Preparation of Decellularized Kidney Scaffolds in Rats.

Tissue engineering is a cutting-edge discipline in biomedicine. Cell culture techniques can be applied for regeneration of functional tissues and organs to replace diseased or damaged organs. Scaffolds are needed to facilitate the generation of three-dimensional organs or tissues using differentiated stem cells in vivo. In this report, we describe a novel method for developing vascularized scaffolds using decellularized rat kidneys. Eight-week-old Sprague-Dawley rats were used in this study, and heparin was injected into the heart to facilitate flow into the renal vessels, allowing heparin to perfuse into the renal vessels. The abdominal cavity was opened, and the left kidney was collected. The collected kidneys were perfused for 9 h using detergents, such as Triton X-100 and sodium dodecyl sulfate, to decellularize the tissue. Decellularized kidney scaffolds were then gently washed with 1% penicillin/streptomycin and heparin to remove cellular debris and chemical residues. Transplantation of stem cells with the decellularized vascular scaffolds is expected to facilitate the generation of new organs. Thus, the vascularized scaffolds may provide a foundation for tissue engineering of organ grafts in the future.

The Immunomodulatory Activity of Mori folium, the Leaf of Morus alba L., in RAW 264.7 Macrophages In Vitro.

BACKGROUND: Immunoregulatory elements have emerged as useful immunotherapeutic agents against cancer. In traditional medicine, Mori folium, the leaf of Morus alba L. (Moraceae), has been used for various medicinal purposes; however, the immunomodulatory effects have not been fully identified. We evaluated the immunoenhancing potential of water extract of Mori folium (WEMF) in murine RAW264.7 macrophages. METHODS: RAW264.7 cells were treated with WEMF for 24 hours and cell viability was detected by an MTT method. Nitric oxide (NO) levels in the culture supernatants were assayed using Griess reagent. The productions of prostaglandin E2 (PGE2) and immune-related cytokines was measured using ELISA detection kits. The mRNA and protein expression levels of Inducible NO synthase, COX-2, and cytokines were assayed by reverse transcription-PCR and Western blotting, respectively. The effect of WEMF on phagocytic activity was measured using a Phagocytosis Assay Kit. RESULTS: WEMF significantly stimulated the production of NO and PGE2 as immune response parameters at noncytotoxic concentrations, which was associated with the increased expression of inducible NO synthase and COX-2. The release and expression of cytokines, such as TNF-α, interleukin (IL)-1ß, IL-6, and IL-10, were also significantly increased in response to treatment with WEMF. Moreover, WEMF promoted the macrophagic differentiation of RAW264.7 cells and the resulting phagocytosis activity. CONCLUSIONS: WEMF has the potential to modulate the immune function by regulating immunological parameters. Further studies are needed to identify the active compounds and to support the use of WEMF as an immune stimulant.

Emodin inhibits TNF alpha-induced MMP-1 expression through suppression of activator protein-1 (AP-1).

Matrix metalloproteinases (MMPs) are the proteases involved in the degradation of the extracellular matrix. MMP-1 is thought to be one of the key enzymes acting in fibrolysis, a process closely related to tissue remodeling. In this study, we found that emodin, an anthraquinone which has been isolated from the rhizome of Rheum palmatum, significantly inhibited TNF alpha-induced MMP-1 gene expression in a concentration-dependent manner. Therefore, we have attempted to characterize the inhibitory mechanism of emodin in TNF alpha-induced MMP-1 expression. Emodin was determined to inhibit TNF alpha-induced activation of AP-1 promoter, an important nuclear transcription factor in MMP-1 expression. Additionally, we detected that emodin suppressed the TNF alpha-induced phosphorylation of two mitogen-activated protein kinases, extracellular signal-regulated protein kinase and c-Jun N-terminal kinase, but it did not suppress the TNF alpha-induced phosphorylation of p38 kinase. In a consistent result, the TNF alpha-induced MMP-1 expression was inhibited by PD98059 (MEK/ERK inhibitor) and SP600125 (JNK inhibitor), but was not inhibited by SB203580, a p38 MAPK inhibitor. Taken together, these results show that emodin suppresses TNF alpha-induced MMP-1 expression through the inhibition of the AP-1 signaling pathway.