Primordial dwarfism (PD) refers to a group of monogenic genetic disorders characterized by intrauterine growth restriction (IUGR) and severe, persistent postnatal growth retardation. These diseases have been associated with variants of multiple genes whose products are mainly involved in critical cellular biological processes such as maintenance of genomic stability, DNA damage repair, mRNA splicing regulation, and centrosome function. Variants of such genes can directly impair cell proliferation and developmental potential. With the widespread application of molecular genetic technologies such as high-throughput sequencing, significant progress has been made in the research of PD. This article focuses on the major subtypes of PD, including Seckel syndrome, Microcephalic osteodysplastic primordial dwarfism (MOPD) types I/III, MOPD type II, and Meier-Gorlin syndrome. It has systematically summarized the advances in their clinical phenotypic characteristics, pathogenic genes, and molecular mechanisms, with an aim to deepen the understanding of the essence of growth disorders associated with PD.
Humans ; Dwarfism/genetics* ; Microcephaly/genetics* ; Phenotype ; Fetal Growth Retardation/genetics* ; Osteochondrodysplasias/genetics* ; Growth Disorders ; Micrognathism ; Patella/abnormalities* ; Congenital Microtia

OBJECTIVE: To analyze the phenotype and genotype of a neonate with Osteo-oto-hepato-enteric syndrome (O2HE) and review the literature. METHODS: A female neonate diagnosed with O2HE syndrome on December 13, 2024 at the First Affiliated Hospital of Zhengzhou University was selected as the study subject, and her clinical characteristics were analyzed, and pathogenic variants were explored by whole exome sequencing (WES). This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2025-KY-1038). RESULTS: The proband, a female infant, was delivered by Cesarean section at 36⁺¹ weeks of gestation. Five days after birth, she had developed severe diarrhea, mild cholestasis, sensorineural hearing loss, and growth retardation. WES revealed that she has harbored novel compound heterozygous variants c.512delA (p.Lys171Serfs*64) and c.698C>A (p.Thr233Asn) of the UNC45A gene, which were inherited from her mother and father, respectively. A total of 8 English papers were retrieved, which involved 16 patients from 14 families. Combined with our case, the 17 patients included 13 (76.5%) females and 4 (23.5%) males. Four patients (23.5%) had consanguineous parents. One case was excluded from further genetic analysis due to co-morbidity with other genetic variants. The primary clinical features included diarrhea (87.5%), cholestasis (81.3%), sensorineural hearing loss (31.3%), bone fragility (37.5%), and developmental delay (50.0%). Bi-allelic compound heterozygous mutations were identified in 12 patients (75.0%), and homozygous variants in 4 (25.0%). These included missense, nonsense, frameshift and deletional variants. The c.710T>C (p.Leu237Pro) variant was identified for 5 times, 3 of which were in homozygote forms. CONCLUSION O2HE syndrome should be suspected in cases with diarrhea, cholestasis, and hearing abnormalities during early postnatal period. Genetic testing facilitate early identification, genetic diagnosis and treatment.
