Novel selective agents for the degradation of AR/AR-V7 to treat advanced prostate cancer.

The androgen receptor AR antagonists, such as enzalutamide and apalutamide, are efficient therapeutics for the treatment of prostate cancer (PCa). Even though they are effective at first, resistance to both drugs occurs frequently. Resistance is mainly driven by aberrations of the AR signaling pathway including AR gene amplification and the expression of AR splice variants (e.g. AR-V7). This highlights the urgent need for alternative therapeutic strategies. Here, a total of 24 compounds were synthesized and biologically evaluated to disclose compound 20i, exhibiting potent AR antagonistic activities (IC50 = 172.85 ± 21.33 nM), promising AR/AR-V7 protein degradation potency, and dual targeting site of probably AR (ligand-binding domain, LBD and N-terminal domain, NTD). It potently inhibits cell growth with IC50 values of 4.87 ± 0.52 and 2.07 ± 0.34 µM in the LNCaP and 22RV1 cell lines, respectively, and exhibited effective tumor growth inhibition (TGI = 50.9 %) in the 22RV1 xenograft study. These data suggest that 20i has the potential for development as an AR/AR-V7 inhibitor with degradation ability to treat advanced prostate cancer.

Lymphatic microcirculation profile in the progression of hypertension in spontaneously hypertensive rats.

OBJECTIVE: The contractile behavior of collecting lymphatic vessels occurs in essential hypertension in response to homeostasis, suggesting a possible role for microcirculation. We aimed to clarify the nature of the lymphatic microcirculation profile in spontaneously hypertensive rats (SHRs) and normotensive controls. METHODS: The vasomotion of collecting lymphatic vessels in eight- and thirteen-week-old SHRs and age-matched Wistar-Kyoto rats (WKYs, n = 4 per group) was visualized by intravital video and VasTrack. The lymphatic vasomotion profile (frequency and amplitude) and contractile parameters (contraction fraction and total contractility activity index) were compared. Plasma nitrite/nitrate levels were assessed by the Griess reaction, and plasma endothelin-1 was measured by enzyme-linked immunosorbent assay. RESULTS: WKYs and SHRs differed in the vasomotion of collecting lymphatic vessels. Both eight- and thirteen-week-old WKYs revealed a high-amplitude pumping pattern, whereas a low-amplitude pattern was observed in SHRs. Moreover, compared with age-matched WKYs, SHRs exhibited deteriorated output and reflux capability and lost the ability to regulate collecting lymphatic vasomotion. Additionally, the chemistry complements the microcirculatory lymphatic profile as demonstrated by an increase in plasma nitrite, nitrate, and endothelin-1 in SHRs. ET-1 inhibitor meliorated the lymphatic contractile capability in SHRs partially through regulating frequency of lymphatic vasomotion. CONCLUSIONS: We used an intravital lymphatic imaging system to observe that SHRs exhibit an impaired collecting lymphatic vasomotion profile and deteriorated contractility and reflux.

Integrated pancreatic microcirculatory profiles of streptozotocin-induced and insulin-administrated type 1 diabetes mellitus.

OBJECTIVE: As an integrated system, pancreatic microcirculatory disturbance plays a vital role in the pathogenesis of type 1 diabetes mellitus (T1DM), which involves changes in microcirculatory oxygen and microhemodynamics. Therefore, we aimed to release type 1 diabetic and insulin-administrated microcirculatory profiles of the pancreas. METHODS: BALB/c mice were assigned to control, T1DM, and insulin-administrated groups randomly. T1DM was induced by intraperitoneal injection of streptozotocin (STZ). 1.5 IU insulin was administrated subcutaneously to keep the blood glucose within the normal range. After anesthetizing by isoflurane, the raw data set of pancreatic microcirculation was collected by the multimodal device- and computer algorithm-based microcirculatory evaluating system. After adjusting outliers and normalization, pancreatic microcirculatory oxygen and microhemodynamic data sets were imported into the three-dimensional module and compared. RESULTS: Microcirculatory profiles of the pancreas in T1DM exhibited a loss of microhemodynamic coherence (significantly decreased microvascular blood perfusion) accompanied by an impaired oxygen balance (significantly decreased PO2 , SO2 , and rHb). More importantly, with insulin administration, the pathological microcirculatory profiles were partially restored. Meanwhile, there were correlations between pancreatic microcirculatory blood perfusion and PO2 levels. CONCLUSIONS: Our findings establish the first integrated three-dimensional pancreatic microcirculatory profiles of STZ-induced and insulin-administrated T1DM.

