Stromal Cell-derived Factor-1 mRNA Research Articles

Prognostic role of the stromal cell derived factor-1 in patients with hepatitis B virus-related acute-on-chronic liver failure.

Stromal cell derived factor-1 (SDF-1) plays a pivotal role in the recruitment of stem cells to injured livers. However, the changes of SDF-l in patients with hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) have yet to be elucidated. To study the SDF-1 changes in patients with HBV-related ACLF. 30 patients with HBV-related ACLF, 27 patients with chronic hepatitis B and 20 healthy individuals are involved in our study. The SDF-l mRNA expression in liver tissue was detected by quantitative real-time polymerase chain reaction. Immunohistochemical staining was performed to illustrate the expression of SDF-l, CXC receptor 4 (CXCR4) and Ki67. The serum SDF-l concentrations were also detected by enzyme-linked immunosorbent assays. The expression of SDF-1 mRNA from ACLF patients was remarkably higher than that from other patients (both P < 0.05). The expression of SDF-l, CXCR4 and Ki67 from ACLF were the highest among the three groups (all P < 0.01). The serum SDF-l levels in ACLF patients were significantly lower than that in other patients (both P < 0.01). Moreover, in ACLF patients, the serum SDF-1 Levels were positively correlated with serum total bilirubin and international normalized ratio. In addition, the serum SDF-l levels in survival were significantly lower compared with the non-survivals (P < 0.05). The area under the curve for the serum SDF-1 level in predicting 28-d mortality was 0.722 (P < 0.05). This study provides the SDF-1 changes in patients with HBV-related ACLF. The SDF-1 Level at admission may serve as a promising prognostic marker for predicting short-term prognosis.

Effects of electroacupuncture on repairing neurological damage following ischemic stroke based on miR-381-mediated SDF-1/CXCR4 signaling pathway.

To investigate the effects of electroacupuncture (EA) on the miR-381, leucine-rich repeat C4 protein (LRRC4), and downstream stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) signaling pathway in rat model of ischemic stroke, and to explore the mechanism by which EA improves neurological damage following ischemic stroke. Among 50 SPF male SD rats, 10 rats were randomly selected into a sham surgery group, and the remaining rats were used to establish the middle cerebral artery occlusion (MCAO) model. The 30 successfully modeled rats were randomly divided into a model group, an EA group, and an agonist group, with 10 rats in each group. The rats in the EA group received EA at "Baihui" (GV 20) and "Dazhui" (GV 14), with disperse-dense wave, a frequency of 2 Hz/10 Hz, and a current intensity of 1 mA, 30 min per session, once daily for a total of 14 days. The rats in the agonist group received miR-381 agonist injections into the lateral ventricle, with 10 μL per injection, every 7 days for a total of 2 injections. After intervention, ZeaLonga neurobehavioral deficit score was observed in each group. HE staining was performed to observe the morphological changes in the ischemic brain tissue of rats in each group. ELISA was used to measure the levels of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and nerve growth factor (NGF) in serum. Western blot was employed to detect the protein expression of LRRC4, SDF-1, CXCR4, and extracellular regulated protein kinase 1 (ERK1) in the ischemic brain tissue. Real-time PCR was utilized to assess the expression of miR-381 and LRRC4, SDF-1, CXCR4, ERK1 mRNA in the ischemic brain tissue. After intervention, the brain tissue showed disordered cell arrangement, reduced quantity, and significant interstitial edema, with numerous vacuoles in the model group. The pathological changes mentioned above were alleviated in the brain tissue of rats in the EA group and the agonist group. Compared with the sham surgery group, the rats in the model group exhibited increased ZeaLonga neurobehavioral deficit scores, elevated levels of serum TNF-α and IL-6 (P<0.01), and decreased serum NGF level (P<0.01)；the protein expression of SDF-1, CXCR4 and ERK1 in ischemic brain tissue was reduced (P<0.01), while LRRC4 protein expression was increased (P<0.01)；the expression of miR-381, as well as SDF-1, CXCR4 and ERK1 mRNA in ischemic brain tissue was decreased (P<0.01), while LRRC4 mRNA expression was increased (P<0.01). Compared with the model group, the rats in the EA group and the agonist group showed decreased ZeaLonga neurobehavioral deficit scores and reduced levels of serum TNF-α and IL-6 (P<0.05, P<0.01), and increased serum NGF levels (P<0.05, P<0.01); the protein expression of SDF-1, CXCR4 and ERK1 in ischemic brain tissue was increased (P<0.01), while LRRC4 protein expression was decreased (P<0.01)；the expression of miR-381, as well as SDF-1, CXCR4 and ERK1 mRNA in ischemic brain tissue was increased (P<0.05, P<0.01), while LRRC4 mRNA expression was decreased (P<0.01). EA at "Baihui" (GV 20) and "Dazhui" (GV 14) may promote the repair of neurological damage following ischemic stroke by up-regulating miR-381 to selectively inhibit LRRC4 expression, thereby activating the SDF-1/CXCR4 signaling pathway.

