[Research progress of critical care ultrasound in volume management of sepsis].

Critical care ultrasound has many operational advantages such as visualization, reproducibility, noninvasiveness, and real-time dynamic monitoring, and is now widely used in the treatment process of various clinical diseases. Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. On the basis of active anti-infection, early administration of fluid resuscitation to maintain organ tissue perfusion and individualized adjustment of volume management is the core of improving patient prognosis and reducing mortality. Currently, there are many shortcomings in the commonly used clinical physical examination and static parameters to assess volume status. Critical care ultrasound has many advantages in volume management of sepsis due to its diversified advantages, which promoted the development of critical care medicine. This article presents a review of critical care ultrasound in volume management in sepsis, aiming to highlight the value and limitations of the application of critical care ultrasound in volume management in sepsis.

Engineering exosomes derived from subcutaneous fat MSCs specially promote cartilage repair as miR-199a-3p delivery vehicles in Osteoarthritis.

Osteoarthritis (OA) is a degenerative joint disease involving cartilage. Exosomes derived from Mesenchymal stem cells (MSCs) therapy improves articular cartilage repair, but subcutaneous fat (SC) stromal cells derived exosomes (MSCsSC-Exos), especially engineering MSCsSC-Exos for drug delivery have been rarely reported in OA therapy. This objective of this study was to clarify the underlying mechanism of MSCsSC-Exos on cartilage repair and therapy of engineering MSCsSC-Exos for drug delivery in OA. MSCsSC-Exos could ameliorate the pathological severity degree of cartilage via miR-199a-3p, a novel molecular highly enriched in MSCsSC-Exos, which could mediate the mTOR-autophagy pathway in OA rat model. Intra-articular injection of antagomiR-199a-3p dramatically attenuated the protective effect of MSCsSC-Exos-mediated on articular cartilage in vivo. Furthermore, to achieve the superior therapeutic effects of MSCsSC-Exos on injured cartilage, engineering exosomes derived from MSCsSC as the chondrocyte-targeting miR-199a-3p delivery vehicles were investigated in vitro and in vivo. The chondrocyte-binding peptide (CAP) binding MSCsSC-Exos could particularly deliver miR-199a-3p into the chondrocytes in vitro and into deep articular tissues in vivo, then exert the excellent protective effect on injured cartilage in DMM-induced OA mice. As it is feasible to obtain human subcutaneous fat from healthy donors by liposuction operation in clinic, meanwhile engineering MSCsSC-Exos to realize targeted delivery of miR-199a-3p into chondrocytes exerted excellent therapeutic effects in OA animal model in vivo. Through combining MSCsSC-Exos therapy and miRNA therapy via an engineering approach, we develop an efficient MSCsSC-Exos-based strategy for OA therapy and promote the application of targeted-MSCsSC-Exos for drug delivery in the future.

Role of Serum Inflammatory Cytokines in Sepsis Rats Following BMSCs Transplantation: Protein Microarray Analysis.

Bone marrow stromal cells (BMSCs) have emerged as a potential therapy for sepsis, yet the underlying mechanisms remain unclear. In this study, we investigated the effects of BMSCs on serum inflammatory cytokines in a rat model of lipopolysaccharide (LPS)-induced sepsis. Sepsis was induced by intravenous injection of LPS, followed by transplantation of BMSCs. We monitored survival rates for 72 h and evaluated organ functions, histopathological changes, and cytokines expression. Sepsis rats showed decreased levels of white blood cells, platelets, lymphocyte ratio, and oxygen partial pressure, along with increased levels of neutrophil ratio, carbon dioxide partial pressure, lactic acid, alanine aminotransferase, and aspartate aminotransferase. Histologically, lung, intestine, and liver tissues exhibited congestion, edema, and infiltration of inflammatory cells. However, after BMSCs treatment, there was improvement in organ functions, histopathological injuries, and survival rates. Protein microarray analysis revealed significant changes in the expression of 12 out of 34 inflammatory cytokines. These findings were confirmed by enzyme-linked immunosorbent assay. Pro-inflammatory factors, such as interleukin-1ß (IL-1ß), IL-1α, tumor necrosis factor-α (TNF-α), tissue inhibitor of metal protease 1 (TIMP-1), matrix metalloproteinase 8 (MMP-8), Leptin, and L-selectin were upregulated in sepsis, whereas anti-inflammatory and growth factors, including IL-4, ß-nerve growth factor (ß-NGF), ciliary neurotrophic factor (CNTF), interferon γ (IFN-γ), and Activin A were downregulated. BMSCs transplantation led to a decrease in pro-inflammatory cytokines and an increase in anti-inflammatory and growth factors. We summarized relevant molecular signaling pathways that resulted from cytokines in BMSCs for treating sepsis. Our results illustrated that BMSCs could promote tissue repair and improve organ functions and survival rates in sepsis through modulating cytokine networks.

