Impact of CD34/CD309 expression in circulating endothelial progenitor cells on prognosis and response to bortezomib therapy in multiple myeloma.

Multiple myeloma (MM) is a prevalent yet incurable hematologic malignancy. Despite the proven efficacy of proteasome inhibitors in treating MM, resistance to Bortezomib-based treatments persists in a subset of patients. This case control study explores the potential of circulating endothelial progenitor cells (EPCs) as biomarkers for predicting response to Proteasome Inhibitor based therapy combined with Dexamethasone in MM patients. This study was conducted on 105 MM patients receiving bortezomib plus dexamethasone therapy and 90 healthy individuals as a control group. Utilizing 8-color multi-parameter flow cytometry, we assessed the levels of circulating EPCs, identified through CD34 FITC and CD309 PE markers at diagnosis and after one treatment cycle (4 weeks). Our findings revealed that patients exhibiting poor response to therapy showed significantly higher CD34/CD309 values than those with a good response (p < 0.001). The delineation of response based on CD34/CD309 expression was established with a cutoff ≤ 0.9 for percentage (yielding 100% sensitivity and 94.1% specificity) and ≤ 12.5 for absolute value (also with 100% sensitivity and 94.1% specificity). These results underscore the potential of EPC population levels, as quantified by CD34/CD309, to serve as a predictive biomarker for immunomodulatory treatment in MM patients undergoing Proteasome Inhibitor and Dexamethasone therapy.

Histological evaluation of renal progenitor/stem cells, renal mesenchymal stem-like cells, and endothelial progenitor cells in chronic kidney disease and end-stage renal disease, and molecular docking analysis of drug-receptor interactions.

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are prevalent and debilitating conditions with a significant impact on patients' quality of life. In this study, we conducted a comprehensive investigation into the histological characteristics of renal progenitor/stem cells (RPCs), renal mesenchymal stem-like cells, and endothelial progenitor cells (EPCs) in CKD and ESRD patients. Additionally, we performed a molecular docking analysis to explore potential drug-receptor interactions involving common medications prescribed to CKD patients. Our histological examination revealed a noteworthy increase in the number of CD24- and CD133-positive cells in CKD and ESRD patients, representing RPCs. These cells are implicated in kidney repair and regeneration, underscoring their potential role in CKD management. Moreover, we observed an elevation in the number of EPCs within the kidneys of CKD and ESRD patients, suggesting a protective role of EPCs in kidney preservation. The molecular docking analysis unveiled intriguing insights into potential drug interventions. Notably, digoxin exhibited the highest in-silico binding affinity to numerous receptors associated with the functions of RPCs, renal mesenchymal stem-like cells, and EPCs, emphasizing the potential multifaceted effects of this cardiac glycoside in CKD patients. Other drugs, including apixaban, glimepiride, and glibenclamide, also displayed strong in-silico affinities to specific receptors, indicating their potential influence on various renal cell functions. In conclusion, this study provides valuable insights into the histological alterations in renal cell populations in CKD and ESRD patients and underscores the potential roles of RPCs and EPCs in kidney repair and preservation. The molecular docking analysis reveals the complex interactions between common drugs and renal cells, suggesting the need for further in-vitro and in-vivo research to fully understand these relationships. These findings contribute to our understanding of CKD and offer new avenues for research into potential therapeutic interventions.

mTORC1 Signaling in Brain Endothelial Progenitors Contributes to CCM Pathogenesis.

