Small Extracellular Vesicles Secreted by iPSC-Derived MSCs Ameliorate Pulmonary Inflammation and Lung Injury Induced by Sepsis through Delivery of miR-125b-5p.

Background: Sepsis-induced acute lung injury is a common critical illness in intensive care units with no effective treatment is currently available. Small extracellular vesicles, secreted by mesenchymal stem cells (MSCs), derived from human-induced pluripotent stem cells (iMSC-sEV), possess striking advantages when incorporated MSCs and iPSCs, which are considered extremely promising cell-free therapeutic agents. However, no studies have yet been conducted to systemically examine the effects and underlying mechanisms of iMSC-sEV application on attenuated lung injury under sepsis conditions. Method: iMSC-sEV were intraperitoneally administered in a rat septic lung injury model induced by cecal ligation and puncture (CLP). The efficacy of iMSC-sEV was assessed by histology, immunohistochemistry, and pro-inflammatory cytokines of bronchoalveolar lavage fluid. We also evaluated the in vitro effects of iMSC-sEV on the activation of the inflammatory response in alveolar macrophages (AMs). Small RNA sequencing was utilized to detect changes in the miRNA expression profile in lipopolysaccharide (LPS)-treated AMs after iMSC-sEV administration. The effects of miR-125b-5p on the function of AMs were studied. Results: iMSC-sEV were able to attenuate pulmonary inflammation and lung injury following CLP-induced lung injury. iMSC-sEV were internalized by AMs and alleviated the release of inflammatory factors by inactivating the NF-κB signaling pathway. Moreover, miR-125b-5p showed a fold-change in LPS-treated AMs after iMSC-sEV administration and was enriched in iMSC-sEV. Mechanistically, iMSC-sEV transmitted miR-125b-5p into LPS-treated AMs to target TRAF6. Conclusion: Our findings demonstrated that iMSC-sEV treatment protects against septic lung injury and exerts anti-inflammatory effects on AMs at least partially through miR-125b-5p, suggesting that iMSC-sEV may provide a novel cell-free strategy for the treatment of septic lung injury.

Autophagy alleviates mitochondrial DAMP-induced acute lung injury by inhibiting NLRP3 inflammasome.

AIM: Acute lung injury (ALI) is characterized by alveolar macrophage overactivation and uncontrolled pulmonary inflammation. Mitochondrial damage-associated molecular patterns (MTDs), one type of damage-associated molecular patterns (DAMPs) released from ruptured mitochondrial, can induce inflammation which participates in the pathogenesis of ALI. Despite the critical role of autophagy in inflammatory response, little is known about its function in MTDs-induced ALI. Herein we have studied how autophagy attenuates MTDs-induced ALI in vitro and in vivo. MAIN METHODS: Exogenous MTDs were injected into mice through tail vein injection or directly treated with cultured alveolar macrophage cell lines to construct MTDs-induced ALI models. Rapamycin and 3-MA were used to regulate autophagy in vivo and in vitro. The expressions of Caspase-1, IL-1ß, and their precursor were measured. Inhibition the activation of NLRP3 inflammasome to discover the candidate targets and potential molecular pathways involved in autophagy mitigating the MTDs-induced ALI. KEY FINDINGS: After treatment with MTDs the expression levels of inflammatory cytokines and NLRP3 inflammasome-associated proteins were gradually increased in vitro and in vivo. Most importantly, with autophagy enhanced by rapamycin, all the secretion of inflammation cytokine, the level of lung injury, and the expression level of NLRP3 inflammasome-associated proteins were greatly decreased in MTDs-induced mouse model. MTDs-induced inflammation and lung injury were alleviated by autophagy enhancement. Autophagy can function as an effective way to alleviate inflammation in MTDs-induced ALI by inhibiting NLRP3 inflammasome and may represent a therapeutic target in modulating MTDs-induced inflammatory response.

Analysis of Differentially Expressed Long Noncoding RNA in Renal Ischemia-Reperfusion Injury.

