Predominant control of PDGF/PDGF receptor signaling in the migration and proliferation of human adipose­derived stem cells under culture conditions with a combination of growth factors.

Human adipose-derived stem cells (hASCs) play important roles in regenerative medicine and tissue engineering. However, their clinical applications are limited because of their instability during cell culture. Platelet lysates (PLTs) contain large amounts of growth factors that are useful for manufacturing cellular products. Platelet-derived growth factor (PDGF) is a major growth factor in PLTs and a potent mitogen in hASCs. To optimize growth conditions, the effects of a combination of growth factors on the promotion of hASC proliferation were investigated. Moreover, PDGF-BB combined with vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) markedly enhanced the viability of hASCs compared with the effects of PDGF-BB alone. Neither VEGF nor HGF had any effect alone. All growth factor receptor inhibitors inhibited cell proliferation. Wound healing assays revealed that VEGF and HGF stimulated PDGF-dependent cell migration. The effects of these growth factors on the activation of their cognate receptors and signaling enzymes were assessed using immunoblotting. Phosphorylation of PDGF receptor (PDGFR)ß, VEGF receptor (VEGFR)2 and MET proto-oncogene and receptor tyrosine kinase was induced by PDGF-BB treatment, and was further increased by treatment with PDGF-BB/VEGF and PDGF-BB/HGF. The levels of phospho-ERK1/2 and phospho-p38MAPK were increased by these treatments in parallel. Furthermore, the expression levels of SRY-box transcription factor 2 and peroxisome proliferator-activated receptor g were increased in PDGF-BB-treated cells, and PDGF-BB played a dominant role in spheroid formation. The findings of the present study highlighted that PDGF/PDGFR signaling played a predominant role in the proliferation and migration of hASCs, and suggested that PDGF was responsible for the efficacy of other growth factors when hASCs were cultured with PLTs.

Activation of cell adhesion and migration is an early event of platelet-rich plasma (PRP)-dependent stimulation of human adipose-derived stem/stromal cells.

Stem cell therapy is a promising treatment in regenerative medicine. Human adipose-derived stem/stromal cells (hASCs), a type of mesenchymal stem cell, are easy to harvest. In plastic and aesthetic surgery, hASC may be applied in the treatment of fat grafting, wound healing, and scar remodeling. Platelet-rich plasma (PRP) contains various growth factors, including platelet-derived growth factor (PDGF), which accelerates wound healing. We previously reported that PRP promotes the proliferation of hASC via multiple signaling pathways, and we evaluated the effect of PRP on the stimulation of hASC adhesion and migration, leading to the proliferation of these cells. When hASCs were treated with PRP, AKT, ERK1/2, paxillin and RhoA were rapidly activated. PRP treatment led to the formation of F-actin stress fibers. Strong signals for integrin ß1, paxillin and RhoA at the cell periphery of RPR-treated cells indicated focal adhesion. PRP promoted cell adhesion and movement of hASC, compared with the control group. Imatinib, an inhibitor of the PDGF receptor tyrosine kinase, inhibited the promotion of PRP-dependent cell migration. PDGF treatment of hASCs also stimulated cell adhesion and migration but to a lesser extent than PRP treatment. PRP promoted the adhesion and the migration of hASC, mediated by the activation of AKT in the integrin signaling pathway. PRP treatment was more effective than PDGF treatment in enhancing cell migration. Thus, the ability of PRPs to promote migration of hASC to enhance cell growth is evident.

Accelerated Angiogenesis of Human Umbilical Vein Endothelial Cells Under Negative Pressure Was Associated With the Regulation of Gene Expression Involved in the Proliferation and Migration.

ABSTRACT: Negative pressure has been used as a preferred therapy for wound healing; however, the mechanisms by which negative pressure promotes tissue restoration remain unclear. In the present study, RNA-sequencing analysis was performed to identify differentially expressed genes in human umbilical vein endothelial cells (HUVECs) exposed to negative pressure. Cell viability and DNA synthesis were examined using the cell counting kit-8 assay and bromodeoxyuridine incorporation, respectively. Cell migration was assessed using tube formation, Transwell, and wound healing assays. Activity of the serine/threonine kinase (AKT) signaling pathway was also examined by measuring the levels of phospho-paxicillin, phospho-focal adhesion kinase (p-FAK), and p-AKT1. The exposure of HUVECs to negative pressure enhanced cell proliferation and DNA synthesis. Negative pressure enhanced the migration and invasion of HUVECs, which was accompanied by upregulation of genes involved in angiogenesis, extracellular matrix organization, and cytoskeletal organization. The mRNA levels of growth factors, including placental growth factor and platelet-derived growth factor B, also increased. In addition, phosphorylation of paxicillin, focal adhesion kinase, and AKT increased under negative pressure. Collectively, the findings of this study demonstrated that negative pressure stimulates the angiogenic activity of HUVECs by increasing their proliferation and migration via activation of the AKT signaling pathway.

