Navigating the Landscape of Coronary Microvascular Research: Trends, Triumphs, and Challenges Ahead.

Coronary microvascular dysfunction (CMD) refers to structural and functional abnormalities of the microcirculation that impair myocardial perfusion. CMD plays a pivotal role in numerous cardiovascular diseases, including myocardial ischemia with non-obstructive coronary arteries, heart failure, and acute coronary syndromes. This review summarizes recent advances in CMD pathophysiology, assessment, and treatment strategies, as well as ongoing challenges and future research directions. Signaling pathways implicated in CMD pathogenesis include adenosine monophosphate-activated protein kinase/Krüppel-like factor 2/endothelial nitric oxide synthase (AMPK/KLF2/eNOS), nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE), Angiotensin II (Ang II), endothelin-1 (ET-1), RhoA/Rho kinase, and insulin signaling. Dysregulation of these pathways leads to endothelial dysfunction, the hallmark of CMD. Treatment strategies aim to reduce myocardial oxygen demand, improve microcirculatory function, and restore endothelial homeostasis through mechanisms including vasodilation, anti-inflammation, and antioxidant effects. Traditional Chinese medicine (TCM) compounds exhibit therapeutic potential through multi-targeted actions. Small molecules and regenerative approaches offer precision therapies. However, challenges remain in translating findings to clinical practice and developing effective pharmacotherapies. Integration of engineering with medicine through microfabrication, tissue engineering and AI presents opportunities to advance the diagnosis, prediction, and treatment of CMD.

Strain- and sex-specific differences in intestinal microhemodynamics and gut microbiota composition.

Background: Intestinal microcirculation is a critical interface for nutrient exchange and energy transfer, and is essential for maintaining physiological integrity. Our study aimed to elucidate the relationships among intestinal microhemodynamics, genetic background, sex, and microbial composition. Methods: To dissect the microhemodynamic landscape of the BALB/c, C57BL/6J, and KM mouse strains, laser Doppler flowmetry paired with wavelet transform analysis was utilized to determine the amplitude of characteristic oscillatory patterns. Microbial consortia were profiled using 16S rRNA gene sequencing. To augment our investigation, a broad-spectrum antibiotic regimen was administered to these strains to evaluate the impact of gut microbiota depletion on intestinal microhemodynamics. Immunohistochemical analyses were used to quantify platelet endothelial cell adhesion molecule-1 (PECAM-1), estrogen receptor α (ESR1), and estrogen receptor ß (ESR2) expression. Results: Our findings revealed strain-dependent and sex-related disparities in microhemodynamic profiles and characteristic oscillatory behaviors. Significant differences in the gut microbiota contingent upon sex and genetic lineage were observed, with correlational analyses indicating an influence of the microbiota on microhemodynamic parameters. Following antibiotic treatment, distinct changes in blood perfusion levels and velocities were observed, including a reduction in female C57BL/6J mice and a general decrease in perfusion velocity. Enhanced erythrocyte aggregation and modulated endothelial function post-antibiotic treatment indicated that a systemic response to microbiota depletion impacted cardiac amplitude. Immunohistochemical data revealed strain-specific and sex-specific PECAM-1 and ESR1 expression patterns that aligned with observed intestinal microhemodynamic changes. Conclusions: This study highlights the influence of both genetic and sex-specific factors on intestinal microhemodynamics and the gut microbiota in mice. These findings also emphasize a substantial correlation between intestinal microhemodynamics and the compositional dynamics of the gut bacterial community.

Current state of endovascular treatment of anterior cerebral artery aneurysms.

The locations of anterior cerebral artery (ACA) aneurysms vary, and various aneurysms can occur along the course of the ACA. Ruptured and some unruptured ACA aneurysms may require aggressive treatment to avoid bleeding or rebleeding. Although open surgery is an effective treatment for ACA aneurysms, endovascular treatment (EVT) is becoming an alternative treatment in select cases. EVT techniques for ACA aneurysms often vary and are performed on a case-by-case basis according to the nature and location of the aneurysm. To better understand the EVT strategy for ACA aneurysms, it is necessary to review EVT for ACA aneurysms. In this review, the following topics are discussed: ACA anatomy and anomalies, classifications of ACA aneurysms, the natural history of ACA aneurysms, open surgery and EVT statuses for ACA aneurysms, EVT techniques for various ACA aneurysms, and the prognosis and complications of EVT for ACA aneurysms. According to our review and experience, traditional coiling EVT is still the preferred therapy for most ACA aneurysms. For A1 aneurysms, EVT is challenging. After the selection of appropriate cases, deployment of a flow diverter and Woven EndoBridge device can result in a good prognosis for patients with ACA aneurysms. In addition, parent artery occlusion can be used to treat A1 aneurysms with good collateral circulation and some distal ACA aneurysms. In general, EVT is gaining popularity as an alternative treatment option for ACA aneurysms.