Differential expression of lncRNAs in hypertension-induced pericytes.

Pericytes facilitate vessel maturation and endothelial barrier functions closely related with the pathogenesis of organ damage from cardiovascular and cerebrovascular diseases such as hypertension. We used a computational-based strategy to first screen for differentially expressed genes and lncRNAs and characterized associations between lncRNAs of microvascular pericytes and hypertension. In total, 22 lncRNAs were upregulated and 46 were downregulated in the rats afflicted with spontaneous hypertension. Expression profiles for lncRNAs were significantly altered in the hypertension afflicted tissue samples and the transcripts have good potential for use as molecular targets to inhibit the progression of hypertension.

Pancreatic Microcirculation Profiles in the Progression of Hypertension in Spontaneously Hypertensive Rats.

BACKGROUND: Emerging evidence indicates that the pancreas serves as a major source of degrading protease activities and that uncontrolled proteolytic receptor cleavage occurs under hypertensive conditions, which leading to systemic dysfunction and end-organic damage. However, changes in pancreatic microcirculation profiles during the progression of hypertension remain unknown. METHODS: Pancreatic microcirculatory blood distribution patterns and microvascular vasomotion of spontaneously hypertensive rats (SHRs) and normotensive control Wistar Kyoto rats at 5, 8, 13, and 18 weeks of age were determined. Wavelet transform analysis was performed to convert pancreatic microhemodynamic signals into time-frequency domains and construct 3-dimensional spectral scalograms. The amplitudes of characteristic oscillators including endothelial, neurogenic, myogenic, respiratory, and cardiac oscillators were compared among groups. Plasma nitrite/nitrate levels were measured using a Griess reaction. Additionally, endothelin-1, malondialdehyde, superoxide dismutase, and interleukin-6 levels were determined by enzyme-linked immunosorbent assay. RESULTS: SHRs exhibited a reduced blood distribution pattern with progressively decreased average blood perfusion, amplitude, and frequency of microvascular vasomotion. Wavelet transform spectral analysis revealed significantly reduced amplitudes of endothelial oscillators from 8- to 18-week-old SHRs. Additionally, the blood microcirculatory chemistry complements explained the microhemodynamic profiles partially, as demonstrated by an increase in plasma nitrite/nitrate, endothelin-1, malondialdehyde, and interleukin-6 levels and a decreased superoxide dismutase level in SHRs. CONCLUSIONS: Pancreatic microcirculation profiles are abnormal in the progression of hypertension in SHRs, including a disarranged blood distribution pattern, impaired microvascular vasomotion, and reduced amplitudes of endothelial oscillators.

Comparison of pancreatic microcirculation profiles in spontaneously hypertensive rats and Wistar-kyoto rats by laser doppler and wavelet transform analysis.

Pancreatic microcirculatory dysfunction emerged as a novel mechanism in the development of hypertension. However, the changes of pancreatic microcirculation profiles in hypertension remain unknown. Pancreatic microcirculatory blood distribution pattern and microvascular vasomotion of spontaneously hypertensive rats (SHRs) and Wistar Kyoto rats (WKYs) were determined by laser Doppler. Wavelet transform analysis was performed to convert micro-hemodynamic signals into time-frequency domains, based on which amplitude spectral scalograms were constructed. The amplitudes of characteristic oscillators were compared between SHRs and WKYs. The expression of eNOS was determined by immunohistochemistry, and plasma nitrite/nitrate levels were measured by Griess reaction. Additionally, endothelin-1, malondialdehyde, superoxide dismutase and interleukin-6 were determined by enzyme-linked immunosorbent assay. SHRs exhibited a lower scale blood distribution pattern with decreased average blood perfusion, frequency and amplitude. Wavelet transform spectral analysis revealed significantly reduced amplitudes of endothelial oscillators. Besides reduced expression of eNOS, the blood microcirculatory chemistry complements micro-hemodynamic profiles as demonstrated by an increase in plasma nitrite/nitrate, endothelin-1, malondialdehyde, interleukin-6 and a decrease of superoxide dismutase in SHRs. Here, we described abnormal pancreatic microcirculation profiles in SHRs, including disarranged blood distribution pattern, impaired microvascular vasomotion and reduced amplitudes of endothelial oscillators.

Multimodal Device and Computer Algorithm-Based Monitoring of Pancreatic Microcirculation Profiles In Vivo.