A Fluorescence-Based Quantitative Analysis for Total Bilirubin in Blood and Urine.

BACKGROUND: Bilirubin is a catabolic product of heme metabolism that circulates in the bloodstream in its unconjugated or glucuronide-conjugated form. Because the accumulation of bilirubin in the blood is a common symptom of liver diseases, its measurement in plasma (serum) is important for the diagnosis of these diseases. METHOD: We developed a method to assess total bilirubin levels in serum and urine, using the fluorescent protein UnaG and ß-glucuronidase. RESULTS: Our results indicate good correlation in serum total bilirubin levels between UnaG and the conventional bilirubin oxidase (BOD) methods. We found low levels of conjugated and unconjugated bilirubin in the urine of healthy subject individuals. Urinary bilirubin levels were elevated in patients with liver or bile duct diseases. A simple spot test of bilirubin using serum and urine showed a strong signal in patients with liver diseases. CONCLUSION: The proposed method to assess bilirubin levels in serum and urine will contribute to the accurate diagnosis of health conditions such as jaundice, anemia, and liver disease.

Moyamoya disease patient mutations in the RING domain of RNF213 reduce its ubiquitin ligase activity and enhance NFκB activation and apoptosis in an AAA+ domain-dependent manner.

Moyamoya disease (MMD) is a cerebrovascular disease characterized by progressive occlusion of the internal carotid arteries. Genetic studies originally identified RNF213 as an MMD susceptibility gene that encodes a large 591 kDa protein with a functional RING domain and dual AAA+ ATPase domains. As the functions of RNF213 and its relationship to MMD onset are unknown, we set out to characterize the ubiquitin ligase activity of RNF213, and the effects of MMD patient mutations on these activities and on other cellular processes. In vitro ubiquitination assays, using the RNF213 RING domain, identified Ubc13/Uev1A as a key ubiquitin conjugating enzyme that together generate K63-linked polyubiquitin chains. However, nearly all MMD patient mutations in the RING domain greatly reduced this activity. When full-length proteins were overexpressed in HEK293T cells, patient mutations that abolished the ubiquitin ligase activities conversely enhanced nuclear factor κB (NFκB) activation and induced apoptosis accompanied with Caspase-3 activation. These induced activities were dependent on the RNF213 AAA+ domain. Our results suggest that the NFκB- and apoptosis-inducing functions of RNF213 may be negatively regulated by its ubiquitin ligase activity and that disruption of this regulation could contribute towards MMD onset.

Fibroblast growth factor-2 stimulates proliferation of human adipose-derived stem cells via Src activation.

BACKGROUND: Human adipose-derived stem cells (hASCs) are a subset of mesenchymal stem cells (MSCs); it has been regarded as one of the most promising stem cells. We previously found that fibroblast growth factor-2 (FGF-2) enhanced the proliferation and differentiation of hASC. However, the mechanisms involved in the growth of hASCs by FGF-2 have not been investigated. METHODS: Human adipose-derived stem cells (hASCs) were cultured with FGF-2, and cell growth was assessed. Effects of FGF Receptor (FGFR) inhibitor (NVP-BGJ398), ERK1/2 inhibitor (PD98059), PI3K/Akt inhibitor (LY294002), JNK inhibitor (SP600125), and p38 MAPK inhibitor (SB203580) and Src inhibitor (PP1) on the proliferation were investigated. At the same time, we assessed the effect of FGFR inhibitor on several signaling enzymes such as ERK1/2, JNK, p38, and Akt, in protein level. The involvement of Src activation by FGF-2 was also examined. RESULTS: FGF-2 markedly promoted proliferation of hASCs at concentrations lower than 10 ng/ml and stimulated cell progression to the S and G2/M phases. Proliferation was blocked by the FGFR inhibitor (NVP-BGJ398) and various signaling pathway inhibitors, such as Erk1/2 inhibitor (PD98059), PI3K/Akt inhibitor (LY294002), JNK inhibitor (SP600125), and p38MAPK inhibitor (SB203580). The FGFR inhibitor reduced the activation of protein kinases, such as AKT, Erk1/2, JNK, and p38, in several signaling pathways. The downstream kinase of FGFR, Src, was activated by FGF-2, and its activation was canceled by the FGFR inhibitor. MEK1/2, a downstream kinase of Src, was parallelly regulated by FGF-2. The Src inhibitor (PP1) markedly blocked the proliferation of hASCs via inhibition of Src and MEK1/2. CONCLUSION: Src activation is indispensable for FGF-2-mediated proliferation of ASCs, as well as the subsequent activation of multi-signaling pathways.

