Collagen, a vital matrix protein for various tissue and functions in animals, is widely applied in biomaterials. In type Ⅰ collagen, missense mutations of glycine (Gly) in the Gly-Xaa-Yaa triplet of the triple helix are a major cause of osteogenesis imperfecta (OI). Clinical manifestations exhibit marked heterogeneity, spanning a broad disease spectrum from mild skeletal fragility (Type Ⅰ) to severe limb deformities (Type Ⅲ) and perinatal lethal forms (Type Ⅱ). This study utilized recombinant collagen as a model to further elucidate whether Gly→Ala/Val mutations at the N-terminus of the integrin-binding sequence GFPGER affect collagen structure and function, and to explore the underlying mechanisms by which missense mutations impact the biological function of collagen. By introducing Ala and Val substitutions at seven Gly positions N-terminal to the GFPGER sequence, we systematically assessed the effects of these amino acid replacements on the triple-helical structure, thermal stability, integrin-binding ability, and cell adhesion of recombinant collagen. All constructs formed a stable triple-helix structure, with slightly compromised thermal stability. Gly→Val substitutions increased the susceptibility of recombinant collagen to trypsin, which suggested local conformational perturbations in the triple helix. In addition, Gly→Val substitutions significantly reduced the integrin-binding affinity and decreased HT1080 cell adhesion, with the effects stronger than Gly→Ala substitutions. Compared with Gly→Ala substitutions, substitution of Gly with the larger residue Val had enhanced negative effects on the structure and function of recombinant collagen. These findings provide new insights into the molecular mechanisms of osteogenesis imperfecta and offer theoretical references and experimental foundations for the design of collagen sequences and the development of collagen-based biomaterials.
Recombinant Proteins/biosynthesis* ; Glycine/genetics* ; Humans ; Osteogenesis Imperfecta/genetics* ; Integrins/metabolism* ; Collagen/metabolism* ; Collagen Type I/metabolism* ; Amino Acid Substitution ; Mutation ; Mutation, Missense

OBJECTIVES: To investigate the changes in blood levels of calcium and bone metabolism biochemical markers in patients with primary osteoporosis receiving treatment with denosumab. METHODS: Seventy-three patients with primary osteoporosis treated in our Department between December, 2021 and December 2023 were enrolled. All the patients were treated with calcium supplements, vitamin D and calcitriol in addition to regular denosumab treatment every 6 months. Blood calcium, parathyroid hormone (PTH), osteocalcin (OC), type I procollagen amino-terminal propeptide (PINP), and type I collagen carboxy-terminal telopeptide β special sequence (β‑CTX) data before and at 3, 6, 9, and 12 months after the first treatment were collected from each patient. RESULTS: Three months after the first denosumab treatment, the bone turnover markers (BTMs) OC, PINP, and β-CTX were significantly decreased compared to their baseline levels by 39.5% (<i>Pi><0.001), 56.2% (<i>Pi><0.001), and 81.8% (<i>Pi><0.001), respectively. At 6, 9, and 12 months of treatment, OC, PINP, and β-CTX remained significantly lower than their baseline levels (<i>Pi><0.001). Blood calcium level was decreased (<i>Pi><0.05) and PTH level increased (<i>Pi><0.05) significantly in these patients at months of denosumab treatment, but their levels were comparable to the baseline levels at 6, 9, and 12 months of the treatment (<i>Pi>>0.05). CONCLUSIONS Denosumab can suppress BTMs and has a good therapeutic effect in patients with primary osteoporosis, but reduction of blood calcium and elevation of PTH levels can occur during the first 3 months in spite of calcium supplementation. Blood calcium and PTH levels can recover the baseline levels as the treatment extended, suggesting the importance of monitoring blood calcium and PTH levels during denosumab treatment.
Humans ; Denosumab/therapeutic use* ; Calcium/blood* ; Parathyroid Hormone/blood* ; Biomarkers/blood* ; Osteoporosis/blood* ; Osteocalcin/blood* ; Procollagen/blood* ; Female ; Collagen Type I/blood* ; Peptide Fragments/blood* ; Bone Density Conservation Agents/therapeutic use* ; Bone and Bones/metabolism* ; Male ; Middle Aged ; Vitamin D ; Peptides/blood* ; Aged

