PPAR-γ Signaling Crosstalk in Mesenchymal Stem Cells

Peroxisome proliferator-activated receptor-gamma (PPAR-γ) is a member of the nuclear receptor (NR) superfamily of ligand-activated transcriptional factors. Among other functions, PPAR-γ acts as a key regulator of the adipogenesis. Since several cytokines (IL-1, TNF-α, TGF-β) had been known to inhibit adipocyte differentiation in mesenchymal stem cells (MSCs), we examined the effect of these cytokines on the transactivation function of PPAR-γ. We found that the TNF-α/IL-1-activated TAK1/TAB1/NIK (NFκB-inducible kinase) signaling cascade inhibited both the adipogenesis and Tro-induced transactivation by PPAR-γ by blocking the receptor binding to the cognate DNA response elements. Furthermore, it has been shown that the noncanonical Wnts are expressed in MSCs and that Wnt-5a was capable to inhibit transactivation by PPAR-γ. Treatment with Wnt5a-activated NLK (nemo-like kinase) induced physical association of the endogenous NLK and H3K9 histone methyltransferase (SETDB1) protein complexes with PPAR-γ. This resulted in histoneH3K9 tri-methylation at PPAR-γ target gene promoters. Overall, our data show that cytokines and noncanonical Wnts play a crucial role in modulation of PPAR-γ regulatory function in its target cells and tissues

The epigenetic function of androgen receptor in prostate cancer progression

Androgen and androgen deprivation (castration) therapies, including androgen receptor antagonists, are clinically used to treat patients with prostate cancer. However, most hormone-dependent prostate cancer patients progress into a malignant state with loss of hormone-dependency, known as castration (drug)-resistant prostate cancer (CRPC), after prolong androgen-based treatments. Even in the CRPC state with irreversible malignancy, androgen receptor (AR) expression is detectable. An epigenetic transition to CRPC induced by the action of AR-mediated androgen could be speculated in the patients with prostate cancer. Androgen receptors belongs to the nuclear receptor superfamily with 48 members in humans, and acts as a ligand-dependent transcriptional factor, leading to local chromatin reorganization for ligand-dependent gene regulation. In this review, we discussed the transcriptional/epigenetic regulatory functions of AR, with emphasis on the clinical applications of AR ligands, AR protein co-regulators, and AR RNA coregulator (enhancer RNA), especially in chromatin reorganization, in patients with prostate cancer

Signaling Crosstalk between PPARγ and BMP2 in Mesenchymal Stem Cells

Recent studies have revealed that PPARγ's transactivation function is regulated by extracellular signals. In particular, cytokines and Wnt family proteins suppress the ligand-inducible transactivation function of PPARγ and attenuate adipogenesis/osteoblastogenesis switching in mesenchymal stem cells (MSCs). For example, Wnt5a suppresses PPARγ transcriptional activity through the NLK/SETDB1/CHD7 pathway. Among these factors, BMP2 strongly induces bone formation, but the effect of BMP2 on PPARγ function remains unclear. We examined the effect of BMP2 and PPARγ in ST2 cells and found that PPARγ activation affected BMP2's signaling pathway through epigenetic regulation. Although BMP2 did not interfere with PPARγ-mediated adipogenesis, BMP2 increased mRNA expression levels of PPARγ target genes (such as Fabp4 and Nr1h3) when cells were first treated with troglitazone (TRO). Moreover, PPARγ activation affected BMP2 through enhancement of histone activation markers (acetylated histone H3 and trimethylated Lys4 of histone H3) on the Runx2 promoter. After TRO treatment for three hours, BMP2 enhanced the levels of active histone marks on the promoter of a PPARγ target gene. These results suggest that the order of treatment with BMP2 and a PPARγ ligand is critical for adipogenesis and osteoblastogenesis switching in MSCs

Bone Marrow-Derived Cells Implanted into Radiation-Injured Urinary Bladders Reconstruct Functional Bladder Tissues in Rats

