BACKGROUND:Flap transplantation technique is a commonly used surgical procedure for the treatment of severe tissue defects,but postoperative flap necrosis is easily triggered by ischemia-reperfusion injury.Therefore,it is still an important research topic to improve the survival rate of transplanted flaps. OBJECTIVE:To review the pathogenesis and latest treatment progress of flap ischemia-reperfusion injury. METHODS:CNKI,WanFang Database and PubMed database were searched for relevant literature published from 2014 to 2024.The search terms used were"flap,ischemia-reperfusion injury,inflammatory response,oxidative stress,Ca2+overload,apoptosis,mesenchymal stem cells,platelet-rich plasma,signaling pathways,shock wave,pretreatment"in Chinese and English.After elimination of irrelevant literature,poor quality and obsolete literature,77 documents were finally included for review. RESULTS AND CONCLUSION:Flap ischemia/reperfusion injury may be related to pathological factors such as inflammatory response,oxidative stress response,Ca2+overload,and apoptosis,which can cause apoptosis of vascular endothelial cells,vascular damage and microcirculation disorders in the flap,and eventually lead to flap necrosis.Studies have found that mesenchymal stem cell transplantation,platelet-rich plasma,signaling pathway modulators,shock waves,and pretreatment can alleviate flap ischemia/reperfusion injuries from different aspects and to varying degrees,and reduce the necrosis rate and necrosis area of the grafted flap.Although there are many therapeutic methods for skin flap ischemia/reperfusion injury,a unified and effective therapeutic method has not yet been developed in the clinic,and the advantages and disadvantages of various therapeutic methods have not yet been compared.Most of the studies remain in the stage of animal experiments,rarely involving clinical observations.Therefore,a lot of research is required in the future to gradually move from animal experiments to the clinic in order to better serve the clinic.

ObjectiveTo observe the clinical effectiveness and safety of Xiaozhong Zhitong Mixture （消肿止痛合剂） combined with antibiotic bone cement in the treatment of diabetic foot ulcer （DFU） with damp-heat obstructing syndrome. MethodsA total of 72 DFU patients with damp-heat obstructing syndrome were randomly assigned to treatment group （36 cases） and the control group （36 cases）. Both groups received standard treatment and topical antibiotic bone cement for ulcer wounds， while the treatment group received oral Xiaozhong Zhitong Mixture （50 ml per time， three times daily） in additionally. Both groups underwent daily wound dressing changes for 21 consecutive days. Ulcer healing rate， serum levels of tumor necrosis factor-alpha （TNF-α）， interleukin-1 beta （IL-1β）， malondialdehyde （MDA）， superoxide dismutase （SOD）， C-reactive protein （CRP）， and white blood cell （WBC） count were observed before and after treatment， and visual analog scale （VAS） scores for wound pain， traditional Chinese medicine （TCM） syndrome scores， and the DFU Healing Scale （DMIST scale） were also compared. Liver and kidney function were evaluated before and after treatment， and adverse events such as allergic reactions， worsening ulcer pain were recorded. ResultsTotally 35 patients in the treatment group and 33 in the control group were included in the final analysis. The ulcer healing rate in the treatment group was （87.93±9.34）%， significantly higher than （81.82±12.02）% in the control group （P = 0.035）. Compared to pre-treatment levels， both groups showed significant reductions in serum CRP， WBC， MDA， IL-1β， and TNF-α levels， with an increase in SOD level （P＜0.05）. TCM syndrome scores， VAS， and DMIST scores also significantly decreased in both groups （P＜0.05）， with greater improvements in the treatment group （P＜0.05）. No significant adverse reactions were observed in either group during treatment. ConclusionXiaozhong Zhitong Mixture combined with antibiotic bone cement has significant advantages in promoting DFU healing， reducing inflammatory response， and alleviating oxidative stress in DFU patients with damp-heat obstructing syndrome， with good safety for DFU patients with damp-heat obstructing syndrome.