Tumor-Derived Exosomes Promote Tumor Growth Through Modulating Microvascular Hemodynamics in a Human Ovarian Cancer Xenograft Model.

OBJECTIVE: Abnormal tumor vascular network contributes to aberrant blood perfusion and reduced oxygenation in tumors, which lead to poor efficacy of chemotherapy and radiotherapy. We aimed to explore the effects of the tumor-derived exosomes (TDEs) and C188-9 (a small molecule inhibitor of signal transducer and activator of transcription 3, STAT3) on tumor microvascular hemodynamics and determine which blood flow oscillations for various frequency intervals are responsible for these changes. METHODS: Microvascular hemodynamics parameters were recorded using a PeriFlux 6000 EPOS system in tumor surface in a nude mouse subcutaneous xenograft model. Oscillations of laser Doppler flowmetry (LDF) signal were investigated by wavelet transform analysis. RESULTS: TDEs facilitated tumor growth at least partially was associated with increasing blood flow in smaller vessels with lower speed and decreasing the blood flow at larger vessels with higher speed. Lower oxyhemoglobin saturation (SO2) on tumor surface was aggravated by TDEs, and C188-9 treatment significantly alleviated this decrease. Wavelet transform spectral analysis revealed that TDEs increased the amplitude of oscillations in four frequency intervals related to endothelial (NO-dependent and -independent), myogenic and neurogenic activities, and C188-9 had no effect on this increase. CONCLUSIONS: TDEs facilitated tumor growth partially was associated with increasing blood flow in distributing vessels, reducing blood perfusion in larger vessels, and lowering SO2 on tumor surface. Enhanced vascular smooth muscle, endothelial and neurogenic activities occurred in tumor superficial zone.

Embolization of an arteriovenous malformation using the "pressure cooker" technique in the AICA via a marathon microcatheter: A case report.

INTRODUCTION AND IMPORTANCE: Embolization of an arteriovenous malformation (AVM) via the anterior inferior cerebellar artery (AICA) is difficult. The "pressure cooker" technique in the AICA via a marathon microcatheter can be effective. CASE STUDY: A 43-year-old man with a cerebellar hematoma involving the brainstem. Angiography revealed an AVM supplied by the right AICA. Embolizing the AVM by casting an Onyx-18 liquid embolic system assisted by the "pressure cooker" technique was planned. An Apollo microcatheter was used for Onyx casting, and a Marathon microcatheter was used to establish a coiling plug to prevent Onyx reflux. The AVM was obliterated. Postoperatively, burr hole drainage of the cerebellar hematoma was performed. Postoperative computed tomography showed that the cerebellar hematoma and hydrocephalus had resolved. Magnetic resonance imaging revealed that there was no new serious infarction from damage to the cerebellum or brainstem. The patient recovered well. CLINICAL DISCUSSION: During Onyx casting, the drawback is that reflux can occlude normal vessels. The "pressure cooker" technique was useful for preventing Onyx reflux and for driving the Onyx to penetrate the AVM. However, it was difficult to use this technique in slim AICA; the Marathon microcatheter had a thinner tip than other microcatheters, and it can be used to establish the "pressure cooker" technique. This technique provides more solutions for AVMs in transarterial embolization through small feeding arteries. CONCLUSION: In a selective case, it was feasible to use the "pressure cooker" technique in the AICA via a Marathon microcatheter to embolize the AVM.

Evaluation of Renal Microhemodynamics Heterogeneity in Different Strains and Sexes of Mice.