Humans ; Female ; Infant, Newborn ; Male ; Mutation ; Hearing Loss, Sensorineural/genetics* ; Diarrhea, Infantile/genetics* ; Exome Sequencing ; Phenotype ; Fetal Growth Retardation ; Hair Diseases ; Facies

OBJECTIVE: To investigate the potential mechanism by which electroacupuncture (EA) induces macrophage polarization to promote muscle satellite cell proliferation and differentiation, accelerating the repair of acute skeletal muscle injury. METHODS: Forty-two SPF-grade SD rats were randomly divided into three groups: a blank group (n=6), a model group (n=18), and an EA group (n=18). The model and EA groups established acute blunt contusion model of the right gastrocnemius muscle using a self-made striking device. From day 1 after modeling, rats in the EA group received EA at "Chengshan" (BL57) and "Yanglingquan" (GB34) on the right side, using disperse-dense wave with a frequency of 2 Hz/100 Hz and a current of approximately 2 mA. The EA treatment was administered once daily for 30 minutes for 3, 7, or 14 days based on the designated sampling time points. Gait analysis was performed using the Cat Walk XT^TM system. Hematoxylin-eosin (HE) staining was used to observe the morphological changes in the gastrocnemius muscle. Masson staining was applied to evaluate collagen fiber content. Immunofluorescence was used to detect the expression of proliferating cell nuclear antigen (PCNA) in muscle satellite cells. Immunohistochemistry was used to assess the expression levels of CD68 and CD206, markers of macrophages. Serum levels of pro-inflammatory cytokines (TNF-α, IL-1β) and anti-inflammatory cytokines (IL-10, IL-13) were detected using ELISA. RESULTS: Compared with the blank group, the model group showed a significant reduction in average movement speed on days 3 and 7 after modeling (P<0.05), and a decrease in the right hind limb stride length on day 3 (P<0.05). Compared with the model group, the EA group showed increased average movement speed and right hind limb stride length on day 7 (P<0.05). In the blank group, the gastrocnemius muscle on the right side showed uniform and consistent inter-fiber spacing, with neatly and regularly arranged muscle cells. In contrast, the model group exhibited enlarged inter-fiber spacing, edema, and significant infiltration of red blood cells and inflammatory cells, with progressively increasing fibrosis over time. By day 14 after modeling, the EA group showed a return to baseline levels of inflammatory cell infiltration, and the degree of fibrosis was significantly lower than that observed in the model group. Compared with the blank group, the ratio of collagen fibers in the gastrocnemius muscle of the model group increased significantly on days 3, 7, and 14 after modeling (P<0.05). Compared with the model group, the EA group exhibited a lower collagen fiber ratio on days 3, 7, and 14 (P<0.05). Compared with the blank group, PCNA positive expression in the gastrocnemius muscle of the model group was significantly increased on days 3, 7, and 14 after modeling (P<0.05). Compared with the model group, the EA group exhibited significantly higher PCNA positive expression on days 3 and 7 (P<0.05). Compared with the blank group, the model group showed a significant increase in CD68-positive macrophage expression in the gastrocnemius muscle on day 3 after modeling (P<0.05), while CD206-positive macrophage expression increased on days 3, 7, and 14 (P<0.05). Compared with the model group, CD68 expression was significantly lower in the EA group on day 3 (P<0.05), whereas CD206 expression was significantly higher on days 3 and 7 (P<0.05), peaking on day 7 with CD206 expression. Compared with the blank group, serum TNF-α levels were significantly elevated in the model group on days 3 and 7 after modeling (P<0.05), while serum IL-1β levels were increased on days 3, 7, and 14 (P<0.05). Serum IL-10 and IL-13 levels were significantly higher on day 7 after modeling (P<0.05). Compared with the model group, the EA group exhibited lower serum TNF-α level on day 3 (P<0.05) and reduced serum IL-1β levels on days 3 and 7 (P<0.05), while serum IL-10 and IL-13 levels were significantly increased on day 7 (P<0.05). CONCLUSION EA could promote the repair of acute blunt contusion-induced gastrocnemius muscle injury by regulating the proliferation and differentiation of muscle satellite cells. This process is closely related to macrophage polarization.
