Insight into the function of tetranectin in human diseases: A review and prospects for tetranectin-targeted disease treatment

Tetranectin (TN), a serum protein, is closely associated with different types of cancers. TN binds plasminogen and promotes the proteolytic activation of plasminogen into plasmin, which suggests that TN is involved in remodeling the extracellular matrix and cancer tissues during cancer development. TN is also associated with other diseases, such as developmental disorders, cardiovascular diseases, neurological diseases, inflammation, and diabetes. Although the functional mechanism of TN in diseases is not fully elucidated, TN binds different proteins, such as structural protein, a growth factor, and a transcription regulator. Moreover, TN changes and regulates protein functions, indicating that TN-binding proteins mediate the association between TN and diseases. This review summarizes the current knowledge of TN-associated diseases and TN functions with TN-binding proteins in different diseases. In addition, potential TN-targeted disease treatment by inhibiting the interaction between TN and its binding proteins is discussed.

Tetranectin as a potential novel prognostic biomarker in anthracycline-related cardiac dysfunction

To assess the association of serum tetranectin levels with cardiac remodeling parameters and to evaluate its prognostic role in women with anthracycline-related cardiac dysfunction (ARCD) and without previous cardiovascular diseases (CVD) during 24-month follow-up period. A total of 362 women with primary diagnosed breast cancer who were planned to be treated with anthracyclines were examined. At 12 months after chemotherapy completion, all women were examined and ARCD was diagnosed in 114 patients. After 24 months of follow-up, all patients with ARCD were divided into 2 groups: group 1 comprised women with the adverse course of ARCD (n = 54), group 2 comprised those without it (n = 60). In group 1, the levels of tetranectin were lower than group 2 by 27.6% (p < 0.001) and the patients without ARCD by 33.7% (p < 0.001). In group 1, the levels of tetranectin decreased (p < 0.001) from 11.8 (7.1; 14.3) to 9.02 (5.3; 14.6) pg/mL at 24 months. Moreover, in group 2 (p = 0.871) and in patients without ARCD (p = 0.716), they did not change. The tetranectin values were the independent predictor (odds ratio 7.08; p < 0.001) and its levels ≤ 15/9 ng/mL (AUC = 0.764; p < 0.001) were identified as the predictors for the adverse course of ARCD. NT-proBNP levels did not show the prognostic role, but the addition of NT-proBNP improved prognostic value of analysis (AUC = 0.954; p = 0.002). The cut-off values of tetranectin were established as predictor for adverse course of ARCD, when NT-proBNP was not. The combined use of tetranectin and NT-proBNP demonstrated higher diagnostic value for prediction of adverse outcomes.

Discovery and validation of a protein biomarker for the diagnosis and classification of disease severity of major depressive disorder

BACKGROUND AND AIMS

Diagnosis and classification of disease severity of major depressive disorder (MDD) are determined through a doctor's consultation and questionnaire-based rating scale. This study aimed to identify and validate a serum protein biomarker for diagnosing and classifying the disease severity of MDD.

MATERIALS AND METHODS

Based on the Hamilton Depression Rating Scale (HAMD) score, participants were divided into control, mild, moderate, and severe groups. Samples prepared from collected sera were analyzed using non-targeted qualitative and targeted quantitative tools to identify potential biomarkers.

RESULTS

Four proteins were selected as biomarker candidates, which showed statistically significant consistent tendencies depending on MDD severity. Among them, tetranectin was the only validated protein in the quantitative analysis that showed the same decreasing tendency as that in the qualitative analysis. Furthermore, tetranectin showed fair discrimination performance between the control and MDD group.

CONCLUSIONS

Tetranectin may be a novel potential biomarker for diagnosing and classifying the severity of MDD, though further verification and validation studies of its efficacy are needed.

Quantitative proteomics analysis of COVID-19 patients: Fetuin-A and tetranectin as potential modulators of innate immune responses

Treatment of severe cases of coronavirus disease 2019 (COVID-19) is extremely important to minimize death and end-organ damage. Here we performed a proteomic analysis of plasma samples from mild, moderate and severe COVID-19 patients. Analysis revealed differentially expressed proteins and different therapeutic potential targets related to innate immune responses such as fetuin-A, tetranectin (TN) and paraoxonase-1 (PON1). Furthermore, protein changes in plasma showed dysregulation of complement and coagulation cascades in COVID-19 patients compared to healthy controls. In conclusion, our proteomics data suggested fetuin-A and TN as potential targets that might be used for diagnosis as well as signatures for a better understanding of the pathogenesis of COVID-19 disease.

Identification of novel inhibitors of tetranectin-plasminogen interaction to suppress breast cancer invasion: an integrated computational and cell-based investigation

Tetranectin-plasminogen interaction plays a defining role in extracellular matrix degradation, enabling tumor cell invasion and metastasis. This interaction occurs via the carbohydrate recognition domain (CRD) and Kringle 4 domain of tetranectin and plasminogen, respectively, leading to activation of the plasminogen-cascade that triggers the proteolytic processes. Thus targeting this interaction represents an important strategy to suppress tumor cell migration and invasion. In this direction, we attempted to target the CRD of tetranectin to inhibit its interaction with the Kringle-4 domain of plasminogen using natural bioactive compounds. A cheminformatics pipeline for drug designing and screening was utilized to obtain lead compound(s) that exhibit conformationally and energetically viable CRD binding. Out of 206 compounds screened, diosgenin and scytonemin displayed the most favorable interactions with CRD. Short-term molecular dynamics simulations of 20 ns were employed to further study the conformational stability of both compounds with tetranectin CRD which reflected at the increased stability of diosgenin in the CRD binding pocket compared to scytonemin. Finally, an extended molecular dynamic simulation of 100 ns affirmed the robust and stable interaction of diosgenin with CRD. Furthermore, diosgenin was observed to exert a pronounced anti-proliferative effect on high tetranectin-expressing MDA-MB-231 breast cancer cells. The inhibitory effect of diosgenin on the tetranectin-plasminogen interaction was corroborated by the reduced migration and invasiveness of MDA-MB-231 cells under diosgenin treatment. Overall the study presents an alternate and safer approach to impede breast cancer metastasis and delineates the novel anti-metastatic activity of diosgenin.Communicated by Ramaswamy H. Sarma.

