related to nerve injury, aiming to enhance our understanding of how neurological repair processes can culminate in HO.

Targeting the Gut Microbiota for Remediating Obesity and Related Metabolic Disorders.

The rate of obesity is rapidly increasing and has become a health and economic burden worldwide. As recent studies have revealed that the gut microbiota is closely linked to obesity, researchers have used various approaches to modulate the gut microbiota to treat the condition. Dietary composition and energy intake strongly affect the composition and function of the gut microbiota. Intestinal microbial changes alter the composition of bile acids and fatty acids and regulate bacterial lipopolysaccharide production, all of which influence energy metabolism and immunity. Evidence also suggests that remodeling the gut microbiota through intake of probiotics, prebiotics, fermented foods, and dietary plants, as well as by fecal microbiota transplantation, are feasible methods to remediate obesity.

Extracellular vesicles derived from CD73 modified human umbilical cord mesenchymal stem cells ameliorate inflammation after spinal cord injury.

BACKGROUND: Spinal cord injury (SCI) is an inflammatory condition, and excessive adenosine triphosphate (ATP) is released into the extracellular space, which can be catabolized into adenosine by CD73. Extracellular vesicles have been designed as nano drug carriers in many diseases. However, their impacts on delivery of CD73 after SCI are not yet known. We aimed to construct CD73 modified extracellular vesicles and explore the anti-inflammatory effects after SCI. METHODS: CD73 engineered extracellular vesicles (CD73+ hucMSC-EVs) were firstly established, which were derived from human umbilical cord mesenchymal stem cells (hucMSCs) transduced by lentiviral vectors to upregulate the expression of CD73. Effects of CD73+ hucMSC-EVs on hydrolyzing ATP into adenosine were detected. The polarization of M2/M1 was verified by immunofluorescence. Furthermore, A2aR and A2bR inhibitors and A2bR knockdown cells were used to investigate the activated adenosine receptor. Biomarkers of microglia and levels of cAMP/PKA were also detected. Repetitively in vivo study, morphology staining, flow cytometry, cytokine analysis, and ELISA assay, were also applied for verifications. RESULTS: CD73+ hucMSC-EVs reduced concentration of ATP and promoted the level of adenosine. In vitro experiments, CD73+ hucMSC-EVs increased macrophages/microglia M2:M1 polarization, activated adenosine 2b receptor (A2bR), and then promoted cAMP/PKA signaling pathway. In mice using model of thoracic spinal cord contusion injury, CD73+ hucMSC-EVs improved the functional recovery after SCI through decreasing the content of ATP in cerebrospinal fluid and improving the polarization from M1 to M2 phenotype. Thus, the cascaded pro-inflammatory cytokines were downregulated, such as TNF-α, IL-1ß, and IL-6, while the anti-inflammatory cytokines were upregulated, such as IL-10 and IL-4. CONCLUSIONS: CD73+ hucMSC-EVs ameliorated inflammation after spinal cord injury by reducing extracellular ATP, promoting A2bR/cAMP/PKA pathway and M2/M1 polarization. CD73+ hucMSC-EVs might be promising nano drugs for clinical application in SCI therapy.

Polymorphisms of pentanucleotide repeats (tttta)n in the promoter of CYP11A1 and their relationships to polycystic ovary syndrome (PCOS) risk: a meta-analysis.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases with an uncertain pathology and the most frequent incretory disorder in women of reproductive age, often leading to female infertility. Evidence has shown that genetic factors may contribute to the etiology of PCOS. Contradictory results have been reported concerning the association between PCOS and the CYP11A1 gene promoter -528 bp pentanucleotide (tttta)n repeat polymorphism. In order to get an overall understanding of the association between the CYP11A1 gene promoter -528 bp pentanucleotide (tttta)n repeat polymorphism and PCOS, case-control studies regarding this association were extracted from MEDLINE, Ovid EMBASE and PubMed and pooled for meta-analysis. In dichotomous allelic analyses with 1,236 PCOS patients and 1,306 control subjects, the odds ratios (ORs) were very close to 1. In dichotomous genotypic analyses with 1,063 PCOS patients and 1,176 control subjects, the (tttta)4 genotype may increase the risk of PCOS in a recessive model with OR 1.44, 95% confidence interval (CI) 1.12-1.85, and the (tttta)6 genotype may decrease the risk of PCOS in a dominant model with OR 0.76, 95% CI 0.61-0.93. In continuous analyses with 1,085 PCOS patients and 1,216 control subjects, the Mean Difference (MD) was -0.07 with a 95% CI -0.18 to 0.05, showing no difference between PCOS and control groups. No publication bias was found in either dichotomous or continuous analyses. Taken together, there may be an association between CYP11A1 promoter pentanucleotide repeat polymorphism and PCOS. Further research is needed to strictly confirm our findings.

