Protein Kinase R-like Endoplasmic Reticulum Kinase-Mediated ER-Mitochondria Coupling Regulates Odontogenic
Yiqing Wang1, Yiqiao Li1, Yu Jin2
1College of Stomatology, Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an Jiaotong University, Xi'an, China.
Introduction And Aims:
Human dental pulp stem cells (hDPSCs) play pivotal roles in the regeneration of pulp-dentin complex, yet their odontogenic differentiation is critically modulated by the inflammatory microenvironment. Protein kinase R-like endoplasmic reticulum kinase (PERK), a key regulator of endoplasmic reticulum stress, is highly enriched in mitochondria-associated endoplasmic reticulum membranes (MAMs) and exerts critical functions. However, its precise mechanisms in inflammatory regulation and cellular differentiation remain elusive. This study elucidates the PERK-centred regulatory mechanism in MAMs that governs inflammation-impaired odontogenic differentiation of hDPSCs, potentially involving IP3R-dependent calcium flux and dynamic protein interactions in MAMs.
Methods:
Rat pulpitis models and in vitro lipopolysaccharide (LPS)-induced inflammatory models of hDPSCs were established to investigate the effects of PERK signalling in odontogenesis under inflammatory conditions. Lentivirus-mediated silencing of PERK was performed to evaluate its role in LPS-induced inflammation. Molecular mechanisms were analysed using RNA sequencing, immunofluorescence, and transmission electron microscopy analyses.
Results:
LPS stimulation activated the PERK signalling pathway, significantly upregulating MAM-related molecules (IP3R, VDAC1, GRP75) and enhancing PERK/VDAC1 colocalization and the formation of endoplasmic reticulum-mitochondria coupling structures. PERK silencing effectively mitigated LPS-induced mitochondrial swelling, ER dilatation, and calcium influx dysregulation, while restoring alkaline phosphatase activity and odontogenic differentiation potential. Mechanistically, PERK suppressed hDPSC mineralization by modulating IP3R-mediated calcium signalling pathway in MAMs.
Conclusion:
This study demonstrates that LPS-induced inflammatory stress reprograms hDPSCs bioactivity via PERK-centric control of MAMs likely through quantitative enhancement, structure specialization, and functional potentiation. The underlying mechanisms may involve IP3R-mediated regulation of calcium ion influx and protein interactions within MAMs.
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