OBJECTIVES: Pancreatic microcirculation has an essential role in orchestrating pancreatic homeostasis. Inherent complexity and technological limitation lead to interobserver variability and 1-sided microcirculatory data. Here, we introduce a multimodal device and computer algorithm-based platform for monitoring and visualizing integrated pancreatic microcirculation profiles. METHODS: After anesthetizing and exposing pancreas tissue of BALB/c mice, probes of Oxygen to See, Microx TX3, and MoorVMS-LDF2 were positioned at pancreas in situ to capture the pancreatic microcirculatory oxygen (hemoglobin oxygen saturation, relative amount of hemoglobin, and partial oxygen pressure) and microhemodynamic data (microvascular blood perfusion and velocity). To assess and visualize pancreatic microcirculation profiles, raw data of pancreatic microcirculation profiles were processed and transformed using interquartile range and min-max normalization by Python and Apache ECharts. RESULTS: The multimodal device-based platform was established and 3-dimensional microcirculatory modules were constructed. Raw data sets of pancreatic microcirculatory oxygen and microhemodynamic were collected. The outlier of data set was adjusted to the boundary value and raw data set was preprocessed. Normalized pancreatic microcirculation profiles were integrated into the 3-dimensional histogram and scatter modules, respectively. The 3-dimensional modules of pancreatic microcirculation profiles were then generated. CONCLUSIONS: We established a multimodal device and computer algorithm-based monitoring platform for visualizing integrated pancreatic microcirculation profiles.

Insulin protects against type 1 diabetes mellitus-induced ultrastructural abnormalities of pancreatic islet microcirculation.

Pancreatic islet microcirculation, consisting of pancreatic islet microvascular endothelial cells (IMECs) and pericytes (IMPCs), provides crucial support for the physiological function of pancreatic islet. Emerging evidence suggests that pancreatic islet microcirculation is impaired in type 1 diabetes mellitus (T1DM). Here, we investigated the potential ultrastructural protective effects of insulin against streptozotocin (STZ)-induced ultrastructural abnormalities of the pancreatic islet microcirculation in T1DM mouse model. For this purpose, pancreatic tissues were collected from control, STZ-induced T1DM and insulin-treated mice, and a pancreatic IMECs cell line (MS1) was cultured under control, 35 mM glucose with or without 10-8 M insulin conditions. Transmission and scanning electron microscopies were employed to evaluate the ultrastructure of the pancreatic islet microcirculation. We observed ultrastructural damage to IMECs and IMPCs in the type 1 diabetic group, as demonstrated by destruction of the cytoplasmic membrane and organelles (mainly mitochondria), and this damage was substantially reversed by insulin treatment. Furthermore, insulin inhibited collagenous fiber proliferation and alleviated edema of the widened pancreatic islet exocrine interface in T1DM mice. We conclude that insulin protects against T1DM-induced ultrastructural abnormalities of the pancreatic islet microcirculation.

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 nebivolol versus other antihypertensive drugs on the endothelial dysfunction in patients with essential hypertension.

We aim to determine whether nebivolol has a better effect on endothelial dysfunction compared with other ß-blockers or other classes of antihypertensive drugs. Searches of the PubMed, Embase etc. were performed to analyze all the randomized controlled trials using nebivolol to treat essential hypertension. The primary end points included a measurement of peripheral endothelial function by brachial flow mediated vasodilatation (FMD) or forearm blood flow (FBF). A random-effect model was used to perform the meta-analysis when the studies showed significant heterogeneity, otherwise a descriptive analysis was conducted. Ten studies (689 patients) were included in qualitative analysis, four of which were included in quantitative synthesis. Meta-analysis showed that the changed FMD value before and after treatment with nebivolol was not statistically different from those treated with other ß-blockers [mean difference = 1.12, 95% confidence interval (CI): -0.56, 2.81, P=0.19]. Descriptive analysis indicated that nebivolol did not have a better endothelium-protective effect than other classes of antihypertensive drugs including olmesartan and perindopril. Nebivolol is not a unique endothelial function-protective agent distinguished from other ß-blockers or other classes of antihypertensive drugs. Reversal of endothelial dysfunction is a key point in the prevention and therapy of essential hypertension.

The circulating level of miR-122 is a potential risk factor for endothelial dysfunction in young patients with essential hypertension.

