Cthrc1, a novel circulating hormone regulating metabolism

CTHRC1: An Emerging Hallmark of Pathogenic Fibroblasts in Lung Fibrosis

Pulmonary fibrosis is a chronic, progressive, irreversible lung disease characterized by fibrotic scarring in the lung parenchyma. This condition involves the excessive accumulation of extracellular matrix (ECM) due to the aberrant activation of myofibroblasts in the alveolar environment. Transforming growth factor beta (TGF-β) signaling is a crucial driver of fibrogenesis because it promotes excessive ECM deposition, thereby leading to scar formation and lung damage. A primary target of TGF-β signaling in fibrosis is Collagen Triple Helix Repeat Containing 1 (CTHRC1), a secreted glycoprotein that plays a pivotal role in ECM deposition and wound repair. TGF-β transcriptionally regulates CTHRC1 in response to tissue injury and controls the wound healing response through functional activity. CTHRC1 may also play an essential role in re-establishing and maintaining tissue homeostasis after wound closure by modulating both the TGF-β and canonical Wnt signaling pathways. This dual function suggests that CTHRC1 regulates tissue remodeling and homeostasis. However, deregulated CTHRC1 expression in pathogenic fibroblasts has recently emerged as a hallmark of fibrosis in multiple organs and tissues. This review highlights recent studies suggesting that CTHRC1 can serve as a diagnostic and prognostic biomarker for fibrosis in idiopathic pulmonary fibrosis, systemic sclerosis, and post-COVID-19 lung fibrosis. Notably, CTHRC1 expression is responsive to antifibrotic drugs that target the TGF-β pathway, such as pirfenidone and bexotegrast, indicating its potential as a biomarker of treatment success. These findings suggest that CTHRC1 may present new opportunities for diagnosing and treating patients with lung fibrosis.

Tranexamic acid reduces inflammation, edema and burn wound conversion in a rodent model

Burn wound conversion is the observed process where superficial partial thickness burns convert into deep partial or full thickness burn injuries. This conversion process often involves surgical excision to achieve timely wound healing. Unfortunately, the pathophysiology of this phenomenon is multifactorial and poorly understood. Thus, a therapeutic intervention that may prevent secondary progression and cell death in burn-injured tissue is desirable. Recent work by our group and others has established that tranexamic acid (TXA) has significant anti-inflammatory properties in addition to its well-known anti-fibrinolytic effects. This study investigates TXA as a novel therapeutic treatment to mitigate burn wound conversion and reduce systemic inflammation. Sprague-Dawley rats were subjected to a hot comb burn contact injury. A subset of animals underwent a similar comb burn with an adjacent 30%TBSA contact injury. The interspaces represent the ischemic zones simulating the zone of stasis. The treatment group received injections of TXA (100 mg/kg) immediately after injury and once daily until euthanasia. Animals were harvested for analyses at 6 h and 7 days after injury. Full-thickness biopsies from the ischemic zones and lung tissue were assessed with established histological techniques. Plasma was collected for measurement of damage associated molecular patterns (DAMPs), and liver samples were used to study inflammatory cytokines expression. Treatment with TXA was associated with reduced burn wound conversion and decreased burn-induced systemic inflammatory response syndrome (SIRS). Lung inflammation and capillary leak were also significantly reduced in TXA treated animals. Future research will elucidate the underlying anti-inflammatory properties of TXA responsible for these findings.

The role of collagen triple helix repeat containing 1 (CTHRC1) in cancer development and progression

INTRODUCTION

Collagen triple helix repeat containing 1 (CTHRC1) is a protein that has been implicated in pro-migratory pathways, arterial tissue-repair processes, and inhibition of collagen deposition via the regulation of multiple signaling cascades. Studies have also demonstrated an upregulation of CTHRC1 in multiple cancers where it has been linked to enhanced proliferation, invasion, and metastasis. However, the understanding of the exact role and mechanisms of CTHRC1 in cancer is far from complete.

AREAS COVERED

This review focuses on analyzing the role of CTHRC1 in cancer as well as its associations with clinicopathologies and cancer-related processes and signaling. We have also summarized the available literature information regarding the role of CTHRC1 in tumor microenvironment and immune signaling. Finally, we have discussed the mechanisms associated with CTHRC1 regulations, and opportunities and challenges regarding the development of CTHRC1 as a potential target for cancer management.

EXPERT OPINION

CTHRC1 is a multifaceted protein with critical roles in cancer progression and other pathological conditions. Its association with lower overall survival in various cancers, and impact on the tumor immune microenvironment make it an intriguing target for further research and potential therapeutic interventions in cancer.

Evidence of Histone H2A.Z Deacetylation and Cardiomyocyte Dedifferentiation in Infarcted/Tip60-depleted Hearts

Myocardial infarction (MI) in the human heart causes death of billions of cardiomyocytes (CMs), resulting in cardiac dysfunction that is incompatible with life or lifestyle. In order to re-muscularize injured myocardium, replacement CMs must be generated via renewed proliferation of surviving CMs. Approaches designed to induce proliferation of CMs after injury have been insufficient. Toward this end, we are targeting the Tip60 acetyltransferase, based on the rationale that its pleiotropic functions conspire to block the CM cell-cycle at several checkpoints. We previously reported that genetic depletion of Tip60 in a mouse model after MI reduces scarring, retains cardiac function, and activates the CM cell-cycle, although it is unclear whether this culminates in the generation of daughter CMs. For pre-existing CMs in the adult heart to resume proliferation, it is becoming widely accepted that they must first dedifferentiate, a process highlighted by loss of maturity, epithelial to mesenchymal transitioning (EMT), and reversion from fatty acid oxidation to glycolytic metabolism, accompanied by softening of the myocardial extracellular matrix. Findings in hematopoietic stem cells, and more recently in neural progenitor cells, have shown that Tip60 induces and maintains the differentiated state via site-specific acetylation of the histone variant H2A.Z. Here, we report that genetic depletion of Tip60 from naïve or infarcted hearts results in the near-complete absence of acetylated H2A.Z in CM nuclei, and that this is accordingly accompanied by altered gene expressions indicative of EMT induction, ECM softening, decreased fatty acid oxidation, and depressed expression of genes that regulate the TCA cycle. These findings, combined with our previous work, support the notion that because Tip60 has multiple targets that combinatorially maintain the differentiated state and inhibit proliferation, its transient therapeutic targeting to ameliorate the effects of cardiac injury should be considered.