Animals ; Electroacupuncture ; Rats, Sprague-Dawley ; Rats ; Macrophages/immunology* ; Muscle, Skeletal/immunology* ; Male ; Humans ; Female ; Tumor Necrosis Factor-alpha/immunology* ; Cell Proliferation

OBJECTIVE: To explore the characteristics and rules of the locations of acupoints selected in weight loss after syndrome differentiation of acupuncture and moxibustion, and provide quantitative evidence for the location specificity of acupoint selection in weight loss. METHODS: Clinical research articles on acupoint selection based on syndrome differentiation of acupuncture and moxibustion in weight loss were retrieved in China National Knowledge Infrastructure (CNKI), from the inception to September 20th, 2024, and the data about acupoints and differentiated syndromes were extracted. Based on graph theory, the acupoint-syndrome network was established and its topological parameters such as node degree, value of betweenness centrality, description length and number of community were calculated. RESULTS: ①The description length of the limbs was 4 255.592, and that of the trunk was 3 274.312. The information contained in the acupoint-syndrome network for the acupoints on the limbs was greater than that for those on the trunk. ②The value of betweenness centrality and node degree showed a nonlinear relationship, with R²of 0.812 1 for the trunk and 0.321 8 for the limbs. The values of betweenness centrality for the acupoints on the trunk were uniformly distributed, and the difference among these values was much smaller than that for the acupoints on the limbs. It suggested that the distance from each trunk acupoint to network center was similar, and the importance among these acupoints to network was similar, while the importance among acupoints located on the limbs was different significantly. ③The frequency proportion of acupoints on the trunk showed uniform distribution among different syndromes, while that of some acupoints located on the limbs such as Taichong (LR3), Neiting (ST44) and Taixi (KI3) presented a correlation with the syndromes. CONCLUSION In weight loss with acupuncture and moxibustion, the correlation between the limb acupoints and syndromes is more diverse and specific than that between the trunk acupoints and syndromes. The differences in acupoint selection for simple obesity treated with acupuncture and moxibustion are mostly reflected in the acupoints on the four limbs rather than those on the trunk. It provides an approach to acupoint selection for "local weight loss" and "general regulation" in treatment with acupuncture and moxibustion.
Humans ; Acupuncture Points ; Moxibustion ; Weight Loss ; Acupuncture Therapy ; Obesity/physiopathology*

OBJECTIVE: To explore the effect and mechanism of acupuncture at "Weizhong" (BL40) on microcirculation of paravertebral skeletal muscle in rats with chronic blunt injury of lumbar muscle based on the insulin-like growth factor-1 (IGF-1)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway. METHODS: Forty-eight SPF-grade SD rats were randomized into a blank group (8 rats) and a modeling group (40 rats). Chronic blunt injury model was established by weight impact method in the modeling group. Forty rats were successfully modeled, and were randomly divided into a model group, an acupuncture at Weizhong group (Weizhong group), an acupuncture at non-acupoint group (non-acupoint group), an inhibitor group, and an inhibitor+acupuncture at Weizhong group (inhibitor+Weizhong group), 8 rats in each group. In the Weizhong group and the inhibitor+Weizhong group, acupuncture was applied at bilateral "Weizhong" (BL40). In the non-acupoint group, acupuncture was applied at non-acupoints, i.e. points 0.5 cm inward from bilateral "Weizhong" (BL40). The acupuncture intervention was delivered 20 min each time, once a day for continuous 2 weeks. In the inhibitor group and the inhibitor+Weizhong group, intraperitoneal injection of IGF-1 receptor (IGF-1R) inhibitor was given once a day, at a dosage of 2 mg/100 g, for continuous 2 weeks. Before modeling and on the 1st, 7th and 14th days of intervention, the body mass was measured. Before and after modeling, and after intervention, the limb grip strength and paw withdrawal threshold (PWT) were measured. After intervention, the morphology of psoas muscle was observed by HE staining; the ultrastructure of psoas muscle capillaries was observed by electron microscopy; the levels of serum vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) were detected by ELISA; and the protein and mRNA expression of IGF-1, IGF-1R, PI3K, AKT of psoas muscle was detected by Western blot and real-time PCR. RESULTS: Compared with the blank group, in the model group, the body mass on the 7th and 14th days of intervention, the limb grip strength, and the PWT of left and right hind feet were decreased (P<0.001, P<0.01); the skeletal muscle cells showed enlarged intercellular space, loosely arranged and irregularly shaped, the capillaries in the psoas muscle tissues were edematous, and the lumen of the blood vessels was obviously atrophied; the levels of serum VEGF and eNOS were decreased (P<0.001); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K, p-AKT/AKT values were