Single-cell RNA sequencing deciphers the mechanism of sepsis-induced liver injury and the therapeutic effects of artesunate.

Liver, as an immune and detoxification organ, represents an important line of defense against bacteria and infection and a vulnerable organ that is easily injured during sepsis. Artesunate (ART) is an anti-malaria agent, that also exhibits broad pharmacological activities including anti-inflammatory, immune-regulation and liver protection. In this study, we investigated the cellular responses in liver to sepsis infection and ART hepatic-protective mechanisms against sepsis. Cecal ligation and puncture (CLP)-induced sepsis model was established in mice. The mice were administered ART (10 mg/kg, i.p.) at 4 h, and sacrificed at 12 h after the surgery. Liver samples were collected for preparing single-cell RNA transcriptome sequencing (scRNA-seq). The scRNA-seq analysis revealed that sepsis-induced a dramatic reduction of hepatic endothelial cells, especially the subtypes characterized with proliferation and differentiation. Macrophages were recruited during sepsis and released inflammatory cytokines (Tnf, Il1b, Il6), chemokines (Ccl6, Cd14), and transcription factor (Nfkb1), resulting in liver inflammatory responses. Massive apoptosis of lymphocytes and abnormal recruitment of neutrophils caused immune dysfunction. ART treatment significantly improved the survival of CLP mice within 96 h, and partially relieved or reversed the above-mentioned pathological features, mitigating the impact of sepsis on liver injury, inflammation, and dysfunction. This study provides comprehensive fundamental proof for the liver protective efficacy of ART against sepsis infection, which would potentially contribute to its clinical translation for sepsis therapy. Single cell transcriptome reveals the changes of various hepatocyte subtypes of CLP-induced liver injury and the potential pharmacological effects of artesunate on sepsis.

[Platelet function tests and Chinese medicines with antiplatelet function:a review].

Platelet function tests have been increasingly used to assist in the diagnosis of platelet disorders and prethrombotic state, monitoring of the efficacy of antiplatelet therapies, and personalized treatment. On the basis of light transmission aggregometry, new methods for platelet function test have been developed successively. At present, the research and development of platelet function detector is in its infancy in China. The active constituents of antiplatelet Chinese medicines can be classified into terpenoids, flavonoids, saponins, organic acids, lignans, diketones, volatile oils, and stilbenes. The results of dose-antiplatelet effect relationship of Chinese medicines and the active constituents showed that the effective concentration of the extracts or monomers of Chinese medicines was at micromolar level(µmol·L~(-1)), among which salvianolic acid B and ginkgolide K, ginkgolide B, and ginkgolide A had the strongest antiplatelet effect. These results suggest that the antiplatelet effect of Chinese medicine may be weaker than that of chemical drugs and biological products. Therefore, it is necessary to explore the structure-activity relationship of the active constituents in existing Chinese medicines and further improve their efficacy through structure modification. The antiplatelet effect of Chinese medicines and the constituents involves multiple pathways and multiple targets. These research results provide a reference for clinical application of them. However, there is still a lack of large-scale multi-center clinical trials to confirm the efficacy and safety of them. The regularity of the relationship between the structures of various constituents and their corresponding functions is still unknown and the relevant signal transduction pathways and structure-activity relationship need to be further studied. This paper summarized and analyzed the determination methods of platelet functions and the research results of antiplatelet Chinese medicines, which is of reference value for the research of effective and safe antiplatelet Chinese medicines.

[Effects of Xueshuantong Injection on thrombosis formation and blood flow in rats].