Activated CTHRC1 promotes glycolysis in endothelial cells: Implications for metabolism and angiogenesis

CTHRC1 is transiently expressed by activated fibroblasts during tissue repair and in certain cancers, and CTHRC1 derived from osteocytes is detectable in circulation. Because its biological activity is poorly understood, we investigated whether the N terminus of CTHRC1 encodes a propeptide requiring cleavage to become activated. The effects of full-length versus cleaved recombinant CTHRC1 on endothelial cell metabolism and gene expression were examined in vitro. Respirometry was performed on Cthrc1 null and wildtype mice to obtain evidence for biological activity of CTHRC1 in vivo. Cleavage of the propeptide observed in vitro was attenuated in the presence of protease inhibitors, and cleaved CTHRC1 significantly promoted glycolysis whereas full-length CTHRC1 was less effective. The respiratory exchange ratio was significantly higher in wildtype mice compared to Cthrc1 null mice, supporting the findings of CTHRC1 promoting glycolysis in vivo. Key enzymes involved in glycolysis were significantly upregulated in endothelial cells in response to treatment with CTHRC1. In healthy human subjects, 58% of the cohort had detectable levels of circulating full-length CTHRC1, whereas all subjects with undetectable levels of full-length CTHRC1 (with one exception) had measurable levels of truncated CTHRC1 (88 pg/ml to >400 ng/ml). Our findings support a concept where CTHRC1 induction in activated fibroblasts at sites of ischemia such as tissue injury or cancer functions to increase glycolysis for ATP production under hypoxic conditions, thereby promoting cell survival and tissue repair. By promoting glycolysis under normoxic conditions, CTHRC1 may also be a contributor to the Warburg effect characteristically observed in many cancers.

CTHRC1, a novel gene with multiple functions in physiology, disease and solid tumors (Review)

Collagen triple helix repeat containing 1 (CTHRC1) is a gene discovered in 2005; it is highly conserved, and no homologous proteins have been disclosed thus far. A number of studies have shown that CTHRC1 is present in normal tissues and organs, and it has vital functions in physiological processes, including participating in the regulation of metabolism, arterial remodeling, bone formation and myelination of the peripheral nervous system. It has been reported that abnormal expression of CTHRC1 is involved in the carcinogenesis of various human organs, such as the breast, colon, pancreas, lung, stomach and liver. Therefore, the present review aims to collate all known findings and results on the regulation of CTHRC1 expression and related signaling pathways. To conclude, this review also provides a hypothesis of the functional mechanism of this gene.

Effects of CTHRC1 on odontogenic differentiation and angiogenesis in human dental pulp stem cells

Objectives

This study aimed to determine whether collagen triple helix repeat containing-1 (CTHRC1), which is involved in vascular remodeling and bone formation, can stimulate odontogenic differentiation and angiogenesis when administered to human dental pulp stem cells (hDPSCs).

Materials and Methods

The viability of hDPSCs upon exposure to CTHRC1 was assessed with the WST-1 assay. CTHRC1 doses of 5, 10, and 20 µg/mL were administered to hDPSCs. Reverse-transcription polymerase reaction was used to detect dentin sialophosphoprotein, dentin matrix protein 1, vascular endothelial growth factor, and fibroblast growth factor 2. The formation of mineralization nodules was evaluated using Alizarin red. A scratch wound assay was conducted to evaluate the effect of CTHRC1 on cell migration. Data were analyzed using 1-way analysis of variance followed by the Tukey post hoc test. The threshold for statistical significance was set at p < 0.05.

Results

CTHRC1 doses of 5, 10, and 20 µg/mL had no significant effect on the viability of hDPSCs. Mineralized nodules were formed and odontogenic markers were upregulated, indicating that CTHRC1 promoted odontogenic differentiation. Scratch wound assays demonstrated that CTHRC1 significantly enhanced the migration of hDPSCs.

Conclusions

CTHRC1 promoted odontogenic differentiation and mineralization in hDPSCs.

Elevated Levels of Plasma Collagen Triple Helix Repeat Containing 1 (CTHRC1) Is Strongly Associated with eGFR and Albuminuria in Chronic Kidney Disease

Background: Chronic kidney disease (CKD) has various etiologies, making it impossible to fully understand its complex pathophysiology. Elevated levels of plasma creatinine, proteinuria, and albuminuria and declined eGFR are traits observed in CKD patients. The current study attempts to highlight the collagen triple helix repeat containing 1 (CTHRC1) protein as a putative blood biomarker for CKD in addition to existing recognized indicators of CKD progression. Methods: A total of 26 CKD patients and 18 healthy controls were enrolled in this study. Clinical characteristics and complete blood and biochemical analyses were collected, and human ELISA kits were used to detect possible CKD biomarkers. Results: The study’s findings showed that CTHRC1 correlates with key clinical markers of kidney function such as 24 h urine total protein, creatinine, urea, and uric acid. In addition, CTHRC1 demonstrated a strong significant difference (p ≤ 0.0001) between the CKD and control group. Conclusions: Our research demonstrates that the plasma level of CTHRC1 can distinguish between those with CKD and healthy patients. Plasma CTHRC1 levels may aid in the diagnosis of CKD given the current state of knowledge, and these results call for further investigation in a wider, more diverse patient group.

Cthrc1 deficiency aggravates wound healing and promotes cardiac rupture after myocardial infarction via non-canonical WNT5A signaling pathway

Cardiac fibroblasts are crucial for scar formation and cardiac repair after myocardial infarction (MI). Collagen triple helix repeat containing 1 (CTHRC1), an extracellular matrix protein, is involved in the pathogenesis of vascular remodeling, bone formation, and tumor progression. However, the role and underlying mechanism of CTHRC1 in post-MI wound repair are not fully clear. Bioinformatics analysis demonstrated CTHRC1 up-regulation in cardiac fibroblasts after ischemic cardiac injury. Serum levels of CTHRC1 were increased in MI mice and CTHRC1 expression was up-regulated in cardiac fibroblasts after MI. In vitro results showed that the induction of CTHRC1 expression in cardiac fibroblasts was mediated by canonical TGFβ1-Smad2/3 signaling axis. Moreover, CTHRC1 improved wound healing and boosted cardiac fibroblast activation in vitro. Cthrc1 deficiency aggravated cardiac function and reduced collagen deposition as well as increased mortality attributable to cardiac rupture after MI. Consistent with above phenotypes, reduced the levels of myocardial CD31, α-smooth muscle actin, collagen I, and collagen III was observed, whereas myocardial expression of matrix metalloproteinase 2 and matrix metalloproteinase 9 were increased in Cthrc1 knockout mice post-MI. Above effects could be partly reversed by rCTHRC1 protein or rWNT5A protein. Our study indicates that cardiac fibroblast-derived, canonical TGFβ1-Smad2/3-dependent CTHRC1 could improve wound repair and prevent cardiac rupture after MI via selectively activating non-canonical WNT5A-PCP signaling pathway.