Exogenous Tetranectin Alleviates Pre-formed-fibrils-induced Synucleinopathies in SH-SY5Y Cells by Activating the Plasminogen Activation System

Parkinson's disease (PD) is a common neurodegenerative disease. Previously we identified tetranectin (TN) as a differentially expressed protein in the cerebrospinal fluid of PD patients, and we were surprised to find that TN knockout mice developed PD features. However, the specific role of TN in PD has not been clarified. In this study, we aimed to determine the effect of exogenous TN on cellular PD models and elucidate the underlying mechanisms. We found that exogenous TN could alleviate pre-formed-fibrils (PFFs)-induced synucleinopathies in SH-SY5Y cells and reduce the cell-to-cell transmission of α-synuclein (SYN). We also found that TN can promote the degradation of SYN by plasmin, which may account for its effect on cellular PD models. Moreover, administration of SYN/PFFs decreased the expression of TN and increased the expression of plasminogen activator inhibitor-1 (PAI-1) in SH-SY5Y cells, thereby reducing plasmin activity. Our findings depict a possible SYN-TN-plasmin interaction in which elevated levels of extracellular SYN monomers and aggregates in PD diminish the production of TN and PAI-1. Such changes lead to a reduced plasmin activity, which in turn reduces the degradation of extracellular SYN, thus forming a vicious cycle.

Tetranectin targeting by epigallocatechin gallate suppresses colon cancer cell proliferation

Tetranectin is a serum protein that binds to plasminogen and enhances its proteolytic activation, which underlies the involvement of tetranectin in the development of several carcinomas including colon cancer. In the present study, structure-based in silico screening of natural products showed that epigallocatechin gallate with anticancer effects binds to tetranectin. Binding to epigallocatechin gallate to tetranectin was confirmed by intrinsic fluorescence quenching assays and isothermal titration calorimetry. Furthermore, epigallocatechin gallate efficiently inhibited the activity of tetranectin to enhance the activation of plasminogen. We also found that tetranectin enhanced the proliferation of CT-26 colon cancer cells. Epigallocatechin gallate showed its cytotoxic effect on CT-26 cells due to its binding to tetranectin and the consequent suppression of the cell proliferation. These results demonstrate that the anticancer effect of epigallocatechin gallate is mediated, at least in part, by inhibiting tetranectin as a binding target.

Adipogenic function of mouse tetranectin and identification of its functional domain

Tetranectin (TN), a plasminogen (Plg) binding protein, enhances the Plg activator (PA)-catalyzed activation of Plg to plasmin (Pln). Previously, TN was identified as an adipogenic serum protein, which promotes adipocyte differentiation. In the present study, we investigated the adipogenic function of mouse TN using recombinant proteins (rmTNs) in full-length and domain-truncated forms. Adipocyte differentiation in TN-depleted-FBS-media was significantly enhanced by rmTNs supplementation. The adipogenic effect of rmTNs was found to be dependent on the presence of a Plg binding domain, indicating the domain is essential for the adipogenic function of mTN. In addition, these results suggested the involvement of Plg activation, however Plg, PA and Pln appeared to have no direct effect on adipocyte differentiation. This study demonstrates the adipogenic function of mTN, which is dependent on the Plg binding domain as its functional domain.

High Intratumoral Expression of Tetranectin Associates with Poor Prognosis of Patients with Gastric Cancer after Gastrectomy

Tetranectin, encoded by the clec3b gene, is a plasminogen kringle-4 binding protein that can be detected in the plasma and the extracellular matrix. In malignancies, tetranectin is thought to enhance proteolytic processes enabling tumor cells to invade and metastasize. Nevertheless, the prognostic value of tetranectin in gastric cancer remains elusive. In this study, we found the expression of tetranectin was decreased in gastric cancer. High intratumoral tetranectin level was positively associated with tumor invasion (P = 0.013), lymph node metastasis (P = 0.005), advanced TNM stage (P = 0.003) and shorter overall survival (OS) (P < 0.001) for patients with gastric cancer. Tetranectin expression was identified as an independent prognostic factor for poor OS, and combining tetranectin expression with other independent prognostic factors generated a predictive nomogram, which showed better prognostic efficiency for OS in patients with gastric cancer. In summary, our study suggests that intratumoral tetranectin is a potential independent unfavorable prognostic biomarker for OS of patients with gastric cancer after gastrectomy.

Identification of tetranectin as adipogenic serum protein

Fetal bovine serum (FBS) is an essential culture supplement for adipocyte differentiation of various adipogenic precursor cells. Adipocyte differentiation greatly varies depending on the type of serum in the differentiation medium. In this study, we found that FBS supported adipocyte differentiation of 3T3-L1 cells to a significantly higher extent than other types of bovine serum such as adult bovine serum (ABS). This differential adipogenic effect of bovine serum was shown to be due to the protein contents of bovine sera, indicating the presence of an adipogenic protein(s) in FBS. Serum proteome analysis identified tetranectin as an adipogenic protein. The adipogenic effect of tetranectin was confirmed by supplementation of FBS-containing differentiation medium with anti-tetranectin antibody, which suppressed adipocyte differentiation of 3T3-L1 cells. These results demonstrate that tetranectin is an adipogenic serum protein mediating the adipogenic effect of FBS.