Profibrotic Inflammatory Cytokines and Growth Factors Are Predicted as the Key Targets of Uncaria gambir (Hunter) Roxb. in Keloids: An Epistatic and Molecular Simulation Approach.

Keloid is characterized as the fibrotic tissue resulting from the increase of fibroblast activity. Uncaria gambir (Hunter) Roxb. possesses bioactive compounds that have potential as antifibrotic agents, while the mechanism of action in keloid has not yet been elucidated. The aim of this study was to investigate the interaction of gambir bioactive compounds with keloid target proteins using an epistatic and molecular simulation approach. The known bioactive compounds of gambir targets and keloid-related protein targets were screened using databases. The network was constructed and analyzed to obtain the core protein targets. The targets were enriched to describe the Gene Ontology (GO) and pathway related to the proteins. Eleven targets were defined as the main targets of gambir bioactive compounds related to keloid disease. Gambiriin C, Isogambirine, and Procyanidin B1 were identified as the most promising compounds with the highest binding energy to transforming growth factor beta 1 (TGFß1), AKT serine/threonine kinase 1 (AKT1), and matrix metallopeptidase 1 (MMP1) as the target proteins. GO enrichment and pathway analysis found that gambir bioactive compounds may act on keloid-related target proteins to regulate cell proliferation, migration, transcription, and signal transduction activity via profibrotic cytokine and growth factor signaling pathways. This study provides a reference for potential targets, compounds, and pathways to explain the mechanism of gambir against keloid.

Role of Hypoxia Inducible Factor-1 Alpha (HIF-1α) in Cytoglobin Expression and Fibroblast Proliferation of Keloids.

BACKGROUND: Keloids are characterized by an overabundance of collagen deposition due to elevated activity and proliferation of fibroblasts, which lead to hypoxic conditions. Adaptation to these conditions is regulated by the transcription factor hypoxia inducible factor-1α (HIF-1α). Cytoglobin (Cygb), a reactive oxygen species scavenger, is a target gene of HIF-1α. In our previous study, we showed that Cygb expression in keloid tissue was correlated with HIF-1α expression. However, whether HIF-1α regulates Cygb expression and the proliferation of keloid fibroblasts remained unclear. Therefore, this study aimed to determine the role of HIF-1α in Cygb expression and fibroblast proliferation of keloids. METHODS: This was an in vitro study using a primary culture of keloid fibroblasts in which ibuprofen was used to inhibit HIF-1α expression. The expression of HIF-1α and Cygb mRNA were analyzed using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) methods, and their protein levels were analyzed using an enzyme-linked immunosorbent assay (ELISA). Fibroblast proliferation was analyzed using a Trypan blue exclusion assay. RESULTS: Inhibition of HIF-1α by ibuprofen decreased Cygb mRNA expression but not in all the samples, followed by a decrease in the protein level of Cygb. There was a positive correlation between the HIF-1α protein and Cygb mRNA, probably due to the regulation of Cygb by HIF-1α at the mRNA level, but not the protein level. The proliferation of keloid fibroblasts was significantly decreased and positively correlated with the HIF-1α protein. CONCLUSION: HIF-1α regulates Cygb expression and fibroblast proliferation in keloids.

Metabolic Interplay between Tumour Cells and Cancer-Associated Fibroblasts (CAFs) under Hypoxia versus Normoxia.

The growth of tumour cells is closely related to cancer-associated fibroblasts (CAFs) present within their microenvironment. CAFs, the most abundant cells in tumour stroma, secrete growth factors that play pivotal roles in tumour cell proliferation, metabolism, angiogenesis and metastasis. Tumour cells adapt to rapid environmental changes from normoxia to hypoxia through metabolic interplay with CAFs. In this mini review, we discuss the role of lactate dehydrogenases (LDHs) and monocarboxylate transporters (MCTs) on the metabolic interplay between tumour cells and CAFs under hypoxia compared to normoxia. The LDHs catalyse the interchange of lactate and pyruvate, whereas MCTs facilitate the influx and efflux of monocarboxylates, especially lactate and pyruvate. To sum up, tumour cells switch their metabolic state between glycolysis and oxidative phosphorylation through metabolic interplay with CAFs, which exhibit the Warburg effect under hypoxia and reverse Warburg effect under normoxia.