The transforming growth factor-β1 (TGF-β1)/Smad3 signal pathway is related to mutiple physiological and pathological generation mechanism of human being. Up to date, however, the spacial and time information on the phosphorylated Smad3 is still unclear. In this study, the process of Smad3 phosphorylation was observed under the physiological state in the living cells. Firstly, the ECFP-Smad3-Citrine (Smad3 biosensor) fusion protein expression vector was constructed and identified. Then the Smad3 biosensor was transfected into 293T cells. The transfection efficiency and the expressions of fusion proteins were observed in 24 hours. Thirdly, Smad3 biosensor flurorescence resonance energy transfer (FRET) was observed with the inversion fluorescence microscope and measured by the MetaFlour FRET 4. 6 software. Smad3 biosensor transfection efficiency was nearly 40% and the fusion protein was seen under the fluorescence microscope. The FRET ratio of Smad3 biosensor in living 293T cells was decreased after 10 minutes incubation with the ligand of TGF-β1. The period of decreasing CFP and enhancing Citrine signals was about 300 seconds. With the technology of FRET, the TGF-β1/Smad3 signal pathway could be real time monitored dynamically under the physiological condition in living cells.
Fluorescence Resonance Energy Transfer ; Genetic Vectors ; HEK293 Cells ; Humans ; Microscopy, Fluorescence ; Phosphorylation ; Signal Transduction ; Smad3 Protein ; metabolism ; Software ; Transfection ; Transforming Growth Factor beta1 ; metabolism

Objective:To observe the clinical efficacy of autologous platelet rich gel (APG) in the treatment of type 2 diabetic foot (DF) patients and the effect of APG on the expression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in peripheral blood mononuclear cells (PBMCs).Methods:A total of 62 patients with DF admitted to the Affiliated Hospital of Kangda College of Nanjing Medical University from February 2021 to May 2022 were randomly divided into a control group (30 cases) and an observation group (32 cases) using a random number table method. The control group received ultrasound debridement and dressing change treatment, while the observation group received ultrasound debridement combined with APG treatment. After 6 weeks of treatment, the effective rate, transcutaneous oxygen partial pressure (TcPO 2), and serum tumor necrosis factor- α (TNF-α), interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), hypoxia inducible factor α (HIF-1 α)and the level of MALAT1 expression in PBMCs of the two groups of patients were observed. The Pearson correlation analysis was used to investigate the relationship between the expression change of MALAT (△ MALAT1) and the total effective rate of treatment. Results:The total effective rate of the observation group was higher than that of the control group [93.75%(30/32) vs 73.33%(22/30), P<0.05]. After treatment, the systolic blood pressure (SBP), diastolic blood pressure (DBP), cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), fasting blood glucose (FPG), glycosylated hemoglobin (HbA 1c), urinary microalbumin/creatinine (UACR), uric acid (UA), white blood cells (WBC), TNF- α and IL-6 of both groups had decreased compared to before; HIF-1 α, VEGF and MALAT1 increased compared to before treatment (all P<0.05); After treatment, there was a statistically significant difference in UA, HIF-1α, VEGF, and MALAT1 between the observation group and the control group (all P<0.05). Pearson correlation analysis showed that Δ MALAT1 in DF patients was negatively correlated with TNF -α ( r=-0.61, P=0.02), IL-6 ( r=-0.52, P=0.04), WBC ( r=-0.53, P=0.03), and positively correlated with VEGF ( r=0.58, P=0.03) and HIF-1α ( r=0.54, P=0.03). The total effective rate of DF treatment was higher in the high change group of△ MALAT [88.37%(38/43) vs 73.68%(14/19), P<0.05]. There was no statistically significant difference in the incidence of adverse reactions between the two groups ( P>0.05). Conclusions:APG can significantly upregulate the expression of MALAT, improve wound tissue blood perfusion, wound angiogenesis, and inflammatory response, promote ulcer healing, and changes in MALAT expression can help determine the prognosis of DF.

Head and neck squamous cell carcinoma (HNSCC) is a common malignant tumor that seriously threatens human health and life. With increasing studies on the mechanism of tumor immune escape, programmed death receptor 1 (PD-1) and programmed death ligand receptor 1 (PD-L1) have been proven to be involved in tumor immune escape. The primary mechanism is that PD-1 recruits protein tyrosine phosphatase (SHP-2) to dephosphorylate downstream tyrosine kinase (SyK) and phosphatidylinositol 3-kinase (PI3K), thereby inhibiting downstream protein kinase B (AKT), extracellular regulated protein kinases (ERK) and other important signaling pathways, ultimately inhibiting T cell activation. In recent years, PD-1/PD-L1 inhibitors have become popular immunotherapies. Pembrolizumab and nivolumab have been approved for HNSCC patients by the U.S. Food and Drug Administration. Both durvalumab and atezolizumab are still in clinical trials, and published data show that both have certain safety and efficacy but still need much clinical data to support them. Meanwhile, the combination of PD-1/PD-L1 inhibitors with radiotherapy, chemotherapy and immunotherapy is still controversial in terms of clinical efficacy and adverse events, and further research is needed. However, serious immune-related adverse reactions limit the clinical application of PD-1/PD-L1 inhibitors, despite promising curative effects. Therefore, developing novel inhibitors and investigating stable and effective biomarkers and upstream and downstream signaling mechanisms are urgent issues.