Effects of sitagliptin activation of the stromal cell-derived factor-1/CXC chemokine receptor 4 signaling pathway on the proliferation, apoptosis, inflammation, and osteogenic differentiation of human periodontal ligament stem cells induced by lipopolysaccharide.

This study aimed to investigate the effects of sitagliptin on the proliferation, apoptosis, inflammation, and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) in lipopolysaccharide (LPS)-induced inflammatory microenvironment and its molecular mechanism. hPDLSCs were cultured in vitro and treated with different concentrations of sitagliptin to detect cell viability and subsequently determine the experimental concentration of sitagliptin. An hPDLSCs inflammation model was established after 24 h of stimulation with 1 µg/mL LPS and divided into blank, control, low-concentration sitagliptin (0.5 µmol/L), medium-concentration sitagliptin (1 µmol/L), and high-concentration sitagliptin (2 µmol/L), high-concentrationsitagliptin+stromal cell derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) pathway inhibitor (AMD3100) (2 µmol/L+10 µg/mL) groups. A cell-counting kit-8 was used to detect the proliferation activity of hPDLSCs after 24, 48, and 72 h culture. The apoptosis of hPDLSCs cultured for 72 h was detected by flow cytometry. After inducing osteogenic differentiation for 21 days, alizarin red staining was used to detect the osteogenic differentiation ability of hPDLSCs. The alkaline phosphatase (ALP) activity in hPDLSCs was determined using a kit. The levels of inflammatory factors [tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6] in the supernatant of hPDLSCs culture were detected by enzyme-linked immunosorbent assay. The mRNA expressions of osteogenic differentiation genes [Runt-associated transcription factor 2 (RUNX2), osteocalcin (OCN), osteopontin (OPN)], SDF-1 and CXCR4 in hPDLSCs were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). Western blot analysis was used to determine SDF-1 and CXCR4 protein expression in hPDLSCs. Compared with the blank group, the proliferative activity, number of mineralized nodules, staining intensity, ALP activity, and RUNX2, OCN, OPN mRNA, SDF-1, and CXCR4 mRNA and protein expression levels of hPDLSCs in the control group significantly decreased. The apoptosis rate and levels of TNF-α, IL-1β, and IL-6 significantly increased (P<0.05). Compared with the control group, the proliferative activity, number of mineralized nodule, staining intensity, ALP activity, and RUNX2, OCN, OPN mRNA, SDF-1, and CXCR4 mRNA and protein expression levels of hPDLSCs in low-, medium-, and high-concentration sitagliptin groups increased. The apoptosis rate and levels of TNF-α, IL-1β, and IL-6 decreased (P<0.05). AMD3100 partially reversed the effect of high-concentration sitagliptin on LPS-induced hPDLSCs (P<0.05). Sitagliptin may promote the proliferation and osteogenic differentiation of hPDLSCs in LPS-induced inflammatory microenvironment by activating the SDF-1/CXCR4 signaling pathway. Furthermore, it inhibited the apoptosis and inflammatory response of hPDLSCs.

Electroacupuncture combined with bone marrow mesenchymal stem cell transplantation promotes repair of thin endometrium by regulating SDF-1/CXCR4 signaling