BACKGROUND: Cerebral vascular malformations (CCMs) are primarily found within the brain, where they result in increased risk for stroke, seizures, and focal neurological deficits. The unique feature of the brain vasculature is the blood-brain barrier formed by the brain neurovascular unit. Recent studies suggest that loss of CCM genes causes disruptions of blood-brain barrier integrity as the inciting events for CCM development. CCM lesions are proposed to be initially derived from a single clonal expansion of a subset of angiogenic venous capillary endothelial cells (ECs) and respective resident endothelial progenitor cells (EPCs). However, the critical signaling events in the subclass of brain ECs/EPCs for CCM lesion initiation and progression are unclear. METHODS: Brain EC-specific CCM3-deficient (Pdcd10BECKO) mice were generated by crossing Pdcd10fl/fl mice with Mfsd2a-CreERT2 mice. Single-cell RNA-sequencing analyses were performed by the chromium single-cell platform (10× genomics). Cell clusters were annotated into EC subtypes based on visual inspection and GO analyses. Cerebral vessels were visualized by 2-photon in vivo imaging and tissue immunofluorescence analyses. Regulation of mTOR (mechanistic target of rapamycin) signaling by CCM3 and Cav1 (caveolin-1) was performed by cell biology and biochemical approaches. RESULTS: Single-cell RNA-sequencing analyses from P10 Pdcd10BECKO mice harboring visible CCM lesions identified upregulated CCM lesion signature and mitotic EC clusters but decreased blood-brain barrier-associated EC clusters. However, a unique EPC cluster with high expression levels of stem cell markers enriched with mTOR signaling was identified from early stages of the P6 Pdcd10BECKO brain. Indeed, mTOR signaling was upregulated in both mouse and human CCM lesions. Genetic deficiency of Raptor (regulatory-associated protein of mTOR), but not of Rictor (rapamycin-insensitive companion of mTOR), prevented CCM lesion formation in the Pdcd10BECKO model. Importantly, the mTORC1 (mTOR complex 1) pharmacological inhibitor rapamycin suppressed EPC proliferation and ameliorated CCM pathogenesis in Pdcd10BECKO mice. Mechanistic studies suggested that Cav1/caveolae increased in CCM3-depleted EPC-mediated intracellular trafficking and complex formation of the mTORC1 signaling proteins. CONCLUSIONS: CCM3 is critical for maintaining blood-brain barrier integrity and CCM3 loss-induced mTORC1 signaling in brain EPCs initiates and facilitates CCM pathogenesis.

The Effect of SGLT2 Inhibitor Therapy on Endothelial Progenitor Cell Function in Patients With Heart Failure.

ABSTRACT: Sodium-glucose cotransporter-2 (SGLT-2) inhibitors have been shown to reduce the risk of cardiovascular mortality and hospitalizations in patients with heart failure (HF) with preserved or reduced ejection fraction (HFpEF or HFrEF). The mechanism for this benefit is not clear. Endothelial progenitor cells (EPCs) are bone marrow-derived cells able to differentiate into functional endothelial cells and participate in endothelial repair. The aim of this study was to evaluate the effect of SGLT-2 inhibitors on the level and function of EPCs in patients with HF. We enrolled 20 patients with symptomatic HF, 12 with HFrEF and 8 with HFpEF (aged 73.3 ± 10.2 years, 95% men). Blood samples were drawn at 2 time points: baseline and ≥3 months after initiation of SGLT-2 inhibitor therapy. Circulating EPC levels were evaluated by expression of vascular endothelial growth factor receptor-2 (VEGFR-2), CD34, and CD133 by flow cytometry. EPC colony forming units (CFUs) were quantified after 7 days in culture. The proportion of cells that coexpressed VEGFR-2 and CD34 or VEGFR-2 and CD133 was higher following 3 months of SGLT-2 inhibitors [0.26% (interquartile range, IQR 0.10-0.33) versus 0.55% (IQR 0.28-0.91), P = 0.002; 0.12% (IQR 0.07-0.15) versus 0.24% (IQR 0.15-0.39), P = 0.001, respectively]. EPC CFUs were also increased following SGLT-2 inhibitor treatment [23 (IQR 3.7-37.8) versus 79.4 (IQR 25.1-110.25) colonies/10 6 cells, P = 0.0039]. In patients with symptomatic HF, both HFpEF and HFrEF, treatment with SGLT-2 inhibitors is associated with an increase in the level and function of circulating EPCs. This augmentation in EPCs may be a contributing mechanism to the clinical benefit of SGLT-2 inhibitors in patients with HF.

Transcriptional and functional profiling identifies inflammation and endothelial-to-mesenchymal transition as potential drivers for phenotypic heterogeneity within a cohort of endothelial colony forming cells.

BACKGROUND: Endothelial colony-forming cells (ECFCs) derived from patients can be used to investigate pathogenic mechanisms of vascular diseases like von Willebrand disease. Considerable phenotypic heterogeneity has been observed between ECFC clones derived from healthy donors. This heterogeneity needs to be well understood in order to use ECFCs as endothelial models for disease. OBJECTIVES: Therefore, we aimed to determine phenotypic and gene expression differences between control ECFCs. METHODS: A total of 34 ECFC clones derived from 16 healthy controls were analyzed. The transcriptome of a selection of ECFC clones (n = 15) was analyzed by bulk RNA sequencing and gene set enrichment analysis. Gene expression was measured in all ECFC clones by quantitative polymerase chain reaction. Phenotypic profiling was performed and migration speed of the ECFCs was measured using confocal microscopy, followed by automated quantification of cell morphometrics and migration speed. RESULTS: Through hierarchical clustering of RNA expression profiles, we could distinguish 2 major clusters within the ECFC cohort. Major differences were associated with proliferation and migration in cluster 1 and inflammation and endothelial-to-mesenchymal transition in cluster 2. Phenotypic profiling showed significantly more and smaller ECFCs in cluster 1, which contained more and longer Weibel-Palade bodies. Migration speed in cluster 1 was also significantly higher. CONCLUSION: We observed a range of different RNA expression patterns between ECFC clones, mostly associated with inflammation and clear differences in Weibel-Palade body count and structure. We developed a quantitative polymerase chain reaction panel that can be used for the characterization of ECFC clones, which is essential for the correct analysis of pathogenic mechanisms in vascular disorders.

