Dihydroquercetin protects against renal fibrosis by activating the Nrf2 pathway.

BACKGROUND: Dihydroquercetin (DHQ) is an antifibrotic agent. However, whether DHQ can prevent renal fibrosis remains unknown. PURPOSE: This study aimed to investigate the effects of DHQ on tubulointerstitial fibrosis and its underlying mechanisms in unilateral ureteral obstruction (UUO) mice in vivo and NRK-49F cells in vitro. METHODS: In vivo, UUO mice received vehicle or DHQ treatment. In vitro, NRK-49F cells were pretreated with DHQ and exposed to transforming growth factor-ß1 (TGF-ß1). Changes in fibroblast activation, collagen synthesis, oxidative stress, and related signaling pathways were assessed by immunohistochemical staining, Western blot analysis, real-time reverse transcription-PCR, and fluorescence microscopy. RESULTS: UUO induced tubular atrophy, inflammation, fibroblast differentiation into myofibroblast, and collagen deposition, whereas DHQ ameliorated these effects. UUO also resulted in decreased levels of nuclear factor-erythroid-2-related factor 2 (Nrf2), catalase, and heme oxygenase-1, but increased H2O2 and malondialdehyde levels. DHQ treatment corrected these changes. In vitro, the intracellular Nrf2 level of NRK-49F exposed to TGF-ß1 decreased. However, DHQ rescued intracellular Nrf2 level and promoted nuclear translocation of Nrf2. DHQ scavenged TGF-ß1-induced accumulation of reactive oxygen species, inhibited TGF-ß1-induced Smad3 phosphorylation, and prevented TGF-ß1-induced fibroblast activation and collagen synthesis in NRK-49F. Nrf2 knockdown could suppress the DHQ-mediated inhibitory effects on oxidative stress, Smad3 phosphorylation, fibroblast activation, and collagen deposition. Furthermore, DHQ ameliorated established renal fibrosis in UUO mice. CONCLUSIONS: DHQ posed remarkable preventive and therapeutic effects on UUO-induced renal fibrosis and suppressed fibroblast activation by reducing oxidative stress and Smad3 phosphorylation via Nrf2 signaling. This study provided a mechanistic basis for the clinical application of DHQ in renal fibrosis treatment.

Inhibition of interleukin-1beta-stimulated dedifferentiation of chondrocytes via controlled release of CrmA from hyaluronic acid-chitosan microspheres.

BACKGROUND: The previous studies indicated that CrmA could ameliorate the interleukin-1ß induced osteoarthritis. In this study, we investigated the controlled-released cytokine response modifier A (CrmA) from hyaluronic acid (HA)-chitosan (CS) microspheres to improve interleukin-1ß (IL-1ß)-stimulated dedifferentiation of chondrocytes. METHODS: A rat model of osteoarthritis (OA) in vitro was established using 10 ng/ml IL-1ß as modulating and chondrocytes inducing agent. HA-CS-CrmA microspheres were added to the medium after IL-1ß was co-cultured with freshly isolated rat chondrocytes for 48 hours. The chondrocytes viability and glycosaminoglycan (GAG) content were determined. The level of CrmA secreted was detected by Enzyme-Linked Immunosorbent Assay (ELISA). The protein levels of type II collagen, aggrecan, collagen I and IL-1ß were detected using western blotting analyses. RESULTS: The CrmA release kinetics were characterized by an initial burst release, which was reduced to a linear release over ten days. The production of GAG and the expression of type II collagen, aggrecan significantly increased compared with the control group, while the expression of collagen I and IL-1ß decreased. CONCLUSIONS: This study demonstrated that HA-CS microspheres containing CrmA could attenuate the degeneration of articular cartilage by maintaining the phenotype of chondrocytes during culture expansion. The suppression of inflammatory cytokines activity within the joint might be one important mechanism of the action of the microspheres in the treatment of OA.

Inhibition of interleukin-1ß-stimulated matrix metalloproteinases via the controlled release of interleukin-1Ra from chitosan microspheres in chondrocytes.

The aim of the study was to determine whether the controlled release of interleukin (IL)-1Ra from chitosan (CS) microspheres inhibits the IL-1ß-stimulated production of matrix metalloproteinases (MMPs) in chondrocytes. The CS-IL-1Ra microspheres were fabricated by an emulsification method using sodium tripolyphosphate as a crosslinker, and the controlled release of IL-1Ra was determined using an enzyme-linked immunosorbent assay. IL-1ß was added to normal rat chondrocytes to stimulate MMP production. The chondrocytes were incubated with CS-IL-1Ra microspheres to assess its effects on IL-1ß-induced MMP expression. Chondrocyte proliferation and glycosaminoglycan (GAG) content were also determined. The mRNA expression and protein levels of IL-1ß, MMP-1, MMP-3 and MMP-13 were detected using reverse transcription-polymerase chain reaction and western blotting analyses, respectively. The IL-1Ra release kinetics were characterized by an initial burst release, which was reduced to a linear release over seven days. The mRNA expression levels and protein levels of IL-1ß, MMP-1, MMP-3 and MMP-13 were reduced compared with the control group. The present study demonstrated the chondroprotective properties of CS microspheres as a controlled release system carrying IL-1Ra, due to the ability of the system to downregulate the expression of osteoarthritis-associated matrix-degrading proteinases in chondrocytes.

[Nutritional risk screening and enteral nutrition in patients with oral and maxillofacial cancers].

PURPOSE: To screen the nutritional risk of patients with oral and maxillofacial cancers using NRS2002 and evaluate the clinical usefulness of NRS2002. Meanwhile, nutritional support was given after screening and the effect was evaluated. METHODS: Fifty-nine patients with oral and maxillofacial cancers were enrolled in this study. The medical history and the intake condition of all patients were recorded, body weight and height were measured.The serum hemoglobin (Hb), lymphocyte count (LC), albumin (Alb), pre-albumin (PA) of the patients were detected. According to the requirements of NRS2002, the patients were screened before and after surgery. The patients with nutritional risks were divided into experimental group and control group randomly. The blood biochemical parameters in the two groups were compared after nutritional intervention. The data was analyzed by student's t test and Chi-square test with SPSS11.5 software package. RESULTS: Nutritional risk pre-operatively was 27.1% while the figure increased to 71.2% after operation (P < 0.05). Compared to pre-operation, nutritional risk increased significantly. Hb, LC, Alb and PA decreased significantly (P < 0.01). Before nutritional intervention,there was no difference of the biochemical stats between the patients in the experimental group and the control group (P > 0.05). After 7 days' treatment, the biochemical parameters except Hb and PA increased significantly in the control group. In the experimental group, LC, Alb and PA increased significantly (P < 0.05), especially Alb (P < 0.01), but Hb decreased. Compared with the control group, the NRS 2002 score decreased significantly in the experimental group after nutritional intervention. CONCLUSIONS: NRS2002 can reflect the nutritional risk of the patients with oral and maxillofacial cancers conveniently and swiftly. Nutritional support after operation can significantly increase the nutritional status of the patients, reduce the infectious complications and improve the prognosis.