Abnormal accumulation of collagen fibrils is a hallmark feature of oral submucous fibrosis (OSF). However, the precise characteristics and underlying mechanisms remain unclear, impeding the advancement of potential therapeutic approaches. Here, we observed that collagen I, the main component of the extracellular matrix, first accumulated in the lamina propria and subsequently in the submucosa of OSF specimens as the disease progressed. Using RNA-seq and Immunofluorescence in OSF specimens, we screened the cartilage oligomeric matrix protein (COMP) responsible for the abnormal collagen accumulation. Genetic COMP deficiency reduced arecoline-stimulated collagen I deposition significantly in vivo. In comparison, both COMP and collagen I were upregulated under arecoline stimulation in wild-type mice. Human oral buccal mucosal fibroblasts (hBMFs) also exhibited increased secretion of COMP and collagen I after stimulation in vitro. COMP knockdown in hBMFs downregulates arecoline-stimulated collagen I secretion. We further demonstrated that hBMFs present heterogeneous responses to arecoline stimulation, of which COMP-positive fibroblasts secrete more collagen I. Since COMP is a molecular bridge with Fibril-associated collagens with Interrupted Triple helices (FACIT) in the collagen network, we further screened and identified collagen XIV, a FACIT member, co-localizing with both COMP and collagen I. Collagen XIV expression increased under arecoline stimulation in wild-type mice, whereas it was hardly expressed in the Comp^-/- mice, even with under stimulation. In summary, we found that COMP may mediates abnormal collagen I deposition by functions with collagen XIV during the progression of OSF, suggesting its potential to be targeted in treating OSF.
Oral Submucous Fibrosis/pathology* ; Cartilage Oligomeric Matrix Protein/genetics* ; Animals ; Mice ; Humans ; Fibroblasts/metabolism* ; Collagen Type I/metabolism* ; Arecoline/pharmacology* ; Mouth Mucosa/metabolism* ; Cells, Cultured ; Fluorescent Antibody Technique

Peri-implant keratinized mucosa (PIKM) augmentation refers to surgical procedures aimed at increasing the width of PIKM. Consensus reports emphasize the necessity of maintaining a minimum width of PIKM to ensure long-term peri-implant health. Currently, several surgical techniques have been validated for their effectiveness in increasing PIKM. However, the selection and application of PIKM augmentation methods may present challenges for dental practitioners due to heterogeneity in surgical techniques, variations in clinical scenarios, and anatomical differences. Therefore, clear guidelines and considerations for PIKM augmentation are needed. This expert consensus focuses on the commonly employed surgical techniques for PIKM augmentation and the factors influencing their selection at second-stage surgery. It aims to establish a standardized framework for assessing, planning, and executing PIKM augmentation procedures, with the goal of offering evidence-based guidance to enhance the predictability and success of PIKM augmentation.
Humans ; Consensus ; Dental Implants ; Mouth Mucosa/surgery* ; Keratins

Five previously undescribed diterpenoids, named succipenoids D‒H (1‒5), along with four undescribed lignans, named succignans A‒D (6‒9), were isolated from the dichloromethane extract of Chinese medicinal succinum. Compounds 1‒5 were characterized as nor-abietane diterpenoids, while compounds 6‒9 were identified as lignans polymerized from two groups of phenylpropanoid units. The structures of these novel compounds, including their absolute configurations, were determined through spectroscopic and computational methods. Biological assessments of renal fibrosis demonstrated that compounds 6 and 7 effectively reduce the expression of proteins associated with renal fibrosis, including α-smooth muscle actin (α-SMA), collagen I, and fibronectin in transforming growth factor-β1 (TGF-β1) induced normal rat kidney proximal tubular epithelial cells (NRK-52e).
Animals ; Rats ; Lignans/isolation & purification* ; Diterpenes/isolation & purification* ; Fibrosis/drug therapy* ; Drugs, Chinese Herbal/pharmacology* ; Molecular Structure ; Cell Line ; Kidney Diseases/pathology* ; Transforming Growth Factor beta1/genetics* ; Kidney/metabolism* ; Actins/genetics* ; Fibronectins/genetics* ; Collagen Type I/genetics* ; Epithelial Cells/metabolism*