ADSCs increase the autophagy of chondrocytes through decreasing miR-7-5p in Osteoarthritis rats by targeting ATG4A.

BACKGROUND: Osteoarthritis (OA) is a highly degenerative joint disease, mainly companying with progressive destruction of articular cartilage. Adipose-derived stromal cells (ADSCs) therapy enhances articular cartilage repair, extracellular matrix (ECM) synthesis and attenuates joints inflammation, but specific mechanisms of therapeutic benefit remain poorly understood. This study aimed to clarify the therapeutic effects and mechanisms of ADSCs on cartilage damage in the keen joint of OA rat model. METHODS: Destabilization of the medial meniscus (DMM) and anterior cruciate ligament transection (ACLT) surgery-induced OA rats were treated with allogeneic ADSCs by intra-articular injections for 6 weeks. The protective effect of ADSCs in vivo was measured using Safranin O and fast green staining, immunofluorescence and western blot analysis. Meanwhile, the miRNA-7-5p (miR-7-5p) expression was assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The mechanism of increased autophagy with ADSCs addition through decreasing miR-7-5p was revealed using oligonucleotides, and adenovirus in rat chondrocytes. The luciferase reporter assay revealed the molecular role of miR-7-5p and autophagy related 4A (ATG4A). The substrate of mTORC1 pathway: (p-)p70S6 and (p-)S6 in OA models with ADSCs addition were detected by western blotting. RESULTS: The ADSCs treatment repaired the articular cartilage and maintained chondrocytes ECM homeostasis through modulating chondrocytes autophagy in the OA model, indicators of the change of autophagic proteins expression and autophagic flux. Meanwhile, the increased autophagy induced by ADSCs treatment was closely related to the decreased expression of host-derived miR-7-5p, a negative modulator of OA progression. Functional genomics (overexpression of genes) in vitro studies demonstrate the inhibition of host-derived miR-7-5p in mediating the benefit of ADSCs administration in OA model. Then ATG4A was defined as a target gene of miR-7-5p, and the negative relation between miR-7-5p and ATG4A was investigated in the OA model treated with ADSCs. Furthermore, miR-7-5p mediated chondrocyte autophagy by targeting ATG4A in the OA model treated with ADSCs was confirmed with the rescue trial of ATG4A/miR-7-5p overexpression on rat chondrocyte. Finally, the mTORC1 signaling pathways mediated by host-derived miR-7-5p with ADSCs treatment were decreased in OA rats. CONCLUSIONS: ADSCs promote the chondrocytes autophagy by decreasing miR-7-5p in articular cartilage by targeting ATG4A and a potential role for ADSCs based therapeutics for preventing of articular cartilage destruction and extracellular matrix (ECM) degradation in OA.

Role of hyperbaric oxygen therapy in PDGF-BB-mediated astrogliosis in traumatic brain injury rats associated with ERK1/2 signaling pathway inhibition.

BACKGROUND: Hyperbaric oxygen (HBO) plays positive roles in the therapy of traumatic brain injury (TBI); however, the mechanism underlying its effects on TBI is largely unknown. The study aims to elucidate the molecular mechanism implicated with the interaction between platelet-derived growth factor-BB (PDGF-BB) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway, which may play critical roles during HBO treatment both in the astrocyte scratching model in vitro and rat TBI model in vivo. METHODS: Changes in neurological function and wound healing were evaluated using the neurological severity scores (NSS) scale, immunohistochemistry, western blotting, and qRT-PCR, respectively. RESULTS: The results showed that PDGF-BBi (PDGB interfered with small RNA) dramatically improves neuronal viability in vitro when transfected into the scratched astrocytes derived from the cerebral cortex of neonatal rats. Moreover, in vivo experiments revealed that HBO therapy substantially elevated the NSS scores and simultaneously reduced the mortality in TBI rats, as indicated by the NSS scales. Notably, HBO therapy was found to possess the ability to inhibit glial cell proliferation, promote the regeneration of neurons and synapses, and ultimately facilitate the wound healing, as revealed by immunohistochemistry and glial scar formation found in TBI rats. Importantly, HBO markedly decreased the expression levels of PDGF-BB and ERK1/2. It can clearly be seen that downregulated PDGF-BB and ERK1/2 levels were corresponding with the status of significant amelioration of the therapeutic effect of HBO. Conversely, the upregulation of PDGF-BB and ERK1/2 levels was in line with the opposite effect. CONCLUSION: It has been concluded that HBO therapy may play its active role in TBI treatment dependent on astrogliosis inhibition, which may be achieved by downregulating the ERK1/2 signaling pathway mediated by PDGF-BB.

