Objective To determine the inhibitory effect of a synthetic hexa-peptide GGWSHW (G peptide) derived from thrombospondin-1 (TSP1) on TGF-? activation induced by angiotensin Ⅱ (Ang Ⅱ) in cultured human renal tubular epithelial cells. Methods Human proximal tubular epithelial cell line (HK-2) was cultured in vitro, untreated HK-2 cells were acted as normal control group. HK-2 cells were then stimulated by Ang Ⅱ for 1-24 hours (Ang Ⅱ stimulation group),so that optimal dosage and duration could be chosen.One hour prior to induction,HK-2 cells were pretreated with 10 ?mol/L peptide G (G peptide treated group)or losartan (losartan treated group), the blocker of I type receptor of Ang Ⅱ was acted as inhibitory control.The mRNA and protein levels of TSP1,TGF-?1,FN and PAI-1 were measured by RT-PCR and Western blot. Confocal microscopy and flow cytometry were performed to detect the presence of TSP1, TGF-?1 and co-positive expression of two protein, respectively.The concentrations of total and active TGF-?1 as well as FN and PAI-1 in cell culture supematants were measured by ELISA. Additionally, the expression of Smad2 and p-Smad2 was also examined for the bioactivity of TGF-?1 signaling protein. Results Ang Ⅱ enhanced the expression of TSP1 and TGF-?1 in a temporal-spatial dependent manner. The optimal dosage and duration were 1 ?mol/L and 6 hours,for TSP1,and 0.1 ?mol/L and 12 hours for TGF-?1 respectively.Comparing with untreated HK-2,the co-expression of TSP1 and TGF-?1 induced by A Ⅱ showed a increase of 5.4 folds.In addition,the protein level of p-Smad2 was elevated remarkedly, the mRNA level of FN and PAI-1 was up-regulated by 3 and 1.5 folds, and the concentration was increased by 2.0 and 1.9 folds respectively. Peptide G had less effect on the expression of TSP1 and TGF-?1,whereas it significantly reduced the secretion of active TGF-?1,though total level of TGF-?1 remained up-regulated. Furthermore,comparing with losartan treated group, p-Smad2 expression was reduced by 28.9%, the mRNA level of FN and PAI-1 was decreased by 34.5% and 26% respectively,and the protein levels were reduced by 11.0% and 8.9% respectively. Conclusion The inhibitory peptide derived from TSP1 effectively suppresses TGF-?1 activation through a competitive mechanism and also reduces the secretion of FN and PAI-1 associated with fibrosis.

Objective:To investigate the regional homogeneity (ReHo) among the major depressive disorder patients without mixed features (MDD noMF), major depressive disorder with mixed features (MMF), bipolar disorder with mixed features (BMF) and bipolar disorder patients without mixed features (BD noMF) patients, and to explore the brain activity and functional connectivity patterns of the MMF and BMF patients. Methods:This was a cross-sectional study. The MDD noMF patients (MDD noMF group), MMF patients (MMF group), BMF patients (BMF group), BD noMF patients (BD noMF group), and age-and gender-matched healthy controls (HC group) were recruited from Beijing Anding Hospital, Capital Medical University between April, 2021 and June, 2022. All the participants underwent resting-state functional MRI scanning. The ReHo values was computed with the DPABI software based on the MATLAB. Firstly, the difference in ReHo among the patients with MDD noMF, MMF, BMF, BD noMF and HC group were estimated by the analysis of covariance and the post-hoc method (LSD or Games-Howell). And then, the brain regions with significant different ReHo values were selected as the seeds to calculate the functional connectivity with the whole brain. Results:A total of 29 cases in the MDD noMF group, 24 cases in the MMF group, 26 cases in the BMF group, 29 cases in the BD noMF group, and 42 in the HC group were included. The differences in ReHo values in the left fusiform and the left precuneus of the 5 groups were statistically significant ( P<0.05). Among of them, the ReHo values of the left fusiform were lower in the MMF, BMF and BD noMF groups compared with the HC group ( P<0.05), while the ReHo values of the left precuneus in MDD noMF, MMF, BMF and BD noMF groups were higher than that in the HC group ( P<0.05). The ReHo value of the left fusiform was lower in the MMF group compared with the MDD noMF group ( P=0.001); the ReHo value of the left fusiform was lower in the BMF group compared with the MDD noMF and BD noMF groups ( P<0.05). The functional connectivity between the left fusiform and vermis, left insula, right putamen, and left medial superior frontal gyrus, and functional connectivity between the left precuneus and right superior frontal gyrus (dorsolateral) showed significant difference among the MDD noMF, MMF, BMF, BD noMF and HC groups ( P<0.05). Compared with HC group, MDD noMF, MMF, BD noMF groups showed higher functional connectivity between the left fusiform and the vermis, and MDD noMF, MMF, BMF, BD noMF group showed higher functional connectivityy between the the left fusiform and the left insula, left medial superior frontal gyrus and right putamen ( P<0.05). Compared with the MDD noMF group, the MMF, BMF and BD noMF groups showed higher functional connectivity between the left fusiform and the left insula ( P<0.05). Compared with the MDD noMF group, the BMF and BD noMF groups had higher functional connectivity between the left fusiform and the left medial superior frontal gyrus ( P<0.05). The BMF group showed higher functional connectivity of the left fusiform with the right putamen than the MDD noMF and BD noMF groups. Additonally, the BMF and BD noMF groups showed higher functional connectivity between the left precuneus and the right superior frontal gyrus (dorsolateral) than HC, MDD noMF and MMF groups ( P<0.05). Conclusions:MMF and BMF patients have local abnormalities of functional activity synchronization in the left fusiform and precuneus and abnormal functional connectivity patterns with multiple brain regions. MMF and BMF patients have specific neuroimaging features compared to MDD noMF or BD noMF patients and also share similar neuroimaging pathogenesis.