Osteoclasts: Other functions

Osteoclasts are the only cells that can efficiently resorb bone. They do so by sealing themselves on to bone and removing the mineral and organic components. Osteoclasts are essential for bone homeostasis and are involved in the development of diseases associated with decreased bone mass, like osteoporosis, or abnormal bone turnover, like Paget's disease of bone. In addition, compromise of their development or resorbing machinery is pathogenic in multiple types of osteopetrosis. However, osteoclasts also have functions other than bone resorption. Like cells of the innate immune system, they are derived from myeloid precursors and retain multiple immune cell properties. In addition, there is now strong evidence that osteoclasts regulate osteoblasts through a process known as coupling, which coordinates rates of bone resorption and bone formation during bone remodeling. In this article we review the non-resorbing functions of osteoclasts and highlight their importance in health and disease.

Molecular profile and response to energy deficit of leptin-receptor neurons in the lateral hypothalamus

Leptin exerts its effects on energy balance by inhibiting food intake and increasing energy expenditure via leptin receptors in the hypothalamus. While LepR neurons in the arcuate nucleus of the hypothalamus, the primary target of leptin, have been extensively studied, LepR neurons in other hypothalamic nuclei remain understudied. LepR neurons in the lateral hypothalamus contribute to leptin's effects on food intake and reward, but due to the low abundance of this population it has been difficult to study their molecular profile and responses to energy deficit. We here explore the transcriptome of LepR neurons in the LH and their response to energy deficit. Male LepR-Cre mice were injected in the LH with an AAV carrying Cre-dependent L10:GFP. Few weeks later the hypothalami from fed and food-restricted (24-h) mice were dissected and the TRAP protocol was performed, for the isolation of translating mRNAs from LepR cells in the LH, followed by RNA sequencing. After mapping and normalization, differential expression analysis was performed with DESeq2. We confirm that the isolated mRNA is enriched in LepR transcripts and other known neuropeptide markers of LepR^LH neurons, of which we investigate the localization patterns in the LH. We identified novel markers of LepR^LH neurons with association to energy balance and metabolic disease, such as Acvr1c, Npy1r, Itgb1, and genes that are differentially regulated by food deprivation, such as Fam46a and Rrad. Our dataset provides a reliable and extensive resource of the molecular makeup of LH LepR neurons and their response to food deprivation.

GPR180 is a component of TGFβ signalling that promotes thermogenic adipocyte function and mediates the metabolic effects of the adipocyte-secreted factor CTHRC1

Activation of thermogenic brown and beige adipocytes is considered as a strategy to improve metabolic control. Here, we identify GPR180 as a receptor regulating brown and beige adipocyte function and whole-body glucose homeostasis, whose expression in humans is associated with improved metabolic control. We demonstrate that GPR180 is not a GPCR but a component of the TGFβ signalling pathway and regulates the activity of the TGFβ receptor complex through SMAD3 phosphorylation. In addition, using genetic and pharmacological tools, we provide evidence that GPR180 is required to manifest Collagen triple helix repeat containing 1 (CTHRC1) action to regulate brown and beige adipocyte activity and glucose homeostasis. In this work, we show that CTHRC1/GPR180 signalling integrates into the TGFβ signalling as an alternative axis to fine-tune and achieve low-grade activation of the pathway to prevent pathophysiological response while contributing to control of glucose and energy metabolism.

Dynamic Evolution of the Cthrc1 Genes, a Newly Defined Collagen-Like Family

Collagen triple helix repeat containing protein 1 (Cthrc1) is a secreted glycoprotein reported to regulate collagen deposition and to be linked to the Transforming growth factor β/Bone morphogenetic protein and the Wnt/planar cell polarity pathways. It was first identified as being induced upon injury to rat arteries and was found to be highly expressed in multiple human cancer types. Here, we explore the phylogenetic and evolutionary trends of this metazoan gene family, previously studied only in vertebrates. We identify Cthrc1 orthologs in two distant cnidarian species, the sea anemone Nematostella vectensis and the hydrozoan Clytia hemisphaerica, both of which harbor multiple copies of this gene. We find that Cthrc1 clade-specific diversification occurred multiple times in cnidarians as well as in most metazoan clades where we detected this gene. Many other groups, such as arthropods and nematodes, have entirely lost this gene family. Most vertebrates display a single highly conserved gene, and we show that the sequence evolutionary rate of Cthrc1 drastically decreased within the gnathostome lineage. Interestingly, this reduction coincided with the origin of its conserved upstream neighboring gene, Frizzled 6 (FZD6), which in mice has been shown to functionally interact with Cthrc1. Structural modeling methods further reveal that the yet uncharacterized C-terminal domain of Cthrc1 is similar in structure to the globular C1q superfamily domain, also found in the C-termini of collagens VIII and X. Thus, our studies show that the Cthrc1 genes are a collagen-like family with a variable short collagen triple helix domain and a highly conserved C-terminal domain structure resembling the C1q family.

Single-Cell RNA Sequencing Analysis Reveals a Crucial Role for CTHRC1 (Collagen Triple Helix Repeat Containing 1) Cardiac Fibroblasts After Myocardial Infarction

BACKGROUND

Cardiac fibroblasts (CFs) have a central role in the ventricular remodeling process associated with different types of fibrosis. Recent studies have shown that fibroblasts do not respond homogeneously to heart injury. Because of the limited set of bona fide fibroblast markers, a proper characterization of fibroblast population heterogeneity in response to cardiac damage is lacking. The purpose of this study was to define CF heterogeneity during ventricular remodeling and the underlying mechanisms that regulate CF function.