Addressing the existing gaps in our understanding of sex- and strain-dependent disparities in renal microhemodynamics, this study conducted an investigation into the variations in renal function and related biological oscillators. Using the genetically diverse mouse models BALB/c, C57BL/6, and Kunming, which serve as established proxies for the study of renal pathophysiology, we implemented laser Doppler flowmetry conjoined with wavelet transform analyses to interrogate dynamic renal microcirculation. Creatinine, urea, uric acid, glucose, and cystatin C levels were quantified to investigate potential divergences attributable to sex and genetic lineage. Our findings reveal marked sexual dimorphism in metabolite concentrations, as well as strain-specific variances, particularly in creatinine and cystatin C levels. Through the combination of Mantel tests and Pearson correlation coefficients, we delineated the associations between renal functional metrics and microhemodynamics, uncovering interactions in female BALB/c mice for creatinine and uric acid, and in male C57BL/6 mice for cystatin C. Histopathologic examination confirmed an augmented microvascular density in female mice and elucidating variations in the expression of estrogen receptor ß among the strains. These data collectively highlight the influence of both sex and genetic constitution on renal microcirculation, providing an understanding that may inform the etiologic exploration of renal ailments.

Ranolazine for improving coronary microvascular function in patients with nonobstructive coronary artery disease: a systematic review and meta-analysis with a trial sequential analysis of randomized controlled trials.

Background: Microvascular dysfunction in patients with nonobstructive coronary artery disease is increasingly being recognized as an important health issue. This systematic review and meta-analysis evaluated the effectiveness of ranolazine, an antianginal agent, in improving coronary microvascular function. Methods: We conducted a comprehensive literature search of the Cochrane Library, PubMed, Embase, China National Knowledge Infrastructure, the Chinese BioMedical Literature Database, and gray literature databases until September 30, 2023. The included studies were randomized controlled trials (RCTs) published in the English or Chinese languages that screened for eligibility using two independent investigators. Risk of bias was evaluated with the Cochrane Collaboration tool. Subgroup and sensitivity analyses were used to identify sources of heterogeneity. Meta-analysis was performed using RevMan version 5.4 (Cochrane) and Stata version 16.0 (StataCorp). Results: From 1,470 citations, 8 RCTs involving 379 participants were included in this analysis. Our findings showed that ranolazine increased coronary flow reserve (CFR) over an 8 to 12-week follow-up period [standardized mean difference =1.16; 95% confidence interval (CI): 0.4-1.89; P=0.002]. Ranolazine increased the global myocardial perfusion reserve index (MPRI) [weighted mean difference (WMD) =0.18; 95% CI: 0.07-0.29; P=0.002] and the midsubendocardial MPRI (WMD =0.10; 95% CI: 0.02-0.19; P=0.02). Moreover, ranolazine improved 3 of the 5 Seattle Angina Questionnaire scores, namely, physical functioning (WMD =4.89; 95% CI: 0.14 to 9.64; P=0.04), angina stability (WMD =17.31; 95% CI: 7.13-27.49; P=0.0009), and quality of life (WMD =10.11; 95% CI: 3.57-16.65; P=0.0003). Trial sequential analysis showed that the meta-analysis of angina stability and quality of life scores had a sufficient sample size and statistical power. Conclusions: Our analysis suggests that ranolazine is associated with improvements in CFR, myocardial perfusion, and the Seattle Angina Questionnaire scores in patients with nonobstructive coronary artery disease. However, further large-scale RCTs with long-term follow-up are recommended to validate these findings and provide a more comprehensive understanding of the effects of ranolazine on coronary microvascular function.

Characteristics of Inflammatory and Normal Endothelial Exosomes on Endothelial Function and the Development of Hypertension.

Endothelial dysfunction is associated with the development of hypertension. We hypothesize that inflammatory and normal endothelial exosomes play their roles by mediating endothelial function, and they induce endothelial angiogenesis through different signaling pathways. Endothelial cell-derived exosomes were isolated from the human umbilical vein endothelial cells (HUVECs) treated with (TExo) or without (CExo) tumor necrosis factor (TNF)-α. We monitored dermal microcirculation profiles in spontaneously hypertensive rats (SHRs) and WKY rats using a laser Doppler imager and a laser Doppler perfusion and temperature monitor. Tube formation, levels of angiogenesis-related proteins in HUVEC-conditioned media, and reactive oxygen species (ROS) levels were assessed following TNF-α, CExo, or TExo treatments. Western blot analysis was conducted to examine signaling proteins associated with inflammation and ROS. The results showed increased blood perfusion and the mean amplitude of endothelial oscillator in SHRs following CExo administration. TNF-α, CExo, and TExo treatments promoted endothelial tube formation and elevated levels of angiogenic factors and ROS. TExo significantly increased phosphorylation levels of STAT3, p38, and level of NF-κB, while decreasing phosphorylation levels of JNK and Erk (P < 0.01 or P < 0.05). CExo significantly increased STAT3 phosphorylation and reduced JNK and Erk phosphorylation (all P < 0.01). In conclusion, TNF-α and TExo induce inflammatory and pathological angiogenesis via the NF-κB pathway, while CExo exhibits a physiologically pro-angiogenic effect on endothelial cells. Increased ROS, interplaying with inflammatory signals, contribute to exosome-mediated alterations of endothelial function, thereby playing a role in the development of hypertension.