First-Trimester Evaluation of Cleft Lip and Palate by A Novel Two-Dimensional Sonographic Technique: A Prospective Study.

OBJECTIVES: The study aims to evaluate the value of the mandible transection head-side shifting method (MTHSM) by 2-dimensional sonography in the screening of fetal cleft lip and palate (CLP) during the nuchal translucency scans. METHODS: A total of 7,336 fetuses enrolled for first-trimester aneuploidy screening were included in this prospective study. A sequential scanning approach from the mandible transection toward the head was used for the assessment of the palate in the midsagittal, axial, and coronal sections. Observe the continuity of the palatal line, upper alveolar ridge, and primary palate. All fetuses were followed by second-trimester scans and postnatal evaluation. RESULTS: A total of 18 cases of CLP were identified in the first trimester based on this method. Out of 18, 9 (50.0%) were unilateral CLP, 4 (22.2%) were bilateral CLP, and 5 (27.8%) were median CLP. There were no false-positive results found. Three were missed but confirmed in the second-trimester anomaly scan, including 2 cases of isolated cleft palate (CP) and one of isolated cleft lip (CL). Firsttrimester diagnosis of CLP using MTHSM had a sensitivity of 85.7%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 99.9%. CONCLUSION: The mandible transection head-side shifting method is feasible in assessing CLP at the time of routine first-trimester sonographic screening.

[Research progress on application of artificial intelligence in early diagnosis and prediction of sepsis].

Machine learning based artificial intelligence technology for big data processing has shown great potential in predicting patients' conditions and aiding clinical decisions, and has been widely used in the development of clinical decision support systems in recent years. Sepsis is a life-threatening organ dysfunction caused by host response disorder caused by infection, and its early recognition and treatment can significantly improve the prognosis of patients. At present, there are many deficiencies in the clinical application of sequential organ failure assessment (SOFA), bedside quick sequential organ failure assessment (qSOFA), national early warning score (NEWS), inflammatory indicators, and novel biomarkers for evaluating sepsis. Artificial intelligence has promoted the development of critical care medicine because of its ability to rapidly process and analyze massive data of severe patients. This paper reviews the recent application of artificial intelligence in the early diagnosis and prediction of sepsis, in order to emphasize the importance and limitations of artificial intelligence in the diagnosis and prediction of sepsis.

ADSCs-derived exosomes ameliorate hepatic fibrosis by suppressing stellate cell activation and remodeling hepatocellular glutamine synthetase-mediated glutamine and ammonia homeostasis.