BACKGROUND: Renal ischemia-reperfusion (IR) injury is one of the major causes of acute renal failure which seriously endangers the health and life of patients. Currently, there is still lack of comprehensive knowledge of the molecular mechanism of renal IR injury, and the regulatory role of long noncoding RNA (lncRNA) in renal IR damage remains poorly understood. AIM: The aim of this study was to analyze the expression spectrum of lncRNA in renal IR damage in mice and to explore specific lncRNA that may be involved in regulating the development of human renal IR injury. METHODS: RNA-Seq was used to investigate the lncRNA profile of renal IR injury in a mouse model, and conservation analysis was performed on mouse lncRNAs with differential expression (fragments per kilobase of transcript per million mapped reads ≥2) by BLASTN. The potential functions and associated pathways of the differentially expressed lncRNA were explored by bioinformatics analysis. The cell hypoxia model was used to detect the expression of the candidate lncRNA. RESULTS: Of the 45,923 lncRNA transcripts detected in the samples, and 5,868 lncRNAs were found to be significantly differentially expressed (p < 0.05 and fold change ≥ 2) in 24-h IR kidney tissue compared to the expression in the control group. It was found that 56 differently expressed mouse lncRNA transcripts have human homology by analyzing the conserved sequences. We also found that lncRNA-NONHSAT183385.1 expression significantly increased in HK2 cells after 24 h of hypoxia and increased further 6 h after reoxygenation, and after 24 h of reoxygenation it was dramatically downregulated, indicating that NONHSAT183385.1 may be involved in the pathophysiological process of renal tubular epithelial cells in response to ischemia in human renal IR. CONCLUSION: Our study revealed differentially expressed lncRNAs in renal IR damage in mice and identified a set of conserved lncRNAs, which would help to explore lncRNAs that may play important regulatory roles in human renal IR injury.

Capn4 overexpression indicates poor prognosis of ovarian cancer patients.

Recent studies have shown a close correlation between Capn4 expression and the prognosis of patients with solid tumors. This study aimed to investigate clinical role of Capn4 in ovarian cancer. The expression of Capn4 in 113 ovarian cancer and 35 non-tumor tissue samples were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Capn4 expression was significantly upregulated in ovarian cancer tissues compared with non-tumor tissues (p < 0.01), and was positively correlated to FIGO stage, tumor grade and distant metastasis of ovarian cancer. Kaplan-Meier analysis indicated that patients with high Capn4 expression had shorter overall survival (HR = 1.929, 95%CI: 1.210-3.077, P= 0.006) and progress-free survival (PFS) (HR = 2.043, 95%CI: 1.276-3.271, P= 0.003). Moreover, univariate Cox regression analysis demonstrated that Capn4 overexpression was an unfavorable prognostic factor for ovarian cancer (HR = 2.819, 95%CI: 1.365-3.645, P = 0.003). After the adjustment with age, histological type and tumor size, multivariate Cox regression analysis showed that Capn4 expression level (HR = 2.157,95%CI: 1.091-3.138, P = 0.014), distant metastasis (HR = 1.576, 95%CI: 1.025-3.012, P = 0.028), tumor grade (HR = 1.408, 95%CI: 0.687-2.884, P = 0.037), and FIGO stage (HR = 1.791, 95%CI: 1.016-3.158, P=0.036) were independent poor prognostic indicators for ovarian cancer. In conclusion, Capn4 has the potential as a new prognostic marker for patients with ovarian cancer.

Generation of special autosomal dominant polycystic kidney disease iPSCs with the capability of functional kidney-like cell differentiation.

BACKGROUND: Human induced pluripotent stem cells (iPSCs) have been verified as a powerful cell model for the study of pathogenesis in hereditary disease. Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations of PKD or non-PKD genes. The pathogenesis of ADPKD remains unexplored because of the lack of a true human cell model. METHODS: Six ADPKD patients and four healthy individuals were recruited as donors of somatic cells from a Chinese ADPKD family without mutations of the PKD genes but carrying SAMSN1 gene deletion. The ADPKD-iPSCs were generated from somatic cells and were induced into kidney-like cells (KLCs) by a novel three-step method involving cytokines and renal epithelium growth medium. Furthermore, we analyzed functional properties of these KLCs by water transportation and albumin absorption assays. RESULTS: We successfully generated iPSCs from ADPKD patients and differentiated them into KLCs that showed morphological and functional characteristics of human kidney cells. Further, we also found that ADPKD-iPSC-KLCs had a significantly higher rate of apoptosis and a significantly lower capacity for water transportation and albumin absorption compared to healthy sibling-derived differentiated KLCs. Furthermore, knockdown of SAMSN1 in control iPSCs may attenuate differentiation and/or function of KLCs. CONCLUSIONS: These data show that we have created the first iPSCs established from ADPKD patients without mutations in the PKD genes, and suggest that the deletion mutation of SAMSN1 might be involved in the differentiation and/or function of KLCs. ADPKD-iPSC-KLCs can be used as a versatile model system for the study of kidney disease.