Long non-coding RNA LINC01128 affects proliferation, migration, and invasion of glioma cells by regulating miR-27b-3p.

INTRODUCTION: Glioma is a collective term for tumors derived from glial cells and neuronal cells in the nervous system, and is the most common malignant tumor in the brain. Nowadays, the problem of poor treatment effect and high recurrence rate of patients remains to be solved. MATERIAL AND METHODS: In this study, the expression levels of LINC01128 in glioma tissues, cells, and normal control group were determined by real-time quantitative PCR (RT-qPCR). Kaplan-Meier curve was used to evaluate the prognosis and survival. Multivariate Cox analysis was chosen to estimate the prognostic risk factors of glioma. Cell counting kit-8 (CCK-8) and Transwell methods were used to detect the effect of silencing LINC01128 on the proliferation, migration, and invasion of glioma cells, and the targeting effect of LINC01128 on miR-27b-3p was determined based on bio-informatics analysis and luciferase activity detection. RESULTS: LINC01128 was up-regulated in glioma tissues and cells. The possibility of LINC01128 as a prognostic factor of glioma was obtained through Kaplan-Meier's clinical data analysis and multivariate Cox analysis. Silencing LINC01128 targeting miR-27b-3p inhibited the proliferation, migration, and invasion activity of glioma cells. Moreover, there was a negative correlation between LINC01128 and miR-27b-3p. CONCLUSIONS: Silencing LINC01128 inhibited the proliferation, migration, and invasion levels of glioma cells by targeting miR-27b-3p, thereby affecting the progression of gliomas.

Sodium Pentobarbital Suppresses Breast Cancer Cell Growth Partly via Normalizing Microcirculatory Hemodynamics and Oxygenation in Tumors.

Breast cancer remains the leading cause of cancer-related death among women worldwide. Sodium pentobarbital was found to play an inhibitory role in glioma growth in rats. In this study, we aimed to evaluate the effects of sodium pentobarbital on breast cancer growth both in vitro and in vivo, and its impacts on the microcirculatory changes on both skin and tumor surface in mice bearing subcutaneous xenograft. Cell counting assay was used to assess the antiproliferative effect of sodium pentobarbital on MDA-MB-231 breast cancer cells. Subcutaneous xenograft model was established to study the role of sodium pentobarbital on in vivo tumor growth. Speed-resolved blood perfusion, hemoglobin oxygen saturation (SO2, %), total hemoglobin tissue concentration (ctTHb, µM), and red blood cell (RBC) tissue fraction (%) were examined simultaneously by using enhanced perfusion and oxygen saturation system to investigate the effects of sodium pentobarbital on microcirculatory hemodynamics and oxygenation. Sodium pentobarbital suppressed breast tumor growth both in vitro and in vivo. Cutaneous blood flux in nutritive capillaries with low-speed flow was significantly increased in tumor-bearing mice, and high-dose sodium pentobarbital treatment cause a reduction in this low-speed blood flux, whereas sodium pentobarbital therapy caused an elevated blood flux in larger microvessels with mid and high speed in a dose-dependent manner. Different doses of sodium pentobarbital exerted different actions on SO2, ctTHb, and RBC tissue fraction. Collectively, the inhibitory effect of sodium pentobarbital on breast tumor growth was at least partly associated with its ability to normalize microcirculatory hemodynamics and oxygenation in tumors. SIGNIFICANCE STATEMENT: This study is the first to demonstrate the inhibiting effect of sodium pentobarbital on breast cancer growth both in vitro and in vivo, and such an inhibition was at least partly associated with its ability to normalize microcirculatory hemodynamics and oxygenation in tumors.