The aim of this paper was to explore the effect of Xueshuantong Injection(freeze-dried powder,XST) on κ-carrageenan-induced thrombosis and blood flow from the aspects of interactions among blood flow,vascular endothelium and platelets. Fifty male Sprague-Dawley rats(190-200 g) were randomized into five groups: control group, model group, heparin sodium(1 000 U·kg~(-1)) group, low-dose and high-dose(50, 150 mg·kg~(-1)) XST groups. Rats were intraperitoneally injected with corresponding drugs and normal saline(normal control and model groups) for 10 days. One hour after drugs were administered intraperitoneally on the 7 th day, each rat was injected with κ-carrageenan(Type Ⅰ, 1 mg·kg~(-1)) which was dissolved in physiological saline by intravenous administration in the tail to establish tail thrombus model. The lengths of black tails of the rats were measured at 2, 6, 24 and 48 h after modeling. Vevo®2100 small animal ultrasound imaging system was used to detect the internal diameter of rat common carotid artery, blood flow velocity and heart rate, and then the blood flow and shear rate were calculated. Meanwhile, the microcirculatory blood flow perfusion in the thigh surface and tail of rats were detected by laser speckle blood flow imaging system. Platelet aggregometry was used to detect the max platelet aggregation rate in rats. Pathological changes in tail were observed through hematoxylin-eosin staining, and Western blot was used to detect the protein content of platelet piezo1. According to the results, XST could inhibit the rat tail arterial thrombosis and significantly reduce the length of black tail(P<0.05). The blood flow of common carotid artery in XST low dose group was significantly higher than that in the model group(P<0.05). XST high dose group could significantly increase the microcirculatory blood flow perfusion of the tail in rats as compared with the model group(P<0.05). XST high dose group could significantly inhibit platelet aggregation rate(P<0.05) and XST low dose group could significantly inhibit platelet piezo1 protein expression(P<0.01). In summary, XST could play an effect in fighting against thrombosis induced by κ-carrageenan in rats, which may be related to significantly inhibiting platelet aggregation, improving body's blood flow state, maintaining normal hemodynamic environment and affecting mechanical ion channel protein piezo1.

[Development of bioassay method in quality control of traditional Chinese medicine].

On the basis of chemical content determination， the bioassay methods can be used to comprehensively evaluate and control the Chinese medicine compound. This paper analyzed the newly published literature on traditional Chinese medicine(TCM) bioassay. The selection of standard control substances and the establishment of experimental system are the main difficulties in bioassay. At present， the standard control substances mainly include： different sources of products with basically similar components， certified medicinal materials， genuine medicinal materials， commonly used chemical drugs or biological products with similar pharmacological functions， as well as Chinese medicine potency conversed by activity of biological products. In this paper， the common bioassays would be summarized from the clinical efficacy of activating blood circulation and removing stasis and clearing heat and detoxification. It is one of the important contents in the industrial production of traditional Chinese medicine to gradually establish the bioassay platform of Chinese medicine from the enterprise's internal control to the industry. recognition.

[Anti-platelet adhesive effect and mechanisms of Xueshuantong capsules under flow conditions].

To investigate the anti-platelet adhesive effect and possible mechanisms of Xueshuantong capsule (XST) under flow conditions. Human umbilical vein endothelial cells (HUVECs) and human platelets were employed as experimental materials, and TNF-α (20 µg•L⁻¹) was used to establish vascular endothelial cell injury models. In vivo flow conditions were simulated under controlled shear stress of 0.1 Pa and 0.9 Pa by Bioflux1000 assays accordingly. Anti-platelet adhesive effects of XST at 0.3 g•L⁻¹ were dynamically monitored by microscopic time-lapse photography. Western blotting was employed to detect the VCAM-1 expression on endothelial cells, and the release of 6-keto-PGF1α and TXB2 was tested by radioimmunoassay. The results showed that XST could inhibit the platelets adhesion under both physiological and pathological flow conditions, and the inhibition rate was 15.0% and 34.1% respectively. Under pathological low shear stress or static conditions, XST could significantly inhibit endothelial cells VCAM-1 expression and TXB2 release (P<0.05). These results suggested that XST inhibited platelets adhering to injured endothelium via decreasing VCAM-1 expression and TXA2 secretion from endothelium. From the interactions among blood flow, vascular endothelium and platelets, the anti-thrombosis effects of XST were possibly related to endothelial cells protection and therefore inhibiting platelets adhesion. Under different flow conditions, the antiplatelet adhesion effect of XST was different, and the pathological low shear stress was more conducive to the efficacy of XST.

[Anti-platelet aggregation bioassay based quality control for XST capsules].

