The antidiabetic effect of MSCs is not impaired by insulin prophylaxis and is not improved by a second dose of cells

Type 1 diabetes mellitus (T1D) is due to autoimmune destruction of pancreatic beta-cells. Previously, we have shown that intravenously administered bone marrow-derived multipotent mesenchymal stromal cells (MSCs) allows pancreatic islet recovery, improves insulin secretion and reverts hyperglycemia in low doses streptozotocin (STZ)-induced diabetic mice. Here we evaluate whether insulin prophylaxis and the administration of a second dose of cells affect the antidiabetic therapeutic effect of MSC transplantation. Insulitis and subsequent elimination of pancreatic beta-cells was promoted in C57BL/6 mice by the injection of 40 mg/kg/day STZ for five days. Twenty-four days later, diabetic mice were distributed into experimental groups according to if they received or not insulin and/or one or two doses of healthy donor-derived MSCs. Three and half months later: glycemia, pancreatic islets number, insulinemia, glycated hemoglobin level and glucose tolerance were determined in animals that did not received exogenous insulin for the last 1.5 months. Also, we characterized MSCs isolated from mice healthy or diabetic. The therapeutic effect of MSC transplantation was observed in diabetic mice that received or not insulin prophylaxis. Improvements were similar irrespective if they received one or two doses of cells. Compared to MSCs from healthy mice, MSCs from diabetic mice had the same proliferation and adipogenic potentials, but were less abundant, with altered immunophenotype and no osteogenic potential.Our preclinical results should be taken into account when designing phase II clinical trials aimed to evaluate MSC transplantation in patients with T1D. Cells should be isolated form healthy donor, insulin prophylaxis could be maintained and a second dose, after an elapse of two months, appears unnecessary in the medium-term.     

Correction to: Computational analysis of viable parameter regions in models of synthetic biological systems

Background

Myocardial infarction (MI) is a common cause of mortality in people. Mesenchymal stem cell (MSC) has been shown to exert therapeutic potential to treat myocardial infarction (MI). However, in patients with diabetes, the diabetic environment affected MSCs activity and could impair the efficacy of treatment. Interleukin-10 (IL-10) has been shown to attenuate MI by suppressing inflammation. In current study, the combination of MSC transplantation with IL-10 was evaluated in a diabetic mice model with MI.

Methods

We engineered bone marrow derived MSCs (BM-MSCs) to overexpress IL-10 by using CRISPR activation. We established the diabetic mice model with MI and monitored the IL-10 expression after BM-MSCs transplantation. We also evaluated the effects of BM-MSCs transplantation on inflammatory response, cell apoptosis, cardiac function and angiogenesis.

Results

CRISPR activation system enabled overexpression of IL-10 in BM-MSCs. Transplantation of BM-MSCs overexpressing IL-10 resulted in IL-10 expression in heart after transplantation. Transplantation of BM-MSCs overexpressing IL-10 inhibited inflammatory cell infiltration and pro-inflammatory cytokines production, improved cardiac functional recovery, alleviated cardiac injury, decreased apoptosis of cardiac cells and increased angiogenesis.

Conclusion

In summary, we have demonstrated the therapeutic potential of IL-10 overexpressed BM-MSCs in the treatment of MI in diabetic mice.

     

MSC attenuate diabetes-induced functional impairment in adipocytes via secretion of insulin-like growth factor-1

The function of subcutaneous adipocytes in promoting wound healing is significantly suppressed in diabetic wounds. Recent studies have demonstrated the ability of mesenchymal stem cell (MSC) to ameliorate impaired diabetic wound healing. We hypothesized that MSC function may involve subcutaneous adipocytes. The abnormal function of subcutaneous adipocytes from STZ induced diabetic mice including glucose uptake and free fatty acid (FFA) secretion level were assessed. Then these cells were co-cultured with MSC via a transwell system to observe the changes of metabolic index and glucose transporter four (GLUT4) as well as phosphoinositide 3-kinase/protein kinase (PI3K/AKT) signaling pathway expression. The results of metabolic index suggest that MSC obviously attenuated the diabetes-induced functional impairment. Both mRNA and protein expression analyses showed that PI3K/AKT insulin signaling pathway and GLUT4 expression were up-regulated. These changes were substantially associated with a increased level of insulin-like growth factor-1 (IGF-1) secretion from MSC. These findings suggest that MSC could attenuate abnormal function of diabetic adipocytes by IGF-1secretion, which was more or less associated with the beneficial effects of MSC on improving diabetic wound healing.     

