Effective reconstruction of functional organotypic kidney spheroid for in vitro nephrotoxicity studies.

Stable and reproducible kidney cellular models could accelerate our understanding of diseases, help therapeutics development, and improve nephrotoxicity screenings. Generation of a reproducible in vitro kidney models has been challenging owing to the cellular heterogeneity and structural complexity of the kidney. We generated mixed immortalized cell lines that stably maintained their characteristic expression of renal epithelial progenitor markers for the different lineages of kidney cellular compartments via the BMP7 signaling pathway from a mouse and a human whole kidney. These cells were used to generate functional and matured kidney spheroids containing multiple renal lineages, such as the proximal tubule, loop of Henle, distal tubules, and podocytes, using extracellular matrix and physiological force, named spheroid-forming unit (SFU). They expressed all apical and basolateral transporters that are important for drug metabolism and displayed key functional aspects of the proximal tubule, including protein endocytosis and increased gamma-glutamyltransferase activity, and cyclic AMP responded to external cues, such as parathyroid hormone. Following exposure, cells fluxed and took up drugs via proximal tubule-specific apical or basolateral transporters, and displayed increased cell death and expression of renal injury marker. Here, we developed a new differentiation method to generate kidney spheroids that structurally recapitulate important features of the kidney effectively and reproducibly using mixed immortalized renal cells, and showed their application for renal toxicity studies.

Korean red ginseng (Panax ginseng) prevents obesity by inhibiting angiogenesis in high fat diet-induced obese C57BL/6J mice.

Adipose tissue growth and development are thought to be associated with angiogenesis and extracellular matrix remodeling. Because ginseng has been shown to inhibit angiogenesis and matrix metalloproteinase (MMP) activity, we hypothesized that adipose tissue growth and obesity can be regulated by Korean ginseng (Panax ginseng C.A. Meyer). Wild-type C57BL/6J mice were fed for 8 weeks with a low fat diet, a high fat diet (HFD), or HFD supplemented with 0.5% or 5% Korean red ginseng extract. We measured body weight, adipose tissue mass, food intake, MMP activity, and the expression of genes involved in angiogenesis and MMPs. Administering ginseng to HFD-induced obese mice produced reductions in body weight and adipose tissue mass compared with untreated counterparts. Ginseng treatment decreased blood vessel density and MMP activity in adipose tissues. Ginseng also reduced mRNA levels of angiogenic factors (e.g., VEGF-A and FGF-2) and MMPs (e.g., MMP-2 and MMP-9), whereas it increased mRNA levels of angiogenic inhibitors (e.g., TSP-1, TIMP-1, and TIMP-2) in adipose tissues. These results demonstrate that ginseng effectively reduces adipose tissue mass and prevents obesity in diet-induced obese mice and that this process may be mediated in part through the anti-angiogenic actions of ginseng.

Ginseng and Its Active Components Ginsenosides Inhibit Adipogenesis in 3T3-L1 Cells by Regulating MMP-2 and MMP-9.

The growth and development of adipose tissue are believed to require adipogenesis, angiogenesis, and extracellular matrix remodeling. As our previous study revealed that ginseng reduces adipose tissue mass in part by decreasing matrix metalloproteinase (MMP) activity in obese mice, we hypothesized that adipogenesis can be inhibited by ginseng and its active components ginsenosides (GSs). Treatment of 3T3-L1 adipocytes with Korean red ginseng extract (GE) inhibited lipid accumulation and the expression of adipocyte-specific genes (PPARγ, C/EBPα, aP2, and leptin). GE decreased both the mRNA levels and activity of MMP-2 and MMP-9 in 3T3-L1 cells. These effects were further inhibited by total GSs (TGSs) and individual GSs. TGSs and individual GSs also significantly decreased MMP-2 and MMP-9 reporter gene activities in the presence of phorbol 12-myristate 13-acetate (PMA), the MMP inducer. Among the GSs, Rb1 most effectively inhibited MMP activity. In addition, PMA treatment attenuated the inhibitory actions of GE and GSs on adipogenesis. Moreover, GE and GSs reduced the expression of NF-κB and AP-1, the transcription factors of MMP-2 and MMP-9. These results demonstrate that ginseng, in particular GSs, effectively inhibits adipogenesis and that this process may be mediated in part through the suppression of MMP-2 and MMP-9. Thus, ginseng and GSs likely have therapeutic potential for controlling adipogenesis.