Patients With Coronary Microvascular Dysfunction Have Less Circulating α-Klotho.

BACKGROUND: Coronary microvascular dysfunction (CMD) represents an early functional characteristic of coronary vascular aging. Klotho (α-klotho) is a circulating protein inversely linked to physiological aging. We examined low klotho as a potential marker for vascular aging in patients with CMD and no coronary artery disease. METHODS AND RESULTS: Patients undergoing nonurgent angiogram for chest pain who had no coronary artery disease underwent invasive coronary microvascular and endothelial function testing. CMD was defined by ≤50% increase in coronary blood flow (percentage change in coronary blood flow) in response to intracoronary acetylcholine or coronary flow reserve ≤2. Fresh arterial whole blood was used to analyze circulating endothelial progenitor cells with flow cytometry. Stored arterial plasma was used for klotho analysis by ELISA. Participants with CMD (n=62) were compared with those without CMD (n=36). Those with CMD were age 55±10 years (versus 51±11 years; P=0.07) and 73% women (versus 81%; P=0.38). Traditional risk factors for coronary artery disease were similar between groups. Patients with CMD had less klotho (0.88±1.50 versus 1.75±2.38 ng/mL; P=0.03), and the odds of low klotho in CMD were significant in a logistic regression model after adjusting for traditional cardiovascular risk factors (odds ratio [OR], 0.80 [95% CI, 0.636-0.996]; P=0.05). Higher klotho was associated with higher numbers of endothelial progenitor cells with vascular regenerative potential (CD34+ and CD34+CD133+KDR+). Among a subgroup of patients with atherosclerotic cardiovascular disease risk <5% (n=58), CMD remained associated with lower klotho (OR, 0.80 [95% CI, 0.636-0.996]; P=0.047). CONCLUSIONS: Klotho may be a biomarker for CMD and may be a therapeutic target for groups of patients without significant traditional cardiovascular risk.

Crosstalk between endothelial progenitor cells and HCC through periostin/CCL2/CD36 supports formation of the pro-metastatic microenvironment in HCC.

Metastasis causes most cancer-related deaths, and the role and mechanism of periostin (POSTN) in the metastasis of hepatocellular carcinoma (HCC) remain undiscovered. In this study, DEN and HTVi HCC models were performed in hepatic-specific Postn ablation and Postn knock-in mouse to reveal the role of POSTN in HCC metastasis. Furthermore, POSTN was positively correlated with circulating EPCs level and promoted EPC mobilization and tumour infiltration. POSTN also mediated the crosstalk between HCC and EPCs, which promoted metastasis ability and upregulated CD36 expression in HCC through indirect crosstalk. Chemokine arrays further revealed that hepatic-derived POSTN induced elevated CCL2 expression and secretion in EPCs, and CCL2 promoted prometastatic traits in HCC. Mechanistic studies showed that POSTN upregulated CCL2 expression in EPCs via the αvß3/ILK/NF-κB pathway. CCL2 further induced CD36 expression via the CCR2/STAT3 pathway by directly binding to the promoter region of CD36. Finally, CD36 was verified to have a prometastatic role in vitro and to be correlated with POSTN expression, metastasis and recurrence in HCC in clinical samples. Our findings revealed that crosstalk between HCC and EPCs is mediated by periostin/CCL2/CD36 signalling which promotes HCC metastasis and emphasizes a potential therapeutic strategy for preventing HCC metastasis.

GroEL of Porphyromonas gingivalis-induced microRNAs accelerate tumor neovascularization by downregulating thrombomodulin expression in endothelial progenitor cells.

