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*

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

Recombinant collagen, as an alternative to natural collagen, has the potential to be widely used in biomaterials, biomedicine, etc. Diverse recombinant collagens and their variants can be industrially produced in a variety of expression systems, which lays a foundation for exploring and expanding the clinical application of recombinant collagens. We reviewed different expression systems for recombinant collagens, such as prokaryotic expression systems, yeast expression systems, as well as plant, insect, mammal, and human cell expression systems, and introduced the advantages, potential applications, and limitations of recombinant collagen. In particularly, we focused on the current progress in the recombinant collagen production, including recombinant expression system construction and hydroxylation strategies of recombinant collagen, and summarized the current biomedical applications of recombinant collagen.
Animals ; Biocompatible Materials ; Collagen/biosynthesis* ; Humans ; Hydroxylation ; Recombinant Proteins/biosynthesis*

OBJECTIVE: To investigate the effects of Ganoderma lucidum polysaccharides (GL-PS) on human fibroblasts and skin wound healing in Kunming male mice and to explore the putative molecular mechanism. METHODS: Primary human skin fibroblasts were cultured. The viability of fibroblasts treated with 0, 10, 20, 40, 80, and 160 μg/mL of GL-PS, respectively were detected by 3-4,5-dimethyl-2-thiazolyl-2,5-diphenyl-2-Htetrazolium bromide (MTT). The migration ability of fibroblasts treated with 0, 10, 20, and 40 μg/mL of GL-PS were measured by transwell assay. The secretion of the C-terminal peptide of procollagen type I (CICP) and transforming growth factor-β1 (TGF-β1) in the cell supernatant was tested by enzyme-linked immunosorbent assay. The expression of β-catenin was detected by Western blot. Furthermore, the Kunming mouse model with full-layer skin resection trauma was established, and was treated with 10, 20, and 40 mg/mL of GL-PS, respectively as external use. The size of the wound was measured daily, complete healing time in each group was recorded and the percentage of wound contraction was calculated. RESULTS: Compared with the control group, 10, 20, and 40 μg/mL of GL-PS significantly increased the viability of fibroblasts, promoted the migration ability of fibroblasts, and up-regulated the expressions of CICP and TGF-β1 in fibroblasts (Plt;0.05 or Plt;0.01). The expression of β-catenin in fibroblasts treated with 20 and 40 μg/mL of GL-PS was significantly higher than that of the control group (Plt;0.01). Furthermore, after external use of 10, 20, and 40 mg/mL of GL-PS, the rates of wound healing in mice were significantly higher and the wound healing time was significantly less than the control group (Plt;0.05 or Plt;0.01). CONCLUSION A certain concentration of GL-PS may promote wound healing via activation of the Wnt/β-catenin signaling pathway and up-regulation of TGF-β1, which might serve as a promising source of skin wound healing.
Animals ; Cell Movement ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Collagen Type I ; biosynthesis ; Fibroblasts ; drug effects ; Humans ; Male ; Mice ; Polysaccharides ; pharmacology ; Reishi ; chemistry ; Skin ; drug effects ; injuries ; Transforming Growth Factor beta1 ; physiology ; Wound Healing ; drug effects ; beta Catenin ; physiology

The present study was designed to elucidate whether the mechanism by which osthole decreases collagenI/III contents and their ratio is regulating the TGF-β/Smad signaling pathway in TGF-β1-overexpressed mouse cardiac fibroblasts (CFs). These CFs were cultured and treated with different concentrations of osthole. Our results showed that the TGF-β1 expression in the CFs transfected with that the recombinant expression plasmids pcDNA3.1(+)-TGF-β1 was significantly enhanced. After the CFs were treated with 1.25-5 μg·mL of osthole for 24 h, the mRNA and protein expression levels of collagensIand III were reduced. The collagen I/III ratio was also reduced. The mRNA and protein expression levels of TGF-β1, TβRI, Smad2/3, P-Smad2/3, Smad4, and α-SMA were decreased, whereas the expression level of Smad7 was increased. These effects suggested that osthole could inhibit collagen I and III expression and reduce their ratio via the TGF-β/Smad signaling pathway in TGF-β1 overexpressed CFs. These effects of osthole may play beneficial roles in the prevention and treatment of myocardial fibrosis.
Actins ; genetics ; Animals ; Cells, Cultured ; Collagen ; biosynthesis ; genetics ; Coumarins ; pharmacology ; Fibroblasts ; drug effects ; metabolism ; Gene Expression Regulation ; drug effects ; Mice ; Myocardium ; cytology ; Protein-Serine-Threonine Kinases ; genetics ; RNA, Messenger ; genetics ; Real-Time Polymerase Chain Reaction ; Receptor, Transforming Growth Factor-beta Type I ; Receptors, Transforming Growth Factor beta ; genetics ; Signal Transduction ; drug effects ; Smad Proteins ; genetics ; Transforming Growth Factor beta1 ; genetics