Objective　To explore the effect of Mp1p on host macrophages through transcriptomics combined with metabolomics. Methods Firstly, a THP-1 macrophage strain (THP-1-Mp1p+) stably expressing Mp1p was constructed using lentivirus. Secondly, using high-throughput RNA sequencing (RNA Seq) technology, the expression level of intracellular mRNA was detected in transcriptomics analysis to determine differentially expressed genes; In metabolomics analysis, metabolite identification was performed through database comparison, and pathway analysis was performed on differential metabolites to reveal potential mechanisms of action. Finally, the results of metabolomics and transcriptomics were combined for analysis, and differential metabolites and genes were analyzed to further elucidate the mechanism of action of Mp1p on macrophages. Results Transcriptome analysis showed that, compared with the negative control group, the THP-1-Mp1p+ group had a total of 1 180 differentially expressed genes (DEGs), with 345 upregulated genes and 835 downregulated genes. GO enrichment analysis of DEGs showed that there were 135 differentially expressed genes, including 105 in biological processes (BP), 28 in cellular components (CC), and 2 in molecular functions (MF). The KEGG analysis results showed that the effect of Mp1p on THP-1 macrophages was highly correlated with the TNF pathway. The metabolomic analysis found that both the blank control group and the THP-1-Mp1p+ macrophage group achieved good separation between QC samples in both positive and negative ion modes. The threshold for significant differential metabolites was set at: VIP≥1 and T-test P<0.05, resulting in the identification of 488 differential metabolites, with 230 in the positive ion mode and 258 in the negative ion mode. Pathway enrichment analysis of the identified metabolites pointed to significant enrichment in metabolic pathways. The combined analysis confirmed that the tumor necrosis factor signaling pathway, interleukin-17 signaling pathway, and NF-kappaB signaling pathway were important metabolic pathways involved. Conclusions The virulence factor Mp1p may affect host macrophages by modulating the tumor necrosis factor signaling pathway, interleukin-17 signaling pathway, and NF-kappaB signaling pathway. The findings contribute to a better understanding of the mechanisms of action of Mp1p and may offer potential directions for the selection of relevant diagnostic and therapeutic targets in the future.

This study was designed to explore the effect of DNA methyltransferase 1(DNMT1)on podocyte apoptosis and inflammatory cytokine release induced by high glucose(HG),and analyze the related molecular mechanisms.Podocyte MPC-5 cells were cultured in vitro and divided into control and HG groups.DNMT1 and SOCS1 were either silenced or overexpressed using small RNA interference technology and liposome transfection technology.The expression levels of DNMT1 and SOCS1 genes were measured using qRT-PCR.Apoptosis was assessed by flow cytometry,while ELISA was employed to determine the levels of inflammatory factors such as tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),interleukin-1β(IL-1β),and monocyte chemoattractant protein-1(MCP-1).Western blot was used to detect the expression of DNMT1,SOCS1 proteins,and the proteins involved in the Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)signaling pathway.Data showed that HG elevated MPC-5 cell apoptosis rate,the level of inflammatory factors and DNMT1 mRNA expression,and the expression of DNMT1,p-JAK2 and p-STAT3 proteins,while reduced SOCS1 mRNA and protein expression(P＜0.05).Both silencing DNMT1 and overexpressing SOCS1 resulted in reduce of MPC-5 cell apoptosis rate,inflammatory factors level,p-JAK2 and p-STAT3 proteins expression(P＜0.05).Additionally,silencing DNMT1 increased SOCS1 mRNA and protein expressions(P＜0.05).Conversely,silencing SOCS1 counteracted the effects of DNMT1 silencing on MPC-5 cell apoptosis,inflammation,p-JAK2 and p-STAT3 proteins expression.Therefore,silencing DNMT1 expression can reduce the apoptosis and inflammation of podocytes induced by HG,and its mechanism may be related to the inhibition of JAK2/STAT3 signaling pathway activation by upregulating SOCS1 expression.