It is to explore, based on stromal cell derived factor 1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) signal axis, whether the electroacupuncture (EA) combined with bone marrow mesenchymal stem cells (BMSCs) transplantation can promote thin endometrium regeneration and improve endometrial receptivity, so as to further study its mechanisms underlying improvement of promoting BMSCs homing to repair thin endometrium. Thirty matured female SD rats were randomly divided into normal control , model , BMSCs transplantation (BMSCs), BMSCs+AMD3100 (a specific antagonist of CXCR4, BMSCs+AMD3100), BMSCs+EA, and BMSCs+EA+AMD3100 groups, with 5 rats in each group. The thin endometrial model was established by intrauterine injection of 95% ethanol during the period of estrus. Rats of the model group received intravenous injection of PBS solution (tail vein) on day 1, 3 and 7 of modeling and intraperitoneal injection of normal saline once daily for 3 estrous cycles. Rats of the BMSCs group received intravenous injection of BMSCs suspension on day 1,3 and 7 of modeling, and those of the BMSCs+EA group received BMSCs transplantation and EA stimulation. EA (2 Hz/15 Hz, 1 mA) was applied to "Guanyuan" (CV4) and bilateral "Sanyinjiao"(SP9), "Zigong" (EX-CA1) for 15 min, once daily for 3 estrous cycles. Rats of the BMSCs+AMD3100 group received intravenous injection of BMSCs suspension (1×106/mL) and intraperitoneal injection of AMD3100 (5 mg/kg), and those of the BMSCs+EA+AMD3100 group received administration of BMSCs, AMD3100 and EA, with both groups being once daily for 3 estrous cycles. H.E. staining was used to observe histopathological changes of endometrium tissues, and immunohistochemistry was used to detect the expressions of cytokeratin (CK19) and vimentin in endometrium (for evaluating the damage and repair of endometrium). The expression levels of homeobox A10 (HOXA10), leukemia inhibitory factor (LIF), SDF-1 and CXCR4 proteins were detected by Western blot, and those of SDF-1 and CXCR4 mRNAs in the endometrium detected by real-time PCR. In comparison with the normal control group, the number of endometrial glands, the immunoactivity of CK19 and vimentin, the expression leve-ls of HOXA10, LIF and CXCR4 proteins and CXCR4 mRNA were significantly down-regulated (P<0.01), and the expression levels of SDF-1 protein and mRNA significantly up-regulated (P<0.05) in the model group. Compared with the model group, the number of endometrial glands, the immunoactivity of CK19 and vimentin, and the expression levels of HOXA10, LIF, CXCR4 proteins and CXCR4 mRNA in the BMSCs group, and the number of endometrial glands, the immunoactivity of CK19 and vimentin, the expression levels of HOXA10, LIF, CXCR4 proteins and CXCR4 mRNA, and SDF-1 protein and mRNA in the BMSCs+EA group were significantly up-regulated (P<0.05, P<0.01). Compared to the BMSCs group, the number of endometrial glands, and the expression levels of LIF, CXCR4 proteins and CXCR4 mRNA in the BMSCs+EA group were up-regulated (P<0.01, P<0.05)； the number of endometrial glands, the immunoactivity of CK19 and vimentin, the expression levels of HOXA10, LIF, CXCR4 proteins and CXCR4 mRNA in the BMSCs+AMD3100 group were down-regulated (P<0.01). Compared to the BMSCs+EA group, the number of endometrial glands, the immunoactivity of CK19 and vimentin, the expression levels of HOXA10, LIF, CXCR4 proteins and CXCR4 mRNA in the BMSCs+EA+AMD3100 group were down-regulated (P<0.01). Results of H.E. staining showed thin endometrium with absence of epithelial cells, and sparse glands and blood vessels, with smaller glandular cavity in the model group, which was relative milder in BMSCs and BMSCs+EA groups. EA can promote the transfer of transplanted BMSCs to the damaged site through SDF-1/CXCR4 signaling related stem cell homing, thereby promoting thin endometrial regeneration, repairing endometrial injury, and improving endometrial tolerance in rats with thin endometrium.

Stromal cell-derived factor 1 (SDF1) attenuates platelet-derived growth factor-B (PDGF-B)-induced vascular remodeling for adipose tissue expansion in obesity.

Platelet-derived growth factor-B (PDGF-B) is a main factor to promote adipose tissue angiogenesis, which is responsible for the tissue expansion in obesity. In this process, PDGF-B induces the dissociation of pericytes from blood vessels; however, its regulatory mechanism remains unclear. In the present study, we found that stromal cell-derived factor 1 (SDF1) plays an essential role in this regulatory mechanism. SDF1 mRNA was increased in epididymal white adipose tissue (eWAT) of obese mice. Ex vivo pharmacological analyses using cultured adipose tissue demonstrated that physiological concentrations (1-100pg/mL) of SDF1 inhibited the PDGF-B-induced pericyte dissociation from vessels via two cognate SDF1 receptors, CXCR4 and CXCR7. In contrast, higher concentrations (> 1ng/mL) of SDF1 alone caused the dissociation of pericytes via CXCR4, and this effect disappeared in the cultured tissues from PDGF receptor β (PDGFRβ) knockout mice. To investigate the role of SDF1 in angiogenesis in vivo, the effects of anagliptin, an inhibitor of dipeptidyl peptidase 4 (DPP4) that degrades SDF1, were examined in mice fed a high-fat diet. Anagliptin increased the SDF1 levels in the serum and eWAT. These changes were associated with a reduction of pericyte dissociation and fat accumulation in eWAT. AMD3100, a CXCR4 antagonist, cancelled these anagliptin effects. In flow-cytometry analysis, anagliptin increased and decreased the PDGF-B expression in endothelial cells and macrophages, respectively, whereas anagliptin reduced the PDGFRβ expression in pericytes of eWAT. These results suggest that SDF1 negatively regulates the adipose tissue angiogenesis in obesity by altering the reactivity of pericytes to PDGF-B.