Change in the developmental fate of the chick optic vesicle from the neural retina to the telencephalon.

The forebrain develops into the telencephalon, diencephalon, and optic vesicle (OV). The OV further develops into the optic cup, the inner and outer layers of which develop into the neural retina and retinal pigmented epithelium (RPE), respectively. We studied the change in fate of the OV by using embryonic transplantation and explant culture methods. OVs excised from 10-somite stage chick embryos were freed from surrounding tissues (the surface ectoderm and mesenchyme) and were transplanted back to their original position in host embryos. Expression of neural retina-specific genes, such as Rax and Vsx2 (Chx10), was downregulated in the transplants. Instead, expression of the telencephalon-specific gene Emx1 emerged in the proximal region of the transplants, and in the distal part of the transplants close to the epidermis, expression of an RPE-specific gene Mitf was observed. Explant culture studies showed that when OVs were cultured alone, Rax was continuously expressed regardless of surrounding tissues (mesenchyme and epidermis). When OVs without surrounding tissues were cultured in close contact with the anterior forebrain, Rax expression became downregulated in the explants, and Emx1 expression became upregulated. These findings indicate that chick OVs at stage 10 are bi-potential with respect to their developmental fates, either for the neural retina or for the telencephalon, and that the surrounding tissues have a pivotal role in their actual fates. An in vitro tissue culture model suggests that under the influence of the anterior forebrain and/or its surrounding tissues, the OV changes its fate from the retina to the telencephalon.

FGF-2 combined with bilayer artificial dermis composed of collagen matrix prompts generation of fat pad in subcutis of mice.

Fibroblast growth factor (FGF)-2 induces mitogenesis, angiogenesis and adipogenesis. In this study, the adipogenesis-inducing effects of FGF-2 combined with bilayer artificial dermis in mice were evaluated. FGF-2-impregnated bilayer artificial dermis composed of collagen matrix, PELNAC (Gunze Corp., Osaka, Japan) was implanted subcutaneously into the thoracic region of mice. At 1, 2, 3, and 4 weeks, samples were collected for H&E staining, von Willebrand factor immunostaining, and perilipin immunostaining to examine adipose tissue localization and angiogenesis. The collagen matrix-implanted group without the addition of FGF-2 was prepared as a control. At 2 weeks after the implantation of FGF-2 combined with dermal substitutes, adipocytes appeared in the collagen fibers. At 3-4 weeks, a fat pad was generated with neovascularization. The thickness of the fat pad had significantly increased at 2, 3, and 4 weeks. The remaining collagen was decreased by absorption over time. In the control group, no fat pad was newly formed. This study has identified a promising method to enhance adipogenic effects in the murine subcutis, representing a potential technique for soft tissue reconstruction.

Regulation of neuronal and photoreceptor cell differentiation by Wnt signaling from iris-derived stem/progenitor cells of the chick in flat vs. Matrigel-embedding cultures.

Previously we developed a simple culture method of the iris tissues and reported novel properties of neural stem/progenitor-like cells in the iris tissues of the chick and pig. When the iris epithelium or connective tissue (stroma) was treated with dispase, embedded in Matrigel, and cultured, neuronal cells extended from the explants within 24 h of culture, and cells positively stained for photoreceptor cell markers were also observed within a few days of culturing. In ordinary flat tissue culture conditions, explants had the same differentiation properties to those in tissue environments. Previously, we suggested that iris neural stem/progenitor cells are simply suppressed from neuronal differentiation within tissue, and that separation from the tissue releases the cells from this suppression mechanism. Here, we examined whether Wnt signaling suppressed neuronal differentiation of iris tissue cells in tissue environments because the lens, which has direct contact with the iris, is a rich source of Wnt proteins. When the Wnt signaling activator 6-bromoindirubin-3'-oxime (BIO) was administered to Matrigel culture, neuronal differentiation was markedly suppressed, but cell proliferation was not affected. When Wnt signaling inhibitors, such as DKK-1 and IWR-1, were applied to the same culture, they did not have any effect on cell differentiation and proliferation. However, when the inhibitors were applied to flat tissue culture, cells with neural properties emerged. These results indicate that the interaction of iris tissue with neighboring tissues and the environment regulates the stemness nature of iris tissue cells, and that Wnt signaling is a major factor.