decreased (P<0.001), the mRNA expression of IGF-1, IGF-1R, PI3K and AKT was decreased (P<0.001, P<0.05). Compared with the model group, in the Weizhong group, the body weight was increased on the 7th and 14th days of intervention (P<0.001), the limb grip strength and the PWT of the left and right hind feet were increased (P<0.001, P<0.01); the arrangement of the skeletal muscle cells was relatively tight and the intercellular space was reduced, the blood vessels tended to be regular and the structure of the basement membrane was continuous, while the lumens of blood vessels were collapsed locally; the levels of serum VEGF and eNOS were increased (P<0.001); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K, p-AKT/AKT values were increased (P<0.001), the mRNA expression of IGF-1, IGF-1R, PI3K and AKT was increased (P<0.001, P<0.01). Compared with the model group, in the inhibitor group, the body mass was decreased on the 7th and 14th days of intervention (P<0.05, P<0.01); the limb grip strength and the PWT of the left hind foot were decreased (P<0.01, P<0.001); the intercellular space of skeletal muscle cells was larger, the nuclei of the cells and erythrocytes were scattered in the intercellular space, the damage of the capillaries in the muscular tissues was serious, the collagen fibers were sparsely distributed and disorganized; the levels of serum VEGF and eNOS were decreased (P<0.001, P<0.01); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K and p-AKT/AKT values were decreased (P<0.01, P<0.05, P<0.001), the mRNA expression of IGF-1, IGF-1R, PI3K, and AKT was decreased (P<0.01, P<0.001, P<0.05). Compared with the Weizhong group, in the non-acupoint group and the inhibitor+Weizhong group, the body mass was decreased on the 7th and 14th days of intervention (P<0.001, P<0.01), the limb grip strength was decreased (P<0.001); the morphology of muscle cell was relatively poor, with generally irregular, there was mild collapse and atrophy in the vascular lumen, and mild edema in the endothelial cells; the levels of serum VEGF and eNOS were decreased (P<0.001); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K and p-AKT/AKT values were decreased (P<0.01, P<0.001), the mRNA expression of IGF-1, IGF-1R, PI3K, and AKT was decreased (P<0.001, P<0.01, P<0.05). Compared with the Weizhong group, the PWT of the left hind foot was decreased in the non-acupoint group (P<0.001), and PWT of the left and right hind feet was decreased in the inhibitor+Weizhong group (P<0.001). CONCLUSION Acupuncture at "Weizhong" (BL40) promotes lumbar muscle repair in chronic low back pain, its mechanism may be related to the activation of the IGF-1/PI3K/AKT pathway, thereby improving the microcirculation.
Animals ; Insulin-Like Growth Factor I/genetics* ; Acupuncture Therapy ; Rats, Sprague-Dawley ; Rats ; Proto-Oncogene Proteins c-akt/genetics* ; Male ; Humans ; Muscle, Skeletal/metabolism* ; Signal Transduction ; Phosphatidylinositol 3-Kinases/genetics* ; Wounds, Nonpenetrating/metabolism* ; Acupuncture Points

BACKGROUND: The sirtuin family is well recognized for its crucial involvement in various cellular processes. Nevertheless, studies on its role in the human endometrium are limited. This study aimed to explore the expression and localization of the sirtuin family in the human endometrium, focusing on sirtuin 3 (SIRT3) and its potential role in the oxidative imbalance of the endometrium in polycystic ovary syndrome (PCOS). METHODS: Endometrial specimens were collected from both patients with PCOS and controls undergoing hysteroscopy at the Center for Reproductive Medicine, Peking University Third Hospital, from July to August 2015 and used for cell culture. The protective effects of SIRT3 were investigated, and the mechanism of SIRT3 in improving endometrial receptivity of patients with PCOS was determined using various techniques, including cellular bioenergetic analysis, small interfering ribonucleic acid (siRNA) silencing, real-time quantitative polymerase chain reaction, Western blot, immunofluorescence, immunohistochemistry, and flow cytometry analysis. RESULTS: The sirtuin family was widely expressed in the human endometrium, with SIRT3 showing a significant increase in expression in patients with PCOS compared with controls ( P <0.05), as confirmed by protein and gene assays. Concurrently, endometrial antioxidant levels were elevated, while mitochondrial respiratory capacity was reduced, in patients with PCOS ( P <0.05). An endometrial oxidative stress (OS) model revealed that the downregulation of SIRT3 impaired the growth and proliferation status of endometrial cells and reduced their receptivity to day 4 mouse embryos. The results suggested that SIRT3 might be crucial in maintaining normal cellular state by regulating antioxidants, cell proliferation, and apoptosis, thereby contributing to enhanced endometrial receptivity. CONCLUSIONS Our findings proposed a significant role of SIRT3 in improving endometrial receptivity in patients with PCOS by alleviating OS and regulating the balance between cell proliferation and apoptosis. Therefore, SIRT3 could be a promising target for predicting and improving endometrial receptivity in this patient population.