Neutrophil in the suppressed immune microenvironment: Critical prognostic factor for lung adenocarcinoma patients with KEAP1 mutation.

Purpose: It is still unclear whether KEAP1 mutation is detrimental to immunotherapy of lung adenocarcinoma (LUAD) patients, we try to analyse the exact changes in the TME in LUAD patients with KEAP1 mutations and to identify key factors influencing prognosis. Experimental design: A total of 1,029 patients with lung squamous carcinoma (LUSC) or LUAD with data obtained from The Cancer Genome Atlas were included in this study. The TME and OS of patients with LUAD stratified by mutant versus wild-type KEAP1 status were comprehensively measured. Moreover, we classified LUAD patients with KEAP1 mutations into three subtypes, by unsupervised consensus clustering. We further analysed the TME, OS, commutated genes and metabolic pathways of different subgroups. A total of 40 LUAD patients underwent immunotherapy were collected and classified into mutant KEAP1 group and wild-type KEAP1 group. We also conducted immunohistochemical staining in KEAP1-MT groups. Result: Suppressed TME was observed not only in LUAD patients but also in LUSC patients. LUAD patients with mutant KEAP1 underwent immunotherapy had worse PFS than wild-type KEAP1. Unsupervised consensus clustering analysis suggested that the three subtypes of patients exhibited different densities of neutrophil infiltration and had different OS results: cluster 2 patients had significantly higher levels of neutrophils had significantly worse prognoses than those of patients in clusters 1 and 3 and patients with wild-type KEAP1. Univariate and multivariate Cox analyses proved that a high density of neutrophils was significantly associated with worse OS and immunohistochemical staining proved that shorter PFS showed high density of neutrophils. Conclusion: KEAP1 mutation significantly suppresses the tumour immune microenvironment in LUAD patients. LUAD patients with mutant KEAP1 underwent immunotherapy had worse PFS than with wild-type KEAP1. Neutrophils may play an important role in the prognosis of LUAD patients with KEAP1 mutations and may provide a promising therapeutic target.

A multifunctional nanogel encapsulating layered double hydroxide for enhanced osteoarthritis treatment via protection of chondrocytes and ECM.

Osteoarthritis (OA) is characterized by progressive and irreversible damage to the articular cartilage and a consecutive inflammatory response. However, the majority of clinical drugs for OA treatment only alleviate symptoms without addressing the fundamental pathology. To mitigate this issue, we developed an inflammation-responsive carrier and encapsulated bioactive material, namely, LDH@TAGel. The LDH@TAGel was designed with anti-inflammatory and antioxidative abilities, aiming to directly address the pathology of cartilage damage. In particular, LDH was confirmed to restore the ECM secretion function of damaged chondrocytes and attenuate the expression of catabolic matrix metalloproteinases (Mmps). While TAGel showed antioxidant properties by scavenging ROS directly. In vitro evaluation revealed that the LDH@TAGel could protect chondrocytes from inflammation-induced oxidative stress and apoptosis via the Nrf2/Keap1 system and Pi3k-Akt pathway. In vivo experiments demonstrated that the LDH@TAGel could alleviated the degeneration and degradation of cartilage induced by anterior cruciate ligament transection (ACLT). The OARSI scores indicating OA severity decreased significantly after three weeks of intervention. Moreover, the IVIS image revealed that LDH@TAGel enhances the controlled release of LDH in a manner that can be customized according to the severity of OA, allowing adaptive, precise treatment. In summary, this novel design effectively alleviates the underlying pathological causes of OA-related cartilage damage and has emerged as a promising biomaterial for adaptive, cause-targeted OA therapies.