Platelet-rich plasma enhances the proliferation of human adipose stem cells through multiple signaling pathways.

BACKGROUND: Platelet-rich plasma (PRP) is an autologous blood product that contains a high concentration of several growth factors. Platelet-derived growth factor (PDGF)-BB is a potential mitogen for human adipose-derived stem cells (hASCs). PRP stimulates proliferation of hASCs; however, the signaling pathways activated by PRP remain unclear. METHODS: hASCs were cultured with or without PRP or PDGF-BB, and proliferation was assessed. hASCs were also treated with PRP or PDGF-BB with or without imatinib, which is a PDGF receptor tyrosine kinase inhibitor, or sorafenib, which is a multikinase inhibitor. Inhibition of cell proliferation was examined using anti-PDGF antibody (Abcam, Cambridge, UK), by cell counting. We assessed the effects of inhibitors of various protein kinases such as ERK1/2, JNK, p38, and Akt on the proliferation of hASCs. RESULTS: The proliferation was remarkably promoted in cells treated with either 1% PRP or 10 ng/ml PDGF-BB, and both imatinib and sorafenib inhibited this proliferation. Anti-PDGF antibody (0.5 and 2 µg/ml) significantly decreased the proliferation of hASCs compared with control. PRP-mediated hASC proliferation was blocked by inhibitors of ERK1/2, Akt, and JNK, but not by an inhibitor of p38. CONCLUSIONS: PRP promotes hASC proliferation, and PDGF-BB in PRP plays a major role in inducing the proliferation of hASCs. PRP promotes hASC proliferation via ERK1/2, PI3K/Akt, and JNK signaling pathways.

A novel culture method reveals unique neural stem/progenitors in mature porcine iris tissues that differentiate into neuronal and rod photoreceptor-like cells.

Iris neural stem/progenitor cells from mature porcine eyes were investigated using a new protocol for tissue culture, which consists of dispase treatment and Matrigel embedding. We used a number of culture conditions and found an intense differentiation of neuronal cells from both the iris pigmented epithelial (IPE) cells and the stroma tissue cells. Rod photoreceptor-like cells were also observed but mostly in a later stage of culture. Neuronal differentiation does not require any additives such as fetal bovine serum or FGF2, although FGF2 and IGF2 appeared to promote neural differentiation in the IPE cultures. Furthermore, the stroma-derived cells were able to be maintained in vitro indefinitely. The evolutionary similarity between humans and domestic pigs highlight the potential for this methodology in the modeling of human diseases and characterizing human ocular stem cells.

The novel heme-dependent inducible protein, SRRD regulates heme biosynthesis and circadian rhythms.

Heme plays a role in the regulation of the expression of genes related to circadian rhythms and heme metabolism. In order to identify new heme-regulated proteins, an RNA sequence analysis using mouse NIH3T3 cells treated without or with 5-aminolevulinic acid (ALA) was performed. Among the changes observed in the levels of various mRNAs including heme oxygenase-1 (HO-1) and ALA synthase-1 (ALAS1), a mouse homologue of the plant circadian-regulating protein SRR1, SRR1 domain containing (SRRD) was induced by the ALA treatment. The expression of SRRD was dependent on heme biosynthesis, and increased the production of heme. SRRD was expressed under circadian rhythms, and influenced the expression of clock genes including PER2, BMAL1, and CLOCK. The knockout of SRRD arrested the growth of cells, indicating that SRRD plays roles in heme-regulated circadian rhythms and cell proliferation.

Upregulation of matrix metalloproteinase triggers transdifferentiation of retinal pigmented epithelial cells in Xenopus laevis: A Link between inflammatory response and regeneration.