OBJECTIVES: The mechanism of the odontogenic differentiation of apical papillary cells (APCs) stimulated by bioactive glass 45S5 is still unclear. This study aims to investigate the effect of autophagy on the odontogenic differentiation of APCs stimulated by bioactive glass 45S5. METHODS: APCs were isolated and cultured <i>in vitroi>, and the cell origin was identified by flow cytometry. The culture medium was prepared with 1 mg/mL 45S5, and its pH and ion concentration were determined. The experiments were divided into control, 45S5, and 3-methyladenine (3-MA) 45S5 groups. In the 45S5 group, APCs were induced to culture with 1 mg/mL 45S5. In the 3-MA 45S5 group, the autophagy inhibitor 3-MA was added to 1 mg/mL 45S5. Protein immunoblotting assay (Western blot) was used to detect the expression of autophagy-associated proteins of microtubule-associated protein 1 light-chain 3β (LC3B) and P62 after 24 h of induction culture in each group. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of bone sialoprotein (BSP), Runt-related transcription factor 2 (Runx2), dentin sialophosphoprotein (DSPP), and dentin matrix protein-1 (DMP-1) after 7 d of induction culture. Cellular alkaline phosphatase (ALP) staining analyzed cellular ALP activity at 7 d of induction, and alizarin red staining evaluated the formation of mineralized nodules at 21 d of induction. RESULTS: The pH of the 45S5 extract culture medium was 8.65±0.01, which was not significantly different from that of the control group (<i>Pi>>0.05). The silicon ion concentration of the 45S5 induction culture medium was (1.56±0.07) mmol/L, which was higher than that of the control group (0.08±0.01) mmol/L (<i>Pi><0.05). The calcium ion concentration of the 45S5 induction culture was (1.57±0.15) mmol/L, which was not significantly different from that of the control group (<i>Pi>>0.05). Western blot results showed that LC3B-Ⅱ/Ⅰ ratio increased and P62 expression decreased in the 45S5 group compared with those in the control group (<i>Pi><0.05). By contrast, the ratio decreased and the expression increased in the 3-MA 45S5 group compared with those in the 45S5 group (<i>Pi><0.05). RT-qPCR results showed that the expression of BSP, Runx2, DMP-1, and DSPP enhanced in the 45S5 group compared with that in the control group (<i>Pi><0.05), but the expression decreased in the 3-MA 45S5 group compared with that in the 45S5 group (<i>Pi><0.05). Semi-quantitative analysis of ALP staining and alizarin red staining showed that the ALP activity was enhanced, and the formation mineralized nodule increased in the 45S5 group compared with those in the control group. The ALP activity weakened, and the formation mineralized nodules were reduced in the 3-MA 45S5 group compared with that those in the 45S5 group. CONCLUSIONS Cell autophagy participates in the odontogenic differentiation of APCs induced by 1 mg/mL 45S5 <i>in vitroi>.
Autophagy/drug effects* ; Cell Differentiation/drug effects* ; Odontogenesis/drug effects* ; Dental Papilla/cytology* ; Humans ; Microtubule-Associated Proteins/metabolism* ; Glass/chemistry* ; Cells, Cultured ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Extracellular Matrix Proteins/metabolism* ; Ceramics/pharmacology* ; Adenine/pharmacology* ; Sialoglycoproteins/metabolism* ; Phosphoproteins/metabolism* ; Integrin-Binding Sialoprotein/metabolism* ; Alkaline Phosphatase/metabolism* ; RNA-Binding Proteins

