Stromal Cell-derived Factor-1 Concentration Research Articles

SDF-1/CXCR4 axis participants in the pathophysiology of adult patients with moyamoya disease

BackgroundMoyamoya disease (MMD) is characterized by an abundance of moyamoya vessels; however, the precise mechanism driving the spontaneous angiogenesis of these compensatory vessels remains unclear. Previous research has established a link between the stromal cell-derived factor-1 (SDF-1)/ CXC receptor 4 (CXCR4) axis and angiogenesis under hypoxic conditions. Nevertheless, the alterations in this axis within the cerebrospinal fluid, arachnoid membranes and vascular tissue of MMD patients have not been fully investigated. MethodsOur study enrolled 66 adult MMD patients and 61 patients with atherosclerotic vascular disease (ACVD). We investigated the SDF-1 concentration in cerebrospinal fluid (CSF) and CXCR4 expression level on the arachnoid membranes and vascular tissue. We utilized enzyme-linked immunosorbent assay and immunohistochemistr. Additionally, we cultured and stimulated human brain microvascular endothelial cells (HBMECs) and smooth muscle cells (SMCs) under oxygen and glucose deprivation (OGD) conditions followed by reoxygenation, to examine any changes in the SDF-1/CXCR4 axis. ResultsThe results demonstrated an elevation in the level of SDF-1 in CSF among MMD patients compared to those with ACVD. Moreover, the expression of CXCR4 in arachnoid membranes and vascular tissue showed a similar trend. Furthermore, the content of CXCR4 in HBMECs and SMCs increased with the duration of ischemia and hypoxia. However, it was observed that the expression of CXCR4 decreased at OGD/R 24h compared to OGD 24h. The temporal pattern of SDF-1 expression in HBMECs and SMCs mirrored that of CXCR4 expression. ConclusionThese findings indicate a critical role for the SDF-1/CXCR4 axis in the angiogenesis of moyamoya disease.

Production of angiogenesis mediators and the structure of the vascular wall in the heart in ischemic cardiomyopathy

Background. In the pathogenesis of ischemic cardiomyopathy (ICMP), angiopoiesis remains unexplored.The aim. To describe the vasculature of the heart and the imbalance of angiogenesis mediators in the coronary circulation in association with the number of endothelial progenitor cells (EPC) and desquamated endothelial cells (DEC) in the blood of patients with coronary heart disease (CHD), suffering and not suffering from ICMP.Methods. Fifty-two patients with CHD (30 patients with ICMP, 22 patients without ICMP), 15 healthy donors were examined. The content of EPC (CD14+CD34+VEGFR2+) in the blood from the cubital vein and DEC (CD45–CD146+) in the blood from the coronary sinus and the cubital vein was determined by flow cytometry. The concentrations of VEGF-A (vascular endothelial growth factor A), PDGF (platelet-derived growth factor), and SDF-1 (stromal cell-derived factor 1) in blood plasma were recorded using immunofluorescence assay; the angiopoietin-2, MMP-9 (matrix metallopeptidase 9) were recorded using enzyme immunoassay. In myocardial biopsies the specific area of vessels and the expression of αSMA (smooth muscle alpha-actin) were determined by morphometric and immunohistochemical methods.Results. In the peripheral blood of patients with CHD, regardless of the presence of ICMP, the DEC content exceeded the physiological level, and the VEGF-A, PDGF, angiopoietin-2, and MMP-9 corresponded to the norm. In CHD patients without cardiomyopathy, there was an excess of SDF-1 and EPC in the blood from the cubital vein, and in ICMP, their physiological significance was noted. In the coronary blood flow in patients with CHD without cardiomyopathy, an increase in the concentration of PDGF was found, which was not determined in patients with ICMP, who had an increased content of DEC, angiopoietin-2 and MMP-9. The specific area of the vessels in the patients of the two groups was comparable; the expression of αSMA in ICMP was 6.2 times lower than in patients with CHD without cardiomyopathy.Conclusion. The development of ICMP is accompanied by impaired maturation of vessels in the myocardium, associated with the absence of a compensatory reaction of activation of cellular and humoral factors of angiogenesis.

Higher Plasma Stromal Cell-Derived Factor 1 Is Associated with Lower Risk for Sarcopenia in Older Asian Adults.