Humans ; Female ; Polycystic Ovary Syndrome/metabolism* ; Endometrium/metabolism* ; Sirtuin 3/genetics* ; Oxidative Stress/genetics* ; Adult ; Animals ; Mice ; Apoptosis/physiology* ; Immunohistochemistry ; Cell Proliferation/physiology*

BACKGROUND: The main cause of restenosis after percutaneous transluminal angioplasty (PTA) is the excessive proliferation and migration of vascular smooth muscle cells (VSMCs). Lin28a has been reported to play critical regulatory roles in this process. However, whether CCAAT/enhancer-binding proteins β (C/EBPβ) binds to the Lin28a promoter and drives the progression of restenosis has not been clarified. Therefore, in the present study, we aim to clarify the role of C/EBPβ-Lin28a axis in restenosis. METHODS: Restenosis and atherosclerosis rat models of type 2 diabetes ( n   =  20, for each group) were established by subjecting to PTA. Subsequently, the difference in DNA methylation status and expression of C/EBPβ between the two groups were assessed. EdU, Transwell, and rescue assays were performed to assess the effect of C/EBPβ on the proliferation and migration of VSMCs. DNA methylation status was further assessed using Methyltarget sequencing. The interaction between Lin28a and ten-eleven translocation 1 (TET1) was analysed using co-immunoprecipitation (Co-IP) assay. Student's t -test and one-way analysis of variance were used for statistical analysis. RESULTS: C/EBPβ expression was upregulated and accompanied by hypomethylation of its promoter in restenosis when compared with atherosclerosis. In vitroC/EBPβ overexpression facilitated the proliferation and migration of VSMCs and was associated with increased Lin28a expression. Conversely, C/EBPβ knockdown resulted in the opposite effects. Chromatin immunoprecipitation assays further demonstrated that C/EBPβ could directly bind to Lin28a promoter. Increased C/EBPβ expression and enhanced proliferation and migration of VSMCs were observed after decitabine treatment. Further, mechanical stretch promoted C/EBPβ and Lin28a expression accompanied by C/EBPβ hypomethylation. Additionally, Lin28a overexpression reduced C/EBPβ methylation via recruiting TET1 and enhanced C/EBPβ-mediated proliferation and migration of VSMCs. The opposite was noted in Lin28a knockdown cells. CONCLUSION Our findings suggest that the C/EBPβ-Lin28a axis is a driver of restenosis progression, and presents a promising therapeutic target for restenosis.