BACKGROUND: Hepatic fibrosis is a common pathologic stage in chronic liver disease development, which might ultimately lead to liver cirrhosis. Accumulating evidence suggests that adipose-derived stromal cells (ADSCs)-based therapies show excellent therapeutic potential in liver injury disease owing to its superior properties, including tissue repair ability and immunomodulation effect. However, cell-based therapy still limits to several problems, such as engraftment efficiency and immunoreaction, which impede the ADSCs-based therapeutics development. So, ADSCs-derived extracellular vesicles (EVs), especially for exosomes (ADSC-EXO), emerge as a promise cell-free therapeutics to ameliorate liver fibrosis. The effect and underlying mechanisms of ADSC-EXO in liver fibrosis remains blurred. METHODS: Hepatic fibrosis murine model was established by intraperitoneal sequential injecting the diethylnitrosamine (DEN) for two weeks and then carbon tetrachloride (CCl4) for six weeks. Subsequently, hepatic fibrosis mice were administrated with ADSC-EXO (10 µg/g) or PBS through tail vein infusion for three times in two weeks. To evaluate the anti-fibrotic capacity of ADSC-EXO, we detected liver morphology by histopathological examination, ECM deposition by serology test and Sirius Red staining, profibrogenic markers by qRT-PCR assay. LX-2 cells treated with TGF-ß (10 ng/ml) for 12 h were conducted for evaluating ADSC-EXO effect on activated hepatic stellate cells (HSCs). RNA-seq was performed for further analysis of the underlying regulatory mechanisms of ADSC-EXO in liver fibrosis. RESULTS: In this study, we obtained isolated ADSCs, collected and separated ADSCs-derived exosomes. We found that ADSC-EXO treatment could efficiently ameliorate DEN/CCl4-induced hepatic fibrosis by improving mice liver function and lessening hepatic ECM deposition. Moreover, ADSC-EXO intervention could reverse profibrogenic phenotypes both in vivo and in vitro, including HSCs activation depressed and profibrogenic markers inhibition. Additionally, RNA-seq analysis further determined that decreased glutamine synthetase (Glul) of perivenous hepatocytes in hepatic fibrosis mice could be dramatically up-regulated by ADSC-EXO treatment; meanwhile, glutamine and ammonia metabolism-associated key enzyme OAT was up-regulated and GLS2 was down-regulated by ADSC-EXO treatment in mice liver. In addition, glutamine synthetase inhibitor would erase ADSC-EXO therapeutic effect on hepatic fibrosis. CONCLUSIONS: These findings demonstrated that ADSC-derived exosomes could efficiently alleviate hepatic fibrosis by suppressing HSCs activation and remodeling glutamine and ammonia metabolism mediated by hepatocellular glutamine synthetase, which might be a novel and promising anti-fibrotic therapeutics for hepatic fibrosis disease.

[Progress on the effect of mesenchymal stem cell derived exosomes on multiple organ dysfunction in sepsis].

Mesenchymal stem cell derived (MSC) exosomes are extracellular vesicles with a diameter of about 50-200 nm. Exosomes contain a large number of biologically active substances including mRNAs, miRNAs, cytokines, chemokines, proteins, lipids, etc. MSC exosomes exert biological effects through paracrine and endocrine pathways in vivo. Uncontrolled inflammation and multiple organ dysfunction are the key roles in the progression of sepsis, moreover, heart, lungs, kidneys and brain are the general target organs to be damaged. MSC exosomes regulate the expression of cytokines, the production of inflammatory cell, the levels of inflammatory response and the recovery of damaged tissues or organ function. Therefore, studying the application of MSC exosomes is significant for the clinical treatment of sepsis. This article reviews the systemic inflammation regulation by MSC exosomes and its protective function on targeted organs such as heart, lungs, kidneys, brain, liver, etc. to provide evidences for the treatment of sepsis.

[Potential regulatory role of long non-coding RNA-microRNA-mRNA axis in sepsis].

Sepsis is a life-threatening multiple organ dysfunction disease with high mortality and has become leading causes of death affecting intensive care unit (ICU) patients. Both long non-coding RNA (lncRNA) and microRNA (miRNA) are involved in the pathophysiological process of sepsis and can regulate the inflammatory response, both of which could be used as important diagnostic indicators and therapeutic targets of sepsis. The interaction among lncRNA, miRNA and mRNA plays an important role in sepsis and multiple organ dysfunction. This paper reviewed the regulatory relationship of lncRNA, miRNA and mRNA, as well as the regulatory role of lncRNA-miRNA-mRNA axis in inflammatory immune response and multiple organ dysfunction syndrome in sepsis, to provide new targets and strategies for the treatment of sepsis and organ dysfunction.

[Role of high mobility group box 1 in intestinal mucosal barrier injury in rat with sepsis induced by endotoxin].