We found that GroEL in Porphyromonas gingivalis accelerated tumor growth and increased mortality in tumor-bearing mice; GroEL promoted proangiogenic function, which may be the reason for promoting tumor growth. To understand the regulatory mechanisms by which GroEL increases the proangiogenic function of endothelial progenitor cells (EPCs), we explored in this study. In EPCs, MTT assay, wound-healing assay, and tube formation assay were performed to analyze its activity. Western blot and immunoprecipitation were used to study the protein expression along with next-generation sequencing for miRNA expression. Finally, a murine tumorigenesis animal model was used to confirm the results of in vitro. The results indicated that thrombomodulin (TM) direct interacts with PI3 K/Akt to inhibit the activation of signaling pathways. When the expression of TM is decreased by GroEL stimulation, molecules in the PI3 K/Akt signaling axis are released and activated, resulting in increased migration and tube formation of EPCs. In addition, GroEL inhibits TM mRNA expression by activating miR-1248, miR-1291, and miR-5701. Losing the functions of miR-1248, miR-1291, and miR-5701 can effectively alleviate the GroEL-induced decrease in TM protein levels and inhibit the proangiogenic abilities of EPCs. These results were also confirmed in animal experiments. In conclusion, the intracellular domain of the TM of EPCs plays a negative regulatory role in the proangiogenic capabilities of EPCs, mainly through direct interaction between TM and PI3 K/Akt to inhibit the activation of signaling pathways. The effects of GroEL on tumor growth can be reduced by inhibiting the proangiogenic properties of EPCs through the inhibition of the expression of specific miRNAs.

Endothelial progenitor cells systemic administration alleviates multi-organ senescence by down-regulating USP7/p300 pathway in chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) has impacted approximately 390 million people worldwide and the morbidity is increasing every year. However, due to the poor treatment efficacy of COPD, exploring novel treatment has become the hotpot of study on COPD. Endothelial progenitor cells (EPCs) aging is a possible molecular way for COPD development. We aimed to explore the effector whether intravenous administration of EPCs has therapeutic effects in COPD mice. METHODS: COPD mice model was induced by cigarette smoke exposure and EPCs were injected intravenously to investigate their effects on COPD mice. At day 127, heart, liver, spleen, lung and kidney tissues of mice were harvested. The histological effects of EPCs intervention on multiple organs of COPD mice were detected by morphology assay. Quantitative real-time PCR and Western blotting were used to detect the effect of EPCs intervention on the expression of multi-organ senescence-related indicators. And we explored the effect of EPCs systematically intervening on senescence-related USP7/p300 pathway. RESULTS: Compared with COPD group, senescence-associated ß-galactosidase activity was decreased, protein and mRNA expression of p16 was down-regulated, while protein and mRNA expression of cyclin D1 and TERT were up-regulated of multiple organs, including lung, heart, liver, spleen and kidney in COPD mice after EPCs system intervention. But the morphological alterations of the tissues described above in COPD mice failed to be reversed. Mechanistically, EPCs systemic administration inhibited the expression of mRNA and protein of USP7 and p300 in multiple organs of COPD mice, exerting therapeutic effects. CONCLUSIONS: EPCs administration significantly inhibited the senescence of multiple organs in COPD mice via down-regulating USP7/p300 pathway, which presents a possibility of EPCs therapy for COPD.

CD133+ endothelial-like stem cells restore neovascularization and promote longevity in progeroid and naturally aged mice.

The stem cell theory of aging dictates that a decline in the number and/or function of stem cells causes tissue degeneration and aging; however, it still lacks unequivocal experimental support. Here, using lineage tracing and single-cell transcriptomics, we identify a population of CD133+ bone marrow-derived endothelial-like cells (ELCs) as potential endothelial progenitor cells, which contribute to tubular structures in vitro and neovascularization in vivo. We demonstrate that supplementation with wild-type and young ELCs respectively restores neovascularization and extends lifespan in progeric and naturally aged mice. Mechanistically, we identify an upregulation of farnesyl diphosphate synthase (FDPS) in aged CD133+ ELCs-a key enzyme in isoprenoid biosynthesis. Overexpression of FDPS compromises the neovascularization capacity of CD133+ ELCs, whereas FDPS inhibition by pamidronate enhances neovascularization, improves health measures and extends lifespan in aged mice. These findings highlight stem cell-based strategies for the treatment of progeria and age-related pathologies.

Sudden Sensorineural Hearing Loss Is Related to Endothelial Progenitor Cells and Lipoprotein-Associated Phospholipase A2.