Adipose-Derived Mesenchymal Stem Cells Transplantation Alleviates Renal Injury in Streptozotocin-Induced Diabetic Nephropathy

Previous studies have illustrated that bone marrow-derived mesenchymal stem cell (BMMSC) transplantation has therapeutic effects on diabetes and can prevent mice from renal damage and diabetic nephropathy (DN). Moreover, adipose-derived MSCs possess similar characteristics to BMMSCs. We investigated the effect of ADMSC transplantation on streptozotocin (STZ)-induced renal injury. Diabetes was induced in rats by STZ injection. After ADMSC treatment, renal histological changes and cell apoptosis were evaluated as were the expression of apoptosis-related proteins, Wnt/β-catenin pathway members, and klotho levels. We found that ADMSCs improved renal histological changes. Next, NRK-52E cells were exposed to normal glucose (NG; 5.5 mM glucose plus 24.5 mM mannitol)/high glucose (HG) or ADMSCs, and then measured for changes in the aforementioned proteins. Similarly, changes in these proteins were also determined following transient transfection of klotho siRNA. We found that both ADMSC transplantation and co-incubation reduced the rate of cellular apoptosis, decreased Bax and Wnt/β-catenin levels, and elevated Bcl-2 and klotho levels. Interestingly, klotho knockdown reversed the effects of ADMSCs on the expression of apoptosis-related proteins and Wnt/β-catenin pathway members. Taken together, ADMSCs transplantation might attenuate renal injury in DN via activating klotho and inhibiting the Wnt/β-catenin pathway. This study may provide evidence for the treatment of DN using ADMSCs.     

Amelioration of type I diabetes-induced osteoporosis by parathyroid hormone is associated with improved osteoblast survival

Type 1 diabetic osteoporosis results from impaired osteoblast activity and death. Therefore, anti-resorptive treatments may not effectively treat bone loss in this patient population. Intermittent parathyroid hormone (PTH) treatment stimulates bone remodeling and increases bone density in healthy subjects. However, PTH effects may be limited in patients with diseases that interfere with its signaling. Here, we examined the ability of 8 and 40 μg/kg intermittent PTH to counteract diabetic bone loss. PTH treatment reduced fat pad mass and blood glucose levels in non-diabetic PTH-treated mice, consistent with PTH-affecting glucose homeostasis. However, PTH treatment did not significantly affect general body parameters, including the blood glucose levels, of type 1 diabetic mice. We found that the high dose of PTH significantly increased tibial trabecular bone density parameters in control and diabetic mice, and the lower dose elevated trabecular bone parameters in diabetic mice. The increased bone density was due to increased mineral apposition and osteoblast surface, all of which are defective in type 1 diabetes. PTH treatment suppressed osteoblast apoptosis in diabetic bone, which could further contribute to the bone-enhancing effects. In addition, PTH treatment (40 μg/kg) reversed preexisting bone loss from diabetes. We conclude that intermittent PTH may increase type 1 diabetic trabecular bone volume through its anabolic effects on osteoblasts.     

α-lipoic acid inhibits high glucose-induced apoptosis in HIT-T15 cells

High blood glucose plays an important role in the pathogenesis of diabetes. α-lipoic acid (LA) has been used to prevent and treat diabetes, and is thought to act by increasing insulin sensitivity in many tissues. However, whether LA also has a cytoprotective effect on pancreatic islet beta cells remains unclear. In this study, we assessed whether LA could inhibit apoptosis in beta cells exposed to high glucose concentrations. HIT-T15 pancreatic beta cells were treated with 30 mmol/L glucose in the presence or absence of 0.5 mmol/L LA for 8 days. LA significantly reduced the numbers of apoptotic HIT-T15 cells and inhibited the cell overgrowth normally induced by high glucose treatment. Additionally, LA inhibited insulin expression and secretion in HIT-T15 cells induced by high glucose. Further study demonstrated that LA upregulated Pdx1 and Bcl2 gene expression, reduced Bax gene expression, and promoted phosphorylation of Akt in HIT-T15 cells treated with high glucose. Intriguingly, knockdown of Pdx1 expression partially offset the anti-apoptotic effect of LA. However, inhibition of Akt by PI3K/AKT antagonist LY294002 only slightly reversed the anti-apoptosis effect of LA and mildly decreased the gene expression level of Pdx1 (P > 0.05). Moreover, LA only slightly attenuated reactive oxygen species (ROS) production and augmented mitochondrial membrane potential. Therefore, our data suggest that α-lipoic acid can effectively attenuate high glucose-induced HIT-T15 cell apoptosis probably by increasing Pdx1 expression. These findings provide a new interpretation on the role of LA in the treatment of diabetes.     

