NCBI Summary:
This gene encodes the pro-alpha1 chains of type I collagen whose triple helix comprises two alpha1 chains and one alpha2 chain. Type I is a fibril-forming collagen found in most connective tissues and is abundant in bone, cornea, dermis and tendon. Mutations in this gene are associated with osteogenesis imperfecta types I-IV, Ehlers-Danlos syndrome type VIIA, Ehlers-Danlos syndrome Classical type, Caffey Disease and idiopathic osteoporosis. Reciprocal translocations between chromosomes 17 and 22, where this gene and the gene for platelet-derived growth factor beta are located, are associated with a particular type of skin tumor called dermatofibrosarcoma protuberans, resulting from unregulated expression of the growth factor. Two transcripts, resulting from the use of alternate polyadenylation signals, have been identified for this gene. [provided by R. Dalgleish, Feb 2008]
General function
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Cellular localization
Extracellular Matrix
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Ovarian function
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Expression regulated by
Growth Factors/ cytokines
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The p38 signaling pathway mediates the TGF-β1-induced increase in type I collagen deposition in human granulosa cells. Li H et al. (2020) Type I collagen, which is mainly composed of collagen type I alpha 1 chain (COL1A1), is the most abundant extracellular matrix (ECM) protein in the mammalian ovary; and the cyclical remodeling of the ECM plays an essential role in the regulation of corpus luteum formation. Our previous studies have demonstrated that TGF-β1 is a potent inhibitor of luteinization in human granulosa-lutein (hGL) cells. Whether TGF-β1 can regulate the expression of COL1A1 during the luteal phase remains to be elucidated. The aim of this study was to investigate the effect of TGF-β1 on the regulation of COL1A1 expression and the underlying molecular mechanisms using an immortalized hGL cell line (SVOG cells) and primary hGL cells (obtained from 20 consenting patients undergoing IVF treatment). The results showed that TGF-β1 significantly upregulated the expression of COL1A1. Using inhibition approaches, including pharmacological inhibition (a specific p38 inhibitor, SB203580, and a specific ERK1/2 inhibitor, U0126) and specific siRNA-mediated knockdown inhibition, we demonstrated that TGF-β1 promoted the expression and production of COL1A1 in hGL cells, most likely via the ALK5-mediated p38 signaling pathway. Our findings provide insights into the molecular mechanisms by which TGF-β1 promotes the deposition of type I collagen during the late follicular phase in humans.//////////////////Transcriptional profiling of long noncoding RNAs and their target transcripts in ovarian cortical tissues from women with normal menstrual cycles and primary ovarian insufficiency. Yao G et al. (2019) Previous studies have shown that long noncoding RNAs (lncRNAs) show a highly tissue- and disease-specific expression pattern and that they regulate the expression of neighboring genes. Because lncRNAs have been shown to be secreted into the general circulation, they may be used as diagnostic tools for some diseases. Primary ovarian insufficiency (POI) is a disease in which women have menstrual cessation before the age of 40, accompanied by elevated follicle stimulating hormone and decreased estrogen levels. In this study, ovarian cortical tissues from five women with normal menstrual cycles and from five POI patients were used for next-generation RNA sequencing. We found 20 differentially expressed lncRNAs with 12 upregulated and eight downregulated lncRNAs in cortical tissues of POI ovaries, compared with normal controls (fold change ≥ 2 and false discovery rate[FDR] ≤ 0.05). We also found 52 differentially expressed messenger RNA transcripts, with 33 upregulated and 19 downregulated ones (foldchange ≥ 2 and FDR ≤ 0.05). Functional annotation showed that these differentially expressed transcripts were associated with follicular development and granulosa cell function. Thirteen differentially expressed lncRNAs and their targeted neighboring transcripts were coregulated in ovarian cortical tissues, including lnc-ADAMTS1-1:1/ADAMTS1, lnc-PHLDA3-3:2/CSRP1, lnc-COL1A1-5:1/COL1A1, lnc-SAMD14-5:3/COL1A1, and lnc-GULP1-2:1/COL3A1. Furthermore, serum levels of these lncRNAs in POI patients were significantly different from those in normal patients ( p < 0.05), and expression differences were consistent with those in ovarian cortical tissues. This study showed that key lncRNAs were differentially expressed in both ovarian cortical tissues and serum samples between women with normal menstrual cycles and POI patients. Further studies on the regulation of ovarian lncRNAs during follicular development are critical in understanding the etiologies of POI. Analyses of lncRNA expression in serum samples might provide a basis for early diagnosis and treatment of POI.//////////////////
Ovarian localization
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Collagens in the human ovary and their changes in the perifollicular stroma during ovulation. Lind AK et al. BACKGROUND: Remodeling of the collagens around the follicle is a major event in ovulation. The aim of the present study was to investigate the distribution of collagen I, III, and IV in the human ovary. METHODS: Biopsies of the perifollicular stroma were obtained at sterilization during the preovulatory phase (follicle size >14 mm) or at any of three intervals (12-18 h after human chorionic gonadotrophin: early ovulatory phase; >18-24 h: late ovulatory phase; 44-77 h: postovulatory phase) after human chorionic gonadotrophin. Excised dominant follicles and whole ovarian sections were also obtained. Immunohistochemistry using antibodies against collagen I, III, IV, vimentin, and CD 45 was performed. RESULTS AND CONCLUSIONS: Collagens I and III were distributed in concentric layers in the capsular stroma with bundles of collagens connecting these layers to form a mesh. Collagen I was present in larger quantities in the outer layers and collagen III showed the inverse distribution. In the theca, collagen I was present in the externa and collagen III in the entire layer. The staining intensity of collagens I and III in the perifollicular stroma decreased from the preovulatory stage. Collagen IV was present in the basal lamina separating granulosa and theca cells. This study shows that collagen I and III are abundant in and around the ovulating human follicle with typical patterns of distribution. Collagen IV is present in the basal membrane that separates the granulosa from the theca cells. Taking into account the abundance of collagens in the follicular wall and their specific localization, major site-directed degradation of collagens seems to be necessary for follicular rupture to occur.