In adult Xenopus eyes, when the whole retina is removed, retinal pigmented epithelial (RPE) cells become activated to be retinal stem cells and regenerate the whole retina. In the present study, using a tissue culture model, it was examined whether upregulation of matrix metalloproteinases (Mmps) triggers retinal regeneration. Soon after retinal removal, Xmmp9 and Xmmp18 were strongly upregulated in the tissues of the RPE and the choroid. In the culture, Mmp expression in the RPE cells corresponded with their migration from the choroid. A potent MMP inhibitor, 1,10-PNTL, suppressed RPE cell migration, proliferation, and formation of an epithelial structure in vitro. The mechanism involved in upregulation of Mmps was further investigated. After retinal removal, inflammatory cytokine genes, IL-1ß and TNF-α, were upregulated both in vivo and in vitro. When the inflammation inhibitors dexamethasone or Withaferin A were applied in vitro, RPE cell migration was severely affected, suppressing transdifferentiation. These results demonstrate that Mmps play a pivotal role in retinal regeneration, and suggest that inflammatory cytokines trigger Mmp upregulation, indicating a direct link between the inflammatory reaction and retinal regeneration. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1086-1100, 2017.

Detection and Removal of Endogenous Carbon Monoxide by Selective and Cell-Permeable Hemoprotein Model Complexes.

Carbon monoxide (CO) is produced in mammalian cells during heme metabolism and serves as an important signaling messenger. Here we report the bioactive properties of selective CO scavengers, hemoCD1 and its derivative R8-hemoCD1, which have the ability to detect and remove endogenous CO in cells. HemoCD1 is a supramolecular hemoprotein-model complex composed of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphinatoiron(II) and a per-O-methylated ß-cyclodextrin dimer having an pyridine linker. We demonstrate that hemoCD1 can be used effectively to quantify endogenous CO in cell lysates by a simple spectrophotometric method. The hemoCD1 assay detected ca. 260 pmol of CO in 106 hepatocytes, which was well-correlated with the amount of intracellular bilirubin, the final breakdown product of heme metabolism. We then covalently attached an octaarginine peptide to a maleimide-appended hemoCD1 to synthesize R8-hemoCD1, a cell-permeable CO scavenger. Indeed, R8-hemoCD1 was taken up by intact cells and captured intracellular CO with high efficiency. Moreover, we revealed that removal of endogenous CO by R8-hemoCD1 in cultured macrophages led to a significant increase (ca. 2.5-fold) in reactive oxygen species production and exacerbation of inflammation after challenge with lipopolysaccharide. Thus, R8-hemoCD1 represents a powerful expedient for exploring specific and still unidentified biological functions of CO in cells.

Potential role of heme metabolism in the inducible expression of heme oxygenase-1.

BACKGROUND: The degradation of heme significantly contributes to cytoprotective effects against oxidative stress and inflammation. The enzyme heme oxygenase-1 (HO-1), involved in the degradation of heme, forms carbon monoxide (CO), ferrous iron, and bilirubin in conjunction with biliverdin reductase, and is induced by various stimuli including oxidative stress and heavy metals. We examined the involvement of heme metabolism in the induction of HO-1 by the inducers sulforaphane and sodium arsenite. METHODS: We examined the expression of HO-1 in sulforaphane-, sodium arsenite- and CORM3-treated HEK293T cells, by measuring the transcriptional activity and levels of mRNA and protein. RESULTS: The blockade of heme biosynthesis by succinylacetone and N-methyl protoporphyrin, which are inhibitors of heme biosynthesis, markedly decreased the induction of HO-1. The knockdown of the first enzyme in the biosynthesis of heme, 5-aminolevulinic acid synthase, also decreased the induction of HO-1. The cessation of HO-1 induction occurred at the transcriptional and translational levels, and was mediated by the activation of the heme-binding transcriptional repressor Bach1 and translational factor HRI. CO appeared to improve the expression of HO-1 at the transcriptional and translational levels. CONCLUSIONS: We demonstrated the importance of heme metabolism in the stress-inducible expression of HO-1, and also that heme and its degradation products are protective factors for self-defense responses. GENERAL SIGNIFICANCE: The key role of heme metabolism in the stress-inducible expression of HO-1 may promote further studies on heme and its degradation products as protective factors of cellular stresses and iron homeostasis in specialized cells, organs, and whole animal systems.

Feedback Response to Selective Depletion of Endogenous Carbon Monoxide in the Blood.

