Our previous study showed that ENSMUST00000147869 was abnormally low expressed in the early stage of
diabetic nephropathy (DN). ENSMUST00000147869 could inhibit the
fibrosis and proliferation of mouse mesangial cells (MMCs), but the mechanism is still unclear. This study aims to explore the specific mechanism underline ENSMUST00000147869 regulates the proliferation and
fibrosis of MMCs in DN. Nucleocytoplasmic fractionation was applied to define the location of ENSMUST00000147869 in MMCs.
RNA-
protein pulldown,
RNA immunoprecipitation and mass spectrometry were used to identify upregulated Hspa9 directly interacting with ENSMUST00000147869.
SiRNA and lentivirus packaging were used to clarify the role of Hspa9 downregulated by ENSMUST00000147869 in promoting proliferation and
fibrosis in MMCs. CHX and
MG132 were used to clarify the regulatory role of ENSMUST00000147869 to Hspa9. Immunoprecipitation confirmed the binding of Hspa9 and
HMGB1. HSPA9 was a direct
binding protein of ENSMUST00000147869, and ENSMUST00000147869 could inhibit proliferation and
fibrosis of MMCs by down-regulating HSPA9 through ubiquitination process.
HMGB1 was the downstream
binding protein of Hspa9, and ENSMUST00000147869 could inhibit the interaction between Hspa9 and
HMGB1. Our data showed that ENSMUST00000147869 regulates Hspa9 through the
ubiquitin proteasome pathway and inhibits the binding of Hspa9 and
HMGB1. The ENSMUST00000147869/Hspa9/
HMGB1 axis may act as a diagnostic molecular marker and an effective therapeutic target for DN.