[Quantitative Analysis of Immuno-fluorescence of Nuclear Factor-κB Activation].

Immuno-fluorescence technique can qualitatively determine certain nuclear translocation, of which NF-κB/ p65 implicates the activation of NF-κB signal pathways. Immuno-fluorescence analysis software with independent property rights is able to quantitatively analyze dynamic location of NF-κB/p65 by computing relative fluorescence units in nuclei and cytoplasm. We verified the quantitative analysis by Western Blot. When we applied the software to analysis of nuclear translocation in lipopolysaccharide (LPS) induced (0. 5 h, 1 h, 2 h, 4 h) primary human umbilical vein endothelial cells (HUVECs) , we found that nuclear translocation peak showed up at 2h as with calculated Western blot verification results, indicating that the inventive immuno-fluorescence analysis software can be applied to the quantitative analysis of immuno-fluorescence.

Inhibition of Notch signaling facilitates the differentiation of human-induced pluripotent stem cells into neural stem cells.

Neural stem cells (NSCs) derived from induced pluripotent stem cells (iPSCs) are becoming an appealing source of cell-based therapies of brain diseases. As such, it is important to understand the molecular mechanisms that regulate the differentiation of iPSCs toward NSCs. It is well known that Notch signaling governs the retention of stem cell features and drives stem cells fate. However, further studies are required to investigate the role of Notch signaling in the NSCs differentiation of iPSCs. In this study, we successfully generated NSCs from human iPSCs using serum-free medium supplemented with retinoic acid (RA) in vitro. We then assessed changes in the expression of Notch signaling-related molecules and some miRNAs (9, 34a, 200b), which exert their regulation by targeting Notch signaling. Moreover, we used a γ-secretase inhibitor (DAPT) to disturb Notch signaling. Data revealed that the levels of the Notch signaling-related molecules decreased, whereas those miRNAs increased, during this differentiation process. Inhibition of Notch signaling accelerated the formation of the neural rosette structures and the expression of NSC and mature neurocyte marker genes. This suggests that Notch signaling negatively regulated the neuralization of human iPSCs, and that this process may be regulated by some miRNAs.

Biological characteristics of human-urine-derived stem cells: potential for cell-based therapy in neurology.

Stem cells in human urine have gained attention in recent years; however, urine-derived stem cells (USCs) are far from being well elucidated. In this study, we compared the biological characteristics of USCs with adipose-derived stem cells (ASCs) and investigated whether USCs could serve as a potential cell source for neural tissue engineering. USCs were isolated from voided urine with a modified culture medium. Through a series of experiments, we examined the growth rate, surface antigens, and differentiation potential of USCs, and compared them with ASCs. USCs showed robust proliferation ability. After serial propagation, USCs retained normal karyotypes. Cell surface antigen expression of USCs was similar to ASCs. With lineage-specific induction factors, USCs could differentiate toward the osteogenic, chondrogenic, adipogenic, and neurogenic lineages. To assess the ability of USCs to survive, differentiate, and migrate, they were seeded onto hydrogel scaffold and transplanted into rat brain. The results showed that USCs were able to survive in the lesion site, migrate to other areas, and express proteins that were associated with neural phenotypes. The results of our study demonstrate that USCs possess similar biological characteristics with ASCs and have multilineage differentiation potential. Moreover USCs can differentiate to neuron-like cells in rat brain. The present study shows that USCs are a promising cell source for tissue engineering and regenerative medicine.

Human induced pluripotent stem cell-derived neural stem cells survive, migrate, differentiate, and improve neurologic function in a rat model of middle cerebral artery occlusion.

