Short-term function and immune-protection of microencapsulated adult porcine islets with alginate incorporating CXCL12 in healthy and diabetic non-human primates without systemic immune suppression: A pilot study.

Replacement of insulin-producing pancreatic beta-cells by islet transplantation offers a functional cure for type-1 diabetes (T1D). We recently demonstrated that a clinical grade alginate micro-encapsulant incorporating the immune-repellent chemokine and pro-survival factor CXCL12 could protect and sustain the integrity and function of autologous islets in healthy non-human primates (NHPs) without systemic immune suppression. In this pilot study, we examined the impact of the CXCL12 micro encapsulant on the function and inflammatory and immune responses of xenogeneic islets transplanted into the omental tissue bilayer sac (OB; n = 4) and diabetic (n = 1) NHPs. Changes in the expression of cytokines after implantation were limited to 2-6-fold changes in blood, most of which did not persist over the first 4 weeks after implantation. Flow cytometry of PBMCs following transplantation showed minimal changes in IFNγ or TNFα expression on xenoantigen-specific CD4+  or CD8+  T cells compared to unstimulated cells, and these occurred mainly in the first 4 weeks. Microbeads were readily retrievable for assessment at day 90 and day 180 and at retrieval were without microscopic signs of degradation or foreign body responses (FBR). In vitro and immunohistochemistry studies of explanted microbeads indicated the presence of functional xenogeneic islets at day 30 post transplantation in all biopsied NHPs. These results from a small pilot study revealed that CXCL12-microencapsulated xenogeneic islets abrogate inflammatory and adaptive immune responses to the xenograft. This work paves the way toward future larger scale studies of the transplantation of alginate microbeads with CXCL12 and porcine or human stem cell-derived beta cells or allogeneic islets into diabetic NHPs without systemic immunosuppression.

miR-126-3p is essential for CXCL12-induced angiogenesis.

Atherosclerosis, in the ultimate stage of cardiovascular diseases, causes an obstruction of vessels leading to ischemia and finally to necrosis. To restore vascularization and tissue regeneration, stimulation of angiogenesis is necessary. Chemokines and microRNAs (miR) were studied as pro-angiogenic agents. We analysed the miR-126/CXCL12 axis and compared impacts of both miR-126-3p and miR-126-5p strands effects in CXCL12-induced angiogenesis. Indeed, the two strands of miR-126 were previously shown to be active but were never compared together in the same experimental conditions regarding their differential functions in angiogenesis. In this study, we analysed the 2D-angiogenesis and the migration assays in HUVEC in vitro and in rat's aortic rings ex vivo, both transfected with premiR-126-3p/-5p or antimiR-126-3p/-5p strands and stimulated with CXCL12. First, we showed that CXCL12 had pro-angiogenic effects in vitro and ex vivo associated with overexpression of miR-126-3p in HUVEC and rat's aortas. Second, we showed that 2D-angiogenesis and migration induced by CXCL12 was abolished in vitro and ex vivo after miR-126-3p inhibition. Finally, we observed that SPRED-1 (one of miR-126-3p targets) was inhibited after CXCL12 treatment in HUVEC leading to improvement of CXCL12 pro-angiogenic potential in vitro. Our results proved for the first time: 1-the role of CXCL12 in modulation of miR-126 expression; 2-the involvement of miR-126 in CXCL12 pro-angiogenic effects; 3-the involvement of SPRED-1 in angiogenesis induced by miR-126/CXCL12 axis.

Stromal derived factor-1 plasmid as a novel injection for treatment of stress urinary incontinence in a rat model.

INTRODUCTION AND HYPOTHESIS: SDF-1 chemokine enhances tissue regeneration through stem cell chemotaxis, neovascularization and neuronal regeneration. We hypothesized that non-viral delivery of human plasmids that express SDF-1 (pSDF-1) may represent a novel regenerative therapy for stress urinary incontinence (SUI). METHODS: Seventy-six female rats underwent vaginal distention (VD). They were then divided into four groups according to treatment: pSDF-1 (n = 42), sham (n = 30), PBS (n = 1) and luciferase-tagged pSDF-1 (n = 3). Immediately after VD, the pSDF-1 group underwent immediate periurethral injection of pSDF-1, and the sham group received a vehicle injection followed by leak point pressure (LPP) measurement at the 4th, 7th and 14th days. Urogenital tissues were collected for histology. H&E and trichrome slides were analyzed for vascularity and collagen/muscle components of the sphincter. For the luciferase-tagged pSDF-1 group, bioluminescence scans (BLIs) were obtained on the 3rd, 7th and 14th days following injections. Statistical analysis was conducted using ANOVA with post hoc LSD tests. The Mann-Whitney U test was employed to make pair-wise comparisons between the treated and sham groups. We used IBM SPSS, version 22, for statistical analyses. RESULTS: BLI showed high expression of luciferase-tagged pSDF-1 in the pelvic area over time. VD resulted in a decline of LPP at the 4th day in both groups. The pSDF1-treated group demonstrated accelerated recovery that was significantly higher than that of the sham-treated group at the 7th day (22.64 cmH2O versus 13.99 cmH2O, p < 0.001). Functional improvement persisted until the 14th day (30.51 cmH2O versus 24.11 cmH2O, p = 0.067). Vascularity density in the pSDF-1-treated group was higher than in the sham group at the 7th and 14th days (p < 0.05). The muscle density/sphincter area increased significantly from the 4th to 14th day only in the pSDF-1 group. CONCLUSIONS: Periurethral injection of pSDF-1 after simulated childbirth accelerated the recovery of continence and regeneration of the urethral sphincter in a rat SUI model. This intervention can potentially be translated to the treatment of post-partum urinary incontinence.