BACKGROUND: This study aimed to investigate the correlation between lipoprotein-associated phospholipase A2, endothelial progenitor cells, and sudden sensorineural hearing loss. METHODS: The number of endothelial progenitor cells and lipoprotein-associated phospholipase A2 levels collected from peripheral blood samples were measured and compared between sudden sensorineural hearing loss group and control group. RESULTS: The number of endothelial progenitor cells was reduced in sudden sensorineural hearing loss group compared to control group (38.88 ± 10.73 in sudden sensorineural hearing loss group vs. 77.14 ± 8.56 in control group, P <.01). The lipoprotein-associated phospholipase A2 level was markedly increased in sudden sensorineural hearing loss group compared to control group (244.94 ± 59.547 in sudden sensorineural hearing loss group vs. 189.00 ± 50.987 in control group, P <.05). CONCLUSION: The number of endothelial progenitor cells was decreased and lipoprotein-associated phospholipase A2 levels were increased in sudden sensorineural hearing loss patients. Changes in the number of endothelial progenitor cells and lipoprotein-associated phospholipase A2 levels may be involved in the pathogenesis of sudden sensorineural hearing loss.

Increase of Circulating Endothelial Progenitor Cells and Released Angiogenic Factors in Children with Moyamoya Arteriopathy.

Moyamoya arteriopathy (MMA) is a rare cerebrovascular disorder that causes recurrent ischemic and hemorrhagic strokes, leading young patients to severe neurological deficits. The pathogenesis of MMA is still unknown. The disease onset in a wide number of pediatric cases raises the question of the role of genetic factors in the disease's pathogenesis. In these patients, MMA's clinical course, or progression, is largely unclear. By performing a comprehensive molecular and cellular profile in the plasma and CSF, respectively, of MMA pediatric patients, our study is aimed at assessing the levels of circulating endothelial progenitor cells (cEPC) and the release of selected proteins at an early disease stage to clarify MMA pathogenesis and progression. We employed cytofluorimetric methods and immunoassays in pediatric MMA patients and matched control subjects by age and sex. We detected increased levels of cEPC in peripheral blood and an upregulation of angiogenic markers in CSF (i.e., angiopoietin-2 and VEGF-A). This finding is probably associated with deregulated angiogenesis, as stated by the moderate severity of collateral vessel network development (Suzuki III-IV). The absence of significant modulation of neurofilament light in CSF led us to rule out the presence of substantial neuronal injury in MMA children. Despite the limited cohort of pediatric patients, we found some peculiar cellular and molecular characteristics in their blood and CSF samples. Our findings may be confirmed by wider and perspective studies to identify predictive or prognostic circulating biomarkers and potential therapeutic targets for personalized care of MMA pediatric patients.

GDF11 promotes wound healing in diabetic mice via stimulating HIF-1ɑ-VEGF/SDF-1ɑ-mediated endothelial progenitor cell mobilization and neovascularization.

Non-healing diabetic wounds (DW) are a serious clinical problem that remained poorly understood. We recently found that topical application of growth differentiation factor 11 (GDF11) accelerated skin wound healing in both Type 1 DM (T1DM) and genetically engineered Type 2 diabetic db/db (T2DM) mice. In the present study, we elucidated the cellular and molecular mechanisms underlying the action of GDF11 on healing of small skin wound. Single round-shape full-thickness wound of 5-mm diameter with muscle and bone exposed was made on mouse dorsum using a sterile punch biopsy 7 days following the onset of DM. Recombinant human GDF11 (rGDF11, 50 ng/mL, 10 µL) was topically applied onto the wound area twice a day until epidermal closure (maximum 14 days). Digital images of wound were obtained once a day from D0 to D14 post-wounding. We showed that topical application of GDF11 accelerated the healing of full-thickness skin wounds in both type 1 and type 2 diabetic mice, even after GDF8 (a muscle growth factor) had been silenced. At the cellular level, GDF11 significantly facilitated neovascularization to enhance regeneration of skin tissues by stimulating mobilization, migration and homing of endothelial progenitor cells (EPCs) to the wounded area. At the molecular level, GDF11 greatly increased HIF-1ɑ expression to enhance the activities of VEGF and SDF-1ɑ, thereby neovascularization. We found that endogenous GDF11 level was robustly decreased in skin tissue of diabetic wounds. The specific antibody against GDF11 or silence of GDF11 by siRNA in healthy mice mimicked the non-healing property of diabetic wound. Thus, we demonstrate that GDF11 promotes diabetic wound healing via stimulating endothelial progenitor cells mobilization and neovascularization mediated by HIF-1ɑ-VEGF/SDF-1ɑ pathway. Our results support the potential of GDF11 as a therapeutic agent for non-healing DW.