The purpose of this study was to determine whether bone marrow-derived cells implanted into radiation-injured urinary bladders could reconstruct functional bladder tissues. The pelvic region of anesthetized female Sprague-Dawley (SD) rats was irradiated with 2 Gy once a week for 5 weeks. After the last irradiation, the rats were maintained for 2 weeks. Bone marrow cells were harvested from the femurs of donor male green fluorescence protein (GFP)-transfected SD rats and cultured for 7 days. Two weeks after the last radiation exposure, the cultured adherent, proliferating bone marrow-derived cells were implanted into the walls of irradiated urinary bladders. For controls, cell-free solutions were similarly injected. Four weeks after donor cell or control implantations, cystometric, histological, and immunohistochemical investigations were performed. Two weeks after the last irradiation, the smooth muscle layers and nerve fibers of the irradiated urinary bladders were disorganized. The proportions of smooth muscle layer and nerve fiber areas were significantly decreased compared with sham-irradiated urinary bladders. In addition, the remaining smooth muscle cells within the irradiated urinary bladders expressed P4HB, an indicator of collagen synthesis. In the cystometric investigations, the voiding interval of irradiated rats was irregularly prolonged, 7.92 +/- 1.09 min, and the residual volume, 0.13 +/- 0.03 mL, was significantly higher compared with the sham-irradiated rats (5.50 +/- 0.43mL and 0.05 +/- 0.01 mL). After 4 weeks, the smooth muscle layers and nerve fibers in the cell-free control urinary bladders remained similar to the pre-implanted irradiated urinary bladders; however, the cell-implanted urinary bladders contained reconstructed smooth muscle layers and nerve fibers, the proportions of each were significantly higher than those in the cell-free injected controls. The expression of P4HB within the cell-implanted urinary bladders decreased. Some GFP-positive implanted cells differentiated into smooth muscle-and nerve-like cells and became organized into the reconstructed tissues. The voiding interval of the cell-implanted rats, 5.46 +/- 0.33 min, was regular and similar to that of the sham-irradiated rats, and significantly less than that of the cell-free injected controls, 7.39 +/- 0.54 min. The residual volume, 0.04 +/- 0.01 mL, was similar to that of the sham-irradiated rats and significantly decreased compared with that of the cell-free injected controls, 0.15 +/- 0.05 mL. Therefore, the implantation of bone marrow-derived cells is a potentially useful treatment for radiotherapy-induced urinary dysfunctions.ArticleTISSUE ENGINEERING PART A. 18(15-16):1698-1709 (2012)journal articl

Conditional deletion of Bmpr1a in differentiated osteoclasts increases osteoblastic bone formation, increasing volume of remodeling bone in mice

Bone undergoes remodeling consisting of osteoclastic bone resorption followed by osteoblastic bone formation throughout life. Although the effects of bone morphogenetic protein (BMP) signals on osteoblasts have been studied extensively, the function of BMP signals in osteoclasts has not been fully elucidated. To delineate the function of BMP signals in osteoclasts during bone remodeling, we deleted BMP receptor type IA ( Bmpr1a ) in an osteoclast‐specific manner using a knock‐in Cre mouse line to the cathepsin K locus ( Ctsk Cre/+ ;Bmpr1a flox/flox , designated as Bmpr1a ΔOc/ΔOc ). Cre was specifically expressed in multinucleated osteoclasts in vivo. Cre‐dependent deletion of the Bmpr1a gene occurred at 4 days after cultivation of bone marrow macrophages obtained from Bmpr1a ΔOc/ΔOc with RANKL. These results suggested that Bmpr1a was deleted after formation of osteoclasts in Bmpr1a ΔOc/ΔOc mice. Expression of bone‐resorption markers increased, thus suggesting that BMPRIA signaling negatively regulates osteoclast differentiation. Trabeculae in tibia and femurs were thickened in 3.5‐, 8‐, and 12‐week‐old Bmpr1a ΔOc/ΔOc mice. Bone histomorphometry revealed increased bone volume associated with increased osteoblastic bone‐formation rates (BFR) in the remodeling bone of the secondary spongiosa in Bmpr1a ΔOc/ΔOc tibias at 8 weeks of age. For comparison, we also induced an osteoblast‐specific deletion of Bmpr1a using Col1a1‐Cre. The resulting mice showed increased bone volume with marked decreases in BFR in tibias at 8 weeks of age. These results indicate that deletion of Bmpr1a in differentiated osteoclasts increases osteoblastic bone formation, thus suggesting that BMPR1A signaling in osteoclasts regulates coupling to osteoblasts by reducing bone‐formation activity during bone remodeling. © 2011 American Society for Bone and Mineral ResearchPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87086/1/477_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/87086/2/jbmr_477_sm_SupplData.pd