The herbal composition GGEx18 from Laminaria japonica, Rheum palmatum, and Ephedra sinica reduces obesity via skeletal muscle AMPK and PPARα.

CONTEXT: Since AMP-activated protein kinase (AMPK) activation in skeletal muscle of obese rodents stimulates fatty acid oxidation, it is reasonable to hypothesize that pharmacological activation of AMPK might be of therapeutic benefit in obesity. OBJECTIVE: To investigate the effects of the traditional Korean anti-obesity drug GGEx18, a mixture of three herbs, Laminaria japonica Aresch (Laminariaceae), Rheum palmatum L. (Polygonaceae), and Ephedra sinica Stapf (Ephedraceae), on obesity and the involvement of AMPK in this process. MATERIALS AND METHODS: After high fat diet-induced obese mice were treated with GGEx18, we studied the effects of GGEx18 on body weight, fat mass, skeletal muscle lipid accumulation, and the expressions of AMPK, peroxisome proliferator-activated receptor ά (PPARα), and PPARα target genes. The effects of GGEx18 and/or the AMPK inhibitor compound C on lipid accumulation and expression of the above genes were measured in C2C12 skeletal muscle cells. RESULTS: Administration of GGEx18 to obese mice for 9 weeks significantly (p < 0.05) decreased body and adipose tissue weights compared with obese control mice (p < 0.05). Lipid accumulation in skeletal muscle was inhibited by GGEx18. GGEx18 significantly (p < 0.05) increased skeletal muscle mRNA levels of AMPKα1 and AMPKα2 as well as PPARα and its target genes. Consistent with the in vivo data, GGEx18 inhibited lipid accumulation, and similar activation of genes was observed in GGEx18-treated C2C12 cells. However, compound C inhibited these effects in C2C12 cells. DISCUSSION AND CONCLUSION: These results suggest that GGEx18 improves obesity through skeletal muscle AMPK and AMPK-stimulated expression of PPARα and its target enzymes for fatty acid oxidation.

The Korean traditional medicine gyeongshingangjeehwan inhibits adipocyte hypertrophy and visceral adipose tissue accumulation by activating PPARalpha actions in rat white adipose tissues.

AIM OF THE STUDY: Gyeongshingangjeehwan (GGEx), which is a polyherbal drug composed of four medicinal plants, has traditionally been used as anti-obesity drug in Korean local clinics. Thus, we investigated the effects of GGEx on visceral adiposity and examined whether adipose peroxisome proliferator-activated receptor alpha (PPARalpha) activation is involved in this process. MATERIALS AND METHODS: After Obese Otsuka Long-Evans Tokushima Fatty (OLETF) rats and differentiated 3T3-L1 adipocytes were treated with GGEx, we studied the effects of GGEx on not only visceral white adipose tissue (WAT) mass and adipocyte size, but also the expression of adipocyte marker and PPARalpha target genes. RESULTS: Administration of GGEx to obese rats for 8 weeks decreased visceral WAT weight by 30% and the size of adipocytes in mesenteric WAT by 31% without weight changes of other organs. Concomitantly, GGEx increased mRNA levels of PPARalpha target genes responsible for fatty acid beta-oxidation in mesenteric WAT whereas decreased mRNA expression of adipocyte markers, such as PPARgamma, aP2 and leptin. Serological studies demonstrated that plasma levels of free fatty acids and triglycerides as well as insulin and glucose were decreased following GGEx treatment. Consistent with the in vivo data, GGEx increased PPARalpha reporter gene activity and induced the mRNA expression of PPARalpha target genes involved in mitochondrial fatty acid beta-oxidation in 3T3-L1 cells. GGEx also inhibited triglyceride accumulation in these cells. CONCLUSION: These results suggest that GGEx promotes the reductions in visceral fat mass and adipocyte size in obese animals, and that this event may be mediated by adipose PPARalpha activation.