METHODS

Collagen1α1-GFP (green fluorescent protein)-positive CFs were characterized after myocardial infarction (MI) by single-cell and bulk RNA sequencing, assay for transposase-accessible chromatin sequencing, and functional assays. Swine and patient samples were studied using bulk RNA sequencing.

RESULTS

We identified and characterized a unique CF subpopulation that emerges after MI in mice. These activated fibroblasts exhibit a clear profibrotic signature, express high levels of Cthrc1 (collagen triple helix repeat containing 1), and localize into the scar. Noncanonical transforming growth factor-β signaling and different transcription factors including SOX9 are important regulators mediating their response to cardiac injury. Absence of CTHRC1 results in pronounced lethality attributable to ventricular rupture. A population of CFs with a similar transcriptome was identified in a swine model of MI and in heart tissue from patients with MI and dilated cardiomyopathy.

CONCLUSIONS

We report CF heterogeneity and their dynamics during the course of MI and redefine the CFs that respond to cardiac injury and participate in myocardial remodeling. Our study identifies CTHRC1 as a novel regulator of the healing scar process and a target for future translational studies.

The Role of CTHRC1 in Regulation of Multiple Signaling and Tumor Progression and Metastasis

Collagen triple helix repeat containing-1 (CTHRC1) has been identified as cancer-related protein. CTHRC1 expresses mainly in adventitial fibroblasts and neointimal smooth muscle cells of balloon-injured vessels and promotes cell migration and tissue repair in response to injury. CTHRC1 plays a pivotal role in some pathophysiological processes, including increasing bone mass, preventing myelination, and reversing collagen synthesis in many tumor cells. The ascended expression of CTHRC1 is related to tumorigenesis, proliferation, invasion, and metastasis in various human malignancies, including gastric cancer, pancreatic cancer, hepatocellular carcinoma, keloid, breast cancer, colorectal cancer, epithelial ovarian cancer, esophageal squamous cell carcinoma, cervical cancer, non-small-cell lung carcinoma, and melanoma. And molecules that regulate the expression of CTHRC1 include miRNAs, lncRNAs, WAIF1, and DPAGT1. Many reports have pointed that CTHRC1 could exert different effects through several signaling pathways such as TGF-β, Wnt, integrin β/FAK, Src/FAK, MEK/ERK, PI3K/AKT/ERK, HIF-1α, and PKC-δ/ERK signaling pathways. As a participant in tissue remodeling or immune response, CTHRC1 may promote early-stage cancer. Several recent studies have identified CTHRC1 as an effectual prognostic biomarker for predicting tumor recurrence or metastasis. It is worth noting that CTHRC1 has different cellular localization and mechanisms of action in different cells and different microenvironments. In this article, we focus on the advances in the signaling pathways mediated by CTHRC1 in tumors.

CTHRC1 affects malignant tumor cell behavior and is regulated by miR-30e-5p in human prostate cancer

Collagen Triple Helix Repeat Containing 1 (CTHRC1) has been picked out as a cancer-related, secreted glycoprotein that possesses multifaceted functions such as wound repair, the formation of adipose tissue, hepatocytes fibrosis, and bone remodeling. This study aims to explore the biological function and the profound regulative mechanism of CTHRC1 in human prostate cancer (PCa). We found that CTHRC1 was upregulated in patients with PCa. The knockdown of CTHRC1 suppressed PCa cell proliferation, invasion, migration, and colony formation significantly. The expression of CTHRC1 was down-regulated and up-regulated by miR-30e-5p mimics and inhibitors, respectively, in PCa cells. The dual-luciferase reporter assay validated the binding of miR-30e-5p with CTHRC1 mRNA, indicating the regulation of CTHC1 by miR-30e-5p. In consequence, this study demonstrated that CTHRC1 acts as an oncogenic gene and targeting the miR-30e-5p-CTHRC1 axis may provide novel therapeutic treatment for PCa.

High CTHRC1 expression may be closely associated with angiogenesis and indicates poor prognosis in lung adenocarcinoma patients

Background

This study aimed to investigate the prognostic value of the potential biomarker collagen triple helix repeat containing 1 (CTHRC1) in lung adenocarcinoma (LUAD) patients.

Methods

A total of 210 LUAD patients diagnosed between 2003 and 2016 in the Department of Pathology of the First Affiliated Hospital of Sun Yat-sen University were included in this study. The expression of CTHRC1 and vascular endothelial growth factor (VEGF), and microvessel density (MVD, determined by CD34 immunostaining) were evaluated by immunohistochemistry in LUAD tissues. The association between the expression of these proteins and clinicopathological features or clinical outcomes was analyzed.

Results

Here, we confirmed that CTHRC1 expression was associated with prognosis and can serve as a significant predictor for overall survival (OS) and progression-free survival (PFS) in LUAD. Additionally, we observed that CTHRC1 expression was positively associated with tumor angiogenesis markers, such as VEGF expression (P < 0.001) and MVD (P < 0.01). Then, we performed gene set enrichment analysis (GESA) and cell experiments to confirm that enhanced CTHRC1 expression can promote VEGF levels. Based on and cox regression analysis, a predictive model that included CTHRC1, VEGF and MVD was constructed and confirmed as a more accurate independent predictor for OS (P = 0.001) and PFS (P < 0.001) in LUAD than other parameters.

Conclusions

These results demonstrated that high CTHRC1 expression may be closely related to tumor angiogenesis and poor prognosis in LUAD. The predictive model based on the CTHRC1 level and tumor angiogenesis markers can be used to predict LUAD patient prognosis more accurately.

Osteoclasts Provide Coupling Signals to Osteoblast Lineage Cells Through Multiple Mechanisms

Bone remodeling is essential for the repair and replacement of damaged and old bone. The major principle underlying this process is that osteoclast-mediated resorption of a quantum of bone is followed by osteoblast precursor recruitment; these cells differentiate to matrix-producing osteoblasts, which form new bone to replace what was resorbed. Evidence from osteopetrotic syndromes indicate that osteoclasts not only resorb bone, but also provide signals to promote bone formation. Osteoclasts act upon osteoblast lineage cells throughout their differentiation by facilitating growth factor release from resorbed matrix, producing secreted proteins and microvesicles, and expressing membrane-bound factors. These multiple mechanisms mediate the coupling of bone formation to resorption in remodeling. Additional interactions of osteoclasts with osteoblast lineage cells, including interactions with canopy and reversal cells, are required to achieve coordination between bone formation and resorption during bone remodeling.