Stromal cell-derived factor-1 (SDF-1) expression in very preterm human lungs: potential relevance for stem cell therapy for bronchopulmonary dysplasia

Background: The axis formed by CXC chemokine receptor 4 (CXCR4), expressed on mesenchymal stromal cells (MSCs), and stromal cell-derived factor-1 (SDF-1), expressed in recipient organs, is a critical mediator of MSC migration in non-pulmonary injury models. The role and regulation of SDF-1 expression in preterm lungs, of potential relevance for MSC-based cell therapy for bronchopulmonary dysplasia (BPD), is unknown. The aim of this study was to determine the spatiotemporal pattern of CXCR4/SDF-1 expression in lungs of extremely preterm infants at risk for BPD.Methods: Postmortem lung samples were collected from ventilated extremely preterm infants who died between 23 and 29 wks (“short-term ventilated”) or between 36 and 39 wks (“long-term ventilated”) corrected postmenstrual age. Results were compared with age-matched infants who had lived <12 h or stillborn infants (“early” and “late” controls). CXCR4 and SDF-1 expression was studied by immunohistochemistry, immunofluorescence/confocal microscopy, and qRT-PCR analysis.Results: Compared with age-matched controls without antenatal infection, lungs of early control infants with evidence of intrauterine infection/inflammation showed significant upregulation of SDF-1 expression, localized to the respiratory epithelium, and of CXCR4 expression, localized to stromal cells. Similarly, pulmonary SDF-1 mRNA levels were significantly higher in long-term ventilated ex-premature infants with established BPD than in age-matched controls. The pulmonary vasculature was devoid of SDF-1 expression at all time points. Endogenous CXCR4-positive stromal cells were preferentially localized along the basal aspect of SDF-1-positive bronchial and respiratory epithelial cells, suggestive of functionality of the CXCR4/SDF-1 axis.Conclusions: Incipient and established neonatal lung injury is associated with upregulation of SDF-1 expression, restricted to the respiratory epithelium. Knowledge of the clinical associations, time-course and localization of pulmonary SDF-1 expression may guide decisions about the optimal timing and delivery route of MSC-based cell therapy for BPD.

Cholesterol modification of SDF-1-specific siRNA enables therapeutic targeting of angiogenesis through Akt pathway inhibition

Neovascularization during ocular tissue repair can cause severe visual loss in the optical axis and is therefore an issue of considerable concern to ophthalmologists. Here, we introduced a cholesterol-modified siRNA delivery system targeting stromal cell-derived factor 1 (SDF-1) to treat ocular angiogenesis in vivo. SDF-1 expression was analyzed in rat endothelial progenitor cells (EPCs) and bone marrow mesenchymal stem cells (BMSCs) using quantitative PCR (qPCR). Migration ability of BMSC and HUVEC were assessed through transwell assay. The proliferation effect of chol-siSDF1 on HUVEC was measured by colony formation assay. In vivo anti-angiogenic effects of chol-siSDF1 were tested in a cornea alkali burn model and the area of cornea neovascularization was measured using computer-imaging analysis system. Then phosphorylated Akt and total Akt protein levels were measured through western blot. Results turned out that rat EPCs and BMSCs showed high SDF-1 mRNA expression, which can be down-regulated by using chol-siSDF-1. Chol-siSDF-1 could significantly inhibit migration of BMSC and HUVEC. In addition, chol-siSDF1 also could inhibit HUVEC proliferation and exert a significant anti-angiogenic effect in corneal alkali burn model. As for the mechanism, chol-siSDF1 may inhibit the neovascularization, proliferation and metastasis through inhibiting the Akt signaling pathway. Thus, cholesterol modification of siRNA targeting SDF-1 displays an effective inhibition of migration and angiogenesis, with a much longer duration of inhibition effect.

Role of SDF-1:CXCR4 in Impaired Post-Myocardial Infarction Cardiac Repair in Diabetes.

Diabetes is a risk factor for worse outcomes following acute myocardial infarction (AMI). In this study, we tested the hypothesis that SDF‐1:CXCR4 expression is compromised in post‐AMI in diabetes, and that reversal of this defect can reverse the adverse effects of diabetes. Mesenchymal stem cells (MSC) isolated from green fluorescent protein (GFP) transgenic mice (control MSC) were induced to overexpress stromal cell‐derived factor‐1 (SDF‐1). SDF‐1 expression in control MSC and SDF‐1‐overexpressing MSC (SDF‐1:MSC) were quantified using enzyme‐linked immunosorbent assay (ELISA). AMI was induced on db/db and control mice. Mice were randomly selected to receive infusion of control MSC, SDF‐1:MSC, or saline into the border zone after AMI. Serial echocardiography was used to assess cardiac function. SDF‐1 and CXCR4 mRNA expression in the infarct zone of db/db mice and control mice were quantified. Compared to control mice, SDF‐1 levels were decreased 82%, 91%, and 45% at baseline, 1 day and 3 days post‐AMI in db/db mice, respectively. CXCR4 levels are increased 233% at baseline and 54% 5 days post‐AMI in db/db mice. Administration of control MSC led to a significant improvement in ejection fraction (EF) in control mice but not in db/db mice 21 days after AMI. In contrast, administration of SDF‐1:MSC produced a significant improvement in EF in both control mice and db/db mice 21 days after AMI. The SDF‐1:CXCR4 axis is compromised in diabetes, which appears to augment the deleterious consequences of AMI. Over‐express of SDF‐1 expression in diabetes rescues cardiac function post AMI. Our results suggest that modulation of SDF‐1 may improve post‐AMI cardiac repair in diabetes. stem cells translational medicine 2018;7:115–124