移植骨髓间充质干细胞治疗大鼠糖尿病的研究

目的 通过移植骨髓间充质干细胞（mesenchymal stem cell,MSC）的方法试治疗大鼠糖尿病。方法 贴壁生长的MSC与大鼠胰腺的细胞共培养以检测其向胰岛细胞分化的潜能。并将体外培养扩增的MSC移植入糖尿病大鼠体内,观测其能否改善糖尿病病情及其在大鼠体内微环境中的分化情况。结果 共培养法可使MSC分化为胰岛样细胞。对大鼠的MSC移植能明显缓解糖尿病病情。结论 MSC移植的方法对大鼠糖尿病有一定的治疗作用。     

Effects of chemical sympathectomy by means of 6-hydroxydopamine on insulin secretion and islet morphology in alloxan-diabetic mice

Activation of sympathetic nerves increases circulating glucose and inhibits insulin release from the islet beta-cells, which might contribute to stress-related diabetes. Accordingly, we have shown previously that blockade of parasympathetic activity aggravates diabetes in alloxan-treated mice, suggesting that unopposed sympathetic activity impairs diabetes. In this study, we tested whether elimination of sympathetic nerve activity by chemical sympathectomy with 6-hydroxydopamine (6-OHDA; 60 mg/kg) ameliorates the diabetogenic effects of alloxan (50 mg/kg) in NMRI mice. Mice given alloxan alone developed manifest diabetes after 2 days, as indicated by hyperglycemia. The diabetes persisted throughout the 35-day study period. Pretreatment with 6-OHDA did not, however, affect the glucose levels or the low, 2-min in vivo insulin response to glucose (1 g/kg) after alloxan. In situ hybridization at day 35 revealed a significantly reduced grain area of insulin-mRNA in the alloxan-treated animals, which was not affected by 6-OHDA, and an altered islet architecture, with accumulation of glucagon cells in the central portion. Also 6-OHDA alone reduced the insulin mRNA area, but this was accompanied by an increase in the total islet area. We conclude that, in contrast to cholinergic inhibition, sympathectomy does not perturb the development of chemically induced diabetes in mice. Alone, however, sympathectomy reduces insulin gene expression and induces increased islet size, suggesting that sympathetic nerves are of importance for long-term islet function.     

The phenotype and functional alterations of macrophages in mice with hyperglycemia for long term

Abnormal immunity and its related complications are the major causes of mortality and morbidity in diabetes patients. Macrophages, as one of the important innate cells, play pivotal roles in controlling immune homeostasis, immunity, and tolerance. The effects of hyperglycemia on the function of macrophages in hosts remain to be determined. Here we used mice with streptozotocin (STZ)-induced diabetes for long term to study the changes of macrophages. We found that F4/80(+) peritoneal exudate macrophages (PEMs) from mice with diabetes for 4 months displayed significantly reduced CD86 and CD54 expression and tumor necrosis factor (TNF)-α and IL-6 production but enhanced nitric oxide (NO) secretion compared with control mice when treated with interferon (IFN)-γ and lipopolysaccharide (LPS), while the activity of arginase in PEMs from diabetic mice was significantly higher than control mice when stimulating with IL-4. These dysfunctions of macrophages could be efficiently reversed by insulin treatment. Importantly, in vitro bone marrow-derived macrophages showed similar functional changes, indicating the epigenetic alteration of macrophage precursors in these mice. In an in vitro culture system, high glucose and insulin significantly altered TNF-α, IL-6, and NO production and arginase activity of macrophages, which was reversed by the treatment with AKT and ERK inhibitors. Therefore, hyperglycemia and insulin deficiency can modify macrophage function through AKT-mTOR and ERK pathways and through epigenetic effects on macrophage precursors. To further identify different components of diabetes on the dysfunction of macrophages is important for efficient prevention of diabetic complications.     