MicroRNAs are key molecules involved in the regulation of endothelial function. They are important risk factors and biomarkers for the development of hypertension related to endothelial dysfunction. However, the gene expression patterns associated with hypertension development related to endothelial dysfunction have not been fully elucidated. We conducted a case-control study of 65 patients with essential hypertension (EH) and 61 controls without EH. Plasma levels of miR-122 and its target protein high-affinity cationic amino acid transporter 1 (CAT-1) were measured by qRT-PCR and ELISA, respectively. miR-122 expression in plasma of patients with EH was significantly higher than that of the control group (p = 0.001), while CAT-1 expression in patients with EH was significantly lower than that in the control group (p = 0.018). miR-122 expression in plasma of young patients with EH was significantly higher than that in young people without EH (p = 0.0004), and CAT-1 expression in plasma of young patients with EH was also significantly lower than that of the control group (p = 0.002). CAT-1 expression in the plasma of young participants was significantly higher than that of individuals aged ≥40 years (p = 0.003), whereas miR-122 expression was significantly lower (p = 0.001). We showed that among patients with EH, the high expression of miR-122 contributed to endothelial dysfunction by suppressing the expression of the CAT-1 protein, which led to a decrease in CAT-1 expression in plasma. Therefore, high expression of miR-122 appears to be a risk factor for endothelial dysfunction in EH, especially in younger patients.

Differential miRNA expression analysis of extracellular vesicles from brain microvascular pericytes in spontaneous hypertensive rats.

OBJECTIVE: This study is to explore the exact roles of extracellular vesicle (EVs) miRNAs from brain microvascular pericytes in the pathogenesis of hypertension. RESULTS: Forty-eight significantly differentially expressed miRNAs were identified, of which 17 were found to be upregulated and 31 were found to be downregulated in brain microvascular pericytes of spontaneous hypertensive rats, compared with that of normotension Wistar Kyoto rats. The GO enrichment analysis verified that the target genes were enriched in signaling pathways and molecular functions, such as metal ion binding, nucleotide binding and ATP binding. The KEGG analysis indicated that the target genes were enriched in Linoleic acid, alpha-linolenic acid and sphingolipid metabolism pathways. CONCLUSIONS: Several EV derived miRNAs, such as miR-21-5p, let-7c-5p and let-7a-5p, were found to be abnormally expressed in brain microvascular pericytes obtained from spontaneous hypertensive rats, compared with that of normotension Wistar Kyoto rats. The results of our research provide more insights into the functional link between brain microvascular pericytes and the pathogenesis of hypertension.

Integrated exosomal miRNA and transcriptome analysis of brain microvascular endothelial cells in spontaneously hypertensive rats.

Endothelial cells, which regulate arterial stiffness via endothelial-derived substances, are independently and strongly associated with hypertension. However, the exact roles of exosome miRNAs from brain endothelial cells in the development of hypertension are still not fully explored. Here, we investigated the miRNA functions systematically by examining both exosomal small RNA and mRNA of endothelial cells in Wistar Kyoto (WKY) rats versus spontaneously hypertensive rats (SHRs). Our findings revealed that miRNAs, representing ~60-70%, account for the majority of small RNAs. Moreover, we found 159 novel miRNAs in total from the unannotated reads across the diverse samples. Afterwards, 76 differentially expressed miRNAs (37 upregulated, 39 downregulated) and 1709 differentially expressed mRNAs (775 upregulated, 934 downregulated) were identified between SHRs and WKY rats, respectively. Finally, 647 genes targeted by 36 miRNAs came to our attention via identification of the target genes of those abnormal miRNAs. The differentially expressed target genes induced by miRNA changes were mapped to a number of genes involved in various gene functions and pathways. These changes lead to dysregulation of angiogenesis, axonogenesis, neuron-to-neuron synapses, focal adhesion, axon guidance, cell adhesion molecules (CAMs), adherens junction, and ECM-receptor interaction pathways. Together, our study revealed that the miRNAs are changed and contribute to the dysregulated functions and pathways of their target genes and provided more insights into their regulation mechanisms during mammalian hypertension development.

Targeting the COX2/MET/TOPK signaling axis induces apoptosis in gefitinib-resistant NSCLC cells.