Neuroprotection by intravenous transplantation of bone marrow mononuclear cells from 5-fluorouracil pre-treated rats in a model of ischemic stroke

Our previous studies showed that bone marrow mononuclear cells (BMMNCs) from 5-fluorouracil (5-FU) pre-treated rats (named BMRMNCs) had a better therapeutic efficacy in ischemia/reperfusion rats as compared to BMMNCs from untreated rats. This study was undertaken to further explore the potential mechanisms underlying the neuroprotective effects of BMRMNCs in the same model. Rats were intravenously pre-treated with 5-FU, and BMRMNCs were collected 7 days later and subjected to flow cytometry for detection of CD34, CD45 and CD90. Middle cerebral artery occlusion (MCAO) was induced in rats, and BMMNCs and BMRMNCs were independently transplanted via the tail vein at 24 h after MCAO. NISSL staining was performed 14 days after cell transplantation and the viable cells in the hippocampus were counted. Stromal cell-derived factor 1 (SDF-1) mRNA expression was detected in the penumbra at 7 and 14 days after treatment. The contents of pro-inflammatory cytokines and growth factors as well as microvessel density (MVD) were determined at 14 days. Results showed more BMRMNCs were positive for CD34, CD45 and CD90. After transplantation, more viable cells were observed in the hippocampus of BMRMNCs treated rats. In addition, BMRMNCs transplantation significantly increased MVD, reduced pro-inflammatory cytokines and raised growth factors in the penumbra. However, the SDF-1 mRNA expression was comparable between BMRMNCs group and BMMNCs group. Our results indicate that BMRMNCs are likely to more effectively improve the local microenvironment to increase viable cells and elevate angiogenesis, exerting neuroprotective effects on cerebral ischemia in rats.

Effect of lipopolysaccharide on the stromal cell-derived factor-1 expression in human stem cells from apical papilla

To investigate the expression of stromal cell-derived factor-1 (SDF-1) in human stem cells from apical papilla (SCAP), and to evaluate the effect of lipopolysaccharide (LPS) on SDF-1 expression by SCAP. SCAP were isolated from dental papilla of human immature third molars. The expression of SDF-1 was evaluated by reverse transcription-PCR (RT-PCR). After SCAP being exposed to different concentrations (0.1, 1.0, 10 mg/L) of LPS for 24 and 48 h, the effect of LPS on cell proliferation and gene expression of SDF-1 was investigated by cell counting kit-8 and real-time PCR respectively, while cells without LPS stimulation were considered as negative control. LPS had no significant effect on SCAP proliferation until day 7. RT-PCR assays demonstrated that SCAP expressed SDF-1 mRNA. Different concentrations of LPS significantly promoted the SDF-1 expression in SCAP after 24 h (F = 12.102, P = 0.002) and 48 h (F = 39.054, P < 0.001) exposure, with relative gene expression ratio (experimental/control) increased to 1.4 ± 0.1, 2.2 ± 0.4, 2.3 ± 0.5 in 24 h group and 2.1 ± 0.4, 3.4 ± 0.3, 3.8 ± 0.5 in 48 h group. Isolated SCAP in cultures have the expression of SDF-1 mRNA. LPS can significantly promote the expression of SDF-1 in SCAP.

Upregulation of stromal cell-derived factor 1 (SDF-1) is associated with macrophage infiltration in renal ischemia-reperfusion injury.

BackgroundStromal cell-derived factor-1(SDF-1) is a chemotactic and angiogenic factor that mediates the repair of various tissues. As macrophages are important contributors to ischemic kidney injury, we examine the role of SDF-1 in a rodent model of ischemia-reperfusion (I/R) injury.MethodsMale wild-type (WT) (C57BL/6) mice were subjected to bilateral I/R injury or sham operation in the presence or absence of macrophage depletion (liposomal clodronate [0.2 ml/20–25 g body weight i.p.]). Macrophage accumulation was assessed by immunohistochemistry. Tissue levels of SDF-1 (ELISA) and SDF-1 mRNA expression (real-time PCR) were measured. The cellular location of SDF-1 was assessed using immunohistochemical staining.ResultsImmunofluorescence staining of renal tissue sections confirmed macrophage depletion by liposomal clodronate. SDF-1 production was elevated in response to I/R injury and was significantly increased upon macrophage depletion. SDF-1 positive cells initially appeared initially in the cortex, and subsequently diffused to the outer medulla after I/R injury.ConclusionsOur study demonstrates that SDF-1 is significantly upregulated during renal I/R. We hypothesize that SDF-1 upregulation may be an important macrophage effector mechanism during I/R injury.