OBJECTIVE: To investigate the role and mechanism of the high mobility group box 1 (HMGB1) in intestinal mucosal barrier injury in rat with sepsis induced by endotoxin lipopolysaccharide (LPS). METHODS: The rats were given intraperitoneal injection of LPS to reproduce a model of sepsis. The effect of HMGB1 inhibitor EP solution (40 mg/kg) on sepsis was observed, and phosphate buffer (PBS) control group was set up. Seventy-two hours after modeling, abdominal aortic blood was obtained, and enzyme-linked immunosorbent assay (ELISA) was used to measure the plasma levels of D-lactic acid and diamine oxidase (DAO) of mucosal barrier permeability. The pathological changes of the intestinal mucosal were observed with light microscope and the Chiu score was recorded. The intestinal mucosal ultrastructural changes were observed with electron microscopy. Real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and Western Blot were used to measure the mRNA and protein expressions of Occludin, inflammatory factor HMGB1 and its downstream signal molecule nuclear transcription factor-κB p65 (NF-κB p65) in the rat small intestine. RESULTS: The results of histopathology and ultrastructure of the small intestine showed that in the LPS group, the intestinal mucosa tissue swelled obviously, part of the glands were incomplete, the infiltration of neutrophils increased, themicrovillus cells were absent, arranged indisorder, and the number of tight connections significantly reduced compared with the PBS control group. The levels of D-lactic acid and DAO indicating mucosal barrier permeability, the levels of inflammatory factor HMGB1 and its downstream signaling molecule NF-κB p65 mRNA and protein expressions in the LPS group were significantly higher than those in the PBS control group, and the mRNA and protein expression of Occludin in the small intestine was significantly lower than that in the PBS control group, suggesting that the intestinal mucosal barrier function in septic rats was damaged, permeability increased, and the structure was damaged. After the administration of the HMGB1 inhibitor EP, the intestinal mucosal barrier damage was significantly improved. The performance was as follows: the Chiu score of the small intestine tissue and the plasma D-lactic acid and DAO levels in the EP intervene group were significantly lower than those in the LPS group [Chiu score: 1.60±0.48 vs. 3.40±0.48, D-lactic acid (mmol/L): 3.30±0.22 vs. 5.30±0.16, DAO (U/L): 23.66±0.97 vs. 30.47±1.11, all P < 0.05]. Occludin mRNA and protein expression levels were significantly higher than those in the LPS group [Occludin mRNA (2-ΔΔCt): 0.82±0.05 vs. 0.37±0.08, Occludin protein (Occludin/ß-actin): 1.04±0.09 vs. 0.75±0.11, both P < 0.05], while the mRNA and protein expression levels of HMGB1 and NF-κB p65 were significantly lower than those in the LPS group [HMGB1 mRNA (2-ΔΔCt): 1.63±0.10 vs. 3.57±0.10, HMGB1 protein (HMGB1/ß-actin): 1.40±0.07 vs. 1.87±0.07; NF-κB p65 mRNA (2-ΔΔCt): 1.47±0.09 vs. 2.62±0.13, NF-ΚB p65 protein (NF-κB p65/ß-actin): 1.24±0.14 vs. 1.60±0.13, all P < 0.05]. CONCLUSIONS: Intestinal mucosal barrier function of septic rats was damaged, permeability increased, and structure was damaged. The mechanism may be that the expression of inflammatory factor HMGB1 was up-regulated and promoted the activation of its downstream signaling molecule NF-κB, thereby mediated the inflammatory cascade reaction and caused damage to the intestinal mucosa.

SDF-1/CXCR4 Augments the Therapeutic Effect of Bone Marrow Mesenchymal Stem Cells in the Treatment of Lipopolysaccharide-Induced Liver Injury by Promoting Their Migration Through PI3K/Akt Signaling Pathway.

Mesenchymal stem cells (MSCs) are thought to have great potential in the therapy of acute liver injury. It is possible that these cells may be regulated by the stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor-4 (CXCR4) signaling axis, which has been shown to promote stem cells migration in the inflammation-associated diseases. However, the effects of SDF-1/CXCR4 axis on the MSCs-transplantation-based treatment for acute liver injury and the underlying mechanisms are largely unknown. In this study, we sought to determine whether SDF-1/CXCR4 would augment the therapeutic effect of bone marrow mesenchymal stem cells (BMSCs) by promoting their migration, which may result from activating the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway, in a rat acute liver injury model induced by lipopolysaccharide (LPS). We found that BMSCs transplantation markedly attenuated liver injury and improved the survival of LPS-treated rats. Of interest, overexpression of CXCR4 in BMSCs could substantially promote their migration both in vitro and in vivo, and result in even better therapeutic effects. This might be attributed to the activation of PI3K/Akt signaling pathway in BMSCs that is downstream of CXCR4, as demonstrated by the use of the CXCR4 antagonist AMD3100 and PI3K pathway inhibitor LY294002 assays in vitro and in vivo. Together, our results unraveled a novel molecular mechanism for the therapeutic effect of BMSCs for the treatment of acute liver injury, which may shed a new light on the clinical application of BMSCs for acute liver failure.

DPYSL2 is a novel regulator for neural stem cell differentiation in rats: revealed by Panax notoginseng saponin administration.