Despite the protective effects of stromal cell-derived factor 1 (SDF-1) in stimulating muscle regeneration shown in experimental research, there is a lack of clinical studies linking circulating SDF-1 concentrations with muscle phenotypes. In order to elucidate the role of SDF-1 as a potential biomarker reflecting human muscle health, we investigated the association of plasma SDF-1 levels with sarcopenia in older adults. This cross-sectional study included 97 community-dwelling participants who underwent a comprehensive geriatric assessment at a tertiary hospital in South Korea. Sarcopenia was defined by specific cutoff values applicable to the Asian population, whereas plasma SDF-1 levels were determined using an enzyme immunoassay. After accounting for sex, age, and body mass index, participants with sarcopenia and low muscle mass exhibited plasma SDF-1 levels that were 21.8% and 18.3% lower than those without these conditions, respectively (P=0.008 and P=0.009, respectively). Consistently, higher plasma SDF-1 levels exhibited a significant correlation with higher skeletal muscle mass index (SMI) and gait speed (both P=0.043), and the risk of sarcopenia and low muscle mass decreased by 58% and 55% per standard deviation increase in plasma SDF-1 levels, respectively (P=0.045 and P=0.030, respectively). Furthermore, participants in the highest SDF-1 tertile exhibited significantly higher SMI compared to those in the lowest tertile (P=0.012). These findings clinically corroborate earlier experimental discoveries highlighting the muscle anabolic effects of SDF- 1 and support the potential role of circulating SDF-1 as a biomarker reflecting human muscle health in older adults.

SDF-1 modulates periodontal ligament-Mesenchymal Stem Cells (pdl-MSCs).

In this in vitro study, the effects of Stromal cell-derived factor-1 (SDF-1) was evaluated on the periodontal ligament-Mesenchymal Stem Cells (pdl-MSCs) functions. Real-time cell analyzer-single plate (RTCA-SP) was employed for proliferation, and RTCA-dual purpose (DP) was utilized for pdl-MSCs migration potential treated with different SDF-1 concentrations (0, 0.1, 1, 10, 100, 200, and 400ng/ml). Based on the dose-response findings, 10ng/ml SDF-1 was used for further mRNA experiments. RNAs isolated at 6 and 24h were checked using quantitative RT-PCR for mineralized tissue-associated genes including type I collagen (COL I), osteocalcin (OCN), osteopontin (OPN), and runt-related transcription factor 2 (Runx2). cRNA was synthesized for 6h, and whole-genome array analysis was performed for over 47.000 probes. Data were subjected to quantile normalization before analysis. Increased proliferation and migration were observed in pdl-MSCs treated with 0.1, 1, and 10ng/ml SDF-1. Increased COL I was observed at both time points: 6 and 24h. While there was no significant change for OCN, OPN, and Runx2 at 6h, SDF-1 up-regulated OCN and OPN, but down-regulated Runx2 mRNA expressions at 24h. IL-8 and ESM1 genes were differentially expressed over twofold when the pdl-MSCs were exposed to SDF-1 at whole-genome array analysis. IL-8 induction was confirmed with RT-PCR. Findings of this study displayed that SDF-1 modulated pdl-MSCs which were important for periodontal regeneration, inducing migration and proliferation, and regulating extracellular matrix synthesis in favor of the formation of new attachment.

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 regulates in vitro sperm migration towards the cumulus-oocyte complex in cattle.

Sperm migration towards an oocyte in the female reproductive tract is an important step for successful fertilization. Although several sperm-chemotactic factors have been identified in mammals, it is unclear whether these chemoattractants contribute to sperm migration towards an oocyte that is the final destination for sperm. Furthermore, chemoattractants for bovine sperm are still undiscovered even though the follicular fluid attracts sperm in cattle. Here, we demonstrated that a single bovine cumulus-oocyte complex (COC) had the ability to attract sperm, suggesting that the COC secreted sperm chemoattractants. We identified stromal cell-derived factor 1 (SDF1), which was expressed in COCs, and its receptor CXCR4 in sperm, as a candidate. Our results showed that bovine sperm preferentially migrated to the area with a high SDF1 concentration and occasionally showed turn movements by asymmetric flagellar bends during the migration. We also demonstrated that increasing the intracellular Ca2+ concentration via Ca2+ channels was related to SDF1-induced sperm chemotaxis. Finally, a CXCR4 inhibitor significantly suppressed the in vitro bovine sperm migration towards a COC. Taken together, we propose that SDF1 is a chemotactic factor for bovine sperm to regulate their migration towards an oocyte via the CXCR4 receptor.