Polymorphism of stromal cell-derived factor-1 selectively upregulates gene expression and is associated with increased susceptibility to coronary artery disease

Stromal cell-derived factor-1 (SDF-1) plays critical roles in vascular development and hematopoiesis. Here, we investigated the function of SDF-1 rs1801157G/A polymorphism in various immune cells and examined its association with susceptibility to coronary artery disease (CAD). Protein and mRNA levels of SDF-1 were tested in peripheral CD4+ T cell, CD8+ T cells, monocytes, and natural killer (NK) T cells from healthy donors with different genotypes of rs1801157G/A polymorphism. Prevalence of the polymorphism was compared between CAD patients and healthy controls. Data revealed that SDF-1 mRNA and protein were detectable in CD4+ T cells, CD8+ T cells, monocytes and NK T cells. Interestingly, both protein level and mRNA level of SDF-1 were significantly increased in the monocytes with rs1801157AA genotype, whereas the same phenomenon was not observed in the other three cell types. Blockage of CD14 completely inhibited the upregulation of SDF-1 in the monocytes with rs1801157AA genotype. Association analysis showed that frequencies of the rs1801157AA genotype and A allele were significantly higher in CAD cases than in controls (odds ratio [OR]=2.28, 95% confidence interval [CI], 1.50–3.29, p<0.0001, and OR=1.46, 95% CI, 1.21–3.73, p<0.0001, respectively). Also, prevalence of rs1801157AA genotype was further increased in cases with ST-elevation myocardial infarction (OR=1.65, 95% CI, 1.04–2.56, p=0.028). Our data suggest a novel pathway for regulating SDF-1 and a new risk factor for CAD.

The role of SDF‐1 and CXCR4 on odontoblastic differentiation in human dental pulp cells

To examine the role of stromal cell-derived factor 1 (SDF-1) signalling during odontogenic differentiation in human dental pulp cells (HDPCs). Human dental pulp cells were treated with differentiation medium, recombinant human SDF-1, neutralizing antibody for SDF-1 or CXCR4, pertussis toxin (PTX) and AMD3100. The expression of SDF-1 and its receptor chemokine receptor type 4 (CXCR4) was measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. Odontoblastic differentiation was determined using alkaline phosphatase (ALP) activity assay, mineralized nodule formation and marker mRNAs by RT-PCR. Marked upregulation of SDF-1 and CXCR4 mRNA and protein was observed in cells grown 7days in osteogenic induction medium. The addition of recombinant human SDF-1 to HDPCs significantly (P<0.05) increased ALP activity, mineralized nodule formation and odontoblast marker mRNAs in a dose-dependent manner. Blocking SDF-1 signalling using antibodies against SDF-1 or CXCR4, or the G-protein-coupled receptor inhibitor PTX, and CXCR4 inhibitor AMD3100, strongly suppressed induction of odontogenic differentiation in HDPCs. Odontoblastic differentiation was stimulated by SDF-1 activation and repressed by SDF-1/CXCR4 inhibition. Thus, SDF-1/CXCR4 signalling may be a new therapeutic target and strategy to promote repair and regeneration in endodontics.

Amelioration of Murine Schistosoma mansoni Induced Liver Fibrosis by Mesenchymal Stem Cells

Schistosomiasis is a common chronic helminthic infection of the liver that causes hepatic fibrosis and portal hypertension,contributing to the death of over half a million people a year. Infusion of autologous bone marrow cells into patients with hepatic cirrhosis has been reported to ameliorate symptoms of portal hypertension and improve liver function, either by conversion of the infused mesenchymal stem cells (MSCs) to hepatocytes or by modulating of the hepatic fibrosis. Here,we have investigated the antifibrotic effect of mesenchymal stem cells (MSCs) using S. mansoni-induced liver fibrosis in mice, which causes an intense, stable fibrosis. MSCs derived from bone marrow of male mice were then infused intravenously into female mice that had received intraperitoneal injection of S.mansoni cercariae. Mice were divided into 4 groups: Untreated control; MSCs infusion only; Schistosomiasis only; and Schistosomiasis plus MSCs infusion. Serum alanine aminotransferase (ALT) and liver histopathology were evaluated. Expression of the collagen gene (type I),transforming growth factor (TGF-β), matrix metalloproteinase (MMP2), tissue inhibitor of metalloproteinase (TIMP-1),stromal cell-derived factor-1(SDF-1) and its receptor (CXCR4) were analyzed. MSC infusion resulted in significant decrease in liver collagen and TGF-β gene expression in the Schistosomiasis mice. The ratio of MMP-2 to TIMP-1 expression increased. SDF-1 and CXCR4 mRNA expression also increased. There was overall improvement of liver histology and a statistically significant reduction of serum ALT level. MSCs infusion ameliorated S. mansoni-induced liver fibrosis, probably by modulating the relative expression of MMP and TIMP. The findings support the hypothesis that MSCs participate in liver regeneration and functional improvement by reducing liver fibrosis.