Pengaruh Kandungan Lemak Dan Energi Yang Berbeda Dalam Pakan Terhadap Pemanfaatan Pakan Dan Pertumbuhan Patin (Pangasius Pangasius)

Pakan merupakan faktor terpenting dalam menunjang pertumbuhan dan perkembangan dalam kegiatan budidaya ikan, didalam pakan harus mengandung nutrisi yang lengkap. Penggunaan lemak dalam pakan sangat penting dalam menunjang pertumbuhan, karena lemak merupakan sumber energi yang memiliki nilai cukup tinggi dibanding protein dan karbohidrat. Pengunaan lemak sebagai “Protein sparing effect” yaitu pengganti protein sebagai sumber energi, sehingga penggunaan energi yang berasal dari protein dapat digunakan untuk menunjang pertumbuhan. Penelitian ini bertujuan untuk mengetahui pengaruh kandungan lemak dan energi yang berbeda dalam pakan terhadap pemanfaatan pakan dan pertumbuhan patin (P. pangasius).Metode penelitian yang dilakukan adalah metode eksperimen dengan rancangan acak lengkap (RAL) yang terdiri dari 4 perlakuan dan 3 kali ulangan. Perlakuan yang diterapkan adalah perbedaan kandungan lemak dan energi antara lain pada perlakuan A (8%, 281,98 kkal); B (9%, 286,74 kkal); C (10%, 289,45 kkal); dan D (11%, 296,21 kkal). Ikan uji yang digunakan adalah patin (Pangasius pangasius) yang berasal dari Banjarnegara, Jawa Tengah. Ikan uji yang digunakan dengan bobot rata-rata 6,48±0,68 g/ekor, dengan padat tebar 1 ekor/liter. Pakan diberikan 3 kali dalam sehari yaitu pada sekitar pukul 08.00 WIB, pukul 12.00 WIB, dan pukul 16.00 WIB. Pemberian pakan diberikan secara at satiation.Hasil penelitian menunjukan bahwa kandungan lemak dan energi yang berbeda dalam pakan buatan, memberikan pengaruh nyata (P<0,05) terhadap EPP, PER, dan RGR pada patin (P. pangasius), sedangkan pada variabel TKP dan SR tidak memberikan pengaruh nyata (P>0,05). Perlakuan D diperoleh hasil tertinggi dengan nilai TKP (25,27±0,06g), EPP (54,62±0,93%), PER (1,82±0,03%), RGR (0,75±0,02%/hari), dan SR (95,83%).Kandungan lemak dan energi yang berbeda dalam pakan, memberikan pengaruh nyata terhadap EPP, PER, dan RGR; tetapi tidak memberikan pengaruh nyata terhadap TKP dan SR patin (P. pangasius). Feed played an important role in fish farming and therefor, it should contain complete nutrition. The use of fat in fish diet was required for energy supply and producing of growth. The fat was used to subtitute energy source from protein, so the use of protein for fish growth can be optimaled. This study was aimed to observe the influence of different fat and energy on the feed utilization and growth of P. pangasius.The experimental method used was completely randomized design, which consisted of 4 treatments and 3 replicats, that were trial diets with ratio of treatment A (8%, 281.98 kkal); B (9%, 286.74 kkal); C (10%, 289.45 kkal); dan D (11%, 296.21 kkal) respectively. The ratio of vegetable oil : animal oil was equal. The fish used was P. pangasius, which was quired from Banjarnegara, Central Java. It\u27s average body weight of 6.48±0.68 g. The fish was maintenance in 8 l-tanks for 35 days. with a stocking density of 1 fish/l. The fish were feed 3 times a day, at 08.00, 12.00, and 16.00 by appliying at satiation method.The fish fed on resulted on dietary of different fat and energy on the feed on values significantly different (P<0.05) on the EPP, PER and RGR. But for feed in TKP and SR values (P>0.05). TKP value (25.27±0.06g) EPP (54.62±0.93%) , PER (1.82±0.03%) , RGR (0.75±0.02%/day), and SR (95.83%).It was concluded that the influence of different fat and energy on the feed utilization and growth of pangasius in feed significantly effect on, EPP, PER, and RGR while for TKP and SR where not significantly different