Rg1 protects H9C2 cells from high glucose‐/palmitate‐induced injury via activation of AKT/GSK‐3β/Nrf2 pathway

Our previous studies have assessed ginsenoside Rg1 (Rg1)‐mediated protection in a type 1 diabetes rat model. To uncover the mechanism through which Rg1 protects against cardiac injury induced by diabetes, we mimicked diabetic conditions by culturing H9C2 cells in high glucose/palmitate. Rg1 had no toxic effect, and it alleviated the high glucose/palmitate damage in a dose‐dependent manner, as indicated by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide assay and lactate dehydrogenase release to the culture medium. Rg1 prevented high glucose/palmitate‐induced cell apoptosis, assessed using cleaved caspase‐3 and terminal deoxynucleotidyl transferase dUTP nick end labelling staining. Rg1 also reduced high glucose‐/palmitate‐induced reactive oxygen species formation and increased intracellular antioxidant enzyme activity. We found that Rg1 activates protein kinase B (AKT)/glycogen synthase kinase‐3 (GSK‐3β) pathway and antioxidant nuclear factor erythroid 2‐related factor 2 (Nrf2) pathway, indicated by increased phosphorylation of AKT and GSK‐3β, and nuclear translocation of Nrf2. We used phosphatidylinositol‐3‐kinase inhibitor Ly294002 to block the activation of the AKT/GSK‐3β pathway and found that it partially reversed the protection by Rg1 and decreased Nrf2 pathway activation. The results suggest that Rg1 exerts a protective effect against high glucose and palmitate damage that is partially AKT/GSK‐3β/Nrf2‐mediated. Further studies are required to validate these findings using primary cardiomyocytes and animal models of diabetes.     

Effect of bone marrow–derived mesenchymal stromal cells on hepatoma

Background aimsThe aim of the study was to evaluate the effect of mesenchymal stromal cells (MSCs) on tumor cell growth in vitro and in vivo and to elucidate the apoptotic and anti-proliferative mechanisms of MSCs on a hepatocellular carcinoma (HCC) murine model.MethodsThe growth-inhibitory effect of MSCs on the Hepa 1–6 cell line was tested by means of methyl thiazolyl diphenyl-tetrazolium assay. Eighty female mice were randomized into four groups: group 1 consisted of 20 mice that received MSCs only by intrahepatic injection; group 2 consisted of 20 HCC mice induced by inoculation of Hepa 1–6 cells into livers without MSC treatment; group 3 consisted of 20 mice that received MSCs after induction of liver cancer; group 4 consisted of 20 mice that received MSCs after induction of liver cancer on top of induced biliary cirrhosis.ResultsMSCs exhibited a growth-inhibitory effect on Hepa 1–6 murine cell line in vitro. Concerning in vivo study, decreases of serum alanine transaminase, aspartate transaminase and albumin levels after MSC transplantation in groups 2 and 3 were found. Gene expression of α-fetoprotein was significantly downregulated after MSC injection in the HCC groups. We found that gene expression of caspase 3, P21 and P53 was significantly upregulated, whereas gene expression of Bcl-2 and survivin was downregulated in the HCC groups after MSC injection. Liver specimens of the HCC groups confirmed the presence of dysplasia. The histopathological picture was improved after administration of MSCs to groups 2 and 3.ConclusionsMSCs upregulated genes that help apoptosis and downregulated genes that reduce apoptosis. Therefore, MSCs could inhibit cell division of HCC and potentiate their death.     

Circ‐AKT3 inhibits the accumulation of extracellular matrix of mesangial cells in diabetic nephropathy via modulating miR‐296‐3p/E‐cadherin signals

