Cthrc1 is a negative regulator of myelination in Schwann cells

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.

Sox2ot /miR-9 /Cthrc1 Promote Proliferation and Migration of Schwann Cells Following Nerve Injury

The effects of traditional treatments for peripheral nerve injury (PNI) are not ideal, which has prompted the identification of new therapeutic strategies. As unique glial cells in the peripheral nervous system, Schwann cells (SCs) play an important role in the repair of PNI. Recent studies have demonstrated that long noncoding RNAs (lncRNAs) are involved in the regulation of nerve repair after PNI. In this study, we used microarray technology to detect mRNA and lncRNA expression profiles at different time points after PNI and identified lncRNA Sox2ot-miR-9-Cthrc1 as a competitive endogenous RNA (ceRNA) for further investigation. Expression of lncRNA Sox2ot was increased after PNI, and overexpression of Sox2ot promoted SCs migration and proliferation. Mechanistic analyses confirmed that Sox2ot can regulate the expression of Cthrc1 through competitive adsorption of miR-9 in SCs, ultimately affecting SCs migration and proliferation. Our findings reveal the key role of lncRNA Sox2ot in nerve regeneration and provide a new direction for PNI treatment.

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.

Mechanisms of Schwann cell plasticity involved in peripheral nerve repair after injury

The great plasticity of Schwann cells (SCs), the myelinating glia of the peripheral nervous system (PNS), is a critical feature in the context of peripheral nerve regeneration following traumatic injuries and peripheral neuropathies. After a nerve damage, SCs are rapidly activated by injury-induced signals and respond by entering the repair program. During the repair program, SCs undergo dynamic cell reprogramming and morphogenic changes aimed at promoting nerve regeneration and functional recovery. SCs convert into a repair phenotype, activate negative regulators of myelination and demyelinate the damaged nerve. Moreover, they express many genes typical of their immature state as well as numerous de-novo genes. These genes modulate and drive the regeneration process by promoting neuronal survival, damaged axon disintegration, myelin clearance, axonal regrowth and guidance to their former target, and by finally remyelinating the regenerated axon. Many signaling pathways, transcriptional regulators and epigenetic mechanisms regulate these events. In this review, we discuss the main steps of the repair program with a particular focus on the molecular mechanisms that regulate SC plasticity following peripheral nerve injury.

Role of collagen triple helix repeat containing-1 in tumor and inflammatory diseases

Initially, collagen triple helix repeat containing-1 (CTHRC1) is expressed mainly in adventitial fibroblasts and neointimal smooth muscle cells of balloon-injured vessels, and increases cell migration, promotes tissue repair in response to injury. A variety of studies demonstrated that over-expression of CTHRC1 in solid tumors results in enhancement of migration and invasion of tumor cells, and is associated with decreased overall survival and disease-free survival. CTHRC1 expression is elevated in hepatitis B virus-infected patients and highly correlated with hepatocellular carcinoma progression as well. Furthermore, CTHRC1 plays a pivotal role in a great many fields, including increases bone mass, prevents myelination, reverses collagen synthesis in keloid fibroblasts, and increases fibroblast-like synoviocytes migration speed and abundant production of arthritic pannus in rheumatoid arthritis. Therefore, it will provide new insight into the pathogenesis of tumor and autoimmune diseases, and will shed new light on the therapy of related clinical diseases.

Molecular Mechanisms Involved in Schwann Cell Plasticity

Schwann cell incredible plasticity is a hallmark of the utmost importance following nerve damage or in demyelinating neuropathies. After injury, Schwann cells undergo dedifferentiation before redifferentiating to promote nerve regeneration and complete functional recovery. This review updates and discusses the molecular mechanisms involved in the negative regulation of myelination as well as in the reprogramming of Schwann cells taking place early following nerve lesion to support repair. Significant advance has been made on signaling pathways and molecular components that regulate SC regenerative properties. These include for instance transcriptional regulators such as c-Jun or Notch, the MAPK and the Nrg1/ErbB2/3 pathways. This comprehensive overview ends with some therapeutical applications targeting factors that control Schwann cell plasticity and highlights the need to carefully modulate and balance this capacity to drive nerve repair.

Transcriptional inhibition in Schwann cell development and nerve regeneration

Schwann cells, the myelinating glial cells of the peripheral nervous system are remarkably plastic after nerve trauma. Their transdifferentiation into specialized repair cells after injury shares some features with their development from the neural crest. Both processes are governed by a tightly regulated balance between activators and inhibitors to ensure timely lineage progression and allow re-maturation after nerve injury. Functional recovery after injury is very successful in rodents, however, in humans, lack of regeneration after nerve trauma and loss of function as the result of peripheral neuropathies represents a significant problem. Our understanding of the basic molecular machinery underlying Schwann cell maturation and plasticity has made significant progress in recent years and novel players have been discovered. While the transcriptional activators of Schwann cell development and nerve repair have been well defined, the mechanisms counteracting negative regulation of (re-)myelination are less well understood. Recently, transcriptional inhibition has emerged as a new regulatory mechanism in Schwann cell development and nerve repair. This mini-review summarizes some of the regulatory mechanisms controlling both processes and the novel concept of “inhibiting the inhibitors” in the context of Schwann cell plasticity.