[Expression and significance of chemokine CXCL12 and receptor CXCR4 in adenomyosis].

Objective: To observe the expression, correlation and significance of chemokine (C-X-C motif) ligand 12 (CXCL12) and chemokine (C-X-C motif) receptor 4 (CXCR4) in endometrium and myometrium of adenomyosis. Methods: Totally 38 patients were selected in this study, who underwent hysterectomy for adenomyosis at Beijing Obstetrics and Gynecology Hospital from October 2017 to December 2018 as the adenomyosis group, and, in the same period, selected 31 patients with cervical intraepithelial neoplasia Ⅲ or cervical cancer undergoing hysterectomy served as control group. The expression levels of mRNA and protein for CXCL12, CXCR4 in the endometrium and myometrium of the two groups were detected by immunohistochemistry and real-time PCR. Results: (1) The protein levels of CXCL12 and CXCR4 in endometrium in uterus with adenomyosis (0.229±0.025 and 0.226±0.016) were significantly higher than those in endometrium in uterus without adenomyosis (0.153±0.018 and 0.178±0.026); compared with each other, the differences were statistically significant (all P<0.05). And the expressions of CXCL12 and CXCR4 proteins in uterine myometrium of adenomyosis were 0.222±0.045 and 0.126±0.058, respectively, which were higher than those in the control group (0.091±0.029 and 0.099±0.020); compared with each other, the differences were statistically significant (all P<0.05). (2) The expression levels of CXCL12 and CXCR4 mRNA in endometrium of patients with adenomyosis were 6.31±0.12 and 8.49±0.21, respectively, which were higher than those in the control group (1.23±0.10 and 1.36±0.13); compared with each other, the differences were statistically significant (all P<0.05). Moreover, the expression levels of CXCL12 and CXCR4 mRNA in myometrium of patients with adenomyosis were 9.11±0.12 and 8.45±0.16, respectively, which were higher than those in the control group (1.18±0.08 and 1.46±0.13); compared with each other, the differences were statistically significant (all P<0.05). (3) In endometrium and myometrium of uterus with adenomyosis, CXCL12 and CXCR4 mRNA expression levels were positively associated (r=0.478, 0.542, all P<0.05). Conclusions: The levels of CXCL12 and CXCR4 in the endometrium and myometrium of adenomyosis are increased and positively correlated. The two chemokine may be involved in the development of adenomyosis.

Elevating CXCR7 Improves Angiogenic Function of EPCs via Akt/GSK-3ß/Fyn-Mediated Nrf2 Activation in Diabetic Limb Ischemia.

RATIONALE: Endothelial progenitor cells (EPCs) respond to stromal cell-derived factor 1 (SDF-1) through chemokine receptors CXCR7 and CXCR4. Whether SDF-1 receptors involves in diabetes mellitus-induced EPCs dysfunction remains unknown. OBJECTIVE: To determine the role of SDF-1 receptors in diabetic EPCs dysfunction. METHODS AND RESULTS: CXCR7 expression, but not CXCR4 was reduced in EPCs from db/db mice, which coincided with impaired tube formation. Knockdown of CXCR7 impaired tube formation of EPCs from normal mice, whereas upregulation of CXCR7 rescued angiogenic function of EPCs from db/db mice. In normal EPCs treated with oxidized low-density lipoprotein or high glucose also reduced CXCR7 expression, impaired tube formation, and increased oxidative stress and apoptosis. The damaging effects of oxidized low-density lipoprotein or high glucose were markedly reduced by SDF-1 pretreatment in EPCs transduced with CXCR7 lentivirus but not in EPCs transduced with control lentivirus. Most importantly, EPCs transduced with CXCR7 lentivirus were superior to EPCs transduced with control lentivirus for therapy of ischemic limbs in db/db mice. Mechanistic studies demonstrated that oxidized low-density lipoprotein or high glucose inhibited protein kinase B and glycogen synthase kinase-3ß phosphorylation, nuclear export of Fyn and nuclear localization of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), blunting Nrf2 downstream target genes heme oxygenase-1, NAD(P)H dehydrogenase (quinone 1) and catalase, and inducing an increase in EPC oxidative stress. This destructive cascade was blocked by SDF-1 treatment in EPCs transduced with CXCR7 lentivirus. Furthermore, inhibition of phosphatidylinositol 3-kinase/protein kinase B prevented SDF-1/CXCR7-mediated Nrf2 activation and blocked angiogenic repair. Moreover, Nrf2 knockdown almost completely abolished the protective effects of SDF-1/CXCR7 on EPC function in vitro and in vivo. CONCLUSIONS: Elevated expression of CXCR7 enhances EPC resistance to diabetes mellitus-induced oxidative damage and improves therapeutic efficacy of EPCs in treating diabetic limb ischemia. The benefits of CXCR7 are mediated predominantly by a protein kinase B/glycogen synthase kinase-3ß/Fyn pathway via increased activity of Nrf2.