INTRODUCTION: Stroke is a major cause of permanent neurologic damage, with few effective treatments available to restore lost function. Induced pluripotent stem cells (iPSCs) have the potential to generate all cell types in vitro and can be generated from a stroke patient. Therefore, iPSCs are attractive donor sources of genetically identical "patient-specific" cells to hold promise in therapy for stroke. In the present study, we established a four-stage culture system by using serum-free medium and retinoic acid (RA) to differentiate iPSCs into neural stem cells (NSCs) effectively and stably. Our hypothesis was that iPSC-derived NSCs would survive, migrate, and differentiate in vivo, and improve neurologic function after transplantation into the brains of rats with ischemic stroke. METHODS: Human iPSCs (iPS-S-01) and human ESCs (HuES17) were used to differentiate into NSCs by using our four-stage culture system. iPSCs and differentiated NSCs were characterized by immunocytochemistry staining and reverse transcription-polymerase chain reaction (RT-PCR) analysis. After establishment of focal cerebral ischemia with occlusion of the middle cerebral artery (MCA) and cell transplantation, animals were killed at 1 week and 2 weeks to analyze survival, migration, and differentiation of implanted cells in brain tissue. Animal behavior was evaluated via rope grabbing, beam walking, and Morris water maze tests. RESULTS: iPSCs were efficiently induced into NSCs by using a newly established four-stage induction system in vitro. iPSCs expressed pluripotency-associated genes Oct4, Sox2, and Nanog before NSC differentiation. The iPSC-derived NSCs spontaneously differentiated into neurons and astrocytes, which highly express ß-tubulin and glial fibrillary acidic protein (GFAP), respectively. On transplantation into the striatum, CM-DiI labeled iPSC-derived NSCs were found to migrate into the ischemia area at 1 week and 2 weeks, and animal-function recovery was significantly improved in comparison with control groups at 3 weeks. CONCLUSIONS: The four-stage induction system is stable and effective to culture, differentiate, and induce iPSCs to NSCs by using serum-free medium combined with retinoic acid (RA). Implanted iPSC-derived NSCs were able to survive, migrate into the ischemic brain area to differentiate into mature neural cells, and seem to have potential to restore lost neurologic function from damage due to stroke in a rat model.

[Regulatory effects of lanthanum chloride on the activation of nuclear factor kappa B inhibitor kinase beta induced by tumor necrosis factor alpha].

OBJECTIVE: To investigate the regulatory effects of lanthanum chloride (LaCl3) on the activation of nuclear factor kappa B inhibitor (IκB) kinase beta (IKKß) induced by tumor necrosis factor alpha (TNF-α). METHODS: (1) Hela cells were cultured routinely in vitro. One portion of cells were collected and divided into TNF-α group (cultured with serum-free RMPI 1640 medium containing 20 ng/mL TNF-α for 30 min), low-dose LaCl3 + TNF-α group, moderate-dose LaCl3 + TNF-α group, high-dose LaCl3 + TNF-α group, LaCl3 group (cultured with serum-free RMPI 1640 medium containing 100 µmol/L LaCl3 for 30 min), and control group (cultured with serum-free RMPI 1640 medium for 30 min) according to the random number table. Cells in low-dose LaCl3 + TNF-α group, moderate-dose LaCl3 + TNF-α group, high-dose LaCl3 + TNF-α group were first cultured with serum-free RMPI 1640 medium containing 5, 25, 100 µmol/L LaCl3 for 4 h, and then stimulated with serum-free RMPI 1640 medium containing 20 ng/mL TNF-α for 30 min. There were 3 samples in each group. Cells were collected for detection of intracellular location of NF-κB/p65 protein by immunofluorescence staining. (2) Another portion of cells were collected and divided into TNF-α group, low-dose LaCl3 + TNF-α group, moderate-dose LaCl3 + TNF-α group, high-dose LaCl3 + TNF-α group, and control group with the same treatment as above. There were 3 samples in each group. The protein levels of NF-κB/p65 in nuclei, and the protein levels of IκBα, phosphorylated IκBα (p-IκBα) as well as IKKß and phosphorylated IKKß (p-IKKß) in cytoplasm were determined by Western blotting. The binding activity between NF-κB/p65 in the nuclear and target gene was determined by NF-κB/p65 transcription factor kit (denoted as absorption value). Data were processed with analysis of variance or LSD-t test. RESULTS: (1) High expression of NF-κB/p65 was observed in cytoplasm of control group. High expression of NF-κB/p65 was observed in nuclei of TNF-α group. The expression of NF-κB/p65 in cytoplasm of LaCl3 group was lower than that of control group. In groups treated with LaCl3 and TNF-α, NF-κB/p65 expression levels in nuclei and cytoplasm were decreased along with the increase in the concentration of LaCl3, which were all lower than those in TNF-α group. (2) There was certain amount of NF-κB/p65 protein expressed in nuclei of control group. The expression of NF-κB/p65 protein in nuclei of TNF-α group was higher than that of control group. In groups treated with LaCl3 and TNF-α, the expressions of NF-κB/p65 protein in nuclei were decreased along with an increase in the concentration of LaCl3. The level of IκBα in TNF-α group was significantly decreased but that of p-IκBα increased as compared with those in control group. Along with the increase in the concentration of LaCl3, the levels of IκBα gradually increased and the levels of p-IκBα gradually decreased in groups treated with LaCl3 and TNF-α. There were no statistical differences in expression levels of IKKß among the 5 groups. The expression of p-IKKß could be hardly observed in control group, but it was obviously increased in TNF-α group. The expression levels of p-IKKß in groups treated with LaCl3 and TNF-α were gradually decreased along with the increase in the concentration of LaCl3. The absorption value in TNF-α group was 0.39 ± 0.03, which was higher than that in control group (0, t = -7.23, P<0.01). The absorption values in low-dose LaCl3 +TNF-α group, moderate-dose LaCl3 + TNF-α group, and high-dose LaCl3 +TNF-α group were respectively 0.17 ± 0.03, 0.15 ± 0.03, and 0, which were obviously lower than that in TNF-α group (with t values respectively -6.54, -5.92, -7.23, P values all below 0.01). CONCLUSIONS: LaCl3 can block the activation of NF-κB signaling pathway by blocking the phosphorylation of IKKß of Hela cells.

