CircRNA circPRKCI is upregulated in osteoporosis and sponges miR-103 to suppress the apoptosis of osteoblast induced by Lipopolysaccharide (LPS)
Authors: Liu Yue , Huang Hongchao , Li Jianan , Zhang Kaihui , Jiang Hongfeng 
Published: February 2023

Background:
Circular RNA circPRKCI is a critical player in cell injury induced by Lipopolysaccharide (LPS), which promotes osteoporosis (OP). However, the function of circPRKCI in OP is unclear. We predicted that circPRKCI could bind to miR-103, which participates in OP, suggesting the potential involvement of circPRKCI in OP.

background:
CircPRKCI is a critical player in cell injury induced by Lipopolysaccharide (LPS), which promotes osteoporosis (OP). However, the function of circPRKCI in OP is unclear. We predicted that circPRKCI could bind to miR-103, which participates in OP.

Objective:
This study aimed to explore the role of circPRKCI and miR-103 in OP.

objective:
This research was conducted to explore the role of circPRKCI and miR-103 involve in OP.

Methods:
Plasma samples of 66 OP patients and 66 healthy controls were collected to prepare RNA samples, followed by RT-qPCR to detect the expression of circPRKCI and miR-103. Correlations between circPRKCI and miR-103 were analyzed by Pearson’s correlation coefficient. Subcellular fractionation assay was used to determine the location of circPRKCI in osteoblasts. RNA pull-down assay was used to explore how circPRKCI and miR-103 interacted. The function of circPRKCI and miR-103 in LPS-induced apoptosis of osteoblasts was evaluated by cell apoptosis assay.

method:
In this study, plasma samples were extracted from 66 OP patients and healthy controls to prepare RNA samples, which were used to determine circPRKCI and miR-103 expression by RT-qPCRs. Correlations between circPRKCI and miR-103 were analyzed by Pearsons’ correlation coefficient. Subcellular fractionation assay was applied to analyze the location of circPRKCI in osteoblasts and RNA pull-down assay was to analyze how circPRKCI and miR-103 interacted between each other. CircPRKCI and miR-103 function in LPS-induced apoptosis of osteoblasts was analyzed with cell apoptosis assay.

Results:
Compared to OP patients, the healthy controls showed downregulation of circPRKCI and upregulation of miR-103. However, circPRKCI and miR-103 were not closely correlated but interacted with each other directly. CircPRKCI was detected in both the cytoplasm and nucleus of osteoblasts, and overexpression of circPRKCI suppressed cell apoptosis induced by LPS. MiR-103 promoted cell apoptosis induced by LPS, and its promotive role was suppressed by circPRKCI.

result:
We found that, compared to OP patients, controls exhibited downregulated circPRKCI and upregulated miR-103. However, circPRKCI and miR-103 are not closely correlated, while they directly interacted with each other. CircPRKCI was detected in both cytoplasm and nucleus of osteoblasts, and its overexpression suppressed cell apoptosis induced by LPS. MiR-103 promoted cell apoptosis induced by LPS and its role was suppressed by circPRKCI.

Conclusion:
CircPRKCI is upregulated in OP, and it sponges miR-103 to suppress osteoblast apoptosis induced by LPS.