AIM:To investigate the effects of Xiaozhong-Zhitong mixture(XZZT)on M2 polarization and Toll-like receptor 4(TLR4)/myeloid differentiation factor 88(MyD88)/nuclear factor-κB(NF-κB)signaling pathway in mouse microglia(BV2 cells).METHODS:The BV2 cells were divided into 5 groups:blank group,model group[lipo-polysaccharide(LPS)+hypoxia],TAK-242(resatorvid,a TLR4 inhibitor)group(LPS+hypoxia+TAK-242),XZZT group(LPS+hypoxia+XZZT),and TAK-242+XZZT group(LPS+hypoxia+TAK-242+XZZT).Flow cytometry was used to detect early apoptosis and cell cycle of BV2 cells,and immunofluorescence staining was employed to detect the positive expres-sion of M1-type marker inducible nitric oxide synthase(iNOS)and M2-type marker CD206.Western blot was utilized to detect the expression of TLR4/MyD88/NF-κB signaling pathway-related proteins,including TLR4,MyD88,NF-κB p65,phosphorylated p65(p-p65),phosphorylated transforming growth factor-β-activated kinase 1(p-TAK1),and phosphory-lated IκB kinase α/β(p-IKKα/β).RT-qPCR was used to detect the mRNA expression of interleukin-1β(IL-1β),IL-10,tumor necrosis factor-α(TNF-α),TLR4,MyD88,and NF-κB p65.RESULTS:Compared with model group,the rate of early apoptosis was significantly decreased in XZZT group(P<0.01),the percentage of cells arrested in the S phase was significantly increased(P<0.01),and the protein levels of TLR4,MyD88,NF-κB p65,p-IKKα/β,p-p65,and p-TAK1 were significantly decreased(P<0.05 or P<0.01).Additionally,IL-1β,TNF-α,TLR4,MyD88 and NF-κB p65 mRNA expression levels were significantly decreased(P<0.05 or P<0.01),while IL-10 mRNA expression was significantly in-creased(P<0.05).Compared with TAK-242 group,the average percentage of iNOS positive area was significantly de-creased,while CD206 was significantly increased in TAK-242+XZZT group(P<0.01).CONCLUSION:The XZZT has the effect of inducing M2 polarization of mouse microglia,and the mechanism may be linked to the inhibition of TLR4/MyD88/NF-κB signaling pathway.

BACKGROUND:In recent years,it has been found that some traditional Chinese medicine monomers can alleviate oxidative stress and apoptosis of the skin flap,promote vascular regeneration of the skin flap and prevent skin flap necrosis by activating autophagy. OBJECTIVE:To review the research progress of traditional Chinese medicine monomer regulating autophagy in preventing flap necrosis. METHODS:The Chinese and English key words were"traditional Chinese medicine(TCM),autophagy,skin flaps".The first author searched the relevant articles published in CNKI and PubMed databases from January 2010 to October 2022.A total of 196 articles were retrieved in the preliminary screening and then screened according to the inclusion and exclusion criteria.The quality assessment was conducted by reading the literature titles and abstracts.Finally,55 articles were summarized. RESULTS AND CONCLUSION:(1)The regulation of autophagy is mediated by AMPK/mTOR,PI3K/AKT and other signaling pathways.Activation of autophagy can alleviate the oxidative stress and apoptosis of the flap,promote the regeneration of blood vessels in the flap,and prevent flap necrosis.(2)Terpenoids(Betulinic acid,Andrographolide,Notoginseng Triterpenes,Catalpa),phenolic compounds(Resveratrol,Curcumin,Gastrodin),phenolic acids(Salvianolic acid B)and steroid compounds(Pseudoginsenoside F11)in traditional Chinese medicine monomers can alleviate oxidative stress and apoptosis of skin flap by regulating related signaling pathways to activate autophagy,promote skin flap angiogenesis and promote skin flap survival.(3)Studying the research progress of traditional Chinese medicine monomer to prevent flap necrosis by regulating autophagy can provide a reference and theoretical basis for traditional Chinese medicine to prevent flap necrosis and promote flap healing in the clinic.