Diabetic nephropathy is a leading cause of end‐stage renal disease globally. The vital role of circular RNAs (circRNAs) has been reported in diabetic nephropathy progression, but the molecular mechanism linking diabetic nephropathy to circRNAs remains elusive. In this study, we investigated the significant function of circ‐AKT3/miR‐296‐3p/E‐cadherin regulatory network on the extracellular matrix accumulation in mesangial cells in diabetic nephropathy. The expression of circ‐AKT3 and fibrosis‐associated proteins, including fibronectin, collagen type I and collagen type IV, was assessed via RT‐PCR and Western blot analysis in diabetic nephropathy animal model and mouse mesangial SV40‐MES13 cells. Luciferase reporter assays were used to investigate interactions among E‐cadherin, circ‐AKT3 and miR‐296‐3p in mouse mesangial SV40‐MES13 cells. Cell apoptosis was evaluated via flow cytometry. The level of circ‐AKT3 was significantly lower in diabetic nephropathy mice model group and mouse mesangial SV40‐MES13 cells treated with high‐concentration (25 mmol/L) glucose. In addition, circ‐AKT3 overexpression inhibited the level of fibrosis‐associated protein, such as fibronectin, collagen type I and collagen type IV. Circ‐AKT3 overexpression also inhibited the apoptosis of mouse mesangial SV40‐MES13 cells treated with high glucose. Luciferase reporter assay and bioinformatics tools identified that circ‐AKT3 could act as a sponge of miR‐296‐3p and E‐cadherin was the miR‐296‐3p direct target. Moreover, circ‐AKT3/miR‐296‐3p/E‐cadherin modulated the extracellular matrix of mouse mesangial cells in high‐concentration (25 mmol/L) glucose, inhibiting the synthesis of related extracellular matrix protein. In conclusion, circ‐AKT3 inhibited the extracellular matrix accumulation in diabetic nephropathy mesangial cells through modulating miR‐296‐3p/E‐cadherin signals, which might offer novel potential opportunities for clinical diagnosis targets and therapeutic biomarkers for diabetic nephropathy.     

人脐带间充质干细胞对1型糖尿病鼠肝脏损伤的保护作用

目的探讨人脐带间充质干细胞（hUCMSCs）对初发1型非肥胖型糖尿病（NOD）小鼠肝脏损伤的保护作用。 方法雌性NOD小鼠共33只,饲养9周后,将成模的21只小鼠随机分为糖尿病组和干细胞组,每组10只,其中干细胞（MSCs）组发病后第3天尾静脉注射hUCMSCs 1?次;另取10只未发病小鼠为正常对照组。各组小鼠每周检测随机血糖（GLU）水平,8周后处死小鼠,取肝脏,HE染色后观察肝脏结构改变,ELISA法检测糖基化终末产物（AGEs）水平,Real-time PCR法检测糖基化终末产物受体（RAGE）、NF-κB P65、白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α） mRNA的表达水平。采用单因素方差分析和SNK-q检验进行统计学分析。 结果MSCs治疗8周后,MSCs组小鼠随机血糖（8.46±1.37）mmol/L比T1DM组（32.82±0.59）?mmol/L降低,差异具有统计学意义（P < 0.05）。同时T1DM组肝脏细胞形态异常,炎症细胞浸润,而MSCs组的较T1DM组明显改善。MSCs组小鼠肝脏组织的AGEs浓度（0.72±0.10）μg/ml低于T1DM组（1.35±0.22）μg/ml;同时MSCs组的NF-κB P65、IL-6、TNF-α、RAGE mRNA水平（分别为10.08±1.94、9.31±1.67、11.92±1.82、3.87±0.27）,均低于T1DM组（分别为15.46±3.09、18.04±1.69、22.12±3.23、5.12±0.26）,差异具有统计学意义（P < 0.05）。 结论hUCMSCs可以降低糖尿病小鼠血糖水平,改善肝脏微观病理状态,降低AGEs浓度及某些炎性因子的水平以减轻肝脏损伤。     

Wnt 3a promotes proliferation and suppresses osteogenic differentiation of adult human mesenchymal stem cells

