Smad3 signaling and transgelin expression are often activated during puromycin aminonucleoside (PAN)-induced podocyte injury. Here, we investigated whether the Smad3 inhibitor SIS3 can ameliorate damage to injured podocytes. A model of PAN-induced podocyte injury was constructed using the MPC5 cell line. The effects of SIS3 on the expression of the podocyte cytoskeletal proteins transgelin, p15(INK4B), phosphor-smad3, phosphor-JAK/stat3, the apoptotic marker cleaved caspase 3, and c-myc were investigated using western blot. The distribution of F-actin in PAN-induced podocyte injury was observed under an immunofluorescence microscope. PAN-induced podocyte injury altered the distribution of F-actin and transgelin, and colocalization of these two proteins was observed. Transgelin expression and Smad3 phosphorylation were increased in the MPC5 cell line with prolonged PAN treatment. In addition, c-myc expression, p15(INK4B), and JAK phosphorylation were all increased after treatment with PAN. Treatment with the Smad3 inhibitor SIS3 reversed these phenomena and protected against PAN-induced podocyte injury. Moreover, stimulating podocytes directly with TGF beta-1 also led to enhanced expression of transgelin or phosphor-JAK/stat3, and this could be inhibited by SIS3. In conclusion, transgelin expression was induced through the Smad3 signaling pathway during PAN-induced podocyte injury, and the resulting abnormal distribution of F-actin and the enhanced expression of transgelin could be reversed by blockade of this pathway.

Aim The aim of the present study was to characterize the role of Smad3 signaling on high glucose‐induced podocyte injury. Methods Synchronized MPC5 cells were treated either with D‐glucose alone or D‐glucose plus the Smad3 inhibitor SIS3. The distribution of F‐actin and transgelin in a high glucose‐induced model of podocyte injury were examined by immunofluorescence. Levels of transgelin and Smad3 signaling proteins in MPC5 cells were determined by western blot. Results A disordered distribution of F‐actin, as well as colocalization of F‐actin and transgelin, were observed in podocytes exposed to high glucose. Increased levels of transgelin were first observed 10 min after treatment with glucose, suggesting that this protein is sensitive to hyperglycemic injury. Levels of phosphorylated Smad3 and cleaved caspase 3 increased significantly with glucose stimulation. Moreover, expression of the downstream protein c‐Myc, but not JAK1/STAT3, was induced in conditions of high glucose. The Smad3‐specific inhibitor SIS3 prevented the effects of high glucose on Smad3 phosphorylation, expression of transgelin and c‐Myc, caspase 3 cleavage, and cytoskeletal organization. Expression of the tumor suppressor protein p15^INK4B increased after podocyte injury but was unaffected by Smad3 inhibition, suggesting that Smad3 regulation of high glucose‐induced podocyte injury occurs through a p15^INK4B‐independent mechanism. Conclusion Smad3 signaling plays a critical role in the modulation of hyperglycemic injury. Targeted inhibition of the Smad3 pathway may offer a novel route for treatment of podocyte damage, especially in cases of diabetic nephropathy.

Objective: To study the effect of intestinal microecology on postnatal weight gain of very preterm infants in neonatal intensive care unit (NICU). Methods: Very preterm infants who met the inclusion criteria were enrolled. The subjects were divided into the extrauterine growth retardation (EUGR) group(defined as a body weight less than the 10th percentile of the corresponding gestational age or a weight loss between birth and a given time of > 2SD were considered EUGR) and normal growth group, and the growth was evaluated at 2 and 4 weeks after birth. Meanwhile, the stool samples were taken to perform16S ribosomal RNA (rRNA) high -throughput 16S rRNA sequencing of the intestinal microflora was performed on stool samples. Results: A total of 22 infants were included. There was no significant difference in the alpha diversity indexes indices between the two groups at 2 weeks or 4 weeks after birth. The beta diversity analysis showed that the two groups had similar principal components of the intestinal microflora were similar between the two groups. Linear discriminant analysis (LDA) effect size (LEfSe) showed that 2 weeks after birth, the bacteria with an absolute LDA score (log10) higher than 4 included Streptococcaceae, Streptococcus, Bacteroidetes, Bacteroidales and Stenotrophomonas in the EUGR group and Enterococcaceae and Enterococcus in the control group. At the 4th week after birth, the bacteria with an absolute LDA score (log10) higher than 3 in the EUGR group includedwere Clostriaceae, Eubacteriaceae and Eubacterium. TheBy comparing the composition of the microbial community composition comparison showed, significant differences were found in the principal components of Enterococcus and Streptococcus on the family and genus levels at 2 weeks after birth. No Bifidobacterium was found in either group at 4 weeks after birth. Conclusion: Intestinal microecology is different between infants with EUGR and those with normal growth. The diversity and richness of the intestinal microflora in preterm infants at the NICU are significantly insufficient and change dynamically with time, and the establishment of intestinal homeostasis is obviously delayed.

Bioinformatics analysis reveals the roles of cytoskeleton protein transgelin in occurrence and development of proteinuria Yingxue Ding, Zongli Diao, Hong Cui, Aijun Yang, Wenhu Liu, Lina Jiang

Medulla oblongata dysplasia is an extremely rare form of neurodevelopmental immaturity in premature infants. Intracranial hemorrhage in premature infants may be closely related to neurodevelopmental immaturity. We report a female premature infant who succumbed to intracranial hemorrhage caused by medulla oblongata dysplasia. The infant was born at 31 weeks gestation. The onset manifestation was symptomatic epilepsy associated with subependymal hemorrhage. Levetiracetam and sodium valproate were administered. During the hospitalization, hydrocephalus developed and the intracranial hemorrhage aggravated. The infant died on day 171 after birth. Early identification and prompt treatment should be emphasized. Clinicians should be aware of this condition, as it can potentially cause neonatal intracranial hemorrhage.