IngredientesCTGF, also known as CCN2 or connective tissue growth factor, is a matricellular protein of the CCN family of extracellular matrix-associated heparin-binding proteins. The protein has undergone an official nomenclature revision: the name "CTGF" has been officially changed by HUGO (the Human Genome Organisation) to "CCN2." The CCN acronym itself has dual origins: the acronym was derived from the first three members discovered — cysteine-rich 61 (CYR61), CTGF, and nephroblastoma overexpressed (NOV).
CTGF is a member of the CCN family named after its three original members: cysteine-rich protein 61 (Cyr61, CCN1), connective tissue growth factor (CTGF, CCN2), and nephroblastoma overexpressed protein (Nov, CCN3). Three additional Wnt-inducible secreted proteins were later identified (CCN4, CCN5, CCN6).
Connective tissue growth factor (CTGF) is a 38 kDa, cysteine-rich, extracellular matrix protein composed of four domains or modules. CTGF is a secreted protein predominantly expressed during development, in various pathological conditions that involve enhanced fibrogenesis and tissue fibrosis, and in several cancers, and is currently an emerging target in several early-phase clinical trials.
CCN2 was initially identified as a protein secreted by cultured human endothelial cells. In adult mammals, CCN2 exhibits a restricted expression, produced only by hepatic stellate cells and kidney mesangial cells under normal physiological conditions, though it is rapidly induced during tissue repair and in pathological states.
Members of the CCN protein family, including CTGF, are structurally characterized by having four conserved, cysteine-rich domains. These domains are, from N- to C-termini: the insulin-like growth factor binding protein (IGFBP) domain, the von Willebrand type C repeats (vWC) domain, the thrombospondin type 1 repeat (TSR) domain, and a C-terminal domain (CT) with a cysteine knot motif.
Full-length CTGF requires activation by proteolytic cleavage of the hinge region to release the biologically active C-terminal fragment comprising domains III and IV. CCN2 is synthesized and secreted as a preproprotein that is autoinhibited by its two N-terminal domains and requires proteolytic processing and homodimerization to become fully biologically active. Furthermore, the C-terminal fragment of CCN2 (domains III and IV) formed homodimers that were approximately 20-fold more potent than the monomeric form in activating intracellular phosphokinase cascades.
In its recombinant form used for research purposes, CTGF Human Recombinant produced in E. coli is a single, non-glycosylated, polypeptide chain containing 98 amino acids and having a molecular mass of 11.2 kDa. When produced in HEK293 cells, the CTGF Human Recombinant is a 36 kDa protein containing a total of 329 amino acid residues (aa 27–349) including a C-terminal 6×His tag.
CTGF/CCN2 is not a botanical or herbal ingredient — it is an endogenous human protein. It is a cysteine-rich peptide produced by fibroblasts and endothelial cells, but not by leukocytes or epithelial cells. CTGF/CCN2 is expressed in several cell types, such as endothelial cells, fibroblasts, and leukocytes, but especially in osteoblasts and chondrocytes. CTGF is constitutively expressed in normal human dermis in vivo, suggesting that CTGF is a physiological regulator of collagen expression.
CCN2 is induced by agents such as angiotensin II, endothelin-1, glucocorticoids, HGF, TGFβ, and VEGF, and by hypoxia and biomechanical and shear stress. CTGF is constitutively expressed in human lung fibroblasts and is stimulated by TGF-β, but not TNF-α or IL-1β.
In the context of mammary biology, CTGF/CCN2 levels are elevated during late pregnancy and early lactation. In supplemental and nutritional product contexts, CTGF is not typically derived from plant or herbal sources; rather, it is produced via recombinant protein technology or studied as a biomarker and pharmacological target.
CTGF/CCN2 is a protein that was discovered and characterized through modern molecular biology techniques. CCN2 was initially identified as a protein secreted by cultured human endothelial cells and has no documented traditional or historical use as a medicinal substance in pre-modern herbal or pharmaceutical traditions. It belongs entirely to the domain of contemporary biomedical science, with its characterization arising from late twentieth-century cell biology research. There is no record in classical pharmacopeias (Chinese, Ayurvedic, Greek, European, or otherwise) of CTGF as a recognized ingredient or remedy, because it was unknown as a distinct entity prior to its scientific isolation.
The broader concept of "connective tissue support" through diet and natural substances has deep roots in traditional medicine — including the use of animal-derived broths, collagen-rich foods, and plant extracts — but these traditions predate and are entirely distinct from the molecular entity CTGF/CCN2. Any association between such traditions and CTGF specifically would be retrospective and speculative rather than documented.
CTGF plays important roles in various biological processes, including cell adhesion, migration, proliferation, angiogenesis, skeletal development, and tissue wound repair, and is critically involved in fibrotic disease and several forms of cancer.