Multipotential adult mesenchymal stem cells (MSCs) are able to differentiate along several known lineages, and lineage commitment is tightly regulated through specific cellular mediators and interactions. Recent observations of a low/high bone-mass phenotype in patients expressing a loss-/gain-of-function mutation in LRP5, a coreceptor of the Wnt family of signaling molecules, suggest the importance of Wnt signaling in bone formation, possibly involving MSCs. To analyze the role of Wnt signaling in mesenchymal osteogenesis, we have profiled the expression of WNTs and their receptors, FRIZZLEDs (FZDs), and several secreted Wnt inhibitors, such as SFRPs, and examined the effect of Wnt 3a, as a representative canonical Wnt member, during MSC osteogenesis in vitro. WNT11, FZD6, SFRP2, and SFRP3 are upregulated during MSC osteogenesis, while WNT9A and FZD7 are downregulated. MSCs also respond to exogenous Wnt 3a, based on increased beta-catenin nuclearization and activation of a Wnt-responsive promoter, and the magnitude of this response depends on the MSC differentiation state. Wnt 3a exposure inhibits MSC osteogenic differentiation, with decreased matrix mineralization and reduced alkaline phosphatase mRNA and activity. Wnt 3a treatment of fully osteogenically differentiated MSCs also suppresses osteoblastic marker gene expression. The Wnt 3a effect is accompanied by increased cell number, resulting from both increased proliferation and decreased apoptosis, particularly during expansion of undifferentiated MSCs. The osteo-suppressive effects of Wnt 3a are fully reversible, i.e., treatment prior to osteogenic induction does not compromise subsequent MSC osteogenesis. The results also showed that sFRP3 treatment attenuates some of the observed Wnt 3a effects on MSCs, and that inhibition of canonical Wnt signaling using a dominant negative TCF1 enhances MSC osteogenesis. Interestingly, expression of Wnt 5a, a non-canonical Wnt member, appeared to promote osteogenesis. Taken together, these findings suggest that canonical Wnt signaling functions in maintaining an undifferentiated, proliferating progenitor MSC population, whereas non-canonical Wnts facilitate osteogenic differentiation. Release from canonical Wnt regulation is a prerequisite for MSC differentiation. Thus, loss-/gain-of-function mutations of LRP5 would perturb Wnt signaling and depress/promote bone formation by affecting the progenitor cell pool. Elucidating Wnt regulation of MSC differentiation is important for their potential application in tissue regeneration.     

Differentiation of mesenchymal stem cells derived from human bone marrow and subcutaneous adipose tissue into pancreatic islet-like clusters in vitro

Although stem cells are present in various adult tissues and body fluids, bone marrow has been the most popular source of stem cells for treatment of a wide range of diseases. Recent results for stem cells from adipose tissue have put it in a position to compete for being the leading therapeutic source. The major advantage of these stem cells over their counterparts is their amazing proliferative and differentiation potency. However, their pancreatic lineage transdifferentiation competence was not compared to that for bone marrow-derived stem cells. This study aims to identify an efficient source for transdifferentiation into pancreatic islet-like clusters, which would increase potential application in curative diabetic therapy. The results reveal that mesenchymal stem cells (MSC) derived from bone marrow and subcutaneous adipose tissue can differentiate into pancreatic islet-like clusters, as evidenced by their islet-like morphology, positive dithizone staining and expression of genes such as Nestin, PDX1, Isl 1, Ngn 3, Pax 4 and Insulin. The pancreatic lineage differentiation was further corroborated by positive results in the glucose challenge assay. However, the results indicate that bone marrow-derived MSCs are superior to those from subcutaneous adipose tissue in terms of differentiation into pancreatic islet-like clusters. In conclusion, bone marrow-derived MSC might serve as a better alternative in the treatment of diabetes mellitus than those from adipose tissue.     

Arsenic trioxide promotes senescence and regulates the balance of adipogenic and osteogenic differentiation in human mesenchymal stem cells

Arsenic trioxide (ATO) as an anti-tumor drug could induce differentiation and apoptosis in tumor cells. Mesenchymal stem cells (MSCs) play important roles in the hematogenesis of bone marrow. Many reports have shown that the disorder of MSC adipogenic and osteogenic differentiation occurs in some diseases. However, reports about the effects of ATO on MSCs are limited. In this study, we found that 1 μM ATO promoted MSC senescence mainly through p21, although it had no effect on apoptosis at this dose. Furthermore, ATO promoted adipogenic differentiation, but inhibited osteogenic differentiation in MSCs. Our study also showed that CCAAT/enhancer-binding protein alpha C/EBPα and peroxisome proliferator-activated receptor gamma PPARγ might be involved in the regulation of adipogenic and osteogenic differentiation induced by ATO. Our results indicated that ATO may exert an anti-tumor effect by influencing bone marrow micro-environment. Moreover, it may regulate the adipogenic and osteogenic differentiation of MSCs.     