A in vitro platelet aggregation bioassay was developed for the quality control of XST capsules. The in vitro anti-platelet aggregation effect in rats was observed to detect the bioactivity of XST capsules. Panax notoginseng saponins and Xuesaitong lyophilizedpowder for injection were taken as standard control substances to determine the potency. According to the results, XST capsules showeda significant inhibitory effect on thrombin-induced platelet aggregation in a dose-dependent manner. The in vitro anti-platelet activity oflyophilized powder for injection was stabler than that of Panax notoginseng saponins, and so suitable to serve as a standard control substance. The biological potency of XST capsules compared with standard control substance was detected by using parallel line assay. According to the results, the established bioassay method had a good repeatability (RSD 2.92%). The sample test results could pass thereliability test(linear deviation P > 0.05, parallel deviation P > 0.05). This bioassay method could be used as one of the complementary quality control methods for XST capsules.

Effect of notoginsenoside R1 on hepatic microcirculation disturbance induced by gut ischemia and reperfusion.

AIM: To assess the effect of notoginsenoside R1 on hepatic microcirculatory disturbance induced by gut ischemia/reperfusion (I/R) in mice. METHODS: The superior mesenteric artery (SMA) of C57/BL mice was ligated for 15 min to induce gut ischemia followed by 30-min reperfusion. In another set of experiments, R1 was continuously infused (10 mg/kg per hour) from 10 min before I/R until the end of the investigation to study the influence of R1 on hepatic microcirculatory disturbance induced by gut I/R. Hepatic microcirculation was observed by inverted microscopy, and the vascular diameter, red blood cell (RBC) velocity and sinusoid perfusion were estimated. Leukocyte rolling and adhesion were observed under a laser confocal microscope. Thirty and 60 min after reperfusion, lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate transaminase (AST) in peripheral blood were determined. The expression of adhesion molecules CD11b/CD18 in neutrophils and tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1) in plasma were evaluated by flow cytometry. E-selectin and intercellular adhesion molecule-1 (ICAM-1) in hepatic tissue were examined by immunofluorescence. RESULTS: After gut I/R, the diameters of terminal portal venules and central veins, RBC velocity and the number of perfused sinusoids were decreased, while the leukocyte rolling and adhesion, the expression of E-selectin in hepatic vessels and CD18 in neutrophils, IL-6, MCP-1, LDH, ALT and AST were increased. R1 treatment attenuated these alterations except for IL-6 and MCP-1. CONCLUSION: R1 prevents I/R-induced hepatic microcirculation disturbance and hepatocyte injury. The effect of R1 is related to its inhibition of leukocyte rolling and adhesion by inhibiting the expression of E-selectin in endothelium and CD18 in neutrophils.

Protective effect of tetramethylpyrazine and salvianolic acid B on apoptosis of rat cerebral microvascular endothelial cell under high shear stress.

Apoptosis induced by high shear stress has been reported for the dysfunction of various vascular endothelial cells. We investigated the protective effects of tetramethylpyrazine (TMP) and salvianolic acid B (SAB) from Chinese medicine on the shear-induced early and late stages of apoptosis in cultured rat cerebral microvascular endothelial cells (rCMECs) under pathological high shear stress. Near-confluent cultures of rCMECs were pretreated with TMP or SAB and their combinational dosages, and exposed to high shear stress generated by a rheometer. Apoptotic death rate of rCMECs was assessed by immunofluorescence microscopy of Annexin V-FITC and propidium iodide (PI). We found that early and late stage apoptosis occurred at 3.0 Pa for a short duration of 450 sec but did not occur at 1.5 Pa. SAB inhibited the cells from apoptosis at concentrations from 10 microM to 20 microM in a dose-dependent manner, while effect of TMP at 0.37 mM and 0.73 mM did not significantly differ. Moreover, the combined use of TMP and SAB had synergistic anti-apoptotic effects (P<0.01). The results indicate that the anti-apoptotic effect of TMP and SAB on rheologically induced endothelial injury is likely involved in their efficacy.

Improving effect of post-treatment with Panax notoginseng saponins on lipopolysaccharide-induced microcirculatory disturbance in rat mesentery.