It is a member of the CCN family of immediate-early gene products which are characterized by four discrete protein modules in which reside growth factor binding domains, functional motifs for integrin recognition, heparin and proteoglycan binding, and dimerization motifs. A primary function of CTGF is to modulate and coordinate signaling responses involving cell surface proteoglycans, key components of the extracellular matrix, and growth factors.
As expression of this protein is potently induced by transforming growth factor-β (TGFβ), it has been hypothesized that CTGF mediates several of the downstream actions of TGFβ. CTGF is primarily induced by TGF-β in human skin fibroblasts and appears to function as a downstream mediator of TGF-β's ability to stimulate extracellular matrix synthesis. Importantly, early studies suggested that these proteins were bona-fide growth factors; however, data now supports the role of CCN proteins as matricellular proteins that can bind to matrix and modulate cellular functions via the modification of signals from other molecules such as TGFβ.
These proteins act through integrin- and heparan sulfate proteoglycan-mediated adhesive signaling to directly modulate adhesion and indirectly modulate the functional activities of other extracellular ligands such as cytokines, growth factors, morphogens, and matrix components. Extensive data have shown that CTGF interacts particularly with the TGFβ, WNT, and MAPK signaling pathways.
The C-terminal homodimer elicited activation of fibroblast migration, stimulated assembly of focal adhesion complexes, enhanced RANKL-induced osteoclast differentiation of RAW264.7 cells, and promoted mammosphere formation of MCF-7 mammary cancer cells.
CTGF stimulates collagen synthesis when injected into mouse skin or added to cultured renal fibroblasts. A role for CTGF in extracellular matrix production is suggested by its ability to mediate collagen deposition during wound healing. CTGF is profibrotic, as CTGF is overexpressed in fibrotic disease and synergizes with TGFβ to promote sustained fibrosis in vivo.
CTGF also induces neovascularization in vitro, suggesting a role in angiogenesis in vivo. CCN2 has been also considered to be one of the most important regulators of both physiologic and pathologic angiogenesis.
Several lines of evidence indicate that CTGF is markedly elevated in numerous fibrotic disorders, involving skin, lungs, and kidneys, where it is believed to stimulate excessive deposition of collagen. Dysregulated expression of CCN2 has also been widely documented in many fibroproliferative diseases.
Important framing note: CTGF/CCN2 is not a conventional dietary supplement that individuals ingest as an exogenous compound. Rather, the scientific literature addresses CTGF in two primary modes: (1) as a therapeutic target whose inhibition is sought in fibrotic and oncological diseases, and (2) as a biomarker whose endogenous levels correlate with tissue health and disease state. The evidence base below reflects these distinctions and is clearly characterized by study type and evidence strength.
Connective tissue growth factor (CTGF) is a secreted glycoprotein that has a central role in the process of fibrosis. The most advanced clinical evidence for CTGF as a pharmacological target comes from the PRAISE trial, a study of the anti-CTGF monoclonal antibody pamrevlumab (FG-3019).
The phase 2, randomised, double-blind, placebo-controlled PRAISE trial was conducted at 39 medical centres in seven countries (Australia, Bulgaria, Canada, India, New Zealand, South Africa, and the USA). Patients with idiopathic pulmonary fibrosis and percentage of predicted forced vital capacity (FVC) of 55% or greater were enrolled and randomly assigned (1:1) by use of interactive responsive technology to intravenous infusion of pamrevlumab 30 mg/kg or placebo every 3 weeks over 48 weeks (16 infusions).
The proportion of patients with disease progression was lower in the pamrevlumab group than in the placebo group at week 48 (10.0% vs 31.4%; p=0.013). Pamrevlumab was well tolerated, with a safety profile similar to that of placebo. Treatment-emergent serious adverse events were observed in 12 (24%) patients in the pamrevlumab group and eight (15%) in the placebo group, with three patients on pamrevlumab and seven on placebo discontinuing treatment.
However, subsequent Phase 3 investigation did not replicate these results: CCN2 blockade by pamrevlumab was shown to reduce the lung function decline in patients with IPF in a phase 2 study; however, results were not reproducible in a larger population during phase 3, leading to discontinuation of the program. The overall evidence for CTGF inhibition in IPF must therefore be characterized as mixed — promising at Phase 2, but failing to demonstrate a clinically meaningful benefit in Phase 3.
CTGF has been shown to regulate a diverse array of cellular functions and has been implicated in more complex biological processes such as angiogenesis, chondrogenesis, and osteogenesis. A role for CTGF in the development and maintenance of skeletal tissues first came to light in studies demonstrating its expression in cartilage and bone cells, which was dramatically increased during skeletal repair or regeneration.