Supplementation of freezing media with stromal cell-derived factor-1α preserves human sperm from cryodamage.

The destructive effects of sperm cryopreservation result in reduced sperm motility and increased apoptosis. Oocytes, endometrium, and follicular fluid express stromal cell-derived factor-1 alpha (SDF-1α) or C-X-C motif chemokine ligand 12 (CXCL12) while its specific receptor chemokine, CXC motif receptor 4 (CXCR4) is expressed in the head of sperm. SDF-1α can increase sperm motility and preserve normal mitochondrial status. The present study intends to investigate whether the addition of SDF-1α to freezing extender can facilitate cryosurvival of spermatozoa and how SDF-1α protects spermatozoa against damages during cryopreservation. In this study, we collected 22 semen samples from healthy donors and treated them with different concentrations of SDF-1α, followed by cryopreservation for one month. We measured sperm motility by CASA, mitochondrial ROS generation by flow cytometry using the probe MitoSOX Red™ (MSR) to measure mitochondrial superoxide anion (O2-•), DNA fragmentation by flow cytometry according to the TUNEL kit, and expressions of Bcl-2 and Bax by RT-qPCR in freeze-thawed sperm. The results showed that SDF-1α attenuated mitochondrial ROS generation at different doses, particularly the 250 ng/ml treated samples which, in turn, reduced the expressions of pro-apoptotic genes such as Bax. Eventually, SDF-1α reduced DNA fragmentation and ameliorated sperm motility in the 1-100 ng/ml treated samples during cryopreservation. The present study, for the first time, demonstrated that SDF-1α dose-dependently moderated oxidative stress injury in human sperm by reduction of mitochondrial ROS generation. It could subsequently cause a decrease in apoptosis during freeze-thawing and protect human spermatozoa from cryodamage.

Cell versus Chemokine Therapy in a Nonhuman Primate Model of Chronic Intrinsic Urinary Sphincter Deficiency.

PURPOSE: Mixed efficacy results of autologous skeletal muscle precursor cell therapy in women with chronic intrinsic urinary sphincter deficiency have increased interest in the therapeutic value of alternative regenerative medicine approaches. The goal of this study was to compare the effects of the cell homing chemokine CXCL12 (C-X-C motif chemokine 12) and skeletal muscle precursor cells on chronic urinary sphincter regeneration in chronic intrinsic urinary sphincter deficiency. MATERIALS AND METHODS: Five million autologous skeletal muscle precursor cells or 100 ng CXCL12 were injected in the urinary sphincter complex of adult female cynomolgus monkeys with chronic (6-month history) intrinsic urinary sphincter deficiency. These treatment groups of 3 monkeys per group were compared to a group of 3 with no intrinsic urinary sphincter deficiency and no injection, and a group of 3 with intrinsic urinary sphincter deficiency plus vehicle injection. Maximal urethral pressure was measured at rest, during stimulation of the urinary sphincter pudendal nerves at baseline and again 6 months after treatment. The monkeys were then necropsied. The urinary sphincters were collected for tissue analysis of muscle and collagen content, vascularization and motor endplates. RESULTS: CXCL12 but not skeletal muscle precursor cells increased resting maximal urethral pressure in nonhuman primates with chronic intrinsic urinary sphincter deficiency compared to that in monkeys with intrinsic urinary sphincter plus vehicle injection (p >0.05). Skeletal muscle precursor cells and CXCL12 only partially restored pudendal nerve stimulated increases in maximal urethral pressure (p >0.05), sphincter vascularization and motor endplate expression in monkeys with chronic intrinsic urinary sphincter deficiency. Additionally, CXCL12 but not skeletal muscle precursor cell injections decreased collagen and increased the muscle content of urinary sphincter complex in monkeys with chronic intrinsic urinary sphincter deficiency compared to those with intrinsic urinary sphincter plus vehicle injection and no intrinsic urinary sphincter plus no injection (p <0.05 and >0.05, respectively). CONCLUSIONS: These results raise questions about cell therapy for chronic intrinsic urinary sphincter deficiency and identify a chemokine treatment (CXCL12) as a potential alternative treatment of chronic intrinsic urinary sphincter deficiency.