Concentrations of stromal cell-derived factor-1 in human follicular fluids are associated with clinical in vitro fertilization outcomes

Concentrations of stromal cell-derived factor-1 in human follicular fluids are associated with clinical in vitro fertilization outcomes

Modelling of the SDF-1/CXCR4 regulated in vivo homing of therapeutic mesenchymal stem/stromal cells in mice.

BackgroundMesenchymal stem/stromal cells (MSCs) are a promising tool for cell-based therapies in the treatment of tissue injury. The stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) axis plays a significant role in directing MSC homing to sites of injury. However in vivo MSC distribution following intravenous transplantation remains poorly understood, potentially hampering the precise prediction and evaluation of therapeutic efficacy.MethodsA murine model of partial ischemia/reperfusion (I/R) is used to induce liver injury, increase the hepatic levels of SDF-1, and study in vivo MSC distribution. Hypoxia-preconditioning increases the expression of CXCR4 in human bone marrow-derived MSCs. Quantitative assays for human DNA using droplet digital PCR (ddPCR) allow us to examine the in vivo kinetics of intravenously infused human MSCs in mouse blood and liver. A mathematical model-based system is developed to characterize in vivo homing of human MSCs in mouse models with SDF-1 levels in liver and CXCR4 expression on the transfused MSCs. The model is calibrated to experimental data to provide novel estimates of relevant parameter values.ResultsImages of immunohistochemistry for SDF-1 in the mouse liver with I/R injury show a significantly higher SDF-1 level in the I/R injured liver than that in the control. Correspondingly, the ddPCR results illustrate a higher MSC concentration in the I/R injured liver than the normal liver. CXCR4 is overexpressed in hypoxia-preconditioned MSCs. An increased number of hypoxia-preconditioned MSCs in the I/R injured liver is observed from the ddPCR results. The model simulations align with the experimental data of control and hypoxia-preconditioned human MSC distribution in normal and injured mouse livers, and accurately predict the experimental outcomes with different MSC doses.DiscussionThe modelling results suggest that SDF-1 in organs is an effective in vivo attractant for MSCs through the SDF-1/CXCR4 axis and reveal the significance of the SDF-1/CXCR4 chemotaxis on in vivo homing of MSCs. This in vivo modelling approach allows qualitative characterization and prediction of the MSC homing to normal and injured organs on the basis of clinically accessible variables, such as the MSC dose and SDF-1 concentration in blood. This model could also be adapted to abnormal conditions and/or other types of circulating cells to predict in vivo homing patterns.

Concentration of stromal cell-derived factor-1 (SDF-1/CXCL12) in the follicular fluid is associated with blastocyst development.

PurposeTo study the association between stromal cell‐derived factor‐1 (SDF‐1/CXCL12) and vascular endothelial growth factor (VEGF) concentrations in individual human ovarian follicles and IVF outcomes.MethodsConcentrations of SDF‐1 and VEGF in 261 follicular fluid samples were measured with enzyme‐linked immunosorbent assay. IVF outcome parameters were included in fertilization rate, cleavage rate, embryo morphology on day 3, and blastocyst morphology on day 5.ResultsThe follicular concentration of SDF‐1 and VEGF was not significantly associated with fertilization and cleavage outcome, and embryo morphology. The rates of full blastocysts and good‐quality blastocysts were significantly higher in follicles with an SDF‐1 concentration of 275‐350 pg/mL than in the follicles with SDF‐1 concentrations of <200 and ≥350 pg/mL (P < 0.05). The follicular concentration of VEGF was not associated with the blastocyst morphology.ConclusionOur findings showed that follicular concentration of SDF‐1, and not VEGF, may be a valuable biochemical marker of blastocyst development.

Kinin and Purine Signaling Contributes to Neuroblastoma Metastasis.