Bone marrow stromal cells enhance the angiogenesis in ischaemic cortex after stroke: involvement of notch signalling.

Angiogenesis takes place after brain ischaemia, and stroke-induced angiogenesis in ischaemic brain may be associated with improved neurological recovery. Bone MSCs (marrow stromal cells) transplantation can promote this vital angiogenesis in ischaemic zones, but the mechanisms by which MSCs promoting angiogenesis are unclear. The Notch signalling pathway may play an important role in embryonic blood vessels development and tumour angiogenesis, but whether it is also involved in angiogenesis after cerebral ischaemia is uncertain. We therefore investigated the Notch signalling pathway in angiogenesis after stroke. Rats were subjected to MCAo (middle cerebral artery occlusion) and treated intravenously with or without MSCs at 24 h after injury. On day 1, 3 and 7 after treatment with MSCs or PBS, immunofluorescent staining, Western blot and RT-PCR (reverse transcription-PCR) assays were carried out to evaluate angiogenesis, and expression of VEGF (vascular endothelial growth factor) and Notch signals in the ischaemic cortex. Immunofluorescent showed a significant increase in both new microvessels, VEGF-positive cells and Notch1-positive microvessels in the ischaemic cortex in MSCs-treated group. RT-PCR indicated that MSC transplantation significantly raised VEGF mRNA and Hes1 mRNA levels in the ischaemic cortex. The data suggest that treatment with MSCs enhances stroke-induced angiogenesis in ischaemic brain, and that the Notch signalling pathway is involved.

miR-210 activates notch signaling pathway in angiogenesis induced by cerebral ischemia.

The compensatory angiogenesis that occurs after cerebral ischemia increases blood flow to the injured area and limits extension of the ischemic penumbra. In this way, it improves the local blood supply. Fostering compensatory angiogenesis is an effective treatment for ischemic cerebrovascular disease. However, angiogenesis in the adult organism is a complex, multi-step process, and the mechanisms underlying the regulation of angiogenesis are not well understood. Although Notch signaling reportedly regulates the vascularization process that occurs in ischemic tissues, little is known about the role of Notch signaling in the regulation of ischemia-induced angiogenesis after ischemic stroke. Recent research has indicated that miR-210, a hypoxia-induced microRNA, plays a crucial role in regulating the biological processes that occur in blood vessel endothelial cells under hypoxic conditions. This study was undertaken to investigate the role of miR-210 in regulating angiogenesis in response to brain ischemia injury and the role of the Notch pathway in the body's response. We found miR-210 to be significantly up-regulated in adult rat ischemic brain cortexes in which the expression of Notch1 signaling molecules was also increased. Hypoxic models of human umbilical vein endothelial cells (HUVE-12) were used to assess changes in miR-210 and Notch1 expression in endothelial cells. Results were consistent with in vivo findings. To determine the molecular mechanisms behind these phenomena, we transfected HUVE-12 cells with miR-210 recombinant lentiviral vectors. We found that miR-210 overexpression caused up-regulation of Notch1 signaling molecules and induced endothelial cells to migrate and form capillary-like structures on Matrigel. These data suggest that miR-210 is involved in the regulation of angiogenesis in response to ischemic injury to the brain. Up-regulation of miR-210 can activate the Notch signaling pathway, which may contribute to angiogenesis after cerebral ischemia.