Effects of Platelet-Rich Plasma & Platelet-Rich Fibrin with and without Stromal Cell-Derived Factor-1 on Repairing Full-Thickness Cartilage Defects in Knees of Rabbits.

BACKGROUND: The purpose of this study was to create biomaterial scaffolds like platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) containing stromal cell-derived factor-1 (SDF1) as a chemokine to induce hyaline cartilage regeneration of rabbit knee in a full thickness defect. METHODS: We created a full thickness defect in the trochlear groove of thirty-six bilateral knees of eighteen mature male rabbits. The knees were randomly divided into six groups (group I: untreated control, group II: PRP, group III: PRF, group IV: Gelatin+SDF1, group V: PRP+SDF1, and group VI: PRF+SDF1). After four weeks, the tissue specimens were evaluated by macroscopic examination and histological grading, immunofluorescent staining for collagen type II, and analyzed for cartilage marker genes by real-time PCR. The data were compared using statistical methods (SPSS 20, Kruskal-Wallis test, Bonferroni post hoc test and P<0.05). RESULTS: Macroscopic evaluations revealed that international cartilage repair society (ICRS) scores of the PRF+SDF1 group were higher than other groups. Microscopic analysis showed that the ICRS score of the PRP group was significantly lower than other groups. Immunofluorescent staining for collagen II demonstrated a remarkable distribution of type II collagen in the Gel+SDF1, PRP+SDF1 and PRF+SDF1 groups compared with other groups. Real-time PCR analysis revealed that mRNA expression of SOX9 and aggrecan were significantly greater in the PRF+SDF1, PRP+SDF1, Gel+SDF1 and PRF groups than the control group (P<0.05). CONCLUSION: Our results indicate that implantation of PRF scaffold containing SDF1 led to the greatest evaluation scores of full-thickness lesions in rabbits.

Chemokine (C-X-C motif) receptor 4 blockade by AMD3100 inhibits experimental abdominal aortic aneurysm expansion through anti-inflammatory effects.

OBJECTIVE: Inflammation plays a critical role in the development of abdominal aortic aneurysms (AAAs). Because stromal cell-derived factor 1 (SDF-1) is known for its ability to attract inflammatory cells, we investigated whether SDF-1/chemokine (C-X-C motif) receptor 4 (CXCR4) axis is expressed in aneurysmal aortic wall and plays a role in AAA physiopathology and asked whether its blockade modulates AAA formation and expansion. APPROACH AND RESULTS: Quantitative real-time polymerase chain reaction analysis showed that SDF-1α and CXCR4 mRNA levels are increased in both human and CaCl2-induced mouse AAA wall and are positively correlated to the aortic diameter in mice. ELISA quantification and immunostaining demonstrated that, in mice, aortic SDF-1α is rapidly induced during AAA formation, first by apoptotic vascular smooth muscle cells in the injured media and then by adventitial macrophages once AAA is fully established. Using green fluorescent protein-positive (GFP(+/-)) bone marrow transplantation experiments, we demonstrated that aortic SDF-1 overexpression is implicated in the recruitment of bone marrow-derived macrophages within the AAA wall. Furthermore, in mice, blockade of CXCR4 by AMD3100 decreases the infiltration of adventitial macrophages, inhibits AAA formation, and prevents aortic wall destruction. AMD3100 reduces the mRNA levels of MMP-12 and MMP-14 as well as that of inflammatory effectors MCP-1, MIP-1ß, MIP-2α, RANTES, IL-1ß, IL-6, TNF-α, and E-selectin. Finally, AMD3100 stabilizes the diameter of formed, expanding AAAs in 2 experimental models. CONCLUSIONS: SDF-1/CXCR4 axis is upregulated in human and mouse AAAs. Blockade of CXCR4 with AMD3100 suppresses AAA formation and progression in two rodent models. Blockade of SDF-1/CXCR4 axis may represent a new strategy to limit progression of small human AAAs.

Stromal cell-derived factor 1 as a biomarker of heart failure and mortality risk.