Anti-angiogenesis effect of AMD3100 in oxygen-induced retinopathy mice

To observe the inhibition of neovascularisation in the oxygen-induced retinopathy (OIR) mice by a stromal cell-derived factor 1 (SDF-1) antagonist. Experimental study. Fifty-eight 7-day-old C57BL/6 mice were divided into 3 groups randomly, the control group (n = 17), the test group (n = 17) and the medication group (n = 24). According to the dosage of AMD3100, the medication group (n = 24) were divided into low dose group, high dose group, low dose control group, and high dose control group (each group n = 6). Each group (19-day-old) was sacrificed to perform ADPase staining, paraffin sections and immunohistochemical staining (anti-VEGF and anti-SDF-1). The average positive staining area percentage (APSAP) was measured as the outcomes and processed with the Students' t-test. Real-time PCR showed expression of both VEGF mRNA (0.080 ± 0.022 vs. 0.123 ± 0.032) and SDF-1 mRNA (0.731 ± 0.099 vs.0.544 ± 0.108) in retinas from the control group and test group, respectively. The expression of these factors in the test group was significantly higher (t = 2.488, P = 0.038;t = 2.864, P = 0.021). The number of neovascular endothelial nuclear that broke through the retinal internal limiting membrane in the paraffin section in the high dose group and the low dose group was significantly less than that in the self-control group (t = -9.507, P = 0.000; t = -10.761, P = 0.000). The appearance of ADPase staining sections in the medication group was more similar to the simple control group than that of the test group. Immunohistochemical staining sections showed that VEGF and SDF-1 expressed in neuroepithelial cells in each group. APSAP in the high dose group and the low dose group was significantly lower than that in the self-control group (VEGF: t = -7.249, P = 0.000; t = -9.02, P = 0.000; SDF-1: t = -5.246, P = 0.000; t = -5.216, P = 0.000). These results indicate that AMD3100 block the SDF-1 receptor to reduce the effect of SDF-1, decrease the production of VEGF protein and inhibite neovascularization.

Role of Stromal Cell‐Derived Factor‐1 Expression in the Injured Mouse Auditory Nerve

The degeneration of hair cells and spiral ganglion neurons (SGNs) is an important pathologic process in the development of sensorineural hearing loss. In a murine model, predictable and reproducible damage to SGNs occurs through the application of ouabain to the round window. Recent evidence has shown that the chemokine stromal cell-derived factor-1 (SDF-1) is a potent chemoattractant of hematopoietic stem cells (HSCs) and provides trophic support to injured tissues during development and maturation. The hypothesis for the current study is that expression of SDF-1 plays an important role in protecting SGNs and preventing further degeneration in the setting of cochlear injury. Prospective, controlled. Academic research laboratory. Auditory brainstem response (ABR) and the expression of SDF-1 mRNA and protein were examined 1, 3, 7, 14, and 30 days after application of ouabain in 35 adult mice. Following ouabain application, real-time reverse-transcription polymerase chain reaction for SDF demonstrates increased mRNA expression following ouabain injury in nontransplanted mice. A significant increase in SDF protein expression was also observed using immunolabeling techniques and Western blot analysis. SDF-1 expression is increased in the auditory nerve following cochlear injury. Further knowledge about the cochlear microenvironment, including SDF-1, is critical to maximizing HSC engraftment in the injured cochlea and providing a therapeutic option for sensorineural hearing loss.

Vascular Gene Transfer of SDF-1 Promotes Endothelial Progenitor Cell Engraftment and Enhances Angiogenesis in Ischemic Muscle

Gene therapy approaches to enhance endothelial progenitor cell (EPC) homing may augment cell engraftment to ischemic tissue and lead to a greater therapeutic response. Therefore, we assessed the effects of ultrasound-mediated (UM) transfection of the chemokine stromal cell-derived factor-1 (SDF-1) on homing and engraftment of intravenously administered EPCs and the subsequent angiogenic response in chronically ischemic skeletal muscle. Bone marrow-derived EPCs were isolated from donor Fisher 344 rats, cultured and labeled in preparation for injection into recipient animals via a jugular vein. Using a model of chronic hindlimb ischemia in rats, we demonstrated that UM destruction of intravenous carrier microbubbles loaded with SDF-1 plasmid DNA resulted in targeted transfection of the vascular endothelium within ischemic muscle and greater local engraftment of EPCs. The combination of SDF-1gene therapy and EPCs lead to the greatest increase in tissue perfusion and microvascular density within ischemic muscle, compared to no treatment or either monotherapy alone. Our results demonstrate that UM transfection of SDF-1 improves EPC targeting to chronically ischemic tissue, enhancing vascular engraftment and leading to a more robust neovascularization response.