[MicroRNA-210 modified human umbilical vein endothelial cells induce capillary formation].

OBJECTIVE: To construct human recombinant lentiviral expression vector of microRNA-210 (miR-210) and to explore the over-expression of miR-210 on the capillary formation in human umbilical vein endothelial cells 12 (HUVE-12). METHODS: The recombinant lentiviral expression vector of pGCSIL-green fluorescent protein (GFP)-pre-miR-210 was constructed by molecular cloning and transfected to HUVE-12 (LV-miR-210-GFP group), only pGCSIL-GFP was transfected as control group (LV-GFP group). The miR-210 expression activity was evaluated by GFP reporter through fluorescence detection and real-time fluorescent quantitative PCR. The ephrinA3 protein expression was measured by flow cytometry. The concentration of vascular endothelial growth factor (VEGF) in culture supernatant was determined by ELISA. The cells were cultured in 96-well culture plate coated with Matrigel to assess the ability of capillary formation. RESULTS: The recombinant plasmid pGCSIL-GFP-pre-miR-210 was confirmed by restriction endonuclease analysis and DNA sequencing. Fluorescence detection showed that the fluorescence intensity of GFP was highest between 48 and 72 hours after transfection. Real-time fluorescent quantitative PCR showed that the miR-210 expression of LV-miR-210-GFP group was 9.72 times higher than that in LV-GFP group (t = -11.10, P = 0.00). Flow cytometry analysis showed that the positive cell rate of enphrinA3 in LV-miR-210-GFP group (12.52% +/- 0.67%) was significantly lower than that in LV-GFP group (73.22% +/- 1.45%) (t = -66.12, P = 0.00). The concentration of VEGF in supernatant in LV-miR-210-GFP group was significantly higher than that in LV-GFP group [(305.29 +/- 16.52) pg/mL vs. (42.52 +/- 3.11) pg/mL, t = -27.06, P = 0.00]. In vitro capillary-like formation assay showed that the number of capillaries was significantly larger in LV-miR-210-GFP group than in LV-GFP group (17.33 +/- 6.33 vs. 6.33 +/- 2.33, t = -2.83, P = 0.04). CONCLUSION: The recombinant lentiviral expression vector of miR-210 is constructed successfully and HUVE-12 over-expressing miR-210 can significantly increase the capillary formation, which facilitates further study on the molecular functions of miR-210 in angiogenesis.

Effects of low temperatures on proliferation-related signaling pathways in the hippocampus after traumatic brain injury.

To evaluate the influence of low temperatures on the proliferation of neural stem cells (NSCs) and the regulation of their signaling pathways after brain trauma, we examined changes in the expression levels of specific miRNAs and their target genes. We also evaluated NSC proliferation in the hippocampus after brain trauma under low-temperature conditions. We found that the expression profile of miRNAs in the hippocampus after trauma changed at both normal and low temperatures, and the expression of miR-34a decreased significantly lower in rats exposed to low temperatures. There was significant proliferation of endogenous NSCs in the hippocampus after brain trauma at both temperatures, but NSC proliferation was slower at low temperatures. In addition, the expression of Notch1 significantly increased in the hippocampus after brain trauma at both temperatures. However, at low temperatures, the degree of up-regulation of Notch signaling molecules was significantly lower. We conclude that low-temperature environments can inhibit the proliferation of endogenous NSCs in the hippocampus, possibly by alleviating the effects of miR-34a down-regulation and Notch signaling up-regulation induced by traumatic brain injury.