To produce bionic bone material that is consistent with human bone in chemical composition and molecular structure using rat tail tendon collagen type Ⅰ.The type Ⅰcollagen derived from rat tail was extracted by acetic acid to form collagen fibers. The reconstructed collagen fibers were placed in the mineralized solution to mimic bone mineralization for 2-6 days. Bone mineralization was observed by transmission electron microscopy and electron diffraction.Collagen fibers with characteristic D-Band structure were reconstructed by using rat tail tendon collagen type Ⅰ extracted with acid hydrolysis method. Transmission electron microscopy and electron diffraction showed that calcium hydroxyapatite precursor infiltrated into the collagen fibers, and the collagen fibers were partially mineralized after 2 days of mineralization; the collagen fibers were completely mineralized and bionic bone material of typeⅠ collagen/calcium hydroxyapatite was formed after 6 days of mineralization.The collagen type Ⅰ can be extracted from rat tail tendon by acid hydrolysis method, and can be reformed and mineralized to form the bionic bone material which mimics human bone in chemical composition and the molecular structure.
Animals ; Biocompatible Materials ; chemical synthesis ; Bone Matrix ; chemistry ; growth & development ; Bone Substitutes ; chemical synthesis ; Bone and Bones ; anatomy & histology ; chemistry ; Calcification, Physiologic ; Collagen Type I ; biosynthesis ; chemistry ; ultrastructure ; Humans ; Hydroxyapatites ; chemistry ; Rats ; Tail ; Tendons ; chemistry ; ultrastructure ; Tissue Engineering ; methods

This study investigated the effects of SIRT1 gene knock-out on osteoarthritis in mice, and the possible roles of SREBP2 protein and the PI3K/AKT signaling pathway in the effects. Mice were randomly divided into a normal group and a SIRT1 gene knock-out group (6 mice in each group). In these groups, one side of the knee anterior cruciate ligament was traversed, and the ipsilateral medial meniscus was cut to establish an osteoarthritis model of knee joint. The countralateral synovial bursa was cut out, serving as controls. The knee joint specimens were then divided into four groups: SIRT1control group (group A, n=6); SIRT1osteoarthritis group (group B, n=6); SIRT1control group (group C, n=6); SIRT1osteoarthritis group (group D, n=6). HE staining, Masson staining, Safranin O-Fast Green staining and Van Gieson staining were used to observe the morphological changes in the articular cartilage of the knee. Immunohistochemical staining was employed to detect the expression of SIRT1, SREBP2, VEGF, AKT, HMGCR and type II collagen proteins. SA-β-gal staining was utilized to evaluate chondrocyte aging. The results showed clear knee joint cartilage destruction and degeneration in the SIRT1osteoarthritis group. The tidal line was twisted and displaced anteriorly. Type II collagen was destroyed and distributed unevenly. Compared with the SIRT1osteoarthritis group and SIRT1control group, SIRT1 protein expression was not obviously changed in the SIRT1osteoarthritis group (P>0.05), while the expression levels of the SREBP2, VEGF and HMGCR proteins were significantly increased (P<0.05) and the levels of AKT and type II collagen proteins were significantly decreased (P<0.05). SIRT1 gene knock-out may aggravate cartilage degeneration in osteoarthritis by activating the SREBP2 protein-mediated PI3K/AKT signalling pathway, suggesting that SIRT1 gene may play a protective role against osteoarthritis.
Animals ; Cartilage ; pathology ; Chondrocytes ; metabolism ; Collagen Type II ; metabolism ; Disease Models, Animal ; Humans ; Knee Joint ; metabolism ; pathology ; Mice ; Mice, Knockout ; Oncogene Protein v-akt ; genetics ; Osteoarthritis ; genetics ; pathology ; Phosphatidylinositol 3-Kinases ; genetics ; Signal Transduction ; genetics ; Sirtuin 1 ; genetics ; Sterol Regulatory Element Binding Protein 2 ; biosynthesis ; genetics ; Vascular Endothelial Growth Factor A ; biosynthesis

OBJECTIVEThis study will explore whether reactive oxygen species (ROS) is involved in TGF-β1-induced JNK activation, pulmonary fibroblast proliferation and collagen type I and III synthesis.

METHODSPulmonary fibroblasts were randomly divided into control (0.4% serum) and TGF-β1 (5 µg/L) groups to detect whether TGF-β1 could induce pulmonary fibroblast proliferation, synthesis of collagen I and III, phosphorylated-JNK (p-JNK) and 8-OHdG (indicator of ROS); while in the part to explore whether NAC (N-acetyl-L-cysteine, antioxidants) has the inhibitory role in TGF-β1-induced pulmonary fibroblast, it did control (0.4% serum), H2O2 (0.1 mmol/L, positive control), H2O2+NAC (10 mmol/L), TGF-β1 (5 µg/L), TGF-β1+NAC groups. Pulmonary fibroblast proliferation, 8-OHdG levels, expressions of JNK and collagen I and III were used by MTT assay, immunofluorescence and western blot respectively.