Human serum albumin-bound paclitaxel nanoparticle inhibits cervical carcinoma cell proliferation and oxidative damage through CYP3A4 and CYP2C8.

Background: Cervical cancer (CC) is currently the most common malignant tumour in the female reproductive tract, and paclitaxel (PTX) is a commonly used chemotherapeutic agent, but tumour cell resistance will seriously affect the therapeutic efficacy of PTX. Nanoparticle human serum albumin-bound paclitaxel (Nano-HSA-PTX) is a novel drug delivery modality that may have superior effects to PTX alone. Objective: To clarify the effect of Nano-HSA-PTX on cervical carcinoma (CC) cells and the underlying mechanisms. Methods: After the preparation of Nano-HSA-PTX, its morphology was observed by electron transmission microscope (TEM), and its entrapment efficiency (EE%) and drug loading rate (DL%) were detected. Nano-HSA-PTX was compared with conventional PTX for drug metabolism. Additionally, CC HeLa and SiHa cells were purchased and divided into three groups to treat with Nano-HSA-PTX, PTX and normal saline, respectively. MTT, cell cloning, Transwell and cell scratch assays were carried out to determine cell proliferation, invasion and migration, flow cytometry and Western blotting were performed to detect apoptosis rate and apoptosis-related protein expression, and PCR was conducted to quantify oxidative damage indicators. Further, CYP3A4 and CYP2C8 expression patterns in CC cells (HeLa and SiHa) and human normal cervical epithelia (End1/E6E7) and the changes of their levels under the intervention of Nano-HSA-PTX were measured. Subsequently, C57BL/6mice were purchased for subcutaneous tumorigenesis experiment to observe the impact of Nano-HSA-PTX on tumor growth. Results: Under TEM, Nano-HSA-PTX was complete and arranged compactly, with a stable structure and markedly higher EE% and DL% than PTX (P < 0.05). Under Nano-HSA-PTX intervention, the proliferation, invasion, migration and oxidative damage of HeLa and SiHa were significantly decreased compared with the control and PTX groups, while the apoptosis was increased (P < 0.05). Besides, elevated CYP3A4 and CYP2C8 levels were observed in CC cells, which were inhibited by Nano-HSA-PTX and PTX (P < 0.05). Finally, tumorigenesis experiments in nude mice revealed that Nano-HSA-PTX could inhibit tumor growth. Conclusion: Compared with PTX, Nano-HSA-PTX has a superior effect of inhibiting CC activity. And this mechanism of action was carried out by inhibiting the expression of CYP3A4 and CYP2C8.

Osteoclasts and osteoarthritis: Novel intervention targets and therapeutic potentials during aging.

Osteoarthritis (OA), a chronic degenerative joint disease, is highly prevalent among the aging population, and often leads to joint pain, disability, and a diminished quality of life. Although considerable research has been conducted, the precise molecular mechanisms propelling OA pathogenesis continue to be elusive, thereby impeding the development of effective therapeutics. Notably, recent studies have revealed subchondral bone lesions precede cartilage degeneration in the early stage of OA. This development is marked by escalated osteoclast-mediated bone resorption, subsequent imbalances in bone metabolism, accelerated bone turnover, and a decrease in bone volume, thereby contributing significantly to the pathological changes. While the role of aging hallmarks in OA has been extensively elucidated from the perspective of chondrocytes, their connection with osteoclasts is not yet fully understood. There is compelling evidence to suggest that age-related abnormalities such as epigenetic alterations, proteostasis network disruption, cellular senescence, and mitochondrial dysfunction, can stimulate osteoclast activity. This review intends to systematically discuss how aging hallmarks contribute to OA pathogenesis, placing particular emphasis on the age-induced shifts in osteoclast activity. It also aims to stimulate future studies probing into the pathological mechanisms and therapeutic approaches targeting osteoclasts in OA during aging.