CTHRC1 promotes M2-like macrophage recruitment and myometrial invasion in endometrial carcinoma by integrin-Akt signaling pathway

The infiltration of tumor-associated macrophages (TAMs) is associated with tumor progression and poor prognosis in endometrial cancer (EC). Collagen triple helix repeat containing 1 (CTHRC1), a secreted ECM protein, has been reported to have important roles in promoting cancer invasion and metastasis, but the functional role of CTHRC1 and its association with TAMs in EC remain unclear. Here we report that, in EC patients, CTHRC1 expression was up-regulated in endometrial cancer tissues compared with normal endometrium (P < 0.0001), and is positively correlated with tumor grade and depth of myometrial invasion (P = 0.024 and P = 0.0002, respectively). Meanwhile, CTHRC1 expression was positively correlated with an increased number of infiltrating TAMs, especially M2-like TAMs (P = 0.003, P = 0.001). In the tumor microenvironment of EC, CTHRC1 not only promoted myometrial invasion by interacting with Integrin β3-Akt signaling pathway, but also promoted infiltration of M2-like TAMs by upregulating Fractalkine chemokine receptor (CX3CR1) expression in macrophages. Changing levels of recombinant CTHRC1 protein (rCTHRC1) promoted tumor migration and invasion via enhancing macrophage recruitment in vitro. In summary, our findings eventually provided a novel role for CTHRC1 in remodeling the tumor immune microenvironment to promote tumor metastasis in EC patients.

CTHRC1 expression in primary biliary cholangitis

OBJECTIVES

Collagen triple helix repeat containing-1 (CTHRC1) is a highly conserved extracellular matrix glycoprotein that is overexpressed in two murine models of cholestatic liver fibrosis. Elevated CTHRC1 has been found to attenuate liver fibrosis in these murine models, thus we aimed to study the expression of CTHRC1 in patients with cholestatic liver diseases and its correlation with hepatic conditions.

METHODS

Ninety patients with chronic liver disease, including 48 had primary biliary cholangitis (PBC), 18 had primary sclerosing cholangitis (PSC) and 24 had chronic hepatitis B (CHB), together with five healthy controls (HC), were recruited to this study. Participants' liver sections were analyzed using immunohistochemistry. Serum CTHRC1 levels in another cohort of 59 patients with PBC and 10 age-matched HC were detected by enzyme-linked immunosorbent assay.

RESULTS

CTHRC1 protein was primarily expressed in activated hepatic stellate cells (HSC). CTHRC1 expression was significantly increased in the PBC and PSC groups, compared with the HC and CHB groups. Importantly, the hepatic fibrosis stage of the PBC group was positively correlated with hepatic CTHRC1 expression (r = 0.425, P = 0.003). Meanwhile, there were significant correlations between serum CTHRC1 levels and both the degrees of hepatic inflammation and fibrosis stage in the PBC group (r = 0.300, P = 0.022; r = 0.321, P = 0.012).

CONCLUSION

CTHRC1 may play a role in hepatic fibrogenesis in PBC and that serum CTHRC1 may be a potential novel noninvasive biomarker in the assessment of liver fibrosis and inflammation.

CTHRC1: A New Candidate Biomarker for Improved Rheumatoid Arthritis Diagnosis

Background: The purpose of this study was to determine whether plasma levels of the collagen triple helix repeat containing 1 (CTHRC1) protein can serve as a blood-based biomarker for improved diagnosis of rheumatoid arthritis (RA) patients and monitoring of RA disease activity.

Methods: We measured levels of CTHRC1 in the plasma of patients diagnosed with RA, osteoarthritis (OA), reactive arthritis (ReA), as well as in healthy individuals. We then assessed the correlation between CTHRC1 protein and a range of indices including the 28-joint disease activity score (DAS28), rheumatoid factor (RF), C-reactive protein (CRP), anti-citrullinated protein antibodies (ACPA), erythrocyte sedimentation rate (ESR), as well as a panel of cytokines, including interleukin 1 beta (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), and interferon gamma (IFNγ). Receiver operating characteristic (ROC) analysis was further performed to assess the diagnostic value of CTHRC1.

Results: CTHRC1 plasma levels were significantly elevated in RA patients compared to healthy individuals, OA and ReA patients. ROC curve and risk score analysis suggested that plasma CTHRC1 can accurately discriminate patients with RA from healthy controls and may have practical value for RA diagnosis. CTHRC1 levels were positively associated with RF, ACPA, CRP, and disease activity based on the combined index of DAS28 with CRP (DAS28-CRP), and also strongly correlated with IL-1β, IL-6, IL-8, and IFNγ.

Conclusion: Our studies show that CTHRC1 is a sensitive and easy-to-measure plasma marker that differentiates between RA and healthy status and also distinguishes between RA and other forms of arthritis, such as OA and ReA. At the current level of understanding, plasma CTHRC1 levels may improve the diagnosis of RA and these findings warrant confirmation in a larger, more comprehensive patient population.

Cthrc1 lowers pulmonary collagen associated with bleomycin-induced fibrosis and protects lung function

Idiopathic pulmonary fibrosis (IPF) involves collagen deposition that results in a progressive decline in lung function. This process involves activation of Smad2/3 by transforming growth factor (TGF)‐β and Wnt signaling pathways. Collagen Triple Helix Repeat‐Containing‐1 (Cthrc1) protein inhibits Smad2/3 activation. To test the hypothesis that Cthrc1 limits collagen deposition and the decline of lung function, Cthrc1 knockout (Cthrc1^−/−) and wild‐type mice (WT) received intratracheal injections of 2.5 U/kg bleomycin or saline. Lungs were harvested after 14 days and Bronchoalveolar lavage (BAL) TGF‐β, IL1‐β, hydroxyproline and lung compliance were assessed. TGF‐β was significantly higher in Cthrc1^−/− compared to WT (53.45 ± 6.15 ng/mL vs. 34.48 ± 11.05) after saline injection. Bleomycin injection increased TGF‐β in both Cthrc1^−/− (66.37 ± 8.54 ng/mL) and WT (63.64 ± 8.09 ng/mL). Hydroxyproline was significantly higher in Cthrc1^−/− compared to WT after bleomycin‐injection (2.676 ± 0.527 μg/mg vs. 1.889 ± 0.520, P = 0.028). Immunohistochemistry of Cthrc1^‐/‐ lung sections showed intracellular localization and activation of β‐catenin Y654 in areas of tissue remodeling that was not evident in WT. Lung compliance was significantly reduced by bleomycin in Cthrc1^−/− but there was no effect in WT animals. These data suggest Cthrc1 reduces fibrotic tissue formation in bleomycin‐induced lung fibrosis and the effect is potent enough to limit the decline in lung function. We conclude that Cthrc1 plays a protective role, limiting collagen deposition and could form the basis of a novel therapy for pulmonary fibrosis.