Bone marrow metastasis occurs in approximately 350,000 patients that annually die in the U.S. alone. In view of the importance of tumor cell migration into the bone marrow, we have here investigated effects of various concentrations of stromal cell-derived factor-1 (SDF-1), bradykinin- and ATP on bone marrow metastasis. We show for first time that bradykinin augmented chemotactic responsiveness of neuroblastoma cells to SDF-1 and ATP concentrations, encountered under physiological conditions. Bradykinin upregulated VEGF expression, increased metalloproteinase activity and induced adhesion of neuroblastoma cells. Bradykinin augmented SDF-1-induced intracellular Ca2+ mobilization as well as resensitization and expression of ATP-sensing P2X7 receptors. Bradykinin treatment resulted in higher gene expression levels of the truncated P2X7B receptor compared to those of the P2X7A full-length isoform. Bradykinin as pro-metastatic factor induced tumor proliferation that was significantly decreased by P2X7 receptor antagonists; however, the peptide did not enhance cell death nor P2X7A receptor-related pore activity, promoting neuroblastoma growth. Furthermore, immunodeficient nude/nude mice transplanted with bradykinin-pretreated neuroblastoma cells revealed significantly higher metastasis rates compared to animals injected with untreated cells. In contrast, animals receiving Brilliant Blue G, a P2X7 receptor antagonist, did not show any specific dissemination of neuroblastoma cells to the bone marrow and liver, and metastasis rates were drastically reduced. Our data suggests correlated actions of kinins and purines in neuroblastoma dissemination, providing novel avenues for clinic research in preventing metastasis.

The relationship between number and function of EPCs and concentration of VEGF165 and SDF-1 in coronary artery spasm.

We aimed at investigating the functions of endothelial progenitor cells (EPCs) in the pathophysiology of coronary artery spasm (CAS) and coronary artery disease (CAD), as well as to evaluate the correlation of these diseases with the number and function of EPCs, the plasma concentration of vascular endothelial growth factor 165 (VEGF165) and stromal cell-derived factor 1 (SDF-1). Participants were recruited into three groups, CAS, CAD and the control. The number and functions of early EPCs and outgrowth endothelial cells (OECs) were determined in peripheral blood samples, and the endothelial function was evaluated by measuring endothelium-dependent flow-mediated vasodilation (FMD). No differences of baseline characteristics were found among CAS, CAD, and the control groups. The OECs isolated from CAS and CAD exhibited significant decrease in the percentage of CD34+/CD45- population, OEC colony formation, OEC proliferation and OEC tubulogenesis, nitric oxide (NO) production, endothelial nitric oxide synthase (eNOS) activity, and the phosphorylation level at Ser1177 of eNOS, compared with OECs isolated from control participants. Meanwhile, FMD was significantly reduced in CAS and CAD (CAS, 4.1% ± 1.9%; CAD, 4.3% ± 1.8%; control, 11.2% ± 3.5%). FMD was positively correlated to OEC functions including NO production, eNOS phosphorylation, colony formation, and proliferation. No differences of plasma VEGF165 and SDF-1 concentrations were recorded among these three groups. Similarly, there was no correlation between plasma VEGF165 (and SDF-1) concentration and EPC number and function. EPCs show the potential of repairing damaged endothelium in CAS and CAD.

Mechanism of tissue-engineered bone recruiting endogenous mesenchymal stem cells towards bone regeneration

Objective To investigate the mechanism of implanted tissue-engineered bone (TEB) recruiting endogenous mesenchymal stem cells (BMSCs) towards bone regeneration after traumatic bone defect. Methods In vivo experiments: 2 mm of diaphysis and periosteum were removed from the middle of the femoral shaft in 8 week old FVB/N mice to form a large segment of bone defect. Demineralized bone matrix (DBM) and TEB were implanted into the defect area and fixated. All mice were randomly divided into DBM group (n=18) and TEB group (n=18). The results were observed 24 hours after implantation: (1) flow cytometry was used to evaluate the number of mobilized host BMSCs into the blood; (2) non-invasive bioluminescent imaging was used to observe the ability of two groups in recruiting mouse bone marrow derived mesenchymal stem cells (mBMSCs) in peripheral blood to the defect area; (3) ELISA was used to evaluate the stromal cell-derived factor 1 (SDF-1) content in peripheral blood of two groups. In vitro experiments: (1) transwell assay was conducted to evaluate the ability of SDF-1 (100 ng/ml) in promoting the migration of human bone marrow derived mesenchymal stem cells (hBMSCs). SDF-1/C-X-C motif chemokine receptor-4 (CXCR4) pathway was blocked by the selective CXCR4 antagonist Plerixafor (AMD3100). The experimental groups were divided into control group, SDF-1 group, and SDF-1+ AMD3100 group. (2) The co-culture system of human umbilical vein endothelial cells (hUVECs) and hBMSCs was established, and cells were stimulated by SDF-1. The experimental groups were divided into hBMSCs group, hBMSCs+ hUVECs group, and hBMSCs+ hUVECs (AMD3100 pretreatment) group. Transwell assays were used to compare the migration of hBMSCs in each group. ELISA was used to detect the concentration of hepatocyte growth factor (HGF) in the co-culture supernatant. (3) In vitro cultured hUVECs were stimulated by SDF-1 and SDF-1/CXCR4 pathway was antagonized by AMD3100. The experimental groups were divided into control group, SDF-1 group, and SDF-1+ AMD3100 group. Quantitative real-time polymerase chain reaction (qRT PCR) was used to evaluate the expression of HGF in each group. Results In vivo experiments: 24 h after transplantation, the number of BMSCs and SDF-1 concentration in the TEB group were significantly higher than those in the DBM group (P 0.05); (3) qRT-PCR showed that the expression of HGF was significantly increased in the SDF-1 group compared with the control group (P<0.05). After antagonizing SDF-1/CXCR4, HGF expression in the SDF-1+ AMD3100 group was significantly lower than that in the SDF-1 group. Conclusions TEB transplantation in traumatic bone defect can significantly increase the concentration of chemokine SDF-1 in vivo and effectively promote the mobilization of endogenous MSCs and recruitment of circulating MSCs. SDF-1 not only directly promotes the migration of hBMSCs through SDF-1/CXCR4 pathway, but also up-regulates the expression and secretion of HGF in vascular cells to further amplify the chemotactic effect of SDF-1 on hBMSCs. Key words: Tissue engineering; Mesenchymal stem cells; Stromal cell-derived factor-1

