The Role of Tissue Inhibitors of Metalloproteinases in Organ Development and Regulation of ADAMTS Family Metalloproteinases in Caenorhabditis elegans

TIMP-1 and its potential diagnostic and prognostic value in pulmonary diseases

Tissue inhibitors of metalloproteases (TIMPs) have caught the attention of many scientists due to their role in various physiological and pathological processes. TIMP-1, 2, 3, and 4 are known members of the TIMPs family. TIMPs exert their biological effects by, but are not limited to, inhibiting the activity of metalloproteases (MMPs). The balance between MMPs and TIMPs is critical for maintaining homeostasis of the extracellular matrix (ECM), while the imbalance between MMPs and TIMPs can lead to pathological changes, such as cancer. In this review, we summarized the current knowledge of TIMP-1 in several pulmonary diseases namely, acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), pneumonia, asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis, and pulmonary fibrosis. Considering the potential of TIMP-1 serving as a non-invasive diagnostic and/or prognostic biomarker, we also reviewed the circulating TIMP-1 levels in translational and clinical studies.

MMPs, ADAMs and ADAMTSs are associated with mammalian sperm fate

Metalloproteinases include matrix metalloproteinases and disintegrin metalloproteinases. They are important members of the ECM degradation and reconstruction process and are associated with tissue development and disease. The ECM is a three-dimensional network of large molecules consisting of a variety of proteins. It is a physical scaffold for organs, and all types of cells can be found within the ECM. The testicle, where sperm are produced, is an organ that is constantly in dynamic flux. Metalloproteinases can regulate testicular tissue development and the maturation of sperm by affecting the ECM. Metalloproteinase disorders can lead to cryptorchidism, azoospermia, poor semen quality and other diseases. As a member of the metalloproteinase family, ADAMTS plays an important role in testicular slippage to the scrotum. ADAM is involved in the fertilization process, and excessive MMP can damage the BTB. In the testis, metalloproteinase stability represents the stability of the extracellular microenvironment in which germ cells are located and is associated with reproductive function. Metalloproteinases have a definite relationship with male reproduction, but the underlying mechanism is still unclear. This paper summarizes the literature on various metalloproteinases in testicular tissue physiology and pathology to elucidate their role in reproductive function and male reproductive mechanisms.

Plasma TIMP-1 as a sex-specific biomarker for acute lung injury

BACKGROUND

Acute respiratory distress syndrome (ARDS) confers high morbidity and mortality, with a death rate reaching 40%. Pre-clinical and clinical studies have cited sex-specific sex hormones as a critical contributor to divergent immunologic responses. Therefore, exploration of sex and sex hormone roles following lung injury and ARDS development is needed. Tissue inhibitor of metalloproteinase-1 (TIMP-1) was the first-discovered natural collagenase inhibitor and is located exclusively on the X chromosome. This study aimed to evaluate the prognostic role of circulating TIMP-1, and if concentration differences between males and females correlate with the mortality of ARDS patients.

METHODS

Human plasma samples from 100 ARDS patients enrolled in Albuterol to Treat Acute Lung Injury (ALTA) trial on the day of randomization were evaluated. The amount of TIMP-1 was measured using an enzyme-linked immunoassay (ELISA). Area under the receiver operating characteristic (AUROC) was computed to assess the predictive power of TIMP-1 for 30 and 90-day mortality. Chi-squared tests and Kaplan-Meier curves were computed to assess different variables and survival.

RESULTS

AUROC analysis of TIMP-1 and 30-day mortality among females showed that TIMP-1 exhibited an AUC of 0.87 (95% confidence interval [CI] 0.78 to 0.97; P = 0.0014) with an optimal cut-off value of 159.7 ng/mL producing a 100% sensitivity and 74% specificity. For 90-day mortality, AUROC analysis showed an AUC of 0.82 (95% confidence interval [CI] 0.67 to 0.97; P = 0.0016) with a similar cut-off value producing a 90% sensitivity and 76.47% specificity. Stratifying subjects by TIMP-1 concentration as high (≥ 159.7 ng/mL) or low (< 159.7 ng/mL) indicated that high TIMP-1 was associated with increased 30 and 90-day mortality rates (all P < 0.0001). Lastly, high TIMP-1 group was associated with worse other outcomes including ventilator-free days (VFDs) and ICU-free days (all P < 0.05).