BACKGROUND: Temozolomide (TMZ) resistance is a significant challenge in treating glioblastoma (GBM). Collagen remodeling has been shown to be a critical factor for therapy resistance in other cancers. This study aimed to investigate the mechanism of TMZ chemoresistance by GBM cells reprogramming collagens. METHODS: Key extracellular matrix components, including collagens, were examined in paired primary and recurrent GBM samples as well as in TMZ-treated spontaneous and grafted GBM murine models. Human GBM cell lines (U251, TS667) and mouse primary GBM cells were used for in vitro studies. RNA-sequencing analysis, chromatin immunoprecipitation, immunoprecipitation-mass spectrometry, and co-immunoprecipitation assays were conducted to explore the mechanisms involved in collagen accumulation. A series of in vitro and in vivo experiments were designed to assess the role of the collagen regulators prolyl 4-hydroxylase subunit alpha 1 (P4HA1) and yes-associated protein (YAP) in sensitizing GBM cells to TMZ. RESULTS: This study revealed that TMZ exposure significantly elevated collagen type I (COL I) expression in both GBM patients and murine models. Collagen accumulation sustained GBM cell survival under TMZ-induced stress, contributing to enhanced TMZ resistance. Mechanistically, P4HA1 directly binded to and hydroxylated YAP, preventing ubiquitination-mediated YAP degradation. Stabilized YAP robustly drove collagen type I alpha 1 ( COL1A1) transcription, leading to increased collagen deposition. Disruption of the P4HA1-YAP axis effectively reduced COL I deposition, sensitized GBM cells to TMZ, and significantly improved mouse survival. CONCLUSION P4HA1 maintained YAP-mediated COL1A1 transcription, leading to collagen accumulation and promoting chemoresistance in GBM.
Temozolomide ; Humans ; Glioblastoma/drug therapy* ; Animals ; Mice ; Cell Line, Tumor ; Drug Resistance, Neoplasm/genetics* ; YAP-Signaling Proteins ; Hydroxylation ; Dacarbazine/pharmacology* ; Adaptor Proteins, Signal Transducing/metabolism* ; Transcription Factors/metabolism* ; Collagen/biosynthesis* ; Collagen Type I/metabolism* ; Prolyl Hydroxylases/metabolism* ; Antineoplastic Agents, Alkylating/therapeutic use*

Idiopathic pulmonary fibrosis(IPF) is a chronic progressive interstitial lung disease characterized by a complex pathogenesis and limited treatment options. Although studies have indicated that lipid metabolism dysregulation is associated with the progression of IPF, the core regulatory mechanisms remain unclear. By integrating RNA sequencing data from the GEO database, we identified four key genes related to lipid metabolism: peroxisome proliferator-activated receptor gamma(PPARG), secreted phosphoprotein 1(SPP1), caspase 3(CASP3), and platelet endothelial cell adhesion molecule 1(PECAM1). Further validation using single-cell RNA sequencing revealed the cell-specific expression patterns of these genes. The results found that PPARG was significantly downregulated in alveolar macrophages while SPP1 was significantly upregulated. Mechanistic studies indicated that PPARG negatively regulated SPP1 expression, and the interaction between SPP1 and cluster of differentiation 44(CD44) activated intercellular signaling pathways that promoted fibrosis. Through network pharmacology and molecular docking, it was predicted that the bioactive components of the traditional Chinese medicine formula, namely Buyang Huanwu Decoction may target PPARG to modulate lipid metabolism pathways. In a bleomycin-induced rat model with IPF, this paper randomly divided the rats into six groups(control, group, model group, pirfenidone group, and low, middle, and high-dose groups of Buyang Huanwu Decoction). The results demonstrated that Buyang Huanwu Decoction treatment significantly improved tissue pathological damage, reduced collagen deposition, and alleviated lipid metabolism dysregulation. Western blot analysis confirmed that Buyang Huanwu Decoction mediated the upregulation of PPARG and inhibited the activation of the SPP1/CD44 pathway. The multi-omics study elucidated the role of the PPARG/SPP1/CD44 pathway as a key regulatory factor in lipid metabolism in IPF, providing evidence that Buyang Huanwu Decoction exerted its antifibrotic effects through this novel mechanism and thus offering new insights into the therapeutic prospects for IPF.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Signal Transduction/drug effects* ; PPAR gamma/genetics* ; Humans ; Osteopontin/genetics* ; Lipid Metabolism/drug effects* ; Idiopathic Pulmonary Fibrosis/genetics* ; Hyaluronan Receptors/genetics* ; Rats ; Male ; Rats, Sprague-Dawley ; Molecular Docking Simulation