Serum SDF-1 levels are a reliable diagnostic marker of feline mammary carcinoma, discriminating HER2-overexpressing tumors from other subtypes.

The feline mammary carcinoma (FMC) is the third most common tumor in cat, sharing many clinicopathological features with human breast cancer and thus, considered a suitable model for comparative oncology. Due to its poor prognosis, further studies are required to improve the diagnostic accuracy and treatment of cats with spontaneous mammary carcinoma. Recently, it was reported that the overexpression of stromal cell-derived factor-1 (SDF-1) has great value in human breast cancer diagnosis, suggesting that diagnostic tools and therapies targeting the SDF-1 ligand can improve the clinical outcome. In this study, we aimed to evaluate if serum SDF-1 levels can also be used as a biomarker of mammary carcinoma in cats and to analyze if serum SDF-1 levels are associated with clinicopathological features, linked to a specific FMC subtype or correlated with the tumor expression of SDF-1 receptor, the chemokine C-X-C motif receptor 4 (CXCR4). Results showed that cats with mammary carcinoma had significantly higher serum SDF-1 levels than healthy controls (p=0.035) and ROC analysis revealed that the best cut-off value to differentiate sick from healthy animals was 2 ng/ml (specificity: 80%; sensitivity: 57%; AUC=0.715). Significant associations were also found between cats with elevated serum SDF-1 concentrations (≥ 2 ng/ml) and HER2-overexpressing mammary carcinomas (Luminal B-like and HER2-positive subtypes, p<0.0001), CXCR4-negative mammary carcinomas (p=0.027), mammary carcinomas with small size (<3 cm, p=0.027) and tumors with low Ki-67 expression (p=0.012). No statistical associations were found between serum SDF-1 levels and overall or disease-free survival. In summary, our results show that serum SDF-1 levels can be used as a biomarker of feline mammary carcinoma, especially in cats with HER2-overexpressing mammary tumors. Data suggest that targeted therapies against the SDF-1 ligand and/or its CXC4 receptor may be effective for the treatment of FMC, as described for human breast cancer, strengthening the concept that spontaneous feline mammary carcinoma is a suitable model for comparative oncology.

Sitagliptin, a dipeptidyl peptidase-4 inhibitor, suppresses CXCL5 and SDF-1 and does not accelerate intestinal neoplasia formation in ApcMin/+ mice fed a high-fat diet.