Involvement of endothelial progenitor cells in blood flow recovery through activation of the Wnt/ß-catenin signaling pathway and inhibition of high oxidative stress in diabetic hindlimb ischemic rats.

BACKGROUND: Diabetes mellitus (DM) often causes stenosis and occlusion of hindlimb blood vessels, which are also the main cause for hindlimb ischemia in elderly people. OBJECTIVES: To investigate the therapeutic effect of endothelial progenitor cell (EPC) transplantation on diabetic hindlimb ischemia. MATERIAL AND METHODS: Endothelial progenitor cells were separated, labeled with PKH-26 and transplanted into rat models (107 cells/100 g). Dichlorodihydrofluorescein diacetate (DCFH-DA) was used to detect any oxidative stress. Streptozotocin (STZ) was injected to establish a diabetic rat model and hindlimb ischemia model was established via operation. Western blotting was used to detect total ß-catenin (T-ß-catenin) and non-phospho-ß-catenin (NP-ß-catenin) levels. The malondialdehyde (MDA), superoxide dismutase (SOD), Wnt3a, Wnt5a and Wnt7a levels were detected using enzyme-linked immunosorbent assay (ELISA). Oxidative stress was measured using DCFH-DA and dihydroethidium (DHE). The endothelial biomarker CD31 was observed to highlight vessels, and PKH-26 to trace migration/adhesion of EPCs. RESULTS: Endothelial progenitor cells were successfully isolated and identified, and diabetic hindlimb ischemic rat models were created. Tempol remarkably improved blood flow in diabetic hindlimb ischemic rats compared to DM+EPCs rats at 14 days (p < 0.001) and 28 days post-operation (p < 0.001). High oxidative stress was observed in diabetic hindlimb ischemic rats. Tempol significantly inhibited oxidative stress levels in diabetic hindlimb ischemic rats. Furthermore, Tempol significantly promoted angiogenesis in diabetic hindlimb ischemic rats compared to DM+EPCs rats. The ß-catenin inhibitor, XAV (DM+EPCs+Tempol+XAV group), significantly suppressed blood flow recovery and angiogenesis in diabetic hindlimb ischemic rats when compared to the DM+EPCs+Tempol group at 14 days (p = 0.026) and 28 days (p < 0.001). The XAV remarkably reduced T-ß-catenin (p < 0.001) and N-ß-catenin (p = 0.030) levels in Tempol-treated diabetic hindlimb ischemic rats, as compared to the DM+EPCs+Tempol group. The Wnt5a participated in the pathology of diabetic hindlimb ischemia. CONCLUSIONS: There are high oxidative stress levels in both EPCs in high-glucose environments and diabetic hindlimb ischemia, which can lead to limited blood flow recovery. The high oxidative stress caused the inhibition of Wnt/ß-catenin signaling pathway, leading to limited blood flow recovery in diabetic hindlimb ischemia. At the same time, Wnt5a participated in the EPC-mediated blood flow recovery.

Loxin Reduced the Inflammatory Response in the Liver and the Aortic Fatty Streak Formation in Mice Fed with a High-Fat Diet.

Oxidized low-density lipoprotein (ox-LDL) is the most harmful form of cholesterol associated with vascular atherosclerosis and hepatic injury, mainly due to inflammatory cell infiltration and subsequent severe tissue injury. Lox-1 is the central ox-LDL receptor expressed in endothelial and immune cells, its activation regulating inflammatory cytokines and chemotactic factor secretion. Recently, a Lox-1 truncated protein isoform lacking the ox-LDL binding domain named LOXIN has been described. We have previously shown that LOXIN overexpression blocked Lox-1-mediated ox-LDL internalization in human endothelial progenitor cells in vitro. However, the functional role of LOXIN in targeting inflammation or tissue injury in vivo remains unknown. In this study, we investigate whether LOXIN modulated the expression of Lox-1 and reduced the inflammatory response in a high-fat-diet mice model. Results indicate that human LOXIN blocks Lox-1 mediated uptake of ox-LDL in H4-II-E-C3 cells. Furthermore, in vivo experiments showed that overexpression of LOXIN reduced both fatty streak lesions in the aorta and inflammation and fibrosis in the liver. These findings were associated with the down-regulation of Lox-1 in endothelial cells. Then, LOXIN prevents hepatic and aortic tissue damage in vivo associated with reduced Lox-1 expression in endothelial cells. We encourage future research to understand better the underlying molecular mechanisms and potential therapeutic use of LOXIN.