Integrated bioinformatics investigation of adenylyl cyclase family co-expression network in bladder cancer followed by preliminary validation of member 2 (ADCY2) in tumorigenesis and prognosis.

Background: The adenylyl cyclase (ADCY) gene family encodes enzymes responsible for the synthesis of cyclic adenosine monophosphate (cAMP) from adenosine triphosphate (ATP), which comprises nine transmembrane isoforms (ADCYs 1-9). Although ADCYs correlate with intracellular signalling and tumorigenesis in different malignancies, their roles in bladder cancer remain unclear. Methods: Utilizing the bladder urothelial carcinoma (BLCA) dataset from The Cancer Genome Atlas (TCGA), we employed the R package 'limma' to identify differential genes. Subsequent correlation analysis with corresponding clinical data was conducted. Prognostic significance of ADCY family genes was assessed through survival analysis. Univariate and multivariate Cox regression determined ADCY2 as a potential independent risk factor for BLCA. Validation was performed using immunohistochemistry results from independent cohorts. Additionally, we delved into the mechanism of genetic variations, methylation modifications, and signalling pathways of ADCY family genes. Evaluation of their role in the immune microenvironment was achieved through R packages single-sample gene set enrichment analysis (ssGSEA), CIBERPORT, and ESTIMATE. Results: Cases of bladder cancer were retrieved from TCGA, and the transcriptionally differentially expressed members of ADCY were identified (members 2, 4, and 5). Genomic alteration, epigenomic modification, clinicopathological characteristics and clinical survival were systematically investigated. A co-expression network was established based on the intersection of correlated genes, which was centred around ADCY2, ADCY4, and ADCY5. Enrichment analysis revealed that correlated genes were involved in epithelial-mesenchymal transition (EMT). The ADCY2 was selected as the most representative biomarker for prognosis in bladder cancer. Bladder tumour with higher ADCY2 expression had higher prognostic risk and worse survival outcomes. Moreover, ADCY2 was correlated with classic immune checkpoints, and a better responsiveness to immunotherapy was exhibited in high-expression subsets. To ameliorate universality of the conclusion, our study also included several real-world cohorts into the preliminary validation, using datasets from the Gene Expression Omnibus (GEO; GSE13507), tissue microarray (TMA) with 80 bladder cancer inclusion and clinical trial IMvigor210, which were associated with immunotherapy sensitivity, prognosis, and common biomarker presentation. Conclusions: Our study reveals that ADCY family has prognostic value in patients with bladder cancer; the ADCY2 is a prominent prognostic biomarker. The bioinformatics analyses and validation provide direction for further functional and mechanistic studies on the screened members of ADCY family.

Stable peptide-assembled nanozyme mimicking dual antifungal actions.

Natural antimicrobial peptides (AMPs) and enzymes (AMEs) are promising non-antibiotic candidates against antimicrobial resistance but suffer from low efficiency and poor stability. Here, we develop peptide nanozymes which mimic the mode of action of AMPs and AMEs through de novo design and peptide assembly. Through modelling a minimal building block of IHIHICI is proposed by combining critical amino acids in AMPs and AMEs and hydrophobic isoleucine to conduct assembly. Experimental validations reveal that IHIHICI assemble into helical ß-sheet nanotubes with acetate modulation and perform phospholipase C-like and peroxidase-like activities with Ni coordination, demonstrating high thermostability and resistance to enzymatic degradation. The assembled nanotubes demonstrate cascade antifungal actions including outer mannan docking, wall disruption, lipid peroxidation and subsequent ferroptotic death, synergistically killing >90% Candida albicans within 10 min on disinfection pad. These findings demonstrate an effective de novo design strategy for developing materials with multi-antimicrobial mode of actions.

Synthesis, characterization, and in vitro anti-tumor activity studies of the hyaluronic acid-mangiferin-methotrexate nanodrug targeted delivery system.