The relationship between type 2 diabetes mellitus and intestinal neoplasia has been shown epidemiologically. A high-fat diet (HFD) is also known to promote insulin resistance, which is a risk factor for intestinal neoplasia. Dipeptidyl peptidase-4 (DPP-4) inhibitors are used in the clinic for the treatment of type 2 diabetes and also to prolong the effects of glucagon-like peptide-1 (GLP-1). However, since the intestinotrophic hormone GLP-2 and chemokines, such as CXCL5 and stromal cell-derived factor-1 (SDF-1), are also substrates of DPP-4, DPP-4 inhibitors may increase the risk of intestinal carcinogenesis. In this study, we evaluated the impact of a DPP-4 inhibitor on intestinal tumorigenesis in ApcMin/+ mice fed a HFD. Six-week-old male ApcMin/+ mice were randomized to either a normal diet (10 kcal% fat) group, a HFD (60 kcal% fat) group, or a HFD group treated with sitagliptin (STG). The mice were euthanized nine weeks after the start of treatment. Daily treatment with STG did not increase number of intestinal tumors in the HFD group; however, this increase was not statistically significant. The mucosal concentration of total GLP-2 was significantly increased in the HFD group. The chemokine protein array showed elevated plasma concentrations of CXCL5 and SDF-1 in the HFD group. The administration of STG significantly suppressed the levels of plasma CXCL5 and SDF-1 in mice fed a HFD. Since CXCL5 expression is increased in patients with type 2 diabetes, and GLP-2, CXCL5 and SDF-1 are associated with tumor progression, DPP-4 inhibition may have potential as an agent for decreasing the risk of cancer in obese or diabetic patients.

Role of SDF-1/CXCR4 axis in the invasion and migration of human choriocarcinoma cells and its significance in preeclampsia

Objective To investigate the effects of stromal cell-derived factor 1 (SDF-1) and an CXC chemokine receptor 4 (CXCR4) antagonist (AMD3100) on the invasion and migration capabilities of the huaman choriocarcinoma cell line JAR for further elucidating the role of SDF-1/CXCR4 axis in the pathogenesis of preeclampsia. Methods JAR cells were divided into four groups: SDF-1 group (treated with 50 ng/ml of SDF-1), SDF-1+ AM3100 mixed group (first treated with 100 ng/ml of AMD3100 for 2 hours and then treated with 50 ng/ml of SDF-1), AMD3100 group (treated with 100 ng/ml of AMD3100) and blank control group (without any treatment). RT-PCR was performed to detect the expression of CXCR4 at mRNA level in JAR cells. Western blot assay was used to measure the expression of CXCR4 and p-AKT at protein level. MTT assay was used to analyze the effects of different concentrations of SDF-1 (10, 30, 50 and 100 ng/ml) on the proliferation of JAR cells at different time points (0, 24, 48, 72 h). Transwell invasion assay and wound-healing assay were used to test the changes in invasion and migration capabilities of JAR cells after different treatments. Results (1) Results of the RT-PCR showed that the expression of CXCR4 at mRNA level in JAR cells was increased in the SDF-1 group (1.839±0.083) as compared with that in the blank control group (1.372±0.086), AMD3100 group (0.694±0.045) or SDF-1+ AM3100 mixed group (0.703±0.093). Moreover, the differences between the SDF-1 group and the other three groups were statistically significant (F=30.67, P<0.05). Compared with the blank control group, the expression of CXCR4 at mRNA level in JAR cells was decreased in the AMD3100 group (P<0.01). (2) Results of the Western blot assay showed that the expression of CXCR4 and p-AKT at protein level in JAR cells were enhanced in the SDF-1 group as compared with that in the blank control group, AMD3100 group or SDF-1+ AM3100 mixed group. Compared with the blank control group, the expression of CXCR4 and p-AKT at protein level in JAR cells were inhibited in the AMD3100 group. (3) Results of the MTT assay showed that SDF-1, especially at the concentration of 50 ng/ml, could enhance the proliferation of JAR cells (P<0.05) and its best effect on proliferation was seen at 48 h. (4) Results of the Transwell invasion assay showed that the number of transmembrane cells in the SDF-1 group (70.49±2.42) was more than that in the blank control group (54.36±2.26), AMD3100 group (21.68±8.31), or SDF-1+ AMD3100 mixed group (28.18±4.61). The differences between the SDF-1 group and the other three groups were statistically significant (F=116.26, P<0.01). Compared with the blank control group, the number of transmembrane cells was reduced in the AMD3100 group (P<0.05). (5) Results of the wound-healing assay showed that the relative migration distance was increased in the SDF-1 group (1.162±0.034) as compared with that in the blank control group (0.823±0.101), AMD3100 group (0.160±0.047), or SDF-1+ AMD3100 mixed group (0.183±0.064). The differences between the SDF-1 group and the other three groups were statistically significant (F=30.500, P<0.05). Compared with the blank control group, the relative migration distance was decreased in the AMD3100 group (P<0.01). Conclusion The invasion and migration of huaman choriocarcinoma JAR cells can be enhanced by SDF-1, but inhibited by AMD3100. This study indicates that the blocked biological axis of SDF-1/CXCR4 may play an important role in the pathogenesis of preeclampsia through inducing abnormal activation of PI3K/AKT pathway, which results in inhibited invasion and migration of trophoblast cells and placenta abnormality. Key words: SDF-1/CXCR4 axis; Invasion; Migration; PI3K/AKT pathway; Trophoblast cell; Preeclampsia