Long non-coding RNA NONMMUG014387 promotes Schwann cell proliferation after peripheral nerve injury

Schwann cells play a critical role in peripheral nerve regeneration through dedifferentiation and proliferation. In a previous study, we performed microarray analysis of the sciatic nerve after injury. Accordingly, we predicted that long non-coding RNA NONMMUG014387 may promote Schwann cell proliferation after peripheral nerve injury, as bioinformatic analysis revealed that the target gene of NONMMUG014387 was collagen triple helix repeat containing 1 (Cthrc1). Cthrc1 may promote cell proliferation in a variety of cells by activating Wnt/PCP signaling. Nonetheless, bioinformatic analysis still needs to be verified by biological experiment. In this study, the candidate long non-coding RNA, NONMMUG014387, was overexpressed in mouse Schwann cells by recombinant adenovirus transfection. Plasmid pHBAd-MCMV-GFP-NONMMUG014387 and pHBAd-MCMV-GFP were transfected into Schwann cells. Schwann cells were divided into three groups: control (Schwann cells without intervention), Ad-GFP (Schwann cells with GFP overexpression), and Ad-NONMMUGO148387 (Schwann cells with GFP and NONMMUGO148387 overexpression). Cell Counting Kit-8 assay was used to evaluate proliferative capability of mouse Schwann cells after NONMMUG014387 overexpression. Polymerase chain reaction and western blot assay were performed to investigate target genes and downstream pathways of NONMMUG014387. Cell proliferation was significantly increased in Schwann cells overexpressing lncRNA NONMMUG014387 compared with the other two groups. Further, compared with the control group, mRNA and protein levels of Cthrc1, Wnt5a, ROR2, RhoA, Rac1, JNK, and ROCK were visibly up-regulated in the Ad-NONMMUGO148387 group. Our findings confirm that long non-coding RNA NONMMUG014387 can promote proliferation of Schwann cells surrounding the injury site through targeting Cthrc1 and activating the Wnt/PCP pathway.

Comparative analysis of ear-hole closure identifies epimorphic regeneration as a discrete trait in mammals

Why mammals have poor regenerative ability has remained a long-standing question in biology. In regenerating vertebrates, injury can induce a process known as epimorphic regeneration to replace damaged structures. Using a 4-mm ear punch assay across multiple mammalian species, here we show that several Acomys spp. (spiny mice) and Oryctolagus cuniculus completely regenerate tissue, whereas other rodents including MRL/MpJ 'healer' mice heal similar injuries by scarring. We demonstrate ear-hole closure is independent of ear size, and closure rate can be modelled with a cubic function. Cellular and genetic analyses reveal that injury induces blastema formation in Acomys cahirinus. Despite cell cycle re-entry in Mus musculus and A. cahirinus, efficient cell cycle progression and proliferation only occurs in spiny mice. Together, our data unite blastema-mediated regeneration in spiny mice with regeneration in other vertebrates such as salamanders, newts and zebrafish, where all healthy adults regenerate in response to injury.

SPARCL1 is a novel predictor of tumor recurrence and survival in hilar cholangiocarcinoma

Secreted protein acidic and rich in cysteines-like protein 1 (SPARCL1) has been implicated in tumor initiation, formation, and progression of various cancers, yet its role in hilar cholangiocarcinoma remains largely uncharacterized. In the present study, tissue microarrays containing resected hilar cholangiocarcinoma specimens from 92 patients were used to evaluate the expression of SPARCL1 protein by immunohistochemistry (IHC). In vitro assays were used to determine the effect of SPARCL1 overexpression on cell growth and migration. Loss of SPARCL1 expression was observed in 46 (50.0 %) of the 92 primary tumors. SPARCL1 expression is inversely associated with poorly or undifferentiation specimens (P = 0.030) in addition to lymph node metastasis (P = 0.047). Survival analysis demonstrated that SPARCL1 is an independent factor in predicting the outcome of patients with hilar cholangiocarcinoma. SPARCL1 overexpression suppressed tumor cell migration in vitro by inhibiting MMP-9, MMP-2, Vimentin, and Fibronectin expression, whereas did not inhibit cell proliferation in vitro. Our results suggest that loss of SPARCL1 is involved in the tumorigenesis of hilar cholangiocarcinoma and may serve as a novel molecular biomarker for patients' outcome.