MET overactivation is one of the crucial reasons for tyrosine kinase inhibitor (TKI) resistance, but the mechanisms are not wholly clear. Here, COX2, TOPK, and MET expression were examined in EGFR-activating mutated NSCLC by immunohistochemical (IHC) analysis. The relationship between COX2, TOPK, and MET was explored in vitro and ex vivo. In addition, the inhibition of HCC827GR cell growth by combining COX2 inhibitor (celecoxib), TOPK inhibitor (pantoprazole), and gefitinib was verified ex vivo and in vivo. We found that COX2 and TOPK were highly expressed in EGFR-activating mutated NSCLC and the progression-free survival (PFS) of triple-positive (COX2, MET, and TOPK) patients was shorter than that of triple-negative patients. Then, we observed that the COX2-TXA2 signaling pathway modulated MET through AP-1, resulting in an inhibition of apoptosis in gefitinib-resistant cells. Moreover, we demonstrated that MET could phosphorylate TOPK at Tyr74 and then prevent apoptosis in gefitinib-resistant cells. In line with these findings, the combination of celecoxib, pantoprazole, and gefitinib could induce apoptosis in gefitinib-resistant cells and inhibit tumor growth ex vivo and in vivo. Our work reveals a novel COX2/MET/TOPK signaling axis that can prevent apoptosis in gefitinib-resistant cells and suggests that a triple combination of FDA-approved drugs would provide a low-cost and practical strategy to overcome gefitinib resistance.

MicroRNA-181a protects against pericyte apoptosis via directly targeting FOXO1: implication for ameliorated cognitive deficits in APP/PS1 mice.

MicroRNAs (miRNAs) have emerged as critical regulators in the pathology of Alzheimer's disease (AD). MiR-181a is associated with hippocampal memory formation and aberrantly expressed in patients with mild cognitive impairment (MCI), however, little is known about its role and underlying mechanism involved in AD. Here, we report that miR-181a expression declines in APP/PS1 mice, synchronous with the increase in amyloid ß (Aß) level, which suggests a reverse correlation between miR-181a level and AD development. Additionally, lentiviral overexpression of miR-181a via intrahippocampal injection ameliorates cognitive deficits and amyloid plaque deposition in APP/PS1 mice, indicating a beneficial role of miR-181a against AD progression. Moreover, miR-181a decelerates pericyte loss and blood-brain barrier breakdown in APP/PS1 mice. Furthermore, miR-181a protects against Aß accumulation-induced pericyte apoptosis in vitro, which is attributed to the negative regulation of FOXO1 by miR-181a, since FOXO1 restoration abolishes miR-181a protective role against pericyte apoptosis. Altogether, these results may identify miR-181a as a novel regulator of AD pathology, and also implicate that the protection of miR-181a in blood-brain barrier pericytes may underlie its ameliorating effect on APP/PS1 mice.

TOPK inhibits autophagy by phosphorylating ULK1 and promotes glioma resistance to TMZ.

ULK1, the upper-most protein of the ULK1 complex, is emerging as a crucial node in autophagy induction. However, the regulation of ULK1 is not fully understood. In this study, we identified TOPK (T-LAK cell-originated protein kinase), an oncokinase, as a novel upstream kinase to phosphorylate ULK1. We found that TOPK could directly bind with and phosphorylate ULK1 at Ser469, Ser495, and Ser533. The phosphorylation of ULK1 at Ser469, Ser495, and Ser533 by TOPK decreased the activity and stability of ULK1. In addition, we want to examine the initiation of autophagy because the reduction activity of ULK1 reduces the occurrence of autophagy. We demonstrated that TOPK could inhibit the initiation and progression of autophagy in glioma cells. Furthermore, TOPK inhibition increased the sensitivity of glioma cells to temozolomide (TMZ). This discovery provides insight into the problem of TMZ-resistance in GBM treatment.

Epitranscriptomic mechanisms of N6-methyladenosine methylation regulating mammalian hypertension development by determined spontaneously hypertensive rats pericytes.

Aim: Pericytes maintain homeostatic functions in the blood-brain barrier. N6-methyladenosine (m6A) is critical for various biological processes, but the role of mRNA m6A methylation in hypertension has not been fully elucidated. Methods: The m6A methylation levels of Wistar Kyoto rat pericytes and spontaneously hypertensive rat pericytes were detected via m6A high-throughput sequencing. Results: The m6A methylations were more enriched in the coding sequence region, 3'UTR and 5'UTR of mRNAs, with the m6A motifs being relatively conserved across the different conditions investigated. The average m6A abundance of spontaneously hypertensive rat pericytes exhibited global reductions in the pericytes. Conclusion: This study revealed the m6A landscapes and identified an epitranscriptomic mechanism during the development of mammalian hypertension.