From the studies to date concerning the effects of CTGF on skeletogenesis, one broad conclusion can be drawn: appropriate physiological levels of CTGF are necessary for normal skeletal development, as animal models with either ablation or overexpression of CTGF have demonstrated phenotypes related to cartilage and/or bone development.
In cartilage-specific transgenic mouse models, over-expression of CCN2 enhanced the production and deposition of extracellular proteoglycans and type II collagen, which is in line with previous in vitro findings. Evidence in this area is predominantly from in vitro and animal studies; robust human clinical evidence for CTGF's role in skeletal health is currently limited.
Topical application of CTGF/CCN2 to rodent diabetic and control wounds was examined. In parallel research, correlation of CTGF wound fluid levels with healing rate in human diabetic foot ulcers was undertaken. Full thickness cutaneous wounds in diabetic and nondiabetic control rats were treated topically with 1 μg rhCTGF or vehicle alone, on 2 consecutive days. CTGF-treated diabetic wounds had an accelerated closure rate compared with vehicle-treated diabetic wounds. Healed skin withstood more strain before breaking in CTGF-treated rat wounds. Granulation tissue from CTGF treatment in diabetic wounds showed collagen IV accumulation compared with nondiabetic animals. In the human study across 32 subjects, serial CTGF regulation was analyzed longitudinally in post-debridement diabetic wound fluid. This constitutes a small observational human correlative study plus animal intervention data; evidence is preliminary.
Reduced production of type I procollagen is a prominent feature of chronologically aged human skin. CTGF/CCN2, a downstream target of the TGF-β/Smad pathway, is highly expressed in numerous fibrotic disorders, where it is believed to stimulate excessive collagen production. CTGF is constitutively expressed in normal human dermis in vivo, suggesting that CTGF is a physiological regulator of collagen expression. The TGF-β/Smad/CTGF axis is significantly reduced in dermal fibroblasts, the major collagen-producing cells, in aged (80+ years) human skin in vivo.
In primary human skin fibroblasts, neutralization of endogenous TGF-β or knockdown of CTGF substantially reduced expression of type I procollagen mRNA, protein, and promoter activity. In contrast, overexpression of CTGF stimulated type I procollagen expression, and increased promoter activity.
Age-related reduction in fibroblast spreading/size drives YAP/TAZ-dependent downregulation of CCN2 expression, which in turn contributes to loss of collagen in aged human skin. This research is conducted using ex vivo human skin samples and cultured human fibroblasts. Evidence is mechanistic and translational rather than from clinical interventional trials; no approved treatment targeting the CTGF/collagen axis in aging skin exists.
Clinical studies have shown that CCN-2 is increased in renal tissue and in urine in evolving diabetic nephropathy. Both urinary CCN-2 excretion and plasma CCN-2 levels were elevated in patients with diabetic nephropathy. CCN2 levels in biological fluids correlate with the levels of fibrosis in patient samples. Urinary CCN2 levels appear to predict those patients who are destined for progressive glomerulosclerosis and end-stage renal disease.
In several independent studies, circulating or urinary levels of CCN2 have been proposed as a risk biomarker of human diabetic nephropathy and other forms of chronic kidney disease. Preclinical studies have shown that inhibition of endogenous CCN2 by antisense oligonucleotides or gene silencing slows disease progression in experimental diabetic nephropathy, unilateral ureteral obstruction, and nephrectomized transgenic mice overexpressing TGF-β1.
Evidence for CTGF as a biomarker of diabetic kidney disease is substantial and supported by multiple clinical observational studies. Evidence for therapeutic inhibition of CTGF in human kidney disease remains early-phase and mostly preclinical.
In skeletal muscle, CCN2/CTGF abundance is elevated in human muscle biopsies and/or animal models for diverse neuromuscular pathologies, including muscular dystrophies, neurodegenerative disorders, muscle denervation, and muscle overuse. Pamrevlumab has completed an open-label, single-arm Phase 2 clinical trial in non-ambulatory DMD patients where each subject received pamrevlumab for up to 156 weeks (NCT02606136).
In an ALS murine model, FG-3019 not only reduces fibrosis in skeletal muscle of hSOD1G93A mice, but also improves muscle and locomotor performance. Treatment with FG-3019 reduces muscle atrophy in hSOD1G93A mice. Improvement of neuromuscular junction innervation together with a reduction in myelin degeneration in the sciatic nerve was found, suggesting that alterations in nerve-muscle communication are partially improved in FG-3019-treated hSOD1G93A mice. Evidence in neuromuscular disease is early-phase clinical and animal-model level.