Animals ; Cell Proliferation/genetics* ; Cell Movement/genetics* ; Muscle, Smooth, Vascular/metabolism* ; Rats ; DNA Methylation/physiology* ; CCAAT-Enhancer-Binding Protein-beta/genetics* ; Male ; Myocytes, Smooth Muscle/cytology* ; Rats, Sprague-Dawley ; RNA-Binding Proteins/genetics* ; Cells, Cultured ; Coronary Restenosis/metabolism*

BACKGROUND: T cell dysfunction, which includes exhaustion, anergy, and senescence, is a distinct T cell differentiation state that occurs after antigen exposure. Although T cell dysfunction has been a cornerstone of cancer immunotherapy, its potential in transplant research, while not yet as extensively explored, is attracting growing interest. Interferon regulatory factor 4 (IRF4) has been shown to play a pivotal role in inducing T cell dysfunction. METHODS: A novel ultra-low-dose combination of Trametinib and Rapamycin, targeting IRF4 inhibition, was employed to investigate T cell proliferation, apoptosis, cytokine secretion, expression of T-cell dysfunction-associated molecules, effects of mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) signaling pathways, and allograft survival in both in vitro and BALB/c to C57BL/6 mouse cardiac transplantation models. RESULTS: In vitro , blockade of IRF4 in T cells effectively inhibited T cell proliferation, increased apoptosis, and significantly upregulated the expression of programmed cell death protein 1 (PD-1), Helios, CD160, and cytotoxic T lymphocyte-associated antigen (CTLA-4), markers of T cell dysfunction. Furthermore, it suppressed the secretion of pro-inflammatory cytokines interferon (IFN)-γ and interleukin (IL)-17. Combining ultra-low-dose Trametinib (0.1 mg·kg -1 ·day -1 ) and Rapamycin (0.1 mg·kg -1 ·day -1 ) demonstrably extended graft survival, with 4 out of 5 mice exceeding 100 days post-transplantation. Moreover, analysis of grafts at day 7 confirmed sustained IFN regulatory factor 4 (IRF4) inhibition, enhanced PD-1 expression, and suppressed IFN-γ secretion, reinforcing the in vivo efficacy of this IRF4-targeting approach. The combination of Trametinib and Rapamycin synergistically inhibited the MAPK and mTOR signaling network, leading to a more pronounced suppression of IRF4 expression. CONCLUSIONS Targeting IRF4, a key regulator of T cell dysfunction, presents a promising avenue for inducing transplant immune tolerance. In this study, we demonstrate that a novel ultra-low-dose combination of Trametinib and Rapamycin synergistically suppresses the MAPK and mTOR signaling network, leading to profound IRF4 inhibition, promoting allograft acceptance, and offering a potential new therapeutic strategy for improved transplant outcomes. However, further research is necessary to elucidate the underlying pharmacological mechanisms and facilitate translation to clinical practice.
Animals ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Interferon Regulatory Factors/metabolism* ; Heart Transplantation/methods* ; T-Lymphocytes/immunology* ; Sirolimus/therapeutic use* ; Pyridones/therapeutic use* ; Graft Survival/drug effects* ; Pyrimidinones/therapeutic use* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Male ; Signal Transduction/drug effects*

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a prevalent type of cancer with a high mortality rate in its late stages. One of the major challenges in OSCC treatment is the resistance to epidermal growth factor receptor (EGFR) inhibitors. Therefore, it is imperative to elucidate the mechanism underlying drug resistance and develop appropriate precision therapy strategies to enhance clinical efficacy. METHODS: To evaluate the efficacy of the combination of the Ca 2+ /calmodulin-dependent protein kinase II (CAMK2) inhibitor KN93 and EGFR inhibitors, we performed in vitro and in vivo experiments using two FAT atypical cadherin 1 ( FAT1 )-deficient (SCC9 and SCC25) and two FAT1 wild-type (SCC47 and HN12) OSCC cell lines. We assessed the effects of EGFR inhibitors (afatinib or cetuximab), KN93, or their combination on the malignant phenotype of OSCC in vivo and in vitro . The alterations in protein expression levels of members of the EGFR signaling pathway