Osteoprotegerin, a new actor in vasculogenesis, stimulates endothelial colony‐forming cells properties

Osteoprotegerin (OPG), a soluble receptor of the tumour necrosis factor family, and its ligand, the receptor activator of nuclear factor-κB ligand (RANKL), are emerging as important regulators of vascular pathophysiology. We evaluated their effects on vasculogenesis induced by endothelial colony-forming cells (ECFC) and on neovessel formation in vivo. Effects of OPG and RANKL on in vitro angiogenesis were evaluated after ECFC incubation with OPG or RANKL (0-50 ng mL(-1)). Effects on microvessel formation were evaluated with an in vivo murin Matrigel plug assay. Vascularization was evaluated by measuring plug hemoglobin and vascular endothelial growth factor (VEGF)-R2 content 14 days after implantation. We found that ECFC expressed OPG and RANK but not RANKL mRNA. Treatment of ECFC with VEGF or stromal cell-derived factor-1 (SDF-1) upregulated OPG mRNA expression. OPG stimulated ECFC migration (P < 0.05), chemotaxis (P < 0.05) and vascular cord formation on Matrigel(®) (P < 0.01). These effects were correlated with SDF-1 mRNA overexpression, which was 30-fold higher after 4 h of OPG stimulation (P < 0.01). OPG-mediated angiogenesis involved the MAPK signaling pathway as well as Akt or mTOR cascades. RANKL also showed pro-vasculogenic effects in vitro. OPG combined with FGF-2 promoted neovessel formation in vivo, whereas RANKL had no effect. OPG induces ECFC activation and is a positive regulator of microvessel formation in vivo. Our results suggest that the OPG/RANK/RANKL axis may be involved in vasculogenesis and strongly support a modulatory role in tissue revascularization.

Cancer-associated fibroblasts correlate with poor prognosis in rectal cancer after chemoradiotherapy

Cancer-associated fibroblasts (CAFs) in the stroma play an important role in influencing the proliferation, invasion and metastasis of cancer cells. Fibroblast activation protein-α (FAP-α) is known as a marker of CAFs, while stromal cell-derived factor-1 (SDF-1) is primarily expressed by CAFs. Herein, we investigated whether the expression levels of these genes are associated with clinical outcome after pre-operative chemoradiotherapy (CRT) in rectal cancer patients. We obtained total RNA from residual cancer stroma using microdissection from a total of 52 rectal cancer specimens from patients who underwent pre-operative CRT, we performed transcriptional analyses, and the serum protein concentrations in 40 matched microdissected specimens were measured by enzyme-linked immunosorbent assay. Additionally, we sought to clarify the location of FAP-α and SDF-1 expression using immunohistochemical staining. Of the 52 patients, 15.6 and 36.8% showed detectable FAP-α and SDF-1 mRNA expression, respectively. A significant correlation was observed between stromal FAP-α and SDF-1 mRNA levels. Moreover, there was a significant correlation between stromal SDF-1 gene expression levels and serum protein levels. Patients who developed distant recurrences after CRT had positive expression of both genes (P<0.05). The positive expression of both genes was also associated with poor probability of recurrence-free and overall survival (P<0.05). Patients with elevated serum SDF-1 levels had equally poor overall survival as those with positive stromal SDF-1 gene expression (P<0.05). In immunohistochemistry, both FAP-α and SDF-1 expression was observed in certain activated fibroblasts. In conclusion, FAP-α and SDF-1 expression was shown to be involved in tumor re-growth and recurrence in rectal cancer patients treated with pre-operative CRT.

CXCR4/SDF-1 axis is involved in lymph node metastasis of gastric carcinoma

To investigate the role of CXC chemokine receptor-4 (CXCR4) and stromal cell-derived factor-1 (SDF-1) in lymph node metastasis of gastric carcinoma. In 40 cases of gastric cancer, expression of CXCR4 mRNA in cancer and normal mucous membrane and SDF-1 mRNA in lymph nodes around the stomach was detected using quantitative polymerase chain reaction (PCR) (TaqMan) and immunohistochemistry assay. SGC-7901 and MGC80-3 cancer cells were used to investigate the effect of SDF-1 on cell proliferation and migration. Quantitative reverse transcription PCR and immunohistochemistry revealed that the expression level of CXCR4 in gastric cancer was significantly higher than that in normal mucous membrane (1.6244 ± 1.3801 vs 1.0715 ± 0.5243, P < 0.05). The expression level of CXCR4 mRNA in gastric cancer with lymph node metastasis was also significantly higher than that without lymph node metastasis (0.823 ± 0.551 vs 0.392 ± 0.338, P < 0.05). CXCR4 expression was significantly related to poorly differentiated, high tumor stage and lymph node metastasis. Significant differences in the expression level of SDF-1 mRNA were found between lymph nodes in metastatic gastric cancer and normal nodes (0.5432 ± 0.4907 vs 0.2640 ± 0.2601, P < 0.05). The positive expression of SDF-1 mRNA in lymph nodes of metastatic gastric cancer was consistent with the positive expression of CXCR4 mRNA in gastric cancer (r = 0.776, P < 0.01). Additionally, human gastric cancer cell lines expressed CXCR4 and showed vigorous proliferation and migratory responses to SDF-1. AMD3100 (a specific CXCR4 antagonist) was also found to effectively reduce the migration of gastric cancer cells. The CXCR4/SDF-1 axis is involved in the lymph node metastasis of gastric cancer. CXCR4 is considered as a potential therapeutic target in the treatment of gastric cancer.