OBJECTIVE: To review the research progress of pathological changes of glenohumeral capsule in patients with recurrent shoulder anterior dislocation (RSAD). METHODS: The literature on shoulder capsules, both domestic and international, was reviewed. The anatomy, histology, and molecular biology characteristics of the glenohumeral capsule in RSAD patients were summarized. RESULTS: Anatomically, the glenohumeral capsule is composed of four distinct parts: the upper, lower, anterior, and posterior sections. The thickness of these sections is uneven, and the stability of the capsule is further enhanced by the presence of the glenohumeral and coracohumeral ligaments. Histologically, the capsule tissue undergoes adaptive changes following RSAD, which improve its ability to withstand stretching and deformation. In the realm of molecular biology, genes associated with the regulation of structure formation, function, and extracellular matrix homeostasis of the shoulder capsule's collagen fibers exhibit varying degrees of expression changes. Specifically, the up-regulation of transforming growth factor β ₁ (TGF-β ₁), TGF-β receptor 1, lysyl oxidase, and procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 facilitates the repair of the joint capsule, thereby contributing to the maintenance of shoulder joint stability. Conversely, the up-regulation of collagen type Ⅰ alpha 1 (COL1A1), COL3A1, and COL5A1 is linked to the recurrence of shoulder anterior dislocation, as these changes reflect the joint capsule's response to dislocation. Additionally, the expressions of tenascin C and fibronectin 1 may play a role in the pathological processes occurring during the early stages of RSAD. CONCLUSION Glenohumeral capsular laxity is both a consequence of RSAD and a significant factor contributing to its recurrence. While numerous studies have documented alterations in the shoulder capsule following RSAD, further research is necessary to confirm the specific pathological anatomy, histological, and molecular biological changes involved.
Humans ; Joint Capsule/metabolism* ; Shoulder Dislocation/metabolism* ; Recurrence ; Shoulder Joint/metabolism* ; Tenascin/metabolism* ; Transforming Growth Factor beta1/genetics* ; Collagen Type I/genetics* ; Extracellular Matrix/metabolism*

OBJECTIVE: To investigate the effect of stretch on long non-coding RNA taurine upregulated gene 1 (TUG1)-mediated miR-545-3p/cannbinoida receptor 2 (CNR2) pathway regulating bone regeneration in the distraction area of rats during distraction osteogenesis. METHODS: Thirty-six 10-week-old male Sprague Dawley rats were randomly divided into 3 groups ( <i>ni>=12 in each group): group A (femoral fracture+injection of interfering RNA), group B (distraction osteogenesis+injection of interfering RNA), and group C (distraction osteogenesis+injection of TUG1). Groups A and B were injected with 60 μg of interfering RNA at the beginning of incubation period (immediate after operation), the beginning of distraction phase (7 days after operation), and the end of distraction phase (21 days after operation), and group C was injected with 60 μg of synthetic TUG1 <i>in vivoi> interfering sequence at the same time. The general situation of rats in each group was observed during the experiment. The mineralization of fracture space or distraction area was observed by X-ray films at 21, 35, and 49 days after operation. At 49 days after operation, the samples of the distraction area were taken for HE staining to observe the mineralization, and real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expressions of osteoblast-related genes such as TUG1, miR-545-3p, CNR2, alkaline phosphatase (ALP), osteocalcin (OCN), and osteopontin (OPN). Blood samples were collected from the abdominal aorta of the rats, and the expressions of ALP and C terminal telopeptide of type Ⅰ (CTX-Ⅰ) protein were detected by ELISA assay. RESULTS: The results of X-ray film and HE staining observations showed that osteogenesis in group C was superior to groups A and B at the same time point. The results of qRT-PCR showed that the relative mRNA expressions of TUG1, CNR2, ALP, OCN, and OPN in group C were significantly higher than those in group A and group B, and the relative mRNA expression of miR-545-3p in group C was significantly lower than that in group A and group B ( <i>Pi><0.05). The relative mRNA expressions of TUG1 and ALP in group B were significantly higher than those in group A, and the relative mRNA expression of miR-545-3p in group B was significantly lower than that in group A ( <i>Pi><0.05). There was no significant difference in the relative mRNA expressions of CNR2, OCN, and OPN between group A and group B ( <i>Pi>>0.05). The results of ELISA showed that the expressions of ALP and CTX-Ⅰ protein were significantly higher in group C than in group A and group B, and in group B than in group A ( <i>Pi><0.05). CONCLUSION Under the action of stretch, the expression of TUG1 in the femoral distraction area of rats increases, which promotes the expression of CNR2 by inhibiting the expression of miR-545-3P, which is helpful to the mineralization of the extension area and osteogenesis.
Animals ; MicroRNAs/genetics* ; Rats, Sprague-Dawley ; Male ; Osteogenesis, Distraction/methods* ; Rats ; RNA, Long Noncoding/metabolism* ; Osteopontin/genetics* ; Osteogenesis ; Bone Regeneration ; RNA, Small Interfering/genetics* ; Osteocalcin/genetics* ; Alkaline Phosphatase/metabolism* ; Osteoblasts/cytology* ; Signal Transduction ; Femoral Fractures/surgery*