Fig 2: The function of CTRP1 in apoptosis and PERK signal pathway in neurons after OGD/R. (A) The expression of CTRP1 in neurons was analyzed by Western blot. n = 4 per group. (B) qRT-PCR analyzed the mRNA expression of CTRP1 after being transfected with siRNA and overexpression lentivirus, respectively. n = 3 per group. (C) Cell viability of neurons analyzed by MTT, n = 4 per group. (D) Apoptosis was analyzed by TUNEL, n = 3 per group. The representative images were acquired under × 200 magnification, scale bars = 100 µm. (E) The expression of CTRP1, BAX, Bcl-2, Cleaved caspase3, and Caspase 12 was analyzed by Western blot. n = 4 per group. (F) The protein expression of CHOP, GRP78, ATF4, PERK, and p-PERK in neurons. n = 4 per group. ****p < 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05 vs. control group, ####p < 0.0001, ###p < 0.001, ##p < 0.01, #p < 0.05 vs. OGD/R + si-NC group, @@@@p < 0.0001, @@@p < 0.001, @p < 0.05 vs. OGD/R + LV-NC group.

Fig 3: Knockdown Sirt1 or FoxO1 in the ARCN affects pro-inflammatory cytokine expressions and immune cell infiltration in the ARCN.A, Representative gel and mean protein expressions of interleukin 6 (IL-6), tumor necrosis factor a (TNF-a), interleukin 1ß (IL-1ß), and C1q/TNF-related protein-1 (CTRP1) in the ARCN in four groups of rats (control+scramble, HFD+scramble, HFD+siRNA Sirt1 and HFD+siRNA FoxO1). *P<0.05 vs control+scramble group. † P<0.05 vs HFD+scramble group; sc indicates scramble. B, Immunofluorescent photomicrographs from the sections of the ARCN region stained for macrophage/microglial cell marker CD11b/c (in green) in the control+scramble, HFD+scramble, HFD+siRNA Sirt1, and HFD+siRNA FoxO1 rats. Blue: 4',6-diamidino-2-phenylindole (DAPI). Scale bar=50 µm.

Fig 4: CTRP1 protected against cerebral ischemia reperfusion injury via alleviating neuron injury and apoptosis. (A) Neuron injury was analyzed by double labeling immunofluorescence staining. n = 3 per group. The representative images were acquired under × 400 magnification, scale bars = 50 µm. (B) Apoptosis in the cortex was analyzed by TUNEL, n = 3 per group. The representative images were acquired under × 200 magnification, scale bars = 100 µm. (C) Western blot analyzed the expression of CTRP1, BAX, Bcl-2, and CHOP in cortex. n = 4 per group. ****p < 0.0001, ***p < 0.01, **p < 0.01, *p < 0.05 vs. sham group; ####p < 0.0001, ##p < 0.01, #p < 0.05 vs. MCAO/R + LV-NC group.

Fig 5: CTRP1 attenuated brain injury in MCAO/R-treated rats. (A) The infection efficiency of LV-CTRP1 in the cortex. n = 3 per group. (B,C) Representative images of TTC staining and quantitative analysis of infarct volume. n = 4 per group. (D) Zea-longe scores. n = 13 per group. (E) HE staining and relative positive cells in the cortex. n = 3 per group. The representative images were acquired under × 400 magnification, scale bars = 50 µm, × 200 magnification, scale bars = 100 µm. ****p < 0.0001, vs. sham group, **p < 0.01 vs. sham + LV-NC group, #### p < 0.0001, ### p < 0.001 vs. MCAO/R + LV-NC group.