OBJECTIVE: CXCL12 encodes stromal cell-derived factor 1α (SDF-1), which binds to the receptor encoded by CXCR4. Variation at the CXCL12 locus is associated with coronary artery disease and endothelial progenitor cell numbers, whereas variation at the CXCR4 locus is associated with leukocyte telomere length, which has been shown to be associated with coronary artery disease. Therefore, we examined the relationships of plasma SDF-1 levels to cardiovascular disease (CVD)-related outcomes, risk factors, leukocyte telomere length, and endothelial progenitor cells. APPROACH AND RESULTS: SDF-1 was measured in 3359 Framingham Heart Study participants. We used Cox regression to examine relationships of SDF-1 to new-onset CVD, myocardial infarction, heart failure, and all-cause mortality; we used linear regression to evaluate associations of SDF-1 with risk factors, leukocyte telomere length, and CD34+ cell phenotypes. In multivariable models, higher SDF-1 levels were associated with older age, lower levels of high-density lipoprotein-cholesterol and cigarette smoking. Higher SDF-1 levels were associated with lower CD34+ cell frequency (P=0.02) but not with leukocyte telomere length. During follow-up (median, 9.3 years), there were 263 new-onset CVD events, 160 myocardial infarctions, 200 heart failure events, and 385 deaths. After adjusting for clinical risk factors, SDF-1 levels were associated with heart failure (P=0.04) and all-cause mortality (P=0.003) but not with CVD (P=0.39) or myocardial infarction (P=0.10). The association of SDF-1 levels with myocardial infarction was attenuated after adjustment for high-density lipoprotein-cholesterol. CONCLUSIONS: After adjusting for traditional CVD risk factors, SDF-1 is associated with heart failure and all-cause mortality risk. Additional studies are needed to determine whether measurement of SDF-1 levels has clinical use.

Deficiency of endothelial CXCR4 reduces reendothelialization and enhances neointimal hyperplasia after vascular injury in atherosclerosis-prone mice.

OBJECTIVE: The Cxcl12/Cxcr4 chemokine ligand/receptor axis mediates the mobilization of smooth muscle cell progenitors, driving injury-induced neointimal hyperplasia. This study aimed to investigate the role of endothelial Cxcr4 in neointima formation. APPROACH AND RESULTS: ß-Galactosidase staining using bone marrow x kinase (Bmx)-CreER(T2) reporter mice and double immunofluorescence revealed an efficient and endothelial-specific deletion of Cxcr4 in Bmx-CreER(T2+) compared with Bmx-CreER(T2-) Cxcr4-floxed apolipoprotein E-deficient (Apoe(-/-)) mice (referred to as Cxcr4(EC-KO)ApoE(-/-) and Cxcr4(EC-WT) ApoE(-/-), respectively). Endothelial Cxcr4 deficiency significantly increased wire injury-induced neointima formation in carotid arteries from Cxcr4(EC-KO)ApoE(-/-) mice. The lesions displayed a higher number of macrophages, whereas the smooth muscle cell and collagen content were reduced. This was associated with a significant reduction in reendothelialization and endothelial cell proliferation in injured Cxcr4(EC-KO)ApoE(-/-) carotids compared with Cxcr4(EC-WT)ApoE(-/-) controls. Furthermore, stimulation of human aortic endothelial cells with chemokine (C-X-C motif) ligand 12 (CXCL12) significantly enhanced their wound-healing capacity in an in vitro scratch assay, an effect that could be reversed with the CXCR4 antagonist AMD3100. Also, flow cytometric analysis showed a reduced mobilization of Sca1(+)Flk1(+)Cd31(+) and of Lin(-)Sca1(+) progenitors in Cxcr4(EC-KO) ApoE(-/-) mice after vascular injury, although Cxcr4 surface expression was unaltered. No differences could be detected in plasma concentrations of Cxcl12, vascular endothelial growth factor, sphingosine 1-phosphate, or Flt3 (fms-related tyrosine kinase 3) ligand, all cytokines with an established role in progenitor cell mobilization. Nonetheless, double immunofluorescence revealed a significant reduction in local endothelial Cxcl12 staining in injured carotids from Cxcr4(EC-KO)ApoE(-/-) mice. CONCLUSIONS: Endothelial Cxcr4 is crucial for efficient reendothelialization after vascular injury through endothelial wound healing and proliferation, and through the mobilization of Sca1(+)Flk1(+)Cd31(+) cells, often referred to as circulating endothelial progenitor cells.

Postacute stromal cell-derived factor-1α expression promotes neurovascular recovery in ischemic mice.