Panax notoginseng saponin (PNS) is the collective of the major effective components of Panax notoginseng. The present study intended to explore the effect of post-treatment of PNS on rat mesentery microcirculatory disturbance induced by lipopolysaccharide (LPS) continuous challenge. By virtue of a microcirculation observation system, the vascular hemodynamics were determined continuously until 60 min of LPS (2 mg/kg/h) infusion through the left femoral vein. After observation, blood was taken for assessment of the expression of CD11b/CD18 in neutrophils and the concentration of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interferon-gamma (INF-gamma) in plasma with flow-cytometry. The number of leukocytes adherent to venular wall, the intensity of hydrogen peroxide dependent dihydrorhodamine 123 (DHR) fluorescence in the venular walls and albumin leakage from venules were increased impressively after 20 min of LPS infusion, the RBCs velocity diminished after 30 min, and degranulated mast cells increased remarkably after 60 min. Post-treatment with PNS (5 mg/kg/h) through the left jugular vein from 20 min of LPS exposure resulted in significant reduction in the number of adherent leukocytes, degranulation of mast cell, expression of CD11b and the concentration of IL-6, INF-gamma, while had no influence on the intensity of DHR fluorescence and albumin leakage. The results suggested that post-treatment with PNS significantly attenuated microcirculatory disturbance induced by LPS.

[Recent pharmacological study on sanshengwan decoction].

OBJECTIVE: To investigate the pharmacological function of Sanshengwan decoction with modern medical and rheological techniques, and also to discuss the differences between injury blood stasis syndrome and yang deficiency blood stasis syndrome. METHOD: Animal model for injury blood stasis syndrome was found by bruise; Animal model for yang deficiency blood stasis syndrome was done by exhausting the animals in a - 15 degrees C freezer for 4 hours. RESULT: Blood fibrinogen content, platelet aggregation and blood coagulation time were significantly increased, plasma viscosity and blood coagulation slope was significantly decreased in injury blood stasis syndrome group. Blood fibrinogen content, platelet aggregation and blood coagulation time were dropped markedly. Blood coagulation slope was raised noticeably in yang deficiency blood stasis syndrome group. Sanshengwan decoction behaved very good effects on removing blood stasis on both of the two kinds of animal models. CONCLUSION: Though hemorheological index and experimental data in the two kinds of animal models were behaved statistically significance, but the experimental representative indexes were obviously difference. Sanshengwan the tipical herbal medicine for eliminating blood stasis syndrome showed significantly effects on both of the two kinds of animal models, but the effects on injury blood stasis syndrome group was better than the other animal model's.

Specific inhibiting effects of Ilexonin A on von Willebrand factor-dependent platelet aggregation under high shear rate.

BACKGROUND: Ilexonin A (IA), purified from the Chinese herbal medicine Maodongqing (Ilex pubescens Hook, et Arn) has been commonly used in south China to treat thrombotic disorders. In this study, we aimed to study the inhibiting effects and mechanism of IA on von Willebrand factor (vWF)-dependent high shear-induced platelet aggregation. METHODS: vWF-dependent high shear (10,800 s(-1)) induced aggregation of platelets obtained from normal donors in the presence or absence of IA was measured by a modified cone-plate viscometer and shear-induced vWF binding was measured by quantitative flow cytometry with monoclonal antibody known to bind exclusively to the C-terminal domain of vWF (LJ-C3) directly labeled with fluorescein isothiocyanate (FITC). P-selectin surface expression was also measured by a similar method with FITC conjugated anti-P-selectin monoclonal antibody (WGA1). RESULTS: Shear-induced platelet aggregation was inhibited by IA in a dose-dependent manner. The extent of aggregation decreased from (78.6 +/- 4.6)% in the absence of IA to (36.5 +/- 2.1)% in the presence of IA (3.3 mmol/L) (P < 0.0001, n = 9) with a high shear rate of 10800 s(-1). vWF binding and P-selectin expression were also inhibited by IA in a dose dependent manner. The number of binding FITC-LJ-C3 molecules increased after exposure of platelet-rich plasma to a high shear rate of 10800 s(-1) for 6 minutes, but this shear-induced increased binding platelet surface vWF molecules and P-selectin expression can be decreased in the presence of IA. CONCLUSION: vWF binding and vWF mediated platelet activation, aggregation occurring under high shear rate were inhibited by IA. IA may be a unique antithrombotic drug inhibiting the vWF-GP Ibalpha interaction, and may thus facilitate drug design targeting arterial thrombosis.