CONCLUSION

Circulating TIMP-1 appeared to be a promising biomarker for mortality among females with ARDS. The high TIMP-1 group showed worse VFDs and ICU-free days. Circulating TIMP-1 may be a sex-specific biomarker in the setting of ARDS and could improve ARDS phenotyping as well as provide a novel therapeutic target in females.

Proteolysis in Reproduction: Lessons From Gene-Modified Organism Studies

The physiological roles of proteolysis are not limited to degrading unnecessary proteins. Proteolysis plays pivotal roles in various biological processes through cleaving peptide bonds to activate and inactivate proteins including enzymes, transcription factors, and receptors. As a wide range of cellular processes is regulated by proteolysis, abnormalities or dysregulation of such proteolytic processes therefore often cause diseases. Recent genetic studies have clarified the inclusion of proteases and protease inhibitors in various reproductive processes such as development of gonads, generation and activation of gametes, and physical interaction between gametes in various species including yeast, animals, and plants. Such studies not only clarify proteolysis-related factors but the biological processes regulated by proteolysis for successful reproduction. Here the physiological roles of proteases and proteolysis in reproduction will be reviewed based on findings using gene-modified organisms.

Ligand-Receptor Interactions Elucidate Sex-Specific Pathways in the Trajectory From Primordial Germ Cells to Gonia During Human Development

The human germ cell lineage originates from primordial germ cells (PGCs), which are specified at approximately the third week of development. Our understanding of the signaling pathways that control this event has significantly increased in recent years and that has enabled the generation of PGC-like cells (PGCLCs) from pluripotent stem cells in vitro. However, the signaling pathways that drive the transition of PGCs into gonia (prospermatogonia in males or premeiotic oogonia in females) remain unclear, and we are presently unable to mimic this step in vitro in the absence of gonadal tissue. Therefore, we have analyzed single-cell transcriptomics data of human fetal gonads to map the molecular interactions during the sex-specific transition from PGCs to gonia. The CellPhoneDB algorithm was used to identify significant ligand–receptor interactions between germ cells and their sex-specific neighboring gonadal somatic cells, focusing on four major signaling pathways WNT, NOTCH, TGFβ/BMP, and receptor tyrosine kinases (RTK). Subsequently, the expression and intracellular localization of key effectors for these pathways were validated in human fetal gonads by immunostaining. This approach provided a systematic analysis of the signaling environment in developing human gonads and revealed sex-specific signaling pathways during human premeiotic germ cell development. This work serves as a foundation to understand the transition from PGCs to premeiotic oogonia or prospermatogonia and identifies sex-specific signaling pathways that are of interest in the step-by-step reconstitution of human gametogenesis in vitro.

Extracellular Matrix: Emerging Roles and Potential Therapeutic Targets for Breast Cancer

Increasing evidence shows that the extracellular matrix (ECM) is an important regulator of breast cancer (BC). The ECM comprises of highly variable and dynamic components. Compared with normal breast tissue under homeostasis, the ECM undergoes many changes in composition and organization during BC progression. Induced ECM proteins, including fibrinogen, fibronectin, hyaluronic acid, and matricellular proteins, have been identified as important components of BC metastatic cells in recent years. These proteins play major roles in BC progression, invasion, and metastasis. Importantly, several specific ECM molecules, receptors, and remodeling enzymes are involved in promoting resistance to therapeutic intervention. Additional analysis of these ECM proteins and their downstream signaling pathways may reveal promising therapeutic targets against BC. These potential drug targets may be combined with new nanoparticle technologies. This review summarizes recent advances in functional nanoparticles that target the ECM to treat BC. Accurate nanomaterials may offer a new approach to BC treatment.