Amelioration of renal injury by Qihuang Jianpi Zishen Granules in lupus mice is correlated with AMPK/ULK1-dependent modulation of macrophage polarisation.

OBJECTIVE

To investigate the effects of Qihuang Jianpi Zishen Granules (QJZG) on renal injury in SLE mice, focusing on macrophage M1/M2 polarisation mediated by the AMPK/ULK1 signalling pathway.

METHODS

Parameters of renal function and proteinuria were assessed. Pathological changes in the kidney were examined using H&E, periodic acid-Schiff and Masson's trichrome staining. Serum inflammatory factor levels were quantified using ELISA. The expression levels of the glycolysis rate-limiting enzymes hexokinase 2 (HK2) and glucose transporter 1 (GLUT1) were determined, and the transcriptional levels of AMPK/ULK1 pathway components were measured using quantitative PCR. The abundance of proteins associated with AMPK/ULK1 signalling was assessed via immunoblotting. Flow cytometry was used to quantify CD86+ M1 type and CD206+ M2 type macrophage populations. Dual immunofluorescence staining was employed to visualise F4/80+CD86+ and F4/80+CD206+ coexpression patterns.

RESULTS

Compared with the Untreated group, mice in the PRED (prednisone acetate), QJZG and 2-Deoxy-D-glucose groups exhibited improved renal histopathology, reduced levels of creatinine, blood urea nitrogen, 24-hour RRO (24-hour urinary protein), ACR (Albumin-to-Creatinine Ratio), TPCR (Urine Total Protein-to-Creatinine Ratio), tumour necrosis factor alpha, interleukin (IL)-1β, IL-12, IL-23, IL-27, HK2, GLUT1, mTOR, CD86 and iNOS messenger RNA (mRNA), CD86 and iNOS proteins, M1 macrophages, M1/M2 macrophages and F4/80+CD86 expression (p<0.05). They also displayed increased expression of transforming growth factor-beta, IL-4, IL-10, C-C motif chemokine ligand 18, AMPK, ULK1, Atg13, CD206 and Arg-1 mRNA, AMPK, ULK1, CD206 and Arg-1 proteins, M2 macrophages and F4/80+CD206 (p<0.05).

CONCLUSION

QJZG effectively improved renal injury in SLE by reducing inflammation and modulating the AMPK/ULK1 signalling pathway to suppress M1 macrophage polarisation.