Norepinephrine inhibits mesenchymal stem cell chemotaxis migration by increasing stromal cell-derived factor-1 secretion by vascular endothelial cells via NE/abrd3/JNK pathway

Mesenchymal stem cells (MSCs), which are physiologically maintained in vascular endothelial cell (VEC)-based niches, play a critical role in tissue regeneration. Our previous studies demonstrated that sympathetic denervation could promote MSC mobilization, thereby enhancing bone formation in distraction osteogenesis (DO), a self-tissue engineering for craniofacial and orthopeadic surgeries. However, the mechanisms on how sympathetic neurotransmitter norepinephrine (NE) regulates MSC migration are not well understood. Here we showed that deprivation of NE by transection of cervical sympathetic trunk (TCST) inhibited stromal cell-derived factor-1 (SDF-1) expression in the perivascular regions in rat mandibular DO. In vitro studies showed that NE treatment markedly upregulated p-JNK and therefore stimulated higher SDF-1 expression in VECs than control groups, and siRNA knockdown of the abrd3 gene abolished the NE-induced p-JNK activation. On the other hand, osteoblasts differentiated from MSCs showed an increase in SDF-1 secretion with lack of NE. Importantly, NE-treated VECs inhibited the MSC chemotaxis migration along the SDF-1 concentration gradient as demonstrated in a novel 3-chamber Transwell assay. Collectively, our study suggested that NE may increase the SDF-1 secretion by VECs via NE/abrd3/JNK pathway, thereby inhibiting the MSC chemotaxis migration from perivascular regions toward bone trabecular frontlines along the SDF-1 concentration gradient in bone regeneration.

Cross-talk between the dipeptidyl peptidase-4 and stromal cell-derived factor-1 in stem cell homing and myocardial repair: Potential impact of dipeptidyl peptidase-4 inhibitors.

Dipeptidyl peptidase-4 (DPP-4), glycyl-prolyl-naphthylamidase, is a serine protease that catalyzes the hydrolysis of various proline-containing polypeptides. It is involved in the inactivation of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), having in this way a profound influence on glucose metabolism. During organ damage, stromal and endothelial cells produce a chemokine known as stromal cell-derived factor-1 (SDF-1), a powerful chemoattractant of stem/progenitor cells. SDF-1 binds to a specific α-chemokine receptor (CXCR4) and can be degraded by proteases, including matrix DPP-4/CD26, presented in the circulation, or activated in injured tissues. DPP-4 inhibition has received considerable attention because of its significant therapeutic benefits in the regulation of insulin secretion and tissue insulin sensitivity, the regulation of tumor growth and metastasis, angiogenesis, tissue repair, especially after myocardial infarction, and regulation of endocrine function. Inhibition of circulating proteases appears to maintain the optimal endogenous SDF-1 concentration and may enhance homing of endothelial progenitor cells. In the present article, we present an overview of some basic facts about the role of DPP-4 in glucose homeostasis, the mechanism of its inhibition, and a brief summary of available DPP-4 inhibitors. Furthermore, since protection against the overactivity of proteases is important for restorating cardiac function and repair after myocardial damage, necrosis and apoptosis, we propose that administration of a DPP-4 inhibitor may also be beneficial following myocardial infarction by the prevention of cleavage of stem cell chemoattractant cytokine SDF-1.

Role of monocyte chemoattractant protein-1, stromal derived factor-1 and retinoic acid in pathophysiology of neuropathic pain in rats.

