ABSTRACT
Alzheimer's disease (AD) is characterized by aggregation of amyloid beta (Aß) plaque. RhoA may serve as a potential target for prevention against AD given its role in the amyloidogenic pathway. The recent emergence of the gut-brain axis has linked lactic acid bacteria (LAB) to neuroprotection against AD. This study assessed the importance of RhoA inhibition in mediating the neuroprotective potential of LAB. To this end, de Man, Rogosa and Sharpe (MRS) broth fermented by lactobacilli or pediococci were tested against SK-N-SH (a human neuroblastoma cell line) in the presence of RhoA activator II for 24 h after which the RhoA activity was measured using the G-LISA Kit. Fluorescence staining of f-actin stress fibres was performed to validate RhoA inhibition. SK-N-SH was transfected with plasmid expressing amyloid precursor protein (APP) gene. The Aß concentration in transfected cells exposed to LAB-derived cell free supernatant (CFS) in the presence of RhoA activator II was measured using the ELISA kit. Furthermore, this study measured organic acids in LAB-derived CFS using the gas chromatography. It was found that LAB-derived CFS yielded strain-dependent inhibition of RhoA, with LAB6- and LAB12-derived CFS being the most potent Pediococcal- and Lactiplantibacillus-based RhoA inhibitor, respectively. Lesser stress fibres were formed under treatment with LAB-derived CFS. The LAB-derived CFS also significantly inhibited Aß in SK-N-SH transfected with APP gene in the presence of RhoA activator II. The LAB-derived CFS was presented with increased lactic acid, acetic acid, butyric acid and propionic acid. The present findings warrant in-depth study using animal models.
ABSTRACT
Extracellular vesicles (EVs), which are released by most of the cells, constitute a new system of cell-cell communication by transporting DNA, RNA, and proteins in various vesicles namely exosomes, apoptotic bodies, protein complexes, high-density lipid (HDL) microvesicles, among others. To ensure accurate regulation of somatic stem cell activity, EVs function as an independent metabolic unit mediating the metabolic homeostasis and pathophysiological of several diseases such as cardiovascular diseases, metabolic diseases, neurodegenerative diseases, immune diseases, and cancer. Whist examining the EV biomolecules cargos and their microenvironments that lead to epigenetic alteration of the cell in tissue regeneration, studies have gained further insights into the biogenesis of EVs and their potential roles in cell biology and pathogenicity. Due to their small size, non-virulence, flexibility, and ability to cross biological barriers, EVs have promising therapeutic potentials in various diseases. In this review, we describe EV's mechanism of action in intercellular communication and transfer of biological information as well as some details about EVinduced epigenetic changes in recipient cells that cause phenotypic alteration during tissue regeneration. We also highlight some of the therapeutic potentials of EVs in organ-specific regeneration.