BACKGROUND:Mesenchymal stem cells have great potential in the treatment of ischemia-reperfusion injury of skin flaps.However,their defects and the decline of their role in the treatment of ischemia-reperfusion injury of skin flaps restrict their wide application. OBJECTIVE:To review the strategies for improving the treatment of ischemia-reperfusion injury of skin flaps with mesenchymal stem cells,and provide a reference for its further theoretical research and clinical application. METHODS:Relevant documents included in CNKI,WanFang and PubMed were searched.The Chinese and English search terms were"mesenchymal stem cell,ischemia-reperfusion adjustment of skin flap,mesenchymal stem cells,stem cells,skin flap,ischemia-reperfusion injury,pretreatment,gene modification,biomaterial packaging,joint application".The relevant documents since 2007 were retrieved,and the documents with little relationship between the research content and the article theme,poor quality and outdated content were eliminated through reading the article,and finally 75 documents were included for summary. RESULTS AND CONCLUSION:(1)Mesenchymal stem cells can inhibit inflammatory reactions,resist oxidative stress and induce angiogenesis,which has great potential in the treatment of skin flap ischemia-reperfusion injury.(2)Although mesenchymal stem cells have shown great potential in the treatment of skin flap ischemia-reperfusion injury,their shortcomings in treatment have limited their widespread clinical application.Through pre-treatment(cytokines,hypoxia,drugs,and other pre-treatment mesenchymal stem cells),gene-modified mesenchymal stem cells,biomaterial encapsulation of mesenchymal stem cells,as well as the combined use of mesenchymal stem cells and other drugs or therapeutic methods,can not only overcome the shortcomings of mesenchymal stem cells in treatment,but also improve their therapeutic effectiveness in skin flap ischemia-reperfusion injury.(3)Therefore,further improving the effectiveness of mesenchymal stem cells in treating skin flap ischemia-reperfusion injury and exploring its therapeutic potential are of great significance for the research of mesenchymal stem cells and the treatment of skin flap ischemia-reperfusion injury.

BACKGROUND:Mesenchymal stem cells are used in flap ischemia-reperfusion injury due to their antioxidant and inflammatory inhibition,and angiogenesis induction. OBJECTIVE:To review the mechanism and latest treatment progress of mesenchymal stem cells in the treatment of flap ischemia-reperfusion injury,and to provide a basis for further theoretical research and clinical rational application. METHODS:We searched the relevant articles indexed in CNKI,WanFang and PubMed databases.Chinese and English search terms were"mesenchymal stem cells;flap ischemia reperfusion injury;conditioned medium;exosomes;oxidative stress;inflammatory reactions;angiogenesis".Relevant literature since 2010 was searched,and 74 articles were finally included after excluding the literature that had little to do with the topic of the article,poor quality and outdated content. RESULTS AND CONCLUSION:(1)Mesenchymal stem cells play significant roles in antioxidation,inhibition of inflammation and induction of angiogenesis and have great potential in the treatment of flap ischemia-reperfusion injury.(2)However,the defects of mesenchymal stem cells themselves and the decline of therapeutic effect in recent years have put the development and application of mesenchymal stem cells into a bottleneck period,and the research on the plasticity of mesenchymal stem cells conditioned medium and its exosomes and mesenchymal stem cells came into being,and the therapeutic effect was significantly better than the use of mesenchymal stem cells alone.(3)Therefore,a more comprehensive understanding of the mechanism of action and the latest treatment progress of mesenchymal stem cells in the treatment of flap ischemia-reperfusion injury is of great significance for the research of mesenchymal stem cells and the treatment of flap ischemia-reperfusion injury.