Roquin2 suppresses breast cancer progression by inhibiting tumor angiogenesis via selectively destabilizing proangiogenic factors mRNA.

Tumor angiogenesis is an essential step in tumor growth and metastasis. The initiation of tumor angiogenesis is dictated by a shift in the balance between proangiogenic and antiangiogenic gene expression programs. Roquin2 is a zinc-finger RNA-binding protein with important roles in mediating the expression of inflammatory genes, such as TNF, IL6 and PTGS2, which are also important angiogenic factors. In this study, we demonstrate that Roquin2 functions as a potent tumor angiogenesis regulator that inhibits breast tumor-induced angiogenesis by selectively destabilizing mRNA of proangiogenic gene transcripts, including endoglin (ENG), endothelin-1 (EDN1), vascular endothelial growth factor B (VEGFB) and platelet derived growth factor C (PDGFC). Roquin2 recognizes and binds the stem-loop structure in the 3'untranslated region (3'UTR) of these mRNAs via its ROQ domain to destabilize mRNA. Moreover, we found that Roquin2 expression was reduced in breast cancer cells and tissues, and associated with poor prognosis in breast cancer patients. Overexpression of Roquin2 inhibited breast tumor-induced angiogenesis in vitro and in vivo, whereas silencing Roquin2 enhanced tumor angiogenesis. In vivo induction of Roquin2 by adenovirus significantly suppressed breast tumor growth, metastasis and angiogenesis. Taken together, our results identify that Roquin2 is a novel breast cancer suppressor that inhibits tumor angiogenesis by selectively downregulating the expression of proangiogenic genes.

TARBP2 promotes tumor angiogenesis and metastasis by destabilizing antiangiogenic factor mRNAs.

Tumor angiogenesis is a crucial step in the further growth and metastasis of solid tumors. However, its regulatory mechanism remains unclear. Here, we showed that TARBP2, an RNA-binding protein, played a role in promoting tumor-induced angiogenesis both in vitro and in vivo through degrading the mRNAs of antiangiogenic factors, including thrombospondin1/2 (THBS1/2), tissue inhibitor of metalloproteinases 1 (TIMP1), and serpin family F member 1 (SERPINF1), by targeting their 3'untranslated regions (3'UTRs). Overexpression of TARBP2 promotes tumor cell-induced angiogenesis, while its knockdown inhibits tumor angiogenesis. Clinical cohort analysis revealed that high expression level of TARBP2 was associated with poor survival of lung cancer and breast cancer patients. Mechanistically, TARBP2 physically interacts with the stem-loop structure located in the 3'UTR of antiangiogenic transcripts, leading to mRNA destabilization by the dsRNA-binding domains 1/2 (dsRBDs1/2). Notably, the expression level of TARBP2 in human tumor tissue is negatively correlated with the expression of antiangiogenic factors, including THBS1/2, and brain-specific angiogenesis inhibitor 1 (BAI1). Moreover, TARBP2 expression is strongly associated with tumor angiogenesis in a group of human lung cancer samples. Collectively, our results highlight that TARBP2 is a novel tumor angiogenesis regulator that could promote tumor angiogenesis by selectively downregulating antiangiogenic gene expression.

Ovarian cancer derived PKR1 positive exosomes promote angiogenesis by promoting migration and tube formation in vitro.

Cancer cell derived exosomes play important roles in cancer progression and modulation of the tumour microenvironment. This study aims to investigate the role of prokineticin receptor 1 (PKR1) positive exosomes on angiogenesis. In the present study, PKR1 expression in tumour samples from ovarian cancer patients were examined firstly. Then, two ovarian cancer cell lines, namely A2780 and HO-8910 cells, were used to isolate and obtain the PKR1 positive exosomes from the serum free medium. The function analysis of PKR1 positive exosomes on angiogenesis was conducted by cell proliferation and migration assay, tube formation analysis, and tumour volume assay. The results showed that PKR1 expression was down regulated in tumour samples of ovarian cancer patients compared with adjacent normal tissues. The intracellular expression of PKR1 could be detected in A2780 and HO-8910 cells. And, the isolated exosomes from the serum free medium were confirmed by transmission electron microscopic and NTA analysis, as well as the co-presence of PKR1 with exosome marker CD63. The function analysis of PKR1 positive exosomes on angiogenesis demonstrated the uptake of PKR1 positive exosomes by human umbilical vein endothelial cells through immunofluorescence staining. The angiogenesis assays in vitro indicated that PKR1 positive exosomes promoted migration and tube formation of HUVECs but not proliferation. The endogenous PKR1 was also verified to help to enhance migration and promote tube formation of vascular endothelial cells, which might involved in the phosphorylation of STAT3. Additionally, The tumour volume from exosomes treated A2780 tumour-bearing mice was significantly increased compared with the control group, accompanied with the induced PKR1 expression and phosphorylation of STAT3 level. SIGNIFICANCE OF THE STUDY: This study proved the important role of PKR1 positive exosomes released from ovarian cancer cells on promoting angiogenesis. The data indicated that PKR1 derived from ovarian cancer cells could act as an important tumour associated antigen and biomolecular factor for cellular communication in tumour microenvironment.