In this study, to increase the accumulation of MTX in the tumor site and reduce the toxicity to normal tissues by MA, a novel nano-drug delivery system comprised of hyaluronic acid (HA)-mangiferin (MA)-methotrexate (MTX) (HA-MA-MTX) was developed by a self-assembly strategy. The advantage of the nano-drug delivery system is that MTX can be used as a tumor-targeting ligand of the folate receptor (FA), HA can be used as another tumor-targeting ligand of the CD44 receptor, and MA serves as an anti-inflammatory agent. 1HNMR and FT-IR results confirmed that HA, MA, and MTX were well coupled together by the ester bond. DLS and AFM images revealed that the size of HA-MA-MTX nanoparticles was about ~138 nm. In vitro cell experiments proved that HA-MA-MTX nanoparticles have a positive effect on inhibiting K7 cancer cells while having relatively lower toxicity to normal MC3T3-E1 cells than MTX does. All these results indicated that the prepared HA-MA-MTX nanoparticles can be selectively ingested by K7 tumor cells through FA and CD44 receptor-mediated endocytosis, thus inhibiting the growth of tumor tissues and reducing the nonspecific uptake toxicity caused by chemotherapy. Therefore, these self-assembled HA-MA-MTX NPs could be a potential anti-tumor drug delivery system.

Inhibition of Protein Disulfide Isomerase Attenuates Osteoclast Differentiation and Function via the Readjustment of Cellular Redox State in Postmenopausal Osteoporosis.

Due to the accumulation of reactive oxygen species (ROS) and heightened activity of osteoclasts, postmenopausal osteoporosis could cause severe pathological bone destruction. Protein disulfide isomerase (PDI), an endoplasmic prototypic thiol isomerase, plays a central role in affecting cellular redox state. To test whether suppression of PDI could inhibit osteoclastogenesis through cellular redox regulation, bioinformatics network analysis was performed on the causative genes, followed by biological validation on the osteoclastogenesis in vitro and ovariectomy (OVX) mice model in vivo. The analysis identified PDI as one of gene targets for postmenopausal osteoporosis, which was positively expressed during osteoclastogenesis. Therefore, PDI expression inhibitor and chaperone activity inhibitor were used to verify the effects of PDI inhibitors on osteoclastogenesis. Results demonstrated that PDI inhibitors could reduce osteoclast number and inhibit resorption function via suppression on osteoclast marker genes. The mechanisms behind the scenes were the PDI inhibitors-caused intracellular ROS reduction via enhancement of the antioxidant system. Micro-CT and histological results indicated PDI inhibitors could effectively alleviate or even prevent bone loss in OVX mice. In conclusion, our findings unveiled the suppressive effects of PDI inhibitors on osteoclastogenesis by reducing intracellular ROS, providing new therapeutic options for postmenopausal osteoporosis.

Microneedle/CD-MOF-mediated transdural controlled release of methylprednisolone sodium succinate after spinal cord injury.

A new method of transdural delivering drugs to the spinal cord has been developed, involving the use of microneedles (MNs) and a ß-cyclodextrin metal-organic framework (CD-MOF). This epidural microneedle array, dubbed MNs@CD-MOF@MPSS, can be utilized to deliver methylprednisolone sodium succinate (MPSS) to the site of spinal cord injury (SCI) in a controlled manner. MNs allows to generate micropores in the dura for direct drug delivery to the spinal cord, overcoming tissue barriers and targeting damaged regions. Additionally, the CD-MOF provides a secondary extended release after separating from the MNs. In in vitro study, inward MNs increased cellular absorption of MPSS and then reduced LPS-induced M1 polarization of microglia. And animal studies have shown that this method of drug delivery results in improved BMS scores and a reduction in M1 phenotype microphage and glial scar formation. Furthermore, the downregulation of the NLRP3-positive inflammasome and related pro-inflammatory cytokines was observed. In conclusion, this new drug platform has potential for clinical application in spinal cord diseases and is a valuable composite for minimally transdural controlled drug delivery. STATEMENT OF SIGNIFICANCE: This research presents a new epidural microneedle patch made up of microneedles (MNs) and a ß-cyclodextrin metal-organic framework (CD-MOF). The epidural microneedle patch boasts high drug loading capacity, the ability to penetrate the dura, and controlled release. When loaded with methylprednisolone sodium succinate (MPSS), it effectively reduces inflammation and improves neurological function after spinal cord injury. Therefore, it is a novel and promising drug platform for the treatment of spinal cord diseases in a clinical setting.