Chemokines have been recently recognized to play a role in chronic pain syndromes' pathophysiology. This study investigated the role of monocyte chemoattractant protein-1 (MCP-1), stromal cell derived factor-1 (SDF-1), and retinoic acid (RA) as targets for the therapeutic approach of neuropathic pain. A chronic constriction injury (CCI) model of neuropathic pain by unilateral ligation of left sciatic nerve was performed in adult female Wistar rats. The effects of doxycycline (Dox, 50 mg/kg/day i.p. for 7 days), single dose of bicyclam (5 mg/kg i.p.), RA (15 mg/kg/day i.p. for 7 days), and their combination(s) on behavioral tests of nociception (Von Frey filaments; paw pressure test) on days 0, 1, 3, 5, and 7 of operation were studied. Serum concentrations of MCP-1 and SDF-1 were measured by ELISA. Histological examination of the sciatic nerve was investigated. CCI of sciatic nerve significantly induced mechanical allodynia and hyperalgesia and an increase of MCP-1 and SDF-1 serum levels. Dox-treated groups (Dox, Dox+bicyclam, Dox+RA, Dox+bicyclam+RA) and bicyclam-treated groups (bicyclam, Dox+bicyclam, bicyclam+RA, Dox+bicyclam+RA) attenuated CCI-induced behavioral and biochemical changes. RA inhibited CCI-induced mechanical hyperalgesia but produced a time-dependent reversal of allodynia. Histological findings showed degenerative changes of sciatic nerve after CCI that were partially recovered in Dox-treated groups. These findings demonstrate an association between serum MCP-1 and SDF-1 concentrations and behavioral manifestations of neuropathic pain. RA administration decreased neuropathic pain (antihyperalgesic effect) but did not cause any improvement in sciatic nerve tissues, either alone or in combination with chemokine antagonists. Thus, chemokines may serve as potential targets for drug development in neuropathic pain treatment.

Stromal Derived Factor-1/CXCR4 Axis Involved in Bone Marrow Mesenchymal Stem Cells Recruitment to Injured Liver.

The molecular mechanism of bone marrow mesenchymal stromal stem cells (BMSCs) mobilization and migration to the liver was poorly understood. Stromal cell-derived factor-1 (SDF-1) participates in BMSCs homing and migration into injury organs. We try to investigate the role of SDF-1 signaling in BMSCs migration towards injured liver. The expression of CXCR4 in BMSCs at mRNA level and protein level was confirmed by RT-PCR, flow cytometry, and immunocytochemistry. The SDF-1 or liver lysates induced BMSCs migration was detected by transwell inserts. CXCR4 antagonist, AMD3100, and anti-CXCR4 antibody were used to inhibit the migration. The Sprague-Dawley rat liver injury model was established by intraperitoneal injection of thioacetamide. The concentration of SDF-1 increased as modeling time extended, which was determined by ELISA method. The Dir-labeled BMSCs were injected into the liver of the rats through portal vein. The cell migration in the liver was tracked by in vivo imaging system and the fluorescent intensity was measured. In vivo, BMSCs migrated into injured liver which was partially blocked by AMD3100 or anti-CXCR4 antibody. Taken together, the results demonstrated that the migration of BMSCs was regulated by SDF-1/CXCR4 signaling which involved in BMSCs recruitment to injured liver.

Searching for a good model for systemic sclerosis: the molecular profile and vascular changes occurring in UCD-200 chickens strongly resemble the early phase of human systemic sclerosis.

IntroductionVascular injury and endothelial cell (EC) apoptosis are the earliest events in systemic sclerosis (SSc), before the onset of fibrosis, and stromal cell-derived factor 1 (SDF-1), vascular endothelial growth factor (VEGFA), endothelin-1 (ET-1) and platelet-derived growth factors (PDGF-BB) represent the key molecules to study the link between vascular injury and fibrosis during SSc. The University of California at Davis line 200 (UCD-200) chickens display the same hallmarks of human SSc: vascular occlusion, perivascular lymphocytic infiltration and fibrosis of skin and internal organs. In this study we assessed both cytokines and growth factors involved in the early phases of the UCD-200 chickens’ skin lesions, to determine whether these animals might represent an appropriate experimental model to study the pathogenesis of SSc.Material and methodsImmunofluorescence analysis was performed on human SSc skin, human healthy control (hHC) skin, UCD-200 combs and HC H.B15 chicken (cHC) combs, using anti-SDF-1, CXCR4, VEGFA, VEGF receptor 1 (VEGFR1), VEGF receptor 2 (VEGFR2), ET-1, ET receptor A (ETAR), ET receptor B (ETBR), PDGF-BB, and PDGF receptor (PDGFR) antibodies. The plasma concentrations of SDF-1, VEGFA, ET-1 and PDGF-BB were determined by ELISA.ResultsAll the molecules analyzed showed higher levels in SSc patients and UCD-200 chickens than in hHC and cHC. Furthermore, the levels of the assessed molecules paralleled the severity of comb involvement.ConclusionsThe molecular similarities between avian and human SSc, observed in this study, suggest that the UCD-200 chickens are an interesting model for translational approaches to SSc.