BACKGROUND AND PURPOSE: Acute interventions of stroke are often challenged by a narrow treatment window. In this study, we explore treatments in the postacute phase of stroke with wider windows of opportunity. We investigated the effects of stromal cell-derived factor (SDF-1α) in neurovascular recovery during the postacute phase and downstream signaling pathways, underlying SDF-1α-mediated neurovascular recovery. METHODS: Adult male Institute of Cancer Research (ICR) mice underwent middle cerebral artery occlusion. One week after middle cerebral artery occlusion, the animals received stereotactic injection of adenoassociated virus (AAV) carrying SDF-1α gene as treatment or AAV-green fluorescent protein as control and were monitored for 5 weeks. Neurobehavioral outcomes were evaluated, and brain atrophy was measured. Neurogenesis and angiogenesis were examined. The proliferation and migration of neural progenitor cells were evaluated. Downstream pathways of SDF-1α were investigated. Inflammatory response was monitored. RESULTS: Neurobehavioral outcomes were improved, and brain atrophy was greatly reduced for ≤5 weeks in AAV-SDF-1α groups when compared with the control. SDF-1 receptor CXCR4 was upregulated and colocalized with neural and endothelial progenitor cells. The number of nestin(+) and doublecortin(+)/bromodeoxyuridine(+) cells in the subventricular zone, doublecortin(+) and neuron(+)/bromodeoxyuridine(+) cells in the perifocal region, and cluster of differentiation (CD)31(+) and bromodeoxyuridine(+)/CD31(+) microvessels are also significantly increased in AAV-SDF-1α groups. Administration of CXCR4 antagonist AMD3100 eliminated the beneficial effects of SDF-1α. SDF-1α/CXCR4 interaction activated AKT, extracellular signal-regulated kinases (ERK), and P38 mitogen-activated protein kinase (MAPK) signaling pathways but not the c-Jun N-terminal kinase (JNK) pathway. CONCLUSIONS: SDF-1α promoted neurogenesis and angiogenesis during the postacute phase of ischemia without eliciting an inflammatory response. AAV-SDF-1α expression represents a promising avenue for ischemic stroke therapy with a wider treatment window.

Differential expression of SDF-1 isoforms in bladder cancer.

PURPOSE: SDF-1 is a ligand of the chemokine receptors CXCR4 and 7. The 6 known SDF-1 isoforms are generated by alternative mRNA splicing. While SDF-1 expression has been detected in various malignancies, only few groups have reported differential expression of SDF-1 isoforms and its clinical significance. We evaluated the expression of 3 SDF-1 isoforms (α, ß and γ) in bladder cancer. MATERIALS AND METHODS: Using quantitative polymerase chain reaction we measured SDF-1α, ß and γ mRNA levels in 25 normal and 44 bladder cancer tissues, and in 210 urine specimens (28 normal, 74 benign, 57 bladder cancer, 35 bladder cancer history, 8 other cancer history and 8 other cancer) from consecutive patients. Levels were correlated with clinical outcome. RESULTS: Of the SDF-1 isoforms only SDF-1ß mRNA was significantly over expressed 2.5-fold to sixfold in bladder cancer compared to normal bladder tissues. SDF-1α was expressed in bladder tissues but SDF-1γ was undetectable. On multivariate analysis SDF-1ß was an independent predictor of metastasis and disease specific mortality (p=0.017 and 0.043, respectively). In exfoliated urothelial cells only SDF-1ß mRNA levels were differentially expressed with 91.2% sensitivity and 73.8% specificity for detecting bladder cancer. In patients with a bladder cancer history increased SDF-1ß levels indicated a 4.3-fold increased risk of recurrence within 6 months (p=0.0001). CONCLUSIONS: SDF-1 isoforms are differentially expressed in bladder tissues and exfoliated urothelial cells. SDF-1ß mRNA levels in bladder cancer tissues predict a poor prognosis. Furthermore, SDF-1ß mRNA levels in exfoliated cells detect bladder cancer with high sensitivity and they are a potential predictor of future recurrence.

Interleukin-17A Promotes Airway Remodeling in Chronic Obstructive Pulmonary Disease by Activating C-X-C Motif Chemokine Ligand 12 Secreted by Lung Fibroblasts.

Background: The interactions between fibroblasts and bronchial epithelial cells play important roles in the development of chronic obstructive pulmonary disease (COPD). Interleukin (IL)-17A triggers the activation of fibroblasts and the secretion of inflammatory mediators, which promotes epithelial-mesenchymal transition (EMT) in bronchial epithelial cells. Fibroblasts secrete C-X-C motif chemokine ligand 12 (CXCL12), which specifically binds to its receptor, C-X-C motif chemokine receptor 4 (CXCR4) to mediate inflammatory responses. This study aims to investigate IL-17A- and CXCL12-induced airway remodeling. Methods: Primary lung fibroblasts were isolated from human and murine lung tissue for the in vitro experiments, and a mouse model of cigarette smoke (CS)-induced COPD was established for the in vivo experiments. The results were analyzed using a one-way analysis of variance and Tukey's test or Bonferroni's test for the post-hoc test. A p-value < 0.05 was considered statistically significant. Results: Through in vitro experiments, we found that IL-17A-activated primary lung fibroblasts secreted CXCL12 and stimulated EMT in bronchial epithelial cells. However, these effects could be blocked by neutralizing IL-17A or CXCL12. In vivo, an anti-IL-17A antibody or a CXCR4 antagonist could reverse the degree of EMT in the lungs of the COPD mouse model. The IL-17A-induced EMT and increased CXCL12 expression occurred via extracellular signal-regulated kinase (ERK)/phosphorylated-ERK pathways. Conclusion: This study showed that exposure of mice to CS and IL-17A stimulation upregulated CXCL12 expression and induced EMT by activating the ERK signaling pathway. These data offer a novel perspective regarding the molecular mechanism of CXCL12/CXCR4 signaling in IL-17A-induced EMT related to airway remodeling.