Periosteum Metabolism and Nerve Fiber Positioning Depend on Interactions between Osteoblasts and Peripheral Innervation in Rat Mandible

The sympathetic nervous system controls bone remodeling by regulating bone formation and resorption. How nerves and bone cells influence each other remains elusive. Here we modulated the content or activity of the neuropeptide Vasoactive Intestinal Peptide to investigate nerve-bone cell interplays in the mandible periosteum by assessing factors involved in nerve and bone behaviors. Young adult rats were chemically sympathectomized or treated with Vasoactive Intestinal Peptide or Vasoactive Intestinal Peptide_10-28, a receptor antagonist. Sympathectomy depleted the osteogenic layer of the periosteum in neurotrophic proNerve Growth Factor and neurorepulsive semaphorin3a; sensory Calcitonin-Gene Related Peptide-positive fibers invaded this layer physiologically devoid of sensory fibers. In the periosteum non-osteogenic layer, sympathectomy activated mast cells to release mature Nerve Growth Factor while Calcitonin-Gene Related Peptide-positive fibers increased. Vasoactive Intestinal Peptide treatment reversed sympathectomy effects. Treating intact animals with Vasoactive Intestinal Peptide increased proNerve Growth Factor expression and stabilized mast cells. Vasoactive Intestinal Peptide_10-28 treatment mimicked sympathectomy effects. Our data suggest that sympathetic Vasoactive Intestinal Peptide modulate the interactions between nervous fibers and bone cells by tuning expressions by osteogenic cells of factors responsible for mandible periosteum maintenance while osteogenic cells keep nervous fibers at a distance from the bone surface.     

Potential Role of HPA Axis and Sympathetic Nervous Responses in Depletion of B Cells Induced by H9N2 Avian Influenza Virus Infection

Except severe pulmonary disease caused by influenza virus infection, an impaired immune system is also a clinic characteristic. However, the mechanism(s) of influenza virus infection-induced depletion of B cells was unknown. Here, we compared the effect of two variant virulence H9N2 virus infections on mouse B cells. Our study found that the infection with highly pathogenic virus (V) of led to depletion of spleen B cells and bone marrow (BM) early B cells, compared to lowly pathogenic virus (Ts). Moreover, high apoptosis and cell cycle arrest in spleen and BM were detected, suggesting important factors for the reduction of B cells in both organs. Further, this effect was not caused by virus replication in spleen and BM. Compared to Ts virus infection, V virus resulted in higher glucocorticoids (GCs) and lower leptin level in plasma. Intraperitoneal GCs receptor antagonist RU486 injection was sufficient to prevent the loss of spleen B cell and BM pro- and immature B cells, but similar result was not observed in leptin-treated mice. Depletion of spleen B cells and BM pro-B cells was also reversed by chemical sympathectomy mediated by the norepinephrine (NE) analog 6-hydroxydopamine (6-OHDA), but the treatment didn''t affect the GCs level. This study demonstrated that depletion of B cells induced by H9N2 AIV was dependent on HPA axis and sympathetic response.     

p62/SQSTM1 indirectly mediates remote multipotent mesenchymal cells and rescues bone loss and bone marrow integrity in ovariectomized rats

Intramuscular administration of p62/SQSTM1 (sequestosome1)-encoding plasmid demonstrated an anticancer effect in rodent models and dogs as well as a high safety profile and the first evidence of clinical benefits in humans. Also, an anti-inflammatory effect of the plasmid was reported in several rodent disease models. Yet, the mechanisms of action for the p62 plasmid remain unknown. Here, we tested a hypothesis that the p62-plasmid can act through the modulation of bone marrow multipotent mesenchymal cells (MSCs). We demonstrated that a p62 plasmid can affect MSCs indirectly by stimulating p62-transfected cells to secrete an active ingredient(s) sensed by untransfected MSCs. When we transfected MSCs with the p62-plasmid, collected their supernatant, and added it to an untransfected MSCs culture, it switched the differentiation state and prompt osteogenic responses of the untransfected MSCs. According to an accepted viewpoint, ovariectomy leads to bone pathology via dysregulation of MSCs, and restoring the MSC homeostasis would restore ovariectomy-induced bone damage. To validate our in vitro observations in a clinically relevant in vivo model, we administered the p62 plasmid to ovariectomized rats. It partially reversed bone loss and notably reduced adipogenesis with concurrent reestablishing of the MSC subpopulation pool within the bone marrow. Overall, our study suggests that remote modulation of progenitor MSCs via administering a p62-encoding plasmid may constitute a mechanism for its previously reported effects and presents a feasible disease-preventing and/or therapeutic strategy.