Roquin1 inhibits the proliferation of breast cancer cells by inducing G1/S cell cycle arrest via selectively destabilizing the mRNAs of cell cycle-promoting genes.

BACKGROUND: Dysregulation of cell cycle progression is a common feature of human cancer cells; however, its mechanism remains unclear. This study aims to clarify the role and the underlying mechanisms of Roquin1 in cell cycle arrest in breast cancer. METHODS: Public cancer databases were analyzed to identify the expression pattern of Roquin1 in human breast cancers and its association with patient survival. Quantitative real-time PCR and Western blots were performed to detect the expression of Roquin1 in breast cancer samples and cell lines. Cell counting, MTT assays, flow cytometry, and in vivo analyses were conducted to investigate the effects of Roquin1 on cell proliferation, cell cycle progression and tumor progression. RNA sequencing was applied to identify the differentially expressed genes regulated by Roquin1. RNA immunoprecipitation assay, luciferase reporter assay, mRNA half-life detection, RNA affinity binding assay, and RIP-ChIP were used to explore the molecular mechanisms of Roquin1. RESULTS: We showed that Roquin1 expression in breast cancer tissues and cell lines was inhibited, and the reduction in Roquin1 expression was associated with poor overall survival and relapse-free survival of patients with breast cancer. Roquin1 overexpression inhibited cell proliferation and induced G1/S cell cycle arrest without causing significant apoptosis. In contrast, knockdown of Roquin1 promoted cell growth and cycle progression. Moreover, in vivo induction of Roquin1 by adenovirus significantly suppressed breast tumor growth and metastasis. Mechanistically, Roquin1 selectively destabilizes cell cycle-promoting genes, including Cyclin D1, Cyclin E1, cyclin dependent kinase 6 (CDK6) and minichromosome maintenance 2 (MCM2), by targeting the stem-loop structure in the 3' untranslated region (3'UTR) of mRNAs via its ROQ domain, leading to the downregulation of cell cycle-promoting mRNAs. CONCLUSIONS: Our findings demonstrated that Roquin1 is a novel breast tumor suppressor and could induce G1/S cell cycle arrest by selectively downregulating the expression of cell cycle-promoting genes, which might be a potential molecular target for breast cancer treatment.

Salvianolic Acid Alleviated Blood-Brain Barrier Permeability in Spontaneously Hypertensive Rats by Inhibiting Apoptosis in Pericytes via P53 and the Ras/Raf/MEK/ERK Pathway.

OBJECTIVE: To investigate the effect of salvianolic acid A (SA) on the permeability of blood-brain barrier (BBB) and brain microvascular pericyte apoptosis in spontaneously hypertensive rats (SHR). METHODS: Evans Blue was used to determine the BBB permeability in control rats and SHR. Western blotting was used to evaluate the expression levels of relevant proteins in the pericytes isolated from the differentially treated animals. An in vitro model of hypertension was established by stimulating pericytes with angiopoietin-2 (Ang2). MTT assay was used to assess cell viability, and apoptosis and cell cycle distribution were analyzed by flow cytometry. RESULTS: SA attenuated BBB permeability in SHR in a dose-dependent manner. It downregulated pro-apoptotic proteins including p53, p21, Fas, FasL, cleaved-caspase 3/caspase 3 and Bax in the pericytes of SHR and upregulated CDK6, cyclin D1, CDK2, cyclin E and Bcl2. In addition, SA activated the Ras/Raf/MEK/ERK pathway in a dose-dependent manner by increasing the levels of Ras, Raf, p-MEK1, p-MEK2, p-ERK1 and p-ERK2. Finally, SA reduced Ang2-induced apoptosis of cerebral microvessels pericytes and decreased the proportion of cells in the G0/G1 phase of the cell cycle by inhibiting the p53 pathway and activating the Ras/Raf/MEK/ERK pathway. CONCLUSION: SA reduced BBB permeability in spontaneously hypertensive rats, possibly by inhibiting Ang2-induced apoptosis of pericytes by activating the Ras/Raf/MEK/ERK pathway.