Impact of immunosuppressive drugs on efficacy of mesenchymal stem cell therapy for suppressing renal fibrosis.

Preemptive regenerative medicine using mesenchymal stem cells (MSCs) may provide a novel therapeutic approach to prevent the progression from organ damage to organ failure. Although immunosuppressive drugs are often used in patients with organ disorder, their impact on MSC therapy remains unclear. We investigated the effects of immunosuppressive drugs on the therapeutic efficacy of MSCs. We created unilateral ureteral obstruction models, as a well-established model of renal fibrosis, a preliminary stage of organ failure. Three immunosuppressive drugs (methylprednisolone, cyclosporine, and cyclophosphamide) were intraperitoneally administered 3 days after surgery, and MSCs were injected via tail vein the following day. Preadministration of methylprednisolone or cyclophosphamide interfered with MSC activation by reducing expression of interferon-gamma (IFN-γ) and high-mobility group box-1 protein, thus significantly attenuating the therapeutic efficacy of MSCs. Preadministration of cyclophosphamide downregulated the expression of stromal cell-derived factor-1/C-X-C motif ligand 12, which is a potent migration factor for MSCs, resulting in reduced MSC engraftment in the renal cortex. IFN-γ-preconditioned activated MSCs were unaffected by these drugs and maintained their beneficial therapeutic effects. Cyclosporine preadministration had no effect on the therapeutic efficacy of MSCs. Our study demonstrated that the administration of certain immunosuppressive drugs interfered with MSC activation and engraftment at the site of injury, resulting in a significant attenuation of their therapeutic efficacy. These findings provide crucial information for selecting patients suitable for MSC therapy. Use of MSCs preactivated with IFN-γ or other means is preferred for patients on methylprednisolone or cyclophosphamide.

Tissue Expression and Prognostic Role of CXCL12 and CXCR4 in High-grade Serous Ovarian Carcinoma.

BACKGROUND/AIM: The complex of C-X-C motif chemokine receptor 4 (CXCR4) and its ligand, C-X-C motif chemokine ligand 12 (CXCL12), plays an essential role in cancer cell proliferation, invasion, and metastasis. These are emerging therapeutic targets, and recent studies have reported that inhibition of CXCL12-CXCR4 signaling pathway enhances the effects of immune checkpoint inhibitors. Thus, we aimed to investigate tissue expression of CXCL12 and CXCR4 in high-grade serous ovarian carcinoma (HGSOC) and to determine their potential as prognostic markers. PATIENTS AND METHODS: We used chemotherapy-naïve, formalin-fixed paraffin-embedded primary ovarian cancer tissues obtained from patients with advanced-stage HGSOC at the time of primary cytoreductive surgery. After histological reassessment, we constructed a tissue microarray and performed immunohistochemical staining for CXCL12 and CXCR4. Thereafter, clinicopathological characteristics and survival outcomes were compared between the high- and low-expression groups. RESULTS: A total of 97 patients with FIGO stage IIIC-IV HGSOC were included: 15 (15.5%), 66 (68.0%), and 13 (13.4%) patients showed high expression of CXCL12, CXCR4, and both, respectively. The expression level of each protein was not associated with germline BRCA1/2 mutational status, FIGO stage, or residual tumor after primary cytoreductive surgery. In multivariate analysis adjusted for confounders, high CXCL12 expression was identified as an independent poor prognostic biomarker for progression-free survival (adjusted hazards ratio, 1.990; 95% confidence interval=1.090-3.633; p=0.025). However, CXCR4 expression was not associated with patient survival outcomes. CONCLUSION: The CXCL12 expression level may represent a prognostic biomarker for HGSOC. Proteins related to the CXCL12/CXCR4 complex may serve as therapeutic targets in HGSOC treatment.

CXCL12-CXCR4/CXCR7 Axis in Cancer: from Mechanisms to Clinical Applications.

Cancer is a multi-step disease caused by the accumulation of genetic mutations and/or epigenetic changes, and is the biggest challenge around the world. Cytokines, including chemokines, exhibit expression changes and disorders in all human cancers. These cytokine abnormalities can disrupt homeostasis and immune function, and make outstanding contributions to various stages of cancer development such as invasion, metastasis, and angiogenesis. Chemokines are a superfamily of small molecule chemoattractive cytokines that mediate a variety of cellular functions. Importantly, the interactions of chemokine members CXCL12 and its receptors CXCR4 and CXCR7 have a broad impact on tumor cell proliferation, survival, angiogenesis, metastasis, and tumor microenvironment, and thus participate in the onset and development of many cancers including leukemia, breast cancer, lung cancer, prostate cancer and multiple myeloma. Therefore, this review aims to summarize the latest research progress and future challenges regarding the role of CXCL12-CXCR4/CXCR7 signaling axis in cancer, and highlights the potential of CXCL12-CXCR4/CXCR7 as a biomarker or therapeutic target for cancer, providing essential strategies for the development of novel targeted cancer therapies.