The physiological roles of endogenous carbon monoxide (CO) have not been fully understood because of the difficulty in preparing a loss-of-function phenotype of this molecule. Here, we have utilized in vivo CO receptors, hemoCDs, which are the supramolecular 1:1 inclusion complexes of meso-tetrakis(4-sulfonatophenyl)porphinatoiron(II) with per-O-methylated ß-cyclodextrin dimers. Three types of hemoCDs (hemoCD1, hemoCD2, and hemoCD3) that exhibit different CO-affinities have been tested as CO-depleting agents in vivo. Intraperitoneally administered hemoCD bound endogenous CO within the murine circulation, and was excreted in the urine along with CO in an affinity-dependent manner. The sufficient administration of hemoCD that has higher CO-affinity than hemoglobin (Hb) produced a pseudoknockdown state of CO in the mouse in which heme oxygenase-1 (HO-1) was markedly induced in the liver, causing the acceleration of endogenous CO production to maintain constant CO-Hb levels in the blood. The contents of free hemin and bilirubin in the blood plasma of the treated mice significantly increased upon removal of endogenous CO by hemoCD. Thus, a homeostatic feedback model for the CO/HO-1 system was proposed as follows: HemoCD primarily removes CO from cell-free CO-Hb. The resulting oxy-Hb is quickly oxidized to met-Hb by oxidant(s) such as hydrogen peroxide in the blood plasma. The met-Hb readily releases free hemin that directly induces HO-1 in the liver, which metabolizes the hemin into iron, biliverdin, and CO. The newly produced CO binds to ferrous Hb to form CO-Hb as an oxidation-resistant state. Overall, the present system revealed the regulatory role of CO for maintaining the ferrous/ferric balance of Hb in the blood.

Enhancements of the production of bilirubin and the expression of ß-globin by carbon monoxide during erythroid differentiation.

Heme is degraded by heme oxygenase to form iron, carbon monoxide (CO), and biliverdin. However, information about the catabolism of heme in erythroid cells is limited. In this study, we showed the production and export of bilirubin in murine erythroleukemia (MEL) cells. The production of bilirubin by MEL cells was enhanced when heme synthesis was induced. When mouse bone marrow cells were induced with erythropoietin to differentiate into erythroid cells, the synthesis of bilirubin increased. The expression of ß-globin was enhanced by CO at the transcriptional level. These results indicate that constant production of CO from heme regulates erythropoiesis.

Localization of Neurensin1 in cerebellar Purkinje cells of the developing chick and its possible function in dendrite formation.

Neurensin1 (Nrsn1) gene, highly specific to neurons, has been considered to play a role in neurite growth during neuronal development and regeneration in mice. Intense expression of Nrsn1 was found particularly in projecting neurons like retinal ganglion cells and spinal motor neurons, suggesting that Neurensin1 is needed for active neurite growth. In the present study we cloned chick Nrsn1 gene and produced an antibody against cNrsn1 to examine Nrsn1 localization in the chick brain, since the chick is a suitable animal model for the study of developmental neurobiology. We found that there are neurons intensely stained for Nrsn1 antibody localized in the optic tectum, the cerebellum and the brain stem. These neurons are large in size and considered to be projecting neurons. In the cerebellum, Purkinje cells are the only one type of neurons stained for Nrsn1. During Purkinje cell development the arborized dendrites and axons become intensely stained at stages E17-18. A siRNA gene knock down was applied to the cultured embryonic cerebellar tissues and the result showed that Nrsn1 has an important role in dendrite formation of Purkinje cells. These findings suggest that Neurensin1 is also involved in neural development in the chick brain and that the embryonic chick brain is a good model to disclose the molecular and physiological functions of Nrsn1.

Stem Cell Replacement Improves Expression of SMP30 in db/db Mice.

We have previously reported that replacing bone marrow stem cells may improve hyperglycemia and oxidative stress in db/db mice, a type 2 diabetic mouse model. Senescence marker protein 30 (SMP30) is an antioxidant protein that decreases with aging. However, it has not been clear whether SMP30 decreases in the livers of obese mice, and whether stem cell replacement would improve SMP30 expression in the liver. Bone marrow stem cells of db/db mice were replaced with the bone marrow stem cells of C57BL/6 mice. Plasma cytokine and insulin levels were measured, and glycogen content, expression of SMP30, and fibrosis in the liver were assessed. Our results showed that stem cell replacement increased the expression of SMP30 in the liver, resulting from decreased plasma inflammation cytokines and hyperinsulinemia in db/db mice. This is the first report that stem cell replacement increased the expression of SMP30 in the liver, and may help prevent fibrosis in the liver of db/db mice.