Effects of tumor necrosis factor-α-induced exosomes on the endothelial cellular behavior, metabolism and bioenergetics.

OBJECTIVE: To investigate the effects of TNF-α-induced exosomes release on the biological behavior, metabolism, and bioenergetics of HUVECs. METHODS: Exosomes were isolated from conditioned media of HUVECs by ultracentrifugation after treatment with or without TNF-α. HUVECs were treated with or without TNF-α, or different concentrations of exosomes isolated from conditioned media with or without TNF-α induction (TExo and CExo , respectively). RESULTS: The results showed that TNF-α significantly inhibited migration, tube formation, and increased apoptosis rate of HUVECs compared with controls. Furthermore, TNF-α-induced exosomes (TExo ) rather than CExo , indicated similar effects to inhibit migration, tube formation and promote endothelial apoptosis. Although TNF-α treatment did not show a statistical difference, TExo significantly inhibited extracellular OCR compared with controls. TExo could significantly inhibited intracellular OCR in a hypoxia condition. TNF-α significantly increased L-ECA compared with control cells, and TExo showed similar stimulative effect on L-ECA. CONCLUSIONS: TNF-α-induced exosomes could significantly (a) change migration, tube formation, and apoptosis; (b) inhibit endothelial extracellular OCR and intracellular OCR (hypoxia); (c) increase glycolysis rate of the endothelial cells. These data provide new evidence for exploring endothelial behavior regulation using exosomes and their effects on endothelial metabolism and bioenergetics.

Insulin treatment restores islet microvascular vasomotion function in diabetic mice.

BACKGROUND: The microcirculation plays an important role in the pathogenesis of diabetes and its complications. We hypothesized that pancreatic islet microvascular (PIM) vasomotion, as a parameter of pancreatic islet microcirculation function, is abnormal in diabetic mice and that insulin treatment may reverse this dysfunction. METHODS: Mice were randomly assigned to non-diabetic control, untreated diabetic, and insulin-treated diabetic groups (n = 6 in each group). Separate groups of streptozotocin (STZ)-induced diabetic and high-fat diet-fed mice were used as a model of hyperglycemia. Insulin-treated diabetic mice were treated with 1-1.5 IU/day insulin for 1 week. Laser Doppler monitors were used to evaluate PIM vasomotion. Morphological and ultrastructural changes in islet endothelial cells were determined by immunohistochemistry and transmission electron microscopy. Glucagon, insulin, vascular endothelial growth factor (VEGF)-A, and platelet endothelial cell adhesion molecule (PECAM-1) expression was determined by immunohistochemistry and Western blotting. RESULTS: In both untreated diabetic groups, the pancreatic islet microcirculation was unable to regulate PIM vasomotion. The rhythm of vasomotion was irregular, and the average blood perfusion, amplitude, frequency, and relative velocity of vasomotion were significantly lower than in non-diabetic controls. Insulin treatment restored the functional status of PIM vasomotion. In islet endothelial cells from both untreated diabetic groups, the mitochondria were swollen with disarrangement of the cristae, and the distribution of PECAM-1 was discontinuous. Insulin treatment significantly increased the reduced expression of PECAM-1 in both untreated diabetic groups and VEGF-A expression in untreated STZ-diabetic mice. CONCLUSION: The results suggest that the functional status of PIM vasomotion is impaired in diabetic mice but can be restored by insulin.

The anti-angiogenic effect of dexamethasone in a murine hepatocellular carcinoma model by augmentation of gluconeogenesis pathway in malignant cells.