Upregulation of microRNA-210 regulates renal angiogenesis mediated by activation of VEGF signaling pathway under ischemia/perfusion injury in vivo and in vitro.

BACKGROUND: MicroRNAs (miRNAs) are endogenous, non-coding, small RNAs that regulate gene expression and function, but little is known about regulation of miRNAs in the kidneys under normal or pathologic conditions. Here, we sought to investigate the potential involvement of miRNAs in renal ischemia/reperfusion (I/R) injury and angiogenesis and to define some of the miRNAs possibly associated with renal angiogenesis. METHODS AND RESULTS: Male Balb/c mice were subjected to a standard renal I/R. CD31 immunostaining indicated a significant increase of microvessels in the ischemic region. VEGF and VEGFR2 expression were increased in renal I/R at both the mRNA and protein levels which were detected by qRT-PCR and Western blot, respectively. More importantly, 76 microRNAs exhibited more than 2-fold changes using Agilent microRNA microarray, which contains downregulation of 40 miRNAs and upregulation of 36 miRNAs. Upregulation of miR-210 was confirmed by qRT-PCR with prominent changes at 4 and 24 h after reperfusion. Furthermore, overexpression of miR-210 in HUVEC-12 cells enhances VEGF and VEGFR2 expression and promotes angiogenesis on Matrigel in vitro. CONCLUSION: These findings suggest miR-210 may be involved in targeting the VEGF signaling pathway to regulate angiogenesis after renal I/R injury, which provides novel insights into the angiogenesis mechanism of renal I/R injury.

Exposure to lanthanum compound diminishes LPS-induced inflammation-associated gene expression: involvements of PKC and NF-kappaB signaling pathways.

Lanthanum chloride, a rare earth compound, possesses antibacterial and cellular immunity regulating properties. However, the underlying molecular mechanisms remain largely unknown. In this study, we examined the effects of lanthanum chloride on the production of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha), the expression of inducible NO synthase (iNOS) and TNF-alpha in RAW 264.7 cells, a mouse macrophage cell line. We found that the LPS-elicited excessive production of NO and TNF-alpha in RAW 264.7 cells was inhibited significantly in the presence of lanthanum chloride, and the attenuation of iNOS and TNF-alpha occurred at mRNA level. Furthermore, the possible signaling components affected by lanthanum chloride in the pathway that lead to LPS-induced iNOS and TNF-alpha expression were explored. The results indicated the involvements of PKC/Ca(2+) and NF-kappaB in the attenuation of NO and pro-inflammatory cytokine production by lanthanum chloride. Our observations suggest a possible therapeutic application of this agent for treating inflammatory diseases.

Mesenchymal stem cells regulate the proliferation and differentiation of neural stem cells through Notch signaling.

The effects of mesenchymal stem cells (MSCs) on proliferation and cell fate determination of neural stem cells (NSCs) have been investigated. NSCs were co-cultured with MSCs or NIH3T3 cells using an in vitro transwell system. After 4 days, immunofluorescence staining showed that the number of cells positive for the cell proliferation antigen, ki-67, in neurospheres in MSCs was greater than in NIH3T3 cells. In some experiments, the top-layers of MSCs and NIH3T3 cells were removed to induce NSCs differentiation. Seven days after initiating differentiation, the levels of the neuronal marker, NSE, were higher in NSCs in MSCs co-culture group, and those of glial fibrillary acidic protein (GFAP) were lower, compared with NIH3T3 cells co-culture group. These were confirmed by immunofluorescence. The role of the Notch signaling pathway analyzed with the specific inhibitor, DAPT, and by examining the expression of Notch-related genes using RT-PCR showed that after co-culturing with MSCs for 24h, NSCs expressed much higher levels of ki-67, Notch1, and Hes1 than did NSCs co-cultured with NIH3T3 cells. Treatment with DAPT decreased ki-67, Notch1 and Hes1 expression in NCSs, and increased Mash1 expression. The data indicate that the interactions between MSCs and NSCs promote NSCs proliferation and are involved in specifying neuronal fate, mediated in part by Notch signaling.

[Inhibitory effect of lanthanum chloride on the expression of inducible nitric oxide synthase in RAW264.7 macrophages induced by lipopolysaccharide].