Study on the serum level of CoQ10B in patients with Moyamoya disease and its mechanism of affecting disease progression.

BACKGROUND: At present, the etiology and pathogenesis of Moyamoya disease (MMD) are not completely clear. Patients are usually diagnosed after cerebrovascular events. Therefore, it is of great clinical significance to explore the predictive factors of MMD. OBJECTIVE: This study aimed to investigate the serum level of CoQ10B, the amount of endothelial progenitor cells (EPCs), and mitochondrial function of EPCs in MMD patients. METHODS: Forty-one MMD patients and 20 healthy controls were recruited in this study. Patients with MMD were divided into two groups: Ischemic type (n=23) and hemorrhagic type (n=18). Blood samples were collected from the antecubital vein and analyzed by CoQ10B ELISA and flow cytometry. Measures of mitochondrial function of EPCs include oxygen consumption rate (OCR), mitochondrial membrane potential, Ca2+ concentration, adenosine triphosphatases activity and ROS level. RESULTS: The serum CoQ10B level in MMD patients was significantly lower than that in healthy controls (p<0.001). The relative number of EPCs in MMD patients was significantly higher than that in healthy controls (p<0.001). Moreover, the OCR, mitochondrial membrane potential and ATPase activity were decreased and the Ca2+ and reactive oxygen species levels were increased in MMD patients (p<0.001). CONCLUSIONS: Our results showed obviously decreased serum CoQ10B level and increased EPCs number in patients with MMD compared with healthy patients, and the mitochondria function of EPCs in MMD patients was abnormal.

Osteocalcin-expressing endothelial progenitor cells and serum osteocalcin forms are independent biomarkers of coronary atherosclerotic disease severity in male and female patients.

PURPOSE: Osteocalcin (OC), an osteoblast-derived regulator of metabolic processes, and circulating early endothelial progenitor cells (EPC, CD34 - /CD133 + /KDR +) expressing OC (OC +) are potential candidates linking bone metabolism and the vasculature and might be involved in vascular atherosclerotic calcification. This study aimed at assessing the association of circulating levels of different OC forms and of EPCs count with disease severity in patients with documented coronary atherosclerosis (CAD). METHODS: Patients (n = 59) undergoing coronary angiography were divided, according to stenosis severity, into (1) early coronary atherosclerosis (ECA) (n = 22), and (2) late coronary atherosclerosis (LCA) (n = 37). Total OC (TOC), carboxylated OC (cOC), undercarboxylated OC (unOC) were quantified by ELISA. EPC OC + count was assessed by flow cytometry. RESULTS: EPC OC + counts showed significant differences between ECA and LCA groups. unOC and unOC/TOC ratio were inversely correlated with EPC OC + count. A significant decrease in TOC and unOC plasma levels was associated with higher cardiovascular risk factors (CVRFs) number. EPC OC + count was correlated with LDL-C, total cholesterol, and triglycerides, with a greater significance in the LCA group. No association between the different forms of circulating OC (TOC, ucOC, cOC) and severity of CAD was found. CONCLUSION: This study showed a significant association between EPCs (CD34 - /CD133 + /KDR + /OC +), CAD severity and CVRFs, suggesting an active role for EPC OC + in the development of CAD. An inverse correlation between TOC, ucOC, and number of CVRFs was observed, suggesting that OC, regardless of its carboxylation status, may be developed as a further cardiovascular risk biomarker.

Integrin α5 Is Regulated by miR-218-5p in Endothelial Progenitor Cells.

BACKGROUND: Endothelial cell injury is a common nidus of renal injury in patients and consistent with the high prevalence of AKI reported during the coronavirus disease 2019 pandemic. This cell type expresses integrin α5 (ITGA5), which is essential to the Tie2 signaling pathway. The microRNA miR-218-5p is upregulated in endothelial progenitor cells (EPCs) after hypoxia, but microRNA regulation of Tie2 in the EPC lineage is unclear. METHODS: We isolated human kidney-derived EPCs (hkEPCs) and surveyed microRNA target transcripts. A preclinical model of ischemic kidney injury was used to evaluate the effect of hkEPCs on capillary repair. We used a genetic knockout model to evaluate the effect of deleting endogenous expression of miR-218 specifically in angioblasts. RESULTS: After ischemic in vitro preconditioning, miR-218-5p was elevated in hkEPCs. We found miR-218-5p bound to ITGA5 mRNA transcript and decreased ITGA5 protein expression. Phosphorylation of 42/44 MAPK decreased by 73.6% in hkEPCs treated with miR-218-5p. Cells supplemented with miR-218-5p downregulated ITGA5 synthesis and decreased 42/44 MAPK phosphorylation. In a CD309-Cre/miR-218-2-LoxP mammalian model (a conditional knockout mouse model designed to delete pre-miR-218-2 exclusively in CD309+ cells), homozygotes at e18.5 contained avascular glomeruli, whereas heterozygote adults showed susceptibility to kidney injury. Isolated EPCs from the mouse kidney contained high amounts of ITGA5 and showed decreased migratory capacity in three-dimensional cell culture. CONCLUSIONS: These results demonstrate the critical regulatory role of miR-218-5p in kidney EPC migration, a finding that may inform efforts to treat microvascular kidney injury via therapeutic cell delivery.

