Chlorella Hot Water Extract Restores Collagen Production in Senescent Fibroblasts Through Reversal of miR-193a-5p-Mediated Translational Repression of COL1A1

Background: Cellular senescence is accompanied by mitochondrial dysfunction and decline in type I collagen production, contributing to age-related tissue deterioration. However, the post-transcriptional mechanisms underlying senescence-associated collagen decline remain poorly understood. Methods: Here, we investigated the effects of chlorella hot water extract (CHWE) on mitochondrial function and collagen production in senescent human fibroblasts. Results: CHWE restored mitochondrial membrane potential, ATP production, and redox balance through upregulation of SOD2. Notably, CHWE increased collagen protein levels without altering COL1A1 mRNA, indicating post-transcriptional regulation. miRNA profiling across young, senescent, and CHWE-treated senescent fibroblasts revealed that miR-193a-5p was upregulated during senescence (1.73-fold) and normalized by CHWE treatment. Functional validation confirmed that miR-193a-5p mimic suppressed COL1A1 protein. These findings identify a senescence–miR-193a-5p–COL1A1 axis in which age-dependent miR-193a-5p accumulation represses collagen translation, and CHWE reverses this process. By simultaneously restoring mitochondrial bioenergetic capacity and relieving miRNA-mediated translational repression, CHWE promotes efficient collagen recovery in senescent cells through complementary mechanisms. Conclusions: This study reveals a translational regulatory mechanism of collagen decline during cellular aging and highlights CHWE as a functional food supplement and a potential multi-target agent for age-related tissue deterioration.