CTHRC1 promotes osteogenic differentiation of periodontal ligament stem cells by regulating TAZ

Collagen triple helix repeat containing 1 (CTHRC1) is associated with bone metabolism. Alveolar bone has an ability to rapidly remodel itself to adapt its biomechanical environment and function. However, whether CTHRC1 is expressed in alveolar bone tissue and the role of CTHRC1 in alveolar bone remodeling remain unclear. We used orthodontic tooth movement (OTM) rat model to study the effects of CHTRC1 in alveolar bone remodeling in vivo. We found that CTHRC1 was expressed in normal physiological condition of osteocytes, bone matrix, and periodontal ligament cells in rat. During the OTM, the expression of CTHRC1, Runx2 and TAZ were increased. We further studied the effects of CTHRC1 on osteogenic differentiation of human periodontal ligament stem cells in vitro. CTHRC1 can positively regulate the expression of TAZ and osteogenic differentiation markers like Col1, ALP, Runx2 and OCN. Overexpression of CHTRC1 increased osteogenic differentiation of PDLSCs, which could be abolished by TAZ siRNA. Our results suggest that CTHRC1 plays an important role in alveolar bone remodeling and osteogenic differentiation of PDLSCs.

Inhibition of osteoclast differentiation and collagen antibody-induced arthritis by CTHRC1

Collagen triple helix repeat-containing1 (Cthrc1) has previously been implicated in osteogenic differentiation and positive regulation of bone mass, however, the underlying mechanisms remain unclear. Here we characterized the bone phenotype of a novel Cthrc1 null mouse strain using bone histomorphometry, μCT analysis and functional readouts for bone strength. In male Cthrc1 null mice both trabecular bone as well as cortical bone formation was impaired, whereas in female Cthrc1 null mice only trabecular bone parameters were altered. Novel and highly specific monoclonal antibodies revealed that CTHRC1 is expressed by osteocytes and osteoblasts, but not osteoclasts. Furthermore, Cthrc1 null mice exhibited increased bone resorption with increased number of osteoclast and increased osteoclast activity together with enhanced expression of osteoclastogenic genes such as c-Fos, Rankl, Trap, and Nfatc1. Differentiation of bone marrow-derived monocytes isolated from Cthrc1 null mice differentiated into osteoclasts as effectively as those from wildtype mice. In the presence of CTHRC1 osteoclastogenic differentiation of bone marrow-derived monocytes was dramatically inhibited as was functional bone resorption by osteoclasts. This process was accompanied by downregulation of osteoclastogenic marker genes, indicating that extrinsically derived CTHRC1 is required for such activity. In vitro, CTHRC1 had no effect on osteogenic differentiation of bone marrow stromal cells, however, calvarial osteoblasts from Cthrc1 null mice exhibited reduced osteogenic differentiation compared to osteoblasts from wildtypes. In a collagen antibody-induced arthritis model Cthrc1 null mice suffered significantly more severe inflammation and joint destruction than wildtypes, suggesting that CTHRC1 expressed by the activated synoviocytes has anti-inflammatory effects. Mechanistically, we found that CTHRC1 inhibited NFκB activation by preventing IκBα degradation while also inhibiting ERK1/2 activation. Collectively our studies demonstrate that CTHRC1 secreted from osteocytes and osteoblasts functions as an inhibitor of osteoclast differentiation via inhibition of NFκB-dependent signaling. Furthermore, our data suggest that CTHRC1 has potent anti-inflammatory properties that limit arthritic joint destruction.

RNA-seq and metabolomic analyses of Akt1-mediated muscle growth reveals regulation of regenerative pathways and changes in the muscle secretome

Background

Skeletal muscle is a major regulator of systemic metabolism as it serves as the major site for glucose disposal and the main reservoir for amino acids. With aging, cachexia, starvation, and myositis, there is a preferential loss of fast glycolytic muscle fibers. We previously reported a mouse model in which a constitutively-active Akt transgene is induced to express in a subset of muscle groups leading to the hypertrophy of type IIb myofibers with an accompanying increase in strength. This muscle growth protects mice in various cardio-metabolic disease models, but little is known about the underlying cellular and molecular mechanisms by which fast-twitch muscle impacts disease processes and regulates distant tissues. In the present study, poly (A) + tail mRNA-seq and non-targeted metabolomics were performed to characterize the transcriptome and metabolome of the hypertrophic gastrocnemius muscle from Akt1-transgenic mice.

Results

Combined metabolomics and transcriptomic analyses revealed that Akt1-induced muscle growth mediated a metabolic shift involving reductions in glycolysis and oxidative phosphorylation, but enhanced pentose phosphate pathway activation and increased branch chain amino acid accumulation. Pathway analysis for the 4,027 differentially expressed genes in muscle identified enriched signaling pathways involving growth, cell cycle regulation, and inflammation. Consistent with a regenerative transcriptional signature, the transgenic muscle tissue was found to be comprised of fibers with centralized nuclei that are positive for embryonic myosin heavy chain. Immunohistochemical analysis also revealed the presence of inflammatory cells associated with the regenerating fibers. Signal peptide prediction analysis revealed 240 differentially expressed in muscle transcripts that potentially encode secreted proteins. A number of these secreted factors have signaling properties that are consistent with the myogenic, metabolic and cardiovascular-protective properties that have previously been associated with type IIb muscle growth.