Metronidazole-loaded nanoparticulate thermoreversible gel for gynecologic infection of Trichomonas vaginalis.

OBJECTIVE: Trichomoniasis is a common sexually-transmitted disease that is associated with increased perinatal morbidity and human immunodeficiency virus (HIV) transmission. This study aimed to develop a Metronidazole-loaded nanoparticulate thermoreversible gel for gynecological infection of Trichomonas vaginalis (T. vaginalis). METHODS: The optimized nanoparticulate formulation was used in thermoreversible gel and characterized for physico-chemical properties, antiparasitic activity, and in vivo efficacy in the BALB/c mouse model. RESULT: A nearly threefold rise in antiparasitic activity of the optimized formulation was observed as compared to that of regular gel. Formulation F5 successfully cured the trichomoniasis within 3 days, while regular gel and pure Metronidazole (MTDZ) failed to cure this infection (P<0.05). CONCLUSION: The present investigation confirms the ability of thermoreversible gel containing nanoparticulate metronidazole againstthe infection by T. vaginalis. The developed gel could be an alternative to the existing drug delivery system for the treatment of trichomoniasis.

Lactic Acid Bacteria: A Promising Tool for Menopausal Health Management in Women.

Menopause is a period during which women undergo dramatic hormonal changes. These changes lead to physical and mental discomfort, are greatly afflictive, and critically affect women's lives. However, the current safe and effective management measures for women undergoing menopause are insufficient. Several probiotic functions of lactic acid bacteria (LAB) have been recognized, including alleviation of lactose intolerance, protection of digestive tract health, activation of the immune system, protection against infections, improvement of nutrient uptake, and improvement of the microbiota. In this review, we highlight the currently available knowledge of the potential protective effects of LAB on preventing or mitigating menopausal symptoms, particularly in terms of maintaining balance in the vaginal microbiota, reducing bone loss, and regulating the nervous system and lipid metabolism. Given the increasing number of women entering menopause and the emphasis on the management of menopausal symptoms, LAB are likely to soon become an indispensable part of clinical/daily care for menopausal women. Herein, we do not intend to provide a comprehensive analysis of each menopausal disorder or to specifically judge the reliability and safety of complementary therapies; rather, we aim to highlight the potential roles of LAB in individualized treatment strategies for the clinical management of menopause.

Crosstalk between the Gut Microbiome and Colonic Motility in Chronic Constipation: Potential Mechanisms and Microbiota Modulation.

Chronic constipation (CC) is a highly prevalent and burdensome gastrointestinal disorder. Accumulating evidence highlights the link between imbalances in the gut microbiome and constipation. However, the mechanisms by which the microbiome and microbial metabolites affect gut movement remain poorly understood. In this review, we discuss recent studies on the alteration in the gut microbiota in patients with CC and the effectiveness of probiotics in treating gut motility disorder. We highlight the mechanisms that explain how the gut microbiome and its metabolism are linked to gut movement and how intestinal microecological interventions may counteract these changes based on the enteric nervous system, the central nervous system, the immune function, and the ability to modify intestinal secretion and the hormonal milieu. In particular, microbiota-based approaches that modulate the levels of short-chain fatty acids and tryptophan catabolites or that target the 5-hydroxytryptamine and Toll-like receptor pathways may hold therapeutic promise. Finally, we discuss the existing limitations of microecological management in treating constipation and suggest feasible directions for future research.