The involvement of CTGF/CCN2 has been well-documented in SSc fibrosis. Ang II-induced skin fibrosis was mitigated in both CTGF KO and FG-3019-treated mice. The blockade of CTGF reduced the number of cells expressing PDGFRβ, procollagen, αSMA, pSmad2, CD45, and Fsp1 in the dermis. In addition, inhibition of CTGF attenuated vascular injury as measured by the presence of vWF-positive cells. Evidence remains largely preclinical; no CTGF-targeting treatment is approved for scleroderma.
CTGF is a secreted protein predominantly expressed during development, in various pathological conditions that involve enhanced fibrogenesis and tissue fibrosis, and in several cancers, and is currently an emerging target in several early-phase clinical trials.
In pancreatic cancer, CTGF has been investigated as a tumor-promoting factor. In neurodegenerative and cancer biology: immunocytochemistry studies indicated that both glioblastoma tumor cells and proliferating endothelial cells stained positive for CCN2. In astrocytomas, CCN2 expression was particularly elevated in high grade tumors, with a marked effect of CCN2 on cell proliferation. Evidence in oncology is predominantly in vitro and animal-model with some emerging early-phase clinical trial data; no approved oncological therapy targeting CTGF currently exists.
CTGF/CCN2 in the research and clinical context is not distributed as a conventional oral dietary supplement with standardized dosage forms. The primary forms reported in scientific literature are as follows:
No established or validated oral supplemental dose of exogenous CTGF has been reported in peer-reviewed human literature. The protein would face significant gastrointestinal degradation challenges if administered orally, and no regulatory authority (FDA, EMA, EFSA) has approved an oral CTGF preparation. Any commercial product claiming to contain or meaningfully deliver biologically active CTGF via oral supplementation lacks a published evidence base as of current literature.
The most clinically significant safety consideration regarding CTGF/CCN2 is its dual role: while physiological levels are essential for normal development and tissue homeostasis, elevated CTGF is associated with pathological fibrosis. Several lines of evidence indicate that CTGF is markedly elevated in numerous fibrotic disorders, involving skin, lungs, and kidneys, where it is believed to stimulate excessive deposition of collagen. Interventions that increase CTGF expression may therefore carry profibrotic risk in susceptible individuals.
Although profibrotic functions of CTGF are most widely recognized, CTGF has also been shown to induce inflammatory responses in various cell types in vitro. The pro-inflammatory role of CTGF was further confirmed in in vivo models of pancreatic and renal inflammation. Data indicate that CTGF provokes an inflammatory response in the kidney which is likely to contribute to the initiation of fibrosis in kidney disease.
Data from clinical trials targeting CTGF provide insight into what can occur when CTGF activity is modulated in humans. In a 48-week phase 2 trial enrolling 103 subjects, pamrevlumab-treated subjects experienced a smaller decrease in FVC and smaller increase in quantitatively measured volume of lung with fibrosis. Serious adverse events were observed in numerically more pamrevlumab-treated (12%, 24%) than placebo-treated (8%, 15%) subjects. The implication is that systemic modulation of CTGF is not without risk of adverse events, though the safety profile in the Phase 2 IPF trial was overall considered acceptable.
Extensive data have shown that CTGF interacts particularly with the TGFβ, WNT, and MAPK signaling pathways. Agents that modulate these pathways — including a wide range of pharmaceuticals and some botanical compounds — would be expected to alter CTGF expression or activity, though specific drug–CTGF interaction data in humans are not well-characterized in the current literature.
The oncological implications of CTGF modulation are complex and not yet fully resolved. In astrocytomas, CCN2 expression was particularly elevated in high grade tumors, with a marked effect of CCN2 on cell proliferation. Downregulation of CCN2 expression in these cells was associated with a growth arrest at the G1/S transition while over-expression of CCN2 induced a two-fold increase of the number of cells in the G1 phase. This context-dependence means that exogenous or endogenous CTGF upregulation in the setting of certain cancers carries theoretical proliferative risk.
Appropriate physiological levels of CTGF are necessary for normal skeletal development, as animal models with either ablation or overexpression of CTGF have demonstrated phenotypes related to cartilage and/or bone development. This underscores that both excess and deficiency of CTGF activity are associated with adverse outcomes in developmental contexts.
Condiciones de salud que Factor de crecimiento del tejido conectivo puede ayudar a apoyar.
Connective tissue growth factor (CTGF/CCN2) is an endogenous matricellular protein that promotes fibroblast proliferation, collagen and proteoglycan synthesis, and connective tissue repair and remodeling. It is a major mediator of TGF-β-induced connective tissue formation. Its relevance is primarily as a biomarker and therapeutic target/mechanism in connective tissue research rather than as a supplement.
Sistemas corporales que Factor de crecimiento del tejido conectivo puede ayudar a apoyar.
Volver