RESULTSIn the experiments to detect the effect of TGF-β1 on pulmonary fibroblasts, compared with control, TGF-β1 significantly stimulated pulmonary fibroblast proliferation and increased collagen I and III protein, p-JNK and 8-OHdG levels. In the next experiments to explore whether NAC has the inhibitory role in TGF-β1-induced pulmonary fibroblasts, compared with control, pulmonary fibroblast proliferation and the levels of collagen I and II, p-JNK, 8-OHdG were all significantly increased in H2O2 and TGF-β1 groups; while these changes were markedly blocked with the treatment of NAC.

CONCLUSIONTGF-β1 induces pulmonary fibroblasts to generate ROS, which contributes to JNK activation and pulmonary fibroblast proliferation as well as collagen synthesis, while ROS inhibition suppresses this effet of TGF-β1 in pulmonary fibroblasts.

Acetylcysteine ; Cell Proliferation ; Collagen ; biosynthesis ; Collagen Type I ; Fibroblasts ; cytology ; Hydrogen Peroxide ; Lung ; cytology ; MAP Kinase Signaling System ; Phosphorylation ; Reactive Oxygen Species ; metabolism ; Transforming Growth Factor beta ; metabolism ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo investigate the effect of Metformin on the proliferation and collagen synthesis of the human keloids fibroblasts as well as the effect on phosphorylation of Akt/FoxO1 signal transduction pathway.

METHODSFibroblasts of keloid were divided into control group treated with medium solution and experimental groups treated with different concentrations of Metformin. 48 h later CCK-8 assay was adopted to evaluate cell survival; Western blot was performed to detect the Akt and FoxO1 phosphorylation; and Hydroxyproline reagent kit was used to detect the collagen synthesis.

RESULTSWith different concentrations (30, 60, 90, 120 mmol/L) of Metformin, the absorbance of cultured keloid fibroblasts detected by CCK8 assay decreased by (13.30 ± 2.04)%, (22.64 ± 4.70)%, (54.00 ± 5.34)% and (63.12 ± 3.48)%. The growth of fibroblasts was suppressed by Metformin in a dose-dependent manner. It showed that the level of phoshpo-akt and phoshpo-foxOl in keloids fibroblasts in experimental groups was lower than that in the control group and the collagen synthesis were also decreased in experimental groups, all in a dose-dependent manner (P < 0.05, P < 0.01).

CONCLUSIONSMetformin can effectively inhibit the proliferation and collagen synthesis of the human keloids fibroblasts in vitro, which may be associated with the suppression of phosphorylation of Akt/FoxO1 signaling pathway

Cell Proliferation ; drug effects ; Collagen ; biosynthesis ; Dose-Response Relationship, Drug ; Fibroblasts ; cytology ; drug effects ; metabolism ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; metabolism ; Humans ; Keloid ; pathology ; Metformin ; pharmacology ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; drug effects

PURPOSE: The degradation of the extracellular matrix has been shown to play an important role in the treatment of hepatic cirrhosis. In this study, the effect of thalidomide on the degradation of extracellular matrix was evaluated in a rat model of hepatic cirrhosis. MATERIALS AND METHODS: Cirrhosis was induced in Wistar rats by intraperitoneal injection of carbon tetrachloride (CCl4) three times weekly for 8 weeks. Then CCl4 was discontinued and thalidomide (100 mg/kg) or its vehicle was administered daily by gavage for 6 weeks. Serum hyaluronic acid, laminin, procollagen type III, and collagen type IV were examined by using a radioimmunoassay. Matrix metalloproteinase-13 (MMP-13), tissue inhibitor of metalloproteinase-1 (TIMP-1), and alpha-smooth muscle actin (alpha-SMA) protein in the liver, transforming growth factor beta1 (TGF-beta1) protein in cytoplasm by using immunohistochemistry and Western blot analysis, and MMP-13, TIMP-1, and TGF-beta1 mRNA levels in the liver were studied using reverse transcriptase polymerase chain reaction. RESULTS: Liver histopathology was significantly better in rats given thalidomide than in the untreated model group. The levels of TIMP-1 and TGF-beta1 mRNA and protein expressions were decreased significantly and MMP-13 mRNA and protein in the liver were significantly elevated in the thalidomide-treated group. CONCLUSION: Thalidomide may exert its effects on the regulation of MMP-13 and TIMP-1 via inhibition of the TGF-beta1 signaling pathway, which enhances the degradation of extracellular matrix and accelerates the regression of hepatic cirrhosis in rats.
Actins ; Animals ; Carbon Tetrachloride/toxicity ; Collagen Type III/metabolism ; Down-Regulation ; Extracellular Matrix/metabolism ; Immunohistochemistry ; Immunosuppressive Agents/*pharmacology ; Liver Cirrhosis, Experimental/chemically induced/*metabolism/pathology/*prevention & control ; Male ; RNA, Messenger/analysis/metabolism ; Rats ; Rats, Wistar ; Thalidomide/*pharmacology ; Tissue Inhibitor of Metalloproteinase-1/biosynthesis/*drug effects ; Transcription Factor RelA/biosynthesis/drug effects ; Transforming Growth Factor beta1/biosynthesis/*drug effects ; Transforming Growth Factors/metabolism