PURPOSE: Angiogenesis is a long-term complex process involving various protein factors in hepatocellular carcinoma (HCC). Dexamethasone (Dex), considered as a synthetic glucocorticoid drug in clinical therapy, has been reported to have the therapeutic efficacy against liver cancer by intervention of abnormal glycolysis. In this study, we investigated the anti-angiogenic effect of Dex in murine liver cancer and attempted to demonstrate the potential mechanism. METHODS: The malignant cells H22 were treated with Dex. Western blotting was used to explore the expression of PEPCK and G6Pase which were the two key enzymes that regulated gluconeogenesis. The supernatants from cultured H22 treated by Dex were collected and co-cultured with HUVECs. In vitro, migration assay, transwell assay and tube formation assay were performed to assess for migration, proliferation and tube formation abilities of HUVECs, respectively. In situ murine hepatoma model with green fluorescent protein markers (HepG2-GFP) was constructed to determine angiogenesis after treatment by Dex. RESULTS: PEPCK and G6Pase were almost deficient in H22 compared with normal liver cells NCTC-1469 (P < 0.01). After treated by Dex, the gluconeogenesis could be restored significantly (P < 0.01) in H22 cells. The supernatant of H22 treated by Dex inhibited the migration, tube formation and endothelial permeability in HUVECs (P < 0.05). In mouse tissue, PEPCK and G6Pase were highly expressed in Dex group than control groups (P < 0.01). 11ß-HSDs abnormally expressed in tumor also could be restored by Dex. Meanwhile, the density and total length of microvessels in Dex-treated group were less than those in HCC groups (P < 0.05). CONCLUSIONS: This study explored the therapeutic efficacy of Dex in murine HCC. Dex might inhibit tumor growth and angiogenesis by augmenting the gluconeogenesis pathway.

Absolute circulating pericyte progenitor cell counts in mice by flow cytometry: comparison of 2 single-platform technologies.

BACKGROUND: Accumulating evidence indicates that circulating pericyte progenitor cells (CPPCs) may be angiogenic biomarkers in cancer and diabetes. Their validity as biomarkers depends on the accuracy of techniques used for enumeration. In this report, absolute CPPC counts were performed by 2 single-platform technologies. The reliability of the 2 methods, including retest reliability and intraobserver and interobserver variability, was assessed according to the intraclass correlation coefficient (ICC). The linear correlation and agreement among both methods were assessed, and the stability of CPPC numbers in blood samples was analyzed. METHODS: The blood samples were obtained from ICR mice. The samples were processed through a no-lyse, 1-wash procedure, and Syto16+CD45-CD31-CD140b+ CPPCs were analyzed by exclusion of dead cells and by fluorescence-minus-one control. CPPCs were enumerated by 2 methods: bead-based 123count eBeads count (eBioscience) and direct volume-based Accuri C6 Flow Cytometer count (BD). The cells were measured immediately and after storage of blood samples for 24 and 48 hours. RESULTS: There were excellent retest correlations and intraobserver and interobserver agreement in both methods. The 2 methods showed a high linear correlation (R2 = 0.923) and with a high level of agreement (0.986). It was demonstrated that CPPCs are unstable in blood samples. CONCLUSIONS: In this study, 2 reproducible protocols for CPPC quantification were established. These protocols should facilitate future studies to further define the role of CPPCs as cellular biomarkers.

Melatonin treatment protects against acute spinal cord injury-induced disruption of blood spinal cord barrier in mice.

The spinal cord microcirculation plays a critically important role in maintaining the normal function of spinal cord neurons, glial cells, and axons. Previous researches were largely focused on improved neurological manifestations of spinal cord injury (SCI) while ignoring to improve spinal cord microcirculation disorder after melatonin treatment. Therefore, the mechanism of melatonin that affects blood spinal cord barrier (BSCB) integrity and microcirculation in SCI remains unclear. The present study was performed to investigate the effect of melatonin on the BSCB in a SCI mice model. Melatonin (5, 10, 25, 50, 100 mg/kg i.p.) was administered to mice immediately following SCI. Compared to the 48 h post-SCI group, mice treated with melatonin (50 mg/kg) exhibited significantly reduced BSCB permeability. Additionally, melatonin treatment restrained microvessel loss; attenuated edema; protected the tight junction proteins, endothelial cells, and pericytes; decreased the number of cell apoptosis; and reduced MMP3/AQP4/HIF-1α/VEGF/VEGFR2 expression after SCI. Above all, our results clearly demonstrated that melatonin could stabilize microvascular barrier function and microcirculation of SCI, whose mechanism was to promote the repair of the damaged BSCB.