Conclusions

This study provides the first extensive transcriptomic sequencing/metabolomics analysis for a model of fast-twitch myofiber growth. These data reveal that enhanced Akt signaling promotes the activation of pathways that are important for the production of proteins and nucleic acids. Numerous transcripts potentially encoding muscle secreted proteins were identified, indicating the importance of fast-twitch muscle in inter-tissue communication.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3548-2) contains supplementary material, which is available to authorized users.

Multidimensional Roles of Collagen Triple Helix Repeat Containing 1 (CTHRC1) in Malignant Cancers

Tumor is one of the principal diseases that seriously threaten human health. Insight into sensitive cancer markers may open a new avenue for the early diagnosis and treatment of this disease. CTHRC1 has been identified as a cancer-related gene. It is a secretory glycoprotein that possesses multidimensional roles associated with wound repair, bone remodeling, hepatocytes fibrosis, adipose tissue formation, and so on. Our previous studies and numerous reports from other researchers have revealed that the ascended expression of CTHRC1 tends to go hand in hand with tumorigenesis, proliferation, invasion and metastasis in various human malignancies through a series of molecular mechanisms and signaling pathways. However, the detailed pathogenic mechanisms of CTHRC1 overexpression in human malignant cancers are not yet clear. Here, we shall focus our description on the functions, expression profile in several representative malignant tumors and a number of molecular mechanisms and signaling pathways involved with CTHRC1. This introductory discussion of CTHRC1 will serve as a reference for further research in understanding this intriguing cancer-related protein.

Collagen triple helix repeat containing 1 is a new promigratory marker of arthritic pannus

BACKGROUND

The formation of destructive hypercellular pannus is critical to joint damage in rheumatoid arthritis (RA). The collagen triple helix repeat containing 1 (CTHRC1) protein expressed by activated stromal cells of diverse origin has previously been implicated in tissue remodeling and carcinogenesis. We recently discovered that the synovial Cthrc1 mRNA directly correlates with arthritis severity in mice. This study characterizes the role of CTHRC1 in arthritic pannus formation.

METHODS

Synovial joints of mice with collagen antibody-induced arthritis (CAIA) and human RA-fibroblast-like synoviocytes (FLS) were immunostained for CTHRC1, FLS and macrophage-specific markers. CTHRC1 levels in plasma from patients with RA were measured using sandwich ELISA. The migratory response of fibroblasts was studied with a transwell migration assay and time-lapse microscopy. Velocity and directness of cell migration was analyzed by recording the trajectories of cells treated with rhCTHRC1.

RESULTS

Immunohistochemical analysis of normal and inflamed synovium revealed highly inducible expression of CTHRC1 in arthritis (10.9-fold). At the tissue level, CTHRC1-expressing cells occupied the same niche as large fibroblast-like cells positive for α-smooth muscle actin (α-SMA) and cadherin 11 (CDH11). CTHRC1 was produced by activated FLS predominantly located at the synovial intimal lining and at the bone-pannus interface. Cultured RA-FLS expressed CDH11, α-SMA, and CTHRC1. Upon treatment with exogenous rhCTHRC1, embryonic fibroblasts and RA-FLS significantly increased migration velocity, directness, and cell length along the front-tail axis (1.4-fold, p < 0.01).

CONCLUSION

CTHRC1 was established as a novel marker of activated synoviocytes in murine experimental arthritis and RA. The pro-migratory effect of CTHRC1 on synoviocytes is considered one of the mechanisms promoting hypercellularity of the arthritic pannus.

Cthrc1 controls adipose tissue formation, body composition, and physical activity

OBJECTIVE

This study investigated the effects of loss of Cthrc1 on adipogenesis, body composition, metabolism, physical activity, and muscle physiology.

METHODS

Complete metabolic and activity monitoring as well as grip strength measurements and muscle myography was performed in Cthrc1 null and wildtype mice.

RESULTS

Compared to wildtypes, Cthrc1 null mice had similar body weights but significantly reduced energy expenditure, decreased lean mass, and increased fat mass, especially visceral fat. In vitro studies demonstrated that Cthrc1 inhibited adipocyte differentiation as well as PPAR and CREB reporter activity, while preadipocytes isolated from Cthrc1 null mice exhibited enhanced adipogenic differentiation. Voluntary physical activity in Cthrc1 null mice as assessed by wheel running was reduced to approximately half the distance covered by wildtypes. Reduced grip strength was observed in Cthrc1 null mice at the age of 15 weeks or older with reduced performance and mass of hyphenate muscle. In the brain, Cthrc1 expression was most prominent in neurons of thalamic and hypothalamic nuclei with evidence for secretion into the circulation in the median eminence.

CONCLUSIONS

Our data indicate that Cthrc1 regulates body composition through inhibition of adipogenesis. In addition, central Cthrc1 may be a mediator of muscle function and physical activity.

Hepatitis B virus hijacks CTHRC1 to evade host immunity and maintain replication

Hepatitis B virus (HBV) infection causes acute and chronic liver diseases, but is not directly cytopathic. Liver injury results from repeated attempts of the cellular immune response system to control the viral infection. Here, we investigate the roles of cellular factors and signaling pathways involved in the regulation of HBV replication to reveal the mechanism underlying HBV infection and pathogenesis. We show that collagen triple helix repeat containing 1 (CTHRC1) expression is elevated in HBV-infected patients and in HBV-transfected cells through epigenetic modification and transcriptional regulation. CTHRC1 facilitates HBV replication in cultured cells and BALB/c mice by activating the PKCα/ERK/JNK/c-Jun cascade to repress the IFN/JAK/STAT pathway. HBV-activated CTHRC1 downregulates the activity of type I interferon (IFN), the production of IFN-stimulated genes (ISGs), and the phosphorylation of signal transducer and activator of transcription 1/2 (STAT1/2), whereas it upregulates the phosphorylation and ubiquitination of type I IFN receptors (IFNARα/β). Thus, our results show that HBV uses a novel mechanism to hijack cellular factors and signal cascades in order to evade host antiviral immunity and maintain persistent infection. We also demonstrate that CTHRC1 has a novel role in viral infection.

microRNA-dependent temporal gene expression in the ureteric bud epithelium during mammalian kidney development

BACKGROUND

Our previous study on mouse mutants with the ureteric bud (UB) epithelium-specific Dicer deletion (Dicer UB mutants) demonstrated the significance of UB epithelium-derived miRNAs in UB development.