Activation of unliganded FGF receptor by extracellular phosphate potentiates proteolytic protection of FGF23 by its O-glycosylation

Fibroblast growth factor (FGF) 23 produced by bone is a hormone that decreases serum phosphate (Pi). Reflecting its central role in Pi control, serum FGF23 is tightly regulated by serum Pi alterations. FGF23 levels are regulated by the transcriptional event and posttranslational cleavage into inactive fragments before its secretion. For the latter, O-glycosylation of FGF23 by GALNT3 gene product prevents the cleavage, leading to an increase in serum FGF23. However, the molecular basis of Pi sensing in the regulation of serum FGF23 remains elusive. In this study, we showed that high Pi diet enhanced the skeletal expression of Galnt3, but not Fgf23, with expected increases in serum FGF23 and Pi in mice. Galnt3 induction by high Pi was further observed in osteoblastic UMR 106 cells, and this was mediated by activation of the extracellular signal-regulated kinase (ERK) pathway. Through proteomic searches for the upstream sensor for high Pi, we identified one subtype of the FGF receptor (FGFR1c), which was phosphorylated by high Pi in the absence of FGFs. The mode of unliganded FGFR activation by high Pi appeared different from that of FGFR bound to a canonical FGFR ligand (FGF2) when phosphorylation of the FGFR substrate 2α and ERK was monitored. Finally, we showed that an FGFR inhibitor and conditional deletion of Fgfr1 in osteoblasts/osteocytes abrogated high Pi diet-induced increases in serum FGF23 and femoral Galnt3 expression in mice. Thus, these findings uncover an unrecognized facet of unliganded FGFR function and illustrate a Pi-sensing pathway involved in regulation of FGF23 production

Lack of the Vitamin D Receptor is Associated with Reduced Epidermal Differentiation and Hair Follicle Growth

The active vitamin D metabolite, 1,25-dihydroxyvitamin D, acting through the vitamin D receptor, regulates the expression of genes in a variety of vitamin D-responsive tissues, including the epidermis. To investigate the role of the vitamin D receptor in mediating epidermal differentiation, we examined the histomorphology and expression of differentiation markers in the epidermis of vitamin D receptor knockout mice generated by gene targeting. The homozygous knockout mouse displayed a phenotype that closely resembles vitamin D-dependent rickets type II in humans, including the development of rickets and alopecia. Hair loss developed by 3mo after birth and gradually led to nearly total hair loss by 8mo. Histologic analysis of the skin of homozygous knockout mice revealed dilation of the hair follicles with the formation of dermal cysts starting at the age of 3wk. These cysts increased in size and number with age. Epidermal differentiation markers, including involucrin, profilaggrin, and loricrin, detected by immunostaining and in situ hybridization, showed decreased expression levels in homozygous knockout mice from birth until 3wk, preceding the morphologic changes observed in the hair follicles. Keratin 10 levels, however, were not reduced. At the ultrastructural level, homozygous knockout mice showed increased numbers of small dense granules in the granular layer with few or no surrounding keratin bundles and a loss of keratohyalin granules. Thus, both the interfollicular epidermis and the hair follicle appear to require the vitamin D receptor for normal differentiation. The temporal abnormalities between the two processes reflect the apparent lack of requirement for the vitamin D receptor during the anagen phase of the first (developmental) hair cycle, but with earlier effects on the terminal differentiation of the interfollicular epidermis

Recurrence of Proliferative Glomerulonephritis with Monoclonal Immunoglobulin G Deposits with a Striated Ultrastructure

This is the peer-reviewed but unedited manuscript version of the following article: Nephron 2020;144(suppl 1):43–48 (DOI: 10.1159/000512330)]. The final, published version is available at http://www.karger.com/?doi=10.1159/000512330