Comparative study on effect of mesenchymal stem cells and endothelial progenitor cells on treatment of experimental CCL4-induced liver fibrosis.

BACKGROUND: We speculated impacts of BM-MSCs and UC-EPCs on reversal of hepatic injury induced by carbon tetrachloride (CCl4). Fifty adult rats were divided into five groups: control group, CCl4A group, CCl4B group, CCl4/BM-MSCs group and CCl4/UC-EPCs group. Blood samples were driven to measure concentration of albumin and ALT. Quantitative expression of HGF, TGF-ß, MMP-2, and VEGF were assessed by PCR. Histological and immunohistochemistry examination of the liver tissue were performed. RESULTS: There was elevating albumin (p < .05) and reducing ALT (p < .05) concentrations in groups treated with BM-MSCs and UC-EPCs compared to untreated CCL4A&B groups. UC-EPCs treated group have significantly higher MMP-2 and VEGF (p < .01) genes expression than BM-MSCs treated group. Furthermore, UC-EPCs were more valuable than BMMSCs in increasing gene expression of HGF (p < .05) and immunohistochemistry of α-SMA and Ki-67 (p < .01). BM-MSCs have significantly lower TGF-ß (p < .00) compared to UC-EPCs. CONCLUSION: This study highlighted on liver regeneration role of both UC-EPCs and BM-MSCs in liver fibrosis.

Endothelial GNAQ p.R183Q Increases ANGPT2 (Angiopoietin-2) and Drives Formation of Enlarged Blood Vessels.

OBJECTIVE: Capillary malformation (CM) occurs sporadically and is associated with Sturge-Weber syndrome. The somatic mosaic mutation in GNAQ (c.548G>A, p.R183Q) is enriched in endothelial cells (ECs) in skin CM and Sturge-Weber syndrome brain CM. Our goal was to investigate how the mutant Gαq (G-protein αq subunit) alters EC signaling and disrupts capillary morphogenesis. Approach and Results: We used lentiviral constructs to express p.R183Q or wild-type GNAQ in normal human endothelial colony forming cells (EC-R183Q and EC-WT, respectively). EC-R183Q constitutively activated PLC (phospholipase C) ß3, a downstream effector of Gαq. Activated PLCß3 was also detected in human CM tissue sections. Bulk RNA sequencing analyses of mutant versus wild-type EC indicated constitutive activation of PKC (protein kinase C), NF-κB (nuclear factor kappa B) and calcineurin signaling in EC-R183Q. Increased expression of downstream targets in these pathways, ANGPT2 (angiopoietin-2) and DSCR (Down syndrome critical region protein) 1.4 were confirmed by quantitative PCR and immunostaining of human CM tissue sections. The Gαq inhibitor YM-254890 as well as siRNA targeted to PLCß3 reduced mRNA expression levels of these targets in EC-R183Q while the pan-PKC inhibitor AEB071 reduced ANGPT2 but not DSCR1.4. EC-R183Q formed enlarged blood vessels in mice, reminiscent of those found in human CM. shRNA knockdown of ANGPT2 in EC-R183Q normalized the enlarged vessels to sizes comparable those formed by EC-WT. CONCLUSIONS: Gαq-R183Q, when expressed in ECs, establishes constitutively active PLCß3 signaling that leads to increased ANGPT2 and a proangiogenic, proinflammatory phenotype. EC-R183Q are sufficient to form enlarged CM-like vessels in mice, and suppression of ANGPT2 prevents the enlargement. Our study provides the first evidence that endothelial Gαq-R183Q is causative for CM and identifies ANGPT2 as a contributor to CM vascular phenotype.