Objective:To investigate the effects of Porphyromonas gingivalis derived outer membrane vesicles (Pg OMV) on osteoclast differentiation of macrophages and its underlying mechanisms. Methods:The morphology and the size distribution of Pg OMV were analyzed by transmission electron microscopy and nanoparticle tracing analysis, respectively. The osteoclast precursors were treated with 1, 3 and 10 mg/L Pg OMV (1, 3 and 10 mg/L OMV treatment group) or phosphate buffer solution (PBS)(control group). The formation of osteoclasts was analyzed by tartrate-resistant acid phosphase (TRAP) staining and F-actin staining and real-time quantitative PCR (RT-qPCR) were used to detect the expression of Fos and matrix metallopeptidase 9 (MMP9). Polymyxin B (PMB) was used to block lipopolysaccharide (LPS) and then Pg OMV was used to treat osteoclast precursor (PMB-OMV treatment group), and OMV treatment group was used as control. TRAP and F-actin staining were used to observe the formation of osteoclasts and actin rings. The effect of Pg OMV on the expression of Toll-like receptor (TLR) 2 and TLR4 in preosteoclasts was detected by Western blotting. The osteoclast precursors were pretreated with 10, 50, 100 and 200 μmol/L C29, an inhibitor of TLR2, and then treated with Pg OMV(OMV+10, 50, 100 and 200 μmol/L C29 treatment group) and OMV treatment group without C29 pretreatment was control. TRAP and F-actin staining were used to observe the formation of osteoclasts and actin rings. The osteoclast precursor cells were treated with OMV (OMV treatment group) and OMV incubated with PMB (PMB-OMV treatment group) and the expression of TLR2 in osteoclast precursor was detected by Western blotting.Results:Pg OMV showed classical vesicular structures, and the average particle size of Pg OMV were 179.2 nm. A large number of actin rings were observed in the 3 and 10 mg/L OMV treatment groups. The percentages of TRAP-positive osteoclast area in 3 mg/L OMV treatment group [(22.6±2.1)%] and 10 mg/L OMV treatment group [(32.0±2.3)%] were significantly increased compared with control group [(4.9±0.5)%] ( P<0.001). Compared with the control group (1.000±0.029), the mRNA relative expression of Fos in 3 mg/L OMV treatment group (1.491±0.114) and 10 mg/L OMV treatment group (1.726±0.254) was significantly increased ( P=0.013, P=0.001). Compared with the control group (1.007±0.148), the mRNA relative expression of MMP9 in the group of 10 mg/L OMV (2.232±0.097) was significantly increased ( P<0.001). Actin ring formation was less in PMB-OMV treatment groups than in OMV treatment groups. The proportion of TRAP-positive osteoclasts area [(14.8±3.8)%] in PMB-OMV treatment group was significantly lower than OMV treatment group [(31.5±6.7) %] ( P=0.004). The relative expression of TLR2 in OMV treatment group (1.359±0.134) was significantly higher than that in the control group (1.000±0.000) ( t=4.62, P=0.044). Compared with the OMV treatment group [(29.4±1.7)%], 50, 100 and 200 μmol/L C29 significantly decreased the formation of osteoclasts [(24.0±1.7)%, (18.5±2.1)%, (9.1±1.3) %] ( P=0.026, P<0.001, P<0.001). TLR2 protein expression in PMB-OMV group (0.780±0.046) was significantly lower than that in OMV group (1.000±0.000)( t=8.32, P=0.001). Conclusions:Pg OMV can promote osteoclast differentiation by carrying LPS, TLR2 plays an important role in Pg OMV mediated osteoclast differentiation.

The oral cavity is the second largest reservoir of microorganisms in the human body, containing more than 700 species. Periodontal microorganisms are an important part of oral microorganisms. Plaque biofilm, the initiator of periodontal disease, contains an abundance of oral microorganisms. The special complex anatomy of the periodontium allows for a higher abundance of the periodontal microbiota. There are growing evidences show that the periodontal microbiota is not only closely associated with oral diseases, but also plays an important role in mouth-brain interactions. Dysbiosis of the periodontal microbiota may facilitate the progression of neurodegenerative diseases including Alzheimer disease, Parkinson disease, and multiple sclerosis. Here, this paper reviews the bidirectional role of periodontal microbiota between the oral cavity and the brain, that is, the bridge effect of periodontal microbiota involved in the interaction between the two diseases, enumerates the epidemiological and biological evidences that dysregulation of the periodontal microbiota induces and exacerbates neurodegenerative diseases, and analyzes their possible mechanisms. The positive implications of periodontal microbial homeostasis in the prevention and treatment of neurodegenerative diseases are described with the aim of providing new ideas and insights into the pathogenesis and therapeutic approaches for neurodegenerative diseases.