Intraspinal administration of interleukin-7 promotes neuronal apoptosis and limits functional recovery through JAK/STAT5 pathway following spinal cord injury.

It has been previously reported that the blockade of interleukin-7 receptor (IL-7R) promotes functional recovery following spinal cord injury (SCI), however, the direct function and molecular mechanism of IL-7 involved in this pathogenic process are unclear. Here, we report that, contrary to IL-7R blockade, the intraspinal administration of IL-7 limits functional recovery following SCI. In addition, IL-7 treatment promotes neuronal apoptosis in spinal cord lesions, which may be attributed to exacerbated focal inflammatory response, as shown by increased accumulation of activated microglia/macrophage and production of proinflammatory mediators. Moreover, IL-7 treatment activates JAK/STAT5 pathway following SCI. At last, more importantly, the pharmacological inhibition of STAT5 abrogates the effects of IL-7 treatment on functional recovery, neuronal apoptosis and focal inflammatory response, suggesting that the effects of IL-7 treatment following SCI are dependent on activating the JAK/STAT5 pathway. Overall, this study reveals the JAK/STAT5 pathway-dependent detrimental role of IL-7 following SCI, and also implies that targeting the IL-7/JAK/STAT5 axis may represent a potential therapeutic approach for SCI treatment.

Exosomes Derived From Pericytes Improve Microcirculation and Protect Blood-Spinal Cord Barrier After Spinal Cord Injury in Mice.

Spinal cord injury (SCI) often leads to severe and permanent paralysis and places a heavy burden on individuals, families, and society. Until now, the therapy of SCI is still a big challenge for the researchers. Transplantation of mesenchymal stem cells (MSCs) is a hot spot for the treatment of SCI, but many problems and risks have not been resolved. Some studies have reported that the therapeutic effect of MSCs on SCI is related to the paracrine secretion of cells. The exosomes secreted by MSCs have therapeutic potential for many diseases. There are abundant pericytes which possess the characteristics of stem cells in the neurovascular unit. Due to the close relationship between pericytes and endothelial cells, the exosomes of pericytes can be taken up by endothelial cells more easily. There are fewer studies about the therapeutic potential of the exosomes derived from pericytes on SCI now. In this study, exosomes of pericytes were transplanted into the mice with SCI to study the restoration of motor function and explore the underlying mechanism. We found that the exosomes derived from pericytes could reduce pathological changes, improve the motor function, the blood flow and oxygen deficiency after SCI. In addition, the exosomes could improve the endothelial ability to regulate blood flow, protect the blood-spinal cord barrier, reduce edema, decrease the expression of HIF-1α, Bax, Aquaporin-4, and MMP2, increase the expression of Claudin-5, bcl-2 and inhibit apoptosis. The experiments in vitro proved that exosomes derived from pericytes could protect the barrier of spinal cord microvascular endothelial cells under hypoxia condition, which was related to PTEN/AKT pathway. In summary, our study showed that exosomes of pericytes had therapeutic prospects for SCI.

Systemic microcirculation dysfunction after low thoracic spinal cord injury in mice.

BACKGROUND: Spinal cord injury (SCI) disturbs the autonomic nervous system and induces dysfunction or failure of multiple organs. The systemic microcirculation disturbance that contributes to the complications associated with SCI remains to be clarified. METHODS: We used male mice (29-32 g) and modified weight-drop injury at T10 to evaluate the systemic microcirculation dysfunction during the first 2 weeks after SCI. We determined permeability and microvascular blood flow in several organs and evaluated their vasomotor function. We also measured circulating endothelial cells (CECs), circulating endothelial progenitor cells (CEPCs), circulating pericyte progenitor cells (CPPCs), and serum proinflammatory cytokines. RESULTS: The endothelial permeability of almost all organs increased after SCI. Microvascular blood flow decreased in the bladder and kidney and increased in the spleen and was accompanied by endothelial vasomotor dysfunction. SCI also induced an increase in CECs, CEPCs, and CPPCs in peripheral blood. Finally, we confirmed changes in a systemic cytokine profile (interleukin [IL]-3, IL-6, IL-10, IL-13, granulocyte colony-stimulating factor, and regulated on activation normal T cell expressed and secreted) after SCI. CONCLUSIONS: These data indicate that a systemic microcirculation disturbance occurs after SCI. This information may play a key role in the development of effective therapeutic strategies for SCI.