Nanozyme-strip for rapid and ultrasensitive nucleic acid detection of SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic has created a huge demand for sensitive and rapid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The current gold standard for SARS-CoV-2 detection is reverse transcription-polymerase chain reaction (RT-PCR)-based nucleic acid amplification. However, RT-PCR is time consuming and requires specialists and large instruments that are unattainable for point-of-care testing (POCT). To develop POCT for SARS-CoV-2, we combined recombinase polymerase amplification (RPA) and FeS2 nanozyme strips to achieve facile nucleic acid amplification and subsequent colorimetric signal enhancement based on the high peroxidase-like activity of the FeS2 nanozymes. This method showed a nucleic acid limit of detection (LOD) for SARS-CoV-2 of 200 copies/mL, close to that of RT-PCR. The unique catalytic properties of the FeS2 nanozymes enabled the nanozyme-strip to amplify colorimetric signals via the nontoxic 3,3',5,5'-tetramethylbenzidine (TMB) substrate. Importantly, the detection of clinical samples of human papilloma virus type 16 (HPV-16) showed 100% agreement with previous RT-PCR results, highlighting the versatility and reliability of this method. Our findings suggest that nanozyme-based nucleic acid detection has great potential in the development of POCT diagnosis for COVID-19 and other viral infections.

IL-6 secretion of CD4+ T cells stimulated by LC3-positive extracellular vesicles in human epithelial ovarian cancer.

BACKGROUND: Ovarian cancer (OC) as the most fatal gynecological malignancy worldwide, with epithelial ovarian cancer (EOC) being the predominant and most lethal form, poses a serious threat to human health. LC3-positive extracellular vesicles (LC3+ EVs) promote tumorigenesis by educating CD4+ T cells in a murine melanoma model. However, regulation of LC3+ EVs in human EOC remains largely unknown.  METHODS: Differential analysis of Rab8a, Hsp90α and Il6 expression was performed using GEPIA2. The number of LC3+ EVs and the frequency of Heat shock protein 90α+ LC3+ EVs (HSP90α+ LC3+ EVs) in the ascites of EOC patients were tested by flow cytometry. IL-6, IL-10, IFN-γ, IL-4 and TGF-ß were measured by ELISA. CD4+ T cells were isolated from peripheral blood of healthy human donors using MACS magnetic bead technology.  RESULTS: Higher Rab8a, Hsp90a and Il6 expression of cancer tissues compared with normal adjacent tissues in OC were found. The level of IL-6 was positively correlated with LC3+ EVs number, HSP90α+ LC3+ EVs percentage in the ascites, and ROMA index of the patient. In addition, elevated IL-6 production by CD4+ T cells induced by LC3+ EVs was observed, which was suppressed by anti-HSP90α or anti-TLR2.  CONCLUSIONS: LC3+ EVs level and HSP90α+ LC3+ EVs percentage were associated with elevated IL-6 in the ascites of EOC patients. HSP90α on LC3+ EVs from human EOC could stimulate CD4+ T cell production of IL-6 via TLR2.

Metastable Iron Sulfides Gram-Dependently Counteract Resistant Gardnerella Vaginalis for Bacterial Vaginosis Treatment.

Bacterial vaginosis (BV) is the most common vaginal infection found in women in the world. Due to increasing drug-resistance of virulent pathogen such as Gardnerella vaginalis (G. vaginalis), more than half of BV patients suffer recurrence after antibotics treatment. Here, metastable iron sulfides (mFeS) act in a Gram-dependent manner to kill bacteria, with the ability to counteract resistant G. vaginalis for BV treatment. With screening of iron sulfide minerals, metastable Fe3 S4 shows suppressive effect on bacterial growth with an order: Gram-variable G. vaginalis >Gram-negative bacteria>> Gram-positive bacteria. Further studies on mechanism of action (MoA) discover that the polysulfide species released from Fe3 S4 selectively permeate bacteria with thin wall and subsequently interrupt energy metabolism by inhibiting glucokinase in glycolysis, and is further synergized by simultaneously released ferrous iron that induces bactericidal damage. Such multiple MoAs enable Fe3 S4 to counteract G. vaginalis strains with metronidazole-resistance and persisters in biofilm or intracellular vacuole, without developing new drug resistance and killing probiotic bacteria. The Fe3 S4 regimens successfully ameliorate BV with resistant G. vaginalis in mouse models and eliminate pathogens from patients suffering BV. Collectively, mFeS represent an antibacterial alternative with distinct MoA able to treat challenged BV and improve women health.