RESULTS

Our whole-genome transcriptional profiling showed that the Dicer mutant UB epithelium abnormally retained transcriptional features of the early UB epithelium and failed to express many genes associated with collecting duct differentiation. Furthermore, we identified a temporal expression pattern of early UB genes during UB epithelium development in which gene expression was detected at early developmental stages and became undetectable by embryonic day 14.5. In contrast, expression of early UB genes persisted at later stages in the Dicer mutant UB epithelium and increased at early stages. Our bioinformatic analysis of the abnormally persistently expressed early genes in the Dicer mutant UB epithelium showed significant enrichment of the let-7 family miRNA targets. We further identified a temporal expression pattern of let-7 miRNAs in the UB epithelium that is anti-parallel to that of some early UB genes during kidney development.

CONCLUSIONS

We propose a model in which the let-7 family miRNAs silence the expression of a subset of early genes in the UB epithelium at later developmental stages to promote collecting duct differentiation. Developmental Dynamics 244:444-456, 2015. © 2014 Wiley Periodicals, Inc.

Elevated plasma levels of the pituitary hormone Cthrc1 in individuals with red hair but not in patients with solid tumors

Background

An increasing number of studies report that Cthrc1 is expressed in various cancer cells. The present study sought to identify which cells in tumors and remodeling tissues express Cthrc1 and investigate the range of circulating human Cthrc1 levels in health and disease.

Methodology/Principle Findings

Highly specific monoclonal antibodies were generated to detect Cthrc1 by ELISA in plasma and in tissues by immunohistochemistry. In human colon, gastric, breast, endometrial, pancreatic, kidney, lung and skin cancer, Cthrc1 was expressed by activated stromal cells and not the cancer cells themselves. Similarly, conditions evoking tissue remodeling, such as wound repair or angiotensin II-mediated hypertension, induced Cthrc1 expression in interstitial and adventitial fibroblasts and perivascular stromal cells. Levels of Cthrc1 in plasma from healthy subjects were near the lower detection limit except for individuals with red hair, who had up to several hundred fold higher levels. Elevated Cthrc1 was also found in patients with diabetes, inflammatory conditions, and infections, but not solid tumors. Transgenic mouse studies suggested that Cthrc1 expression by stromal cells does not contribute to circulating levels. In human pituitaries, Cthrc1 was expressed in the anterior and intermediate lobes with unencapsulated Cthrc1 accumulations typically surrounded by chromophobe cells.

Conclusions

We identify Cthrc1 as a marker for activated stromal cells. Cthrc1 is a pituitary hormone with significantly elevated levels in subjects carrying variant alleles of the melanocortin-1 receptor as wells as in patients with inflammatory conditions.

miR-9 inhibits Schwann cell migration by targeting CTHRC1 following sciatic nerve injury

The regulative effects of microRNAs (miRNAs) on responses of Schwann cells to a nerve injury stimulus are not yet clear. In this study, we noted that the expression of 8 miRNAs was downregulated at different time points following rat sciatic nerve transection, and found that 368 potential targets of the 8 miRNAs were mainly involved in phenotypic modulation of Schwann cells. Out of the 8 miRNAs, miR-9 was identified as an important functional regulator of Schwann cell migration that represented a critical regenerative response of Schwann cells to nerve injury. In vitro, upregulated expression of miR-9 inhibited Schwann cell migration while silencing of miR-9 promoted Schwann cell migration. Intriguingly, miR-9 exerted this regulative function by directly targeting collagen triple helix repeat containing protein 1 (CTHRC1), which in turn inactivated downstream Rac1 GTPase. Rac1 inhibitor reduced the promotive effects of anti-miR-9 on Schwann cell migration. In vivo, high expression of miR-9 reduced Schwann cell migration within a nerve regenerative microenvironment. Collectively, our results confirmed the role of miR-9 in regulating Schwann cell migration after nerve injury, thus offering a new approach to peripheral nerve repair.

Quantitative proteomic analysis of cultured skin fibroblast cells derived from patients with triglyceride deposit cardiomyovasculopathy

Background

Triglyceride deposit cardiomyovasculopathy (TGCV) is a rare disease, characterized by the massive accumulation of triglyceride (TG) in multiple tissues, especially skeletal muscle, heart muscle and the coronary artery. TGCV is caused by mutation of adipose triglyceride lipase, which is an essential molecule for the hydrolysis of TG. TGCV is at high risk for skeletal myopathy and heart dysfunction, and therefore premature death. Development of therapeutic methods for TGCV is highly desirable. This study aims to discover specific molecules responsible for TGCV pathogenesis.

Methods

To identify differentially expressed proteins in TGCV patient cells, the stable isotope labeling with amino acids in cell culture (SILAC) method coupled with LC-MS/MS was performed using skin fibroblast cells derived from two TGCV patients and three healthy volunteers. Altered protein expression in TGCV cells was confirmed using the selected reaction monitoring (SRM) method. Microarray-based transcriptome analysis was simultaneously performed to identify changes in gene expression in TGCV cells.

Results

Using SILAC proteomics, 4033 proteins were quantified, 53 of which showed significantly altered expression in both TGCV patient cells. Twenty altered proteins were chosen and confirmed using SRM. SRM analysis successfully quantified 14 proteins, 13 of which showed the same trend as SILAC proteomics. The altered protein expression data set was used in Ingenuity Pathway Analysis (IPA), and significant networks were identified. Several of these proteins have been previously implicated in lipid metabolism, while others represent new therapeutic targets or markers for TGCV. Microarray analysis quantified 20743 transcripts, and 252 genes showed significantly altered expression in both TGCV patient cells. Ten altered genes were chosen, 9 of which were successfully confirmed using quantitative RT-PCR. Biological networks of altered genes were analyzed using an IPA search.

Conclusions

We performed the SILAC- and SRM-based identification-through-confirmation study using skin fibroblast cells derived from TGCV patients, and first identified altered proteins specific for TGCV. Microarray analysis also identified changes in gene expression. The functional networks of the altered proteins and genes are discussed. Our findings will be exploited to elucidate the pathogenesis of TGCV and discover clinically relevant molecules for TGCV in the near future.