Icariside II improves cerebral microcirculatory disturbance and alleviates hippocampal injury in gerbils after ischemia-reperfusion.

OBJECTIVE: the purpose of the present study was to examine the protective effect of Icariside II (IS) on cerebral microcirculatory disturbance and neuronal injury in hippocampal CA1 region induced by global cerebral I/R and the underlying mechanism. METHODS: male Mongolian gerbils (50-70 g) were subjected to bilateral common carotid arteries occlusion for 30 min and followed by reperfusion for 72 h. IS (20 mg/kg) was administered orally 2 h before ischemia and 6, 24, 48, 70 h after reperfusion. After 72 h of reperfusion, the leukocyte adhesion, albumin leakage, and velocity of RBC in the venules were determined with an upright microscope. Neuronal injury in hippocampal CA1 region was assessed by Nissl staining and the in situ TUNEL assay. Bax, Bcl-2, and cleaved caspase-3 proteins were detected by Western blot, and MDA content and complex I activity by ELISA assay in hippocampus. RESULTS: IS inhibited I/R-elicited leukocyte adhesion, albumin leakage and increased the velocity of RBC in cerebral venules. IS down-regulated Bax and cleaved caspase-3 expression, up-regulated Bcl-2 expression of hippocampus and decreased the number of TUNEL positive neurons and the neuronal loss induced by I/R in hippocampal CA1 region. In addition, IS could increase the activity of complex I and decrease the production of MDA after I/R. CONCLUSIONS: IS could alleviate the microcirculatory disturbance and neuronal injury in hippocampal CA1 region induced by global cerebral I/R, which might involve regulating complex I activity.

Total salvianolic acid improves ischemia-reperfusion-induced microcirculatory disturbance in rat mesentery.

AIM: To investigate the effect of total salvianolic acid (TSA) on ischemia-reperfusion (I/R)-induced rat mesenteric microcirculatory dysfunctions. METHODS: Male Wistar rats were randomly distributed into 5 groups (n = 6 each): Sham group and I/R group (infused with saline), TSA group, TSA + I/R group and I/R + TSA group (infused with TSA, 5 mg/kg per hour). Mesenteric I/R were conducted by a ligation of the mesenteric artery and vein (10 min) and subsequent release of the occlusion. TSA was continuously infused either starting from 10 min before the ischemia or 10 min after reperfusion. Changes in mesenteric microcirculatory variables, including diameter of venule, velocity of red blood cells in venule, leukocyte adhesion, free radicals released from venule, albumin leakage and mast cell degranulation, were observed through an inverted intravital microscope. Meanwhile, the expression of adhesion molecules CD11b/CD18 on neutrophils was evaluated by flow cytometry. Ultrastructural evidence of mesenteric venules damage was assessed after microcirculation observation. RESULTS: I/R led to multiple responses in mesenteric post-capillary venules, including a significant increase in the adhesion of leukocytes, production of oxygen radicals in the venular wall, albumin efflux and enhanced mast cell degranulation in vivo. All the I/R-induced manifestations were significantly reduced by pre- or post-treatment with TSA, with the exception that the I/R-induced increase in mast cell degranulation was inhibited only by pre-treatment with TSA. Moreover, pre- or post-treatment with TSA significantly attenuated the expression of CD11b/CD18 on neutrophils, reducing the increase in the number of caveolae in the endothelial cells of mesentery post-capillary venules induced by I/R. CONCLUSION: The results demonstrated that TSA protects from and ameliorates the microcirculation disturbance induced by I/R, which was associated with TSA inhibiting the production of oxygen-free radicals in the venular wall and the expression of CD11b/CD18 on neutrophils.