BACKGROUND: The limited neuronal differentiation of the endogenous or grafted neural stem cells (NSCs) after brain injury hampers the clinic usage of NSCs. Panax notoginseng saponins (PNS) were extensively used for their clinical value, such as in controlling blood pressure, blood glucose, and inhibiting neuronal apoptosis and enhancing neuronal protection, but whether or not it exerts an effect in promoting neuronal differentiation of the endogenous NSCs is completely unclear and the potential underlying mechanism requires further exploration. METHODS: Firstly, we determined whether PNS could successfully induce NSCs to differentiate to neurons under the serum condition. Mass spectrometry and quantitative polymerase chain reaction (Q-PCR) were then performed to screen the differentially expressed proteins (genes) between the PNS + serum and serum control group, upon which dihydropyrimidinase-like 2 (DPYSL2), a possible candidate, was then selected for the subsequent research. To further investigate the actual role of DPYSL2 in the NSC differentiation, DPYSL2-expressing lentivirus was employed to obtain DPYSL2 overexpression in NSCs. DPYSL2-knockout rats were constructed to study its effects on hippocampal neural stem cells. Immunofluorescent staining was performed to identify the differentiation direction of NSCs after 7 days from DPYSL2 transfection, as well as those from DPYSL2-knockout rats. RESULTS: Seven differentially expressed protein spots were detected by PD Quest, and DPYSL2 was found as one of the key factors of NSC differentiation in a PNS-treated condition. The results of immunostaining further showed that mainly Tuj1 and GFAP-positive cells increased in the DPYSL2-overexpressed group, while both were depressed in the hippocampal NSCs in the DPYSL2-knockout rat. CONCLUSIONS: The present study revealed that the differentiation direction of NSCs could be enhanced through PNS administration, and the DPYSL2 is a key regulator in promoting NSC differentiation. These results not only emphasized the effect of PNS but also indicated DPYSL2 could be a novel target to enhance the NSC differentiation in future clinical trials.

[Role of HMGB1-RAGE/TLRs-NF-κB signaling pathway on bone mesenchymal stem cells transplantation therapy for lipopolysaccaride-induced coagulation disorder rats].

OBJECTIVE: To determine the effect of bone mesenchymal stem cells (BMSCs) in transplantation therapy for lipopolysaccharide (LPS)-induced coagulation disorder and the underlying mechanism of high mobility group protein B1-receptors for advanced glycation end products/Toll-like receptors-nuclear factor-κB (HMGB1-RAGE/TLRs-NF-κB) signaling pathway. METHODS: BMSCs of female Sprague-Dawley (SD) rats ageing 4-5 weeks old were extracted and cultivated in vitro, and the fourth-passaged BMSCs phenotype was identified by flow cytometry for transplantation in the following experimental study. The rats were randomly divided into normal saline (NS) control group, LPS group, and BMSC group according to the random number table with 15 rats in each group. Coagulation disorders model was reproduced by injection of 1 mg/kg LPS via saphenous vein, and the rats in the NS control group was injected with equal volume NS. Those in the BMSC group were infused BMSC 0.5 mL containing 1×106 cells via tail vein at 2 hours after LPS injection, and the rats in other groups were injected with equal volume NS. Abdominal aorta blood was collected at 1, 3 and 7 days post operation. Coagulation indexes such as platelet count (PLT), platelet volume distribution width (PDW), mean platelet volume (MPV), plateletcrit (PCT), platelet large cell ratio (P-LCR), activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), international normalized ratio (INR), and fibrinogen (FIB) were determined. The mRNA levels and contents of HMGB1, RAGE, TLR2/4 and NF-κB were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: (1) The cells cultured in vitro were spindle shaped or flat. The fourth-passaged BMSCs phenotype was successfully identified by flow cytometry technology. (2) Coagulation indexes: compared with NS control group, PLT, PCT and FIB in LPS group were significantly decreased, PDW, MPV, P-LCP, and INR were significantly increased, and APTT, PT, and TT were significantly prolonged from the first day. Furthermore, those in LPS group were gradually ameliorated with prolongation of LPS induction time. The coagulation function abnormality induced by LPS was reversed by BMSCs with significant difference at 1 day as compared with LPS group [PLT (×109/L): 398.8±17.9 vs. 239.1±15.8, PCT (%): 0.35±0.04 vs. 0.23±0.06, FIB (g/L): 1.7±0.6 vs. 0.8±0.1, PDW (%): 12.4±1.6 vs. 16.2±1.5, MPV (fl): 11.0±1.6 vs. 13.7±1.1, P-LCP (%): 13.0±2.1 vs. 15.3±2.7, INR: 1.52±0.17 vs. 1.82±0.19, APTT (s): 66.3±4.1 vs. 89.5±4.5, PT (s): 18.3±0.7 vs. 25.1±1.9, TT (s): 87.5±7.8 vs. 115.0±9.7, all P < 0.05], till 7 days. (3) HMGB1-RAGE/TLRs-NF-κB signaling pathway related molecules: compared with NS control group, the mRNA expressions and contents of HMGB1, RAGE, TLR2/4 and NF-κB were significantly increased in LPS group from the first day. However, the mRNA expressions and contents of the molecules in LPS group were gradually decreased with prolongation of LPS induction time. After BMSC intervention, the mRNA expressions and contents of molecules at 1 day were significantly lower than those of LPS group [HMGB1 mRNA (2-ΔΔCt): 10.77±0.04 vs. 24.51±3.69, HMGB1 content (µg/L): 0.48±0.01 vs. 0.95±0.06; RAGE mRNA (2-ΔΔCt): 11.57±1.11 vs. 18.08±0.29, RAGE content (µg/L): 0.73±0.04 vs. 1.37±0.06; TLR2 mRNA (2-ΔΔCt): 2.60±0.22 vs. 12.61±0.27, TLR2 content (µg/L): 0.81±0.03 vs. 1.59±0.09; TLR4 mRNA (2-ΔΔCt): 2.95±0.52 vs. 4.06±0.11, TLR4 content (µg/L): 0.80±0.09 vs. 1.18±0.11; NF-κB mRNA (2-ΔΔCt): 1.29±0.06 vs. 7.79±0.25, NF-κB content (µg/L): 1.22±0.24 vs. 2.42±0.26, all P < 0.05], till 7 days. CONCLUSIONS: BMSCs administration could ameliorate the coagulation function in LPS-induced coagulation disorder rats and these might be associated with HMGB1-RAGE/TLRs-NF-κB signaling pathway inhibition.