and SRY-box transcription factor 2 (SOX2) were analyzed. Changes in the yes-associated protein 1 (YAP1) protein were characterized. Moreover, we analyzed mitochondrial dysfunction. Besides, the effects of combination therapy on mitochondrial dynamics were also evaluated. RESULTS: OSCC with FAT1 mutations exhibited resistance to EGFR inhibitors treatment. The combination of KN93 and EGFR inhibitors significantly inhibited the proliferation, survival, and migration of FAT1 -mutated OSCC cells and suppressed tumor growth in vivo . Mechanistically, combination therapy enhanced the therapeutic sensitivity of FAT1 -mutated OSCC cells to EGFR inhibitors by modulating the EGFR pathway and downregulated tumor stemness-related proteins. Furthermore, combination therapy induced reactive oxygen species (ROS)-mediated mitochondrial dysfunction and disrupted mitochondrial dynamics, ultimately resulting in tumor suppression. CONCLUSION Combination therapy with EGFR inhibitors and KN93 could be a novel precision therapeutic strategy and a potential clinical solution for EGFR-resistant OSCC patients with FAT1 mutations.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/metabolism* ; Cell Line, Tumor ; Animals ; Drug Resistance, Neoplasm/genetics* ; Cadherins/metabolism* ; Carcinoma, Squamous Cell/metabolism* ; Mice ; Mutation/genetics* ; Mice, Nude ; Protein Kinase Inhibitors/therapeutic use* ; Cetuximab/pharmacology* ; Afatinib/therapeutic use* ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects*

BACKGROUND: Fibrosis of the connective tissue in the vaginal wall predominates in pelvic organ prolapse (POP), which is characterized by excessive fibroblast-to-myofibroblast differentiation and abnormal deposition of the extracellular matrix (ECM). Our study aimed to investigate the effect of ECM stiffness on vaginal fibroblasts and to explore the role of methyltransferase 3 (METTL3) in the development of POP. METHODS: Polyacrylamide hydrogels were applied to create an ECM microenvironment with variable stiffness to evaluate the effects of ECM stiffness on the proliferation, differentiation, and expression of ECM components in vaginal fibroblasts. METTL3 small interfering RNA and an overexpression vector were transfected into vaginal fibroblasts to evaluate the effects of METTL3 silencing and overexpression on matrix stiffness-induced vaginal fibroblast-to-myofibroblast differentiation and abnormal modulation of the ECM. Both procedures were detected by 5-ethynyl-2'-deoxyuridine (EdU) staining, Western blotting (WB), quantitative real-time polymerase chain reaction (RT-qPCR), and immunofluorescence (IF). RESULTS: Vaginal fibroblasts from POP patients exhibited increased proliferation ability, increased expression of α-smooth muscle actin (α-SMA), decreased expression of collagen I/III, and significantly decreased expression of tissue inhibitors of matrix metalloproteinases (TIMPs) in the stiff matrix ( P <0.05). Compared with those from non-POP patients, vaginal wall tissues from POP patients demonstrated a significant increase in METTL3 content ( P <0.05). However, silencing METTL3 expression in vaginal fibroblasts with high ECM stiffness resulted in decreased proliferation ability, decreased α-SMA expression, an increased ratio of collagen I/III, and increased TIMP1 and TIMP2 expression. Conversely, METTL3 overexpression significantly promoted the process of increased proliferation ability, increased α-SMA expression, decreased ratio of collagen I/III and decreased TIMP1 and TIMP2 expression in the soft matrix ( P <0.05). CONCLUSIONS Elevated ECM stiffness can promote excessive proliferation, differentiation, and abnormal ECM modulation, and the expression of METTL3 plays an important role in alleviating or aggravating matrix stiffness-induced vaginal fibroblast-to-myofibroblast differentiation and abnormal ECM modulation.
Humans ; Female ; Extracellular Matrix/metabolism* ; Cell Differentiation/genetics* ; Methyltransferases/metabolism* ; Pelvic Organ Prolapse/pathology* ; Fibroblasts/metabolism* ; Myofibroblasts/metabolism* ; Vagina/metabolism* ; Cell Proliferation/physiology* ; Cells, Cultured ; Middle Aged