Effect of fecal microbiota transplantation on the TGF-β1/Smad signaling pathway in rats with TNBS-induced colitis

Background

Traditional treatments for inflammatory bowel disease (IBD) have adverse side effects, and patients who receive such treatments have high recurrence rates. Fecal microbiota transplantation (FMT) has become an increasingly popular therapeutic option for patients with IBD. However, the mechanism by which FMT alleviates this disease remains unclear.

Methods

In this study, a rat model of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis was established and used to explore whether the transforming growth factor-beta 1 (TGF-β1)/small mothers against decapentaplegic (Smad) signaling pathway plays a critical role in the FMT alleviation of IBD.

Results

After the FMT intervention, the disease activity index and histologic scores were significantly decreased. In addition, the TGF-β1 expression level in the FMT group was significantly decreased by approximately 0.72-fold relative to the level in the TNBS colitis group, whereas the Smad3, Smad4, and Smad7 expression levels had increased by approximately 1.21, 1.40, and 1.18 folds, respectively. Similarly, SB431542 inhibited the expression of TGF-β1 and promoted the expression of Smad3, Smad4, and Smad7. Further, the serum levels of the inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were significantly decreased, whereas that of the interferon-gamma (IFN-γ) was not significantly changed after the FMT intervention.

Conclusions

These results suggest that FMT inhibits the TGF-β1/Smad signaling pathway to attenuate inflammation.

Identifying the clinical presentations, progression, and sequela of pelvic inflammatory disease through physiological, histological and ultrastructural evaluation of a rat animal model

Background

Patients with pelvic inflammatory disease (PID) are at an increased risk of ectopic pregnancy, infertility, and varying degrees of chronic pelvic pain. The aims of this study were to establish a rat model of PID and characterize its progression in order to assist in the study of pathophysiological mechanisms and to provide animal model for future studies of PID treatments.

Methods

Fifty Sprague-Dawley rats (female, 6-weeks-old) were divided into a model group (n=28) and a control group (n=22). The rat endometrium was mechanically injured by a needle which moved back and forth 3 times on the endometrial tissue, and a mixed bacterial solution (6×10⁸ CFU) of equal concentrations of Escherichiacoli and Staphylococcus aureus was injected into both horns of the rat uterus. Physiological characteristics including weight, temperature, blood, and inflammatory factors were compared, and immunohistochemistry and transmission electron microscopy were used to evaluate the progress and sequela of PID.

Results

The model rats experienced acute PID in the first 14 days and exhibited higher body temperatures and decreased body weight. Infection-related factors in the blood were also significantly changed compared with the normal group, with obviously increased serum levels of C-reactive protein (CRP), interferon gamma (IFN-γ), and interleukin-4 (IL-4). Congestion and edema were observed in the uteri of the model rats, followed by infiltration of numerous inflammatory cells and ultrastructural morphology changes. Histological examination of the uterus showed that adhesion initially appeared at approximately 21 days. In addition to the increased collagen fibers biomass, the expression of transforming growth factor-beta 1 (TGF-β1) was elevated, which might have contributed to pelvic tissue adhesion formation in the PID sequela.

Conclusions

This study clearly described the characteristics and progression of PID in a rat model. The detailed evidence increased our understanding of the pathogenesis and progression of PID and may be useful for future studies of PID treatments.

A Phase IIb Randomized Controlled Trial Investigating the Effects of Tocotrienol-Rich Vitamin E on Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a debilitating complication of diabetes, which develops in 40% of the diabetic population and is responsible for up to 50% of end-stage renal disease (ESRD). Tocotrienols have shown to be a potent antioxidant, anti-inflammatory, and antifibrotic agent in animal and clinical studies. This study evaluated the effects of 400 mg tocotrienol-rich vitamin E supplementation daily on 59 DKD patients over a 12-month period. Patients with stage 3 chronic kidney disease (CKD) or positive urine microalbuminuria (urine to albumin creatinine ratio; UACR > 20–200 mg/mmol) were recruited into a randomized, double-blind, placebo-controlled trial. Patients were randomized into either intervention group (n = 31) which received tocotrienol-rich vitamin E (Tocovid SupraBio^TM; Hovid Berhad, Ipoh, Malaysia) 400 mg daily or a placebo group which received placebo capsules (n = 28) for 12 months. HbA1c, renal parameters (i.e., serum creatinine, eGFR, and UACR), and serum biomarkers were collected at intervals of two months. Tocovid supplementation significantly reduced serum creatinine levels (MD: −4.28 ± 14.92 vs. 9.18 ± 24.96), p = 0.029, and significantly improved eGFR (MD: 1.90 ± 5.76 vs. −3.29 ± 9.24), p = 0.011 after eight months. Subgroup analysis of 37 patients with stage 3 CKD demonstrated persistent renoprotective effects over 12 months; Tocovid improved eGFR (MD: 4.83 ± 6.78 vs. −1.45 ± 9.18), p = 0.022 and serum creatinine (MD: −7.85(20.75) vs. 0.84(26.03), p = 0.042) but not UACR. After six months post washout, there was no improvement in serum creatinine and eGFR. There were no significant changes in the serum biomarkers, TGF-β1 and VEGF-A. Our findings verified the results from the pilot phase study where tocotrienol-rich vitamin E supplementation at two and three months improved kidney function as assessed by serum creatinine and eGFR but not UACR.

Sphingosine kinase 1 is required for TGF-β mediated fibroblastto- myofibroblast differentiation in ovarian cancer

Sphingosine kinase 1 (SPHK1), the enzyme that produces sphingosine 1 phosphate (S1P), is known to be highly expressed in many cancers. However, the role of SPHK1 in cells of the tumor stroma remains unclear. Here, we show that SPHK1 is highly expressed in the tumor stroma of high-grade serous ovarian cancer (HGSC), and is required for the differentiation and tumor promoting function of cancer-associated fibroblasts (CAFs). Knockout or pharmacological inhibition of SPHK1 in ovarian fibroblasts attenuated TGF-β-induced expression of CAF markers, and reduced their ability to promote ovarian cancer cell migration and invasion in a coculture system. Mechanistically, we determined that SPHK1 mediates TGF-β signaling via the transactivation of S1P receptors (S1PR2 and S1PR3), leading to p38 MAPK phosphorylation. The importance of stromal SPHK1 in tumorigenesis was confirmed in vivo, by demonstrating a significant reduction of tumor growth and metastasis in SPHK1 knockout mice. Collectively, these findings demonstrate the potential of SPHK1 inhibition as a novel stroma-targeted therapy in HGSC.