The role of HMGB1 in BMSC transplantation for treating MODS in rats.

The effect of bone marrow mesenchymal stem cells (BMSCs) in treatment for multiple organ dysfunction syndrome (MODS) remains unknown and the mechanism is still unclear. Therefore, the goal of this study is to investigate the effects of intracellular high mobility group box 1 protein (HMGB1) on BMSCs treating for MODS. The rats were given 15% blood loss plus 1 mg/kg lipopolysaccharide (LPS) via lower extremity superficial venous, then randomly allocated into four groups: sham group, MODS group, MODS plus BMSC group, MODS plus ethyl pyruvate (EP) group, MODS plus BMSCs plus EP group. Twenty-four hours later, rats in groups were sacrificed and then the blood and tissues were collected to evaluate the changes of tissue histopathology, cell apoptosis, inflammation level and organ function. The HGMB1 expression was monitored by RT-qPCR and Western blot. The expression of RAGE/TLR2/TLR4 and NF-κB at the protein levels was also assessed. BMSCs and/or EP exhibits an outstanding protective effect against LPS-induced histopathological injury by improving cell apoptosis, inflammatory response and the organ dysfunction but no effect on BMSC homing to the injury site. Moreover, BMSCs and/or EP inhibited LPS-induced upregulation of HMGB1, RAGE, TLR2 and TLR4 expression at protein levels and compromised p65 phosphorylation in the rat model of MODS. These findings suggest that HMGB1 is involved in BMSC treatment for MODS, through regulation of the TLR2, TLR4-mediated NF-κB signal pathway. It suggests that HMGB1 is an attractive potential target for the development of new therapeutic strategies for MODS.

Role of Bone Marrow Mesenchymal Stromal Cells in Attenuating Inflammatory Reaction in Lipopolysaccaride-induced Acute Kidney Injury of Rats Associated with TLR4-NF-κB Signaling Pathway Inhibition.