OBJECTIVE: To explore the influence of lanthanum chloride (LaCl3) on inducible nitric oxide synthase (iNOS) expression in RAW264.7 macrophages with lipopolysaccharide (LPS) induction, and to investigate its possible mechanisms. METHODS: The RAW264.7 macrophages were randomly divided into four groups: i. e, control group (without treatment), LaCl3 group (with treatment of 2.5 micromol/L of LaCl3 for 24 hrs), LaCl3 + LPS group (with treatment of 2.5 micromol/L LaCl3 for 24h), and LPS group (with treatment of 1 mg/L LPS for 24 hrs). The iNOS protein expression was measured by immunofluorescence and Western blot. iNOS gene expression was assayed by reverse transcription-polymerase chain reaction (RT-PCR). NO production in culture supernatant was assayed by nitrate reductase method. RESULTS: Immunofluorescence analysis showed that iNOS was located mainly in the cytoplasm. RAW264.7 cells with overexpression of iNOS accounted for 44.4%, which was obviously higher than that in LaCl3 + LPS group (11.8%, P < 0.05). There was a faint signal of FITC-labeled green tint in control group or LaCl3 group. The iNOS mRNA and protein expression, and the NO content in LPS group were significantly higher than those in control, LaCl3, and LaCl3 + LPS groups (P < 0.05). CONCLUSION: LaCl3 can suppress LPS-induced iNOS overexpression at mRNA and protein level and reduce NO production, indicating that LaCl3 can antagonize the excessive activation of iNOS induced by LPS.

[Effects of lanthanum on inhibition of lipopolysaccharide induced NF-kappaB activation].

OBJECTIVE: To investigate the influence of lanthanum on lipopolysaccharide (LPS) induced NF-KB activation in murine peritoneal macrophage. METHODS: Peritoneal macrophages were isolated and cultured by routine method, and randomly divided into 5 groups: i. e, control group, LPS group (with LPS stimulation for 30 min), La3+ group (with 2.5 micromol/L La3+ group for 30 min) , La3+ + LPS group( with 1 microg/ml LPS stimulation for 30 min after 30 min incubation with DMEM-F12 containing 2.5 microM of lanthanum.) ; La3+/LPS group (with 2.5 microM of lanthanum stimulation for 30 min, and then with 1 microg/ml of LPS for another 30 min after lanthanum was removed. The location of NF-kappaB p65 subunit (NF-kappaB/p65) in Mphi was detected by immunofluorescence and fluorescence microscope. The binding activity of NF-kappaB/p65 with DNA in nuclei was detected by TransAMTM NF-kappaB/p65 Transcription Factor assay kit. Meanwhile, the expression of NF-kappaB/p65 in nuclei, as well as IkappaBalpha in cytoplasm was measured by Western blotting. TNF-alpha content in culture supernatant were detected by ELISA. RESULTS: (1) The green fluorescence in control, La3+, La3+ LPS and La+/LPS groups was mainly located in cytoplasm, while that in LPS group was located in nuclei. The fluorescent intensity in LPS group was (116 +/- 14), which was obviously higher than that in other 4 groups (42 +/-7,73 +/-30,48 +/- 11 and 67 +/- 19, respectively, P <0.01). (2) The IkappaBalpha protein level in cytoplasm in control (0.048 +/- 0.027), La3+ group (0.062 +/- 0.049), La3+ + LPS group (0.066 +/-0.031) and La3+/LPS group (0.108 +/- 0.017) was significantly lower than that in LPS group (0.435 +/-0.066, P <0.01). (3) The expression and activation of nucleus p65 protein in Mphi in LPS group was obviously higher than the other 4 groups, but changes in the IkappaBalpha expression between LPS group and other 4 groups was of controversy. (4) TNFalpha level in the culture supernatant in La3+ group was lower than that in control group ( P < 0.05) and below the detection limit (25 pg/ml). Moreover, it in La3+ + LPS group and La3*/LPS group was lower than that in LPS group (P <0.01), but higher than that in control group. CONCLUSION: LPS can activate the nucleus translocation of NF-kappaB/p65 in Mphi of mice, increase NF-KB/p65 expression and activity, but reduce IkappaBalpha protein expression, which lead to increase of TNFalpha secretion. Lanthanum can inhibit lipopolysaccharide induced NF-kappaB activation.