CCL2, CCL8, CXCL12 chemokines in resectable non-small cell lung cancer (NSCLC).

BACKGROUND: Complex networks of chemokines are part of the immune reaction targeted against tumor cells. Chemokines influence cancer growth. It is unclear whether the concentrations of chemokines at the time of NSCLC (non-small cell lung cancer) diagnosis differ from healthy controls and reflect the extent of NSCLC. AIMS: To compare chemokine concentrations (CCL2, CCL8, CXCL12) in the plasma of patients with resectable NSCLC to those without cancer. To determine whether the chemokine concentrations differ relative to the stage of disease. METHODS: Sixty-nine patients undergoing surgery for proven/suspected NSCLC were enrolled. They underwent standard diagnostic and staging procedures to determine resectability, surgery was performed. Forty-two patients were diagnosed with NSCLC, while 27patients had benign lung lesions and functioned as the control group. Chemokine concentrations in peripheral blood were assessed using ELISA. Parametric statistics were used for the analysis of results. RESULTS: There were no differences in plasma chemokine concentrations in NSCLC patients compared to controls. CXCL12 concentrations correlated positively with tumor extent expressed as clinical stage, (mean values: stage I 5.08 ng/mL, SEM 0.59; stage II and IIIA 7.82 ng/mL; SEM 1.06; P=0.022). Patients with NSCLC stages II+IIIA had significantly higher CXCL12 concentrations than controls (mean values: stage II+IIIA 7.82 ng/mL; SEM 1.06; controls 5.3 ng/mL; SEM 0.46; P=0.017). CONCLUSION: CXCL12 was related to tumor growth and could potentially be used as a biomarker of advanced disease.

LPS-induced migration of peritoneal B-1 cells is associated with upregulation of CXCR4 and increased migratory sensitivity to CXCL12.

B-1 cells, which constitute a predominant lymphocyte subset in serosal cavities and produce most of natural antibodies, are subdivided into the CD5(+) B-1a and CD5(-) B-1b cell subpopulations, but the differential roles of B-1a and B-1b cells are not well understood. We report that B-1a cells preferentially migrate out of the peritoneal cavity and upregulate the expression of CXCR4 with heightened sensitivity to CXCL12 and CXCL13 upon LPS treatment compared to B-1b and B-2 cells. Whereas B-1a cells were slightly more abundant than B-1b and B-2 cells in the homeostatic condition, the number of B-1a cells preferentially decreased 48 hr after LPS treatment. The decrease in the peritoneal B-1a cell number was accompanied with increased migration of B-1a cells toward CXCL-12 and CXCL-13 in in vitro transmigration assay using peritoneal B cells from LPS treated mice. The expression level of CXCR4, but not of CXCR5, was also more prominently increased in B-1a cells upon LPS stimulation. LPS-stimulated B-1a cells did not accumulate in omental milky spots in contrast to B-2 cells. These results suggest that B-1a cells actively migrate out of the peritoneal cavity through the regulation of the migratory responsiveness to chemokines and actively participate in systemic immune responses.

The contributory roles of the CXCL12/CXCR4/CXCR7 axis in normal and malignant hematopoiesis: A possible therapeutic target in hematologic malignancies.

C-X-C motif chemokine 12 (CXCL12), also known as stromal cell-derived factor-1 (SDF-1), is produced by the bone marrow microenvironment. This chemokine binds and activates its cognate receptors C-X-C chemokine receptor type 4 (CXCR4) and C-X-C chemokine receptor type 7 (CXCR7) to widely regulate cell proliferation, survival, differentiation, as well as homing and mobilization of hematopoietic stem cells (HSCs) in specialized niches within the bone marrow. Given this key role in hematopoiesis, it comes as no surprise that any aberrancies in CXCL12/CXCR4 or CXCL12/CXCR7 pathways might lead to excessive proliferation of HSCs, an event that leads to the development of leukemia. So far, numerous therapeutic interventions have been developed to harness CXCL12/CXCR4 and CXCL12/CXCR7 axes in leukemic cells. Plerixafor, BKT140, LY2510924, PF-06747143, ulocuplumab, and NOX-A12 are among the most well-known CXCR4 and CXCL12 modulators that their therapeutic efficacies have been evaluated in different pre-clinical and clinical studies of hematologic malignancies. To have an overview of the importance of CXCL12/CXCR4 and CXCL12/CXCR7 axes in the pathogenesis of leukemia and to gather information about the latest advances as well as challenges in targeting these axes in clinical settings, the present review has begun with a discussion about how aberrant expression of CXCL12/CXCR4 and CXCL12/CXCR7 pathways might regulate leukemogenesis and ended by outlining the key news of preclinical and clinical investigations in leukemia treatment.