Bone marrow mesenchymal stromal cells (BMSCs) have positive therapeutic effects on inflammation associated diseases. However, the underlying mechanism is largely unknown. This study was conducted to investigate whether BMSCs could alleviate the inflammation reaction in lipopolysaccaride (LPS)-induced acute kidney injury (septic-AKI) of rats via inhibition of toll-like receptors (TLR4)-nuclear factor-kappa B (NF-κB) signaling pathway. The septic-AKI rat model was established by injecting the 1ml/mg LPS through the femoral vein. Based on this model, rats were subjected to BMSC transplantation, PDTC (a kind of NF-κB inhibitor) administration alone, and combined treatment of the first two together. Results showed that LPS treatment caused the increases of the concentration of blood urea nitrogen (BUN) and serum creatinine (SCr), accompanied by tissue injury and the up-regulation of TLR4 and NF-κB, that was its key downstream signaling molecule, in both mRNA and protein level. Notably, it has been found that BMSCs transplantation significantly reversed the already upregulated concentration of BUN and SCr, dramatically attenuated the event of the tissue injury, and prominently reduced mortality after AKI. These were paralleled by down-regulation of the level of TLR4 and NF-κB. These effects of BMSCs transplantation were similar to those of PDTC treatment. Importantly, the effects in the combination therapy of BMSCs transplantation and PDTC group were much stronger than those of either BMSCs or PDTC used alone. These findings suggest that BMSCs transplantation contributes to therapeutic effects in LPS-induced AKI rat model, and that the most obvious effects occurred in the combined treatment group, with BMSCs and PDTC together, which was tightly associated with inhibition of the TLR4-NF-κB signaling pathway.

[Bone marrow mesenchymal stem cells modulated the inflammatory response by regulating the expression of IL-4 and RAGE products in the rats with MODS].

OBJECTIVE: To investigate the underlying mechanism of bone marrow mesenchymal stem cells (BMSC) modulating the inflammatory response during the multiple organ dysfunction syndrome (MODS), especially the expression of inflammatory cytokines, which will provide new theoretical and experimental basis of MODS in clinic. METHODS: BMSC of Sprague-Dawley (SD) rat (female, 4 weeks) was extracted and cultivated, and the 4th passage were used in experimental study. According to the random number table, 60 female SD rats were divided into three groups (n = 20 per group): sham group, MODS group, BMSC group. MODS model in rats was induced by lipopolysaccaride (LPS, 1 mg/kg) via femoral vein injection. Sham group was injected with the sterile phosphate buffer saline (PBS) in the same volume. BMSC group, in which BMSC infusion was started at 2 hours after 0.5 mL LPS stimulation (1×106/cells) through the tail vein. The survival rate was observed after 72 hours in each group. Abdominal aortic blood was collected for routine blood and biochemical examination at 72 hours after operation. Protein microarray was used to detect the related 34 inflammatory cytokines. Signal ratio was defined as the differentially expressed factors when it was more than 2.0 or less than 0.5. And enzyme linked immunosorbent assay (ELISA) was be applied to validate the significant inflammation factor. Meanwhile, the heart, kidney, intestine tissue was harvested, then their pathological changes were observed by hematoxylin eosin (HE) staining. RESULTS: 20, 12, 16 rats lived in sham group, MODS group and BMSC group respectively at 72 hours after operation. Compared with the sham group, the indicators (routine blood, liver and kidney function, myocardial enzyme) were apparently unusual, and the heart, kidney, intestine tissue were injured obviously in the MODS group. After BMSC administration, the organ function was improved and tissue damaged was alleviated significantly. Protein microarray showed that interleukin-4 (IL-4) and receptor for advanced glycation end products (RAGE) were significantly different in 34 goal cytokines. The signal ratio change of IL-4 was 0.397, 1.124, 2.826 respectively, and the signal ratio of RAGE was 6.197, 1.552, 0.250, respectively in MODS/sham group, BMSC/sham group, BMSC/MODS group. ELISA validated the result that the expression level of IL-4 decreased significantly (ng/L: 3.59±1.21 vs. 29.10±5.78) and the expression level of RAGE increased significantly (ng/L: 1.09±0.04 vs. 0.11±0.03) in MODS group as compared with sham group (both P < 0.05). Compared with the MODS group, the level of IL-4 was obviously higher than that in BMSC group (ng/L: 9.59±2.21 vs. 3.59±1.21, P < 0.01), and RAGE decreased significantly (ng/L: 0.29±0.07 vs. 1.09±0.04, P < 0.05). CONCLUSIONS: BMSC administration can regulate the expression of IL-4 and RAGE in the rats subjected to MODS. Moreover, BMSC can promote the restoration of tissue and organ function, thus improve the survival rate. BMSC may be the target in cell therapy for the inflammatory disease.