STELLATE GANGLION BLOCK REVERSES PHSML-INDUCED VASCULAR HYPOREACTIVITY THROUGH INHIBITING AUTOPHAGY-MEDIATED PHENOTYPIC TRANSFORMATION OF VSMCs.

ABSTRACT: Posthemorrhagic shock mesenteric lymph (PHSML) return-contributed excessive autophagy of vascular smooth muscle cells (VSMCs) is involved in vascular hyporeactivity, which is inhibited by stellate ganglion block (SGB) treatment. The contractile phenotype of VSMCs transforms into a synthetic phenotype after stimulation with excessive autophagy. Therefore, we hypothesized that SGB ameliorates PHSML-induced vascular hyporeactivity by inhibiting autophagy-mediated phenotypic transformation of VSMCs. To substantiate this hypothesis, a hemorrhagic shock model in conscious rats was used to observe the effects of SGB intervention or intravenous infusion of the autophagy inhibitor 3-methyladenine (3-MA) on intestinal blood flow and the expression of autophagy- and phenotype-defining proteins in mesenteric secondary artery tissues. We also investigated the effects of intraperitoneal administration of PHSML intravenous infusion and the autophagy agonist rapamycin (RAPA) on the beneficial effect of SGB. The results showed that hemorrhagic shock decreased intestinal blood flow and enhanced the expression of LC3 II/I, Beclin 1, and matrix metalloproteinase 2, which were reversed by SGB or 3-MA treatment. In contrast, RAPA and PHSML administration abolished the beneficial effects of SGB. Furthermore, the effects of PHSML or PHSML obtained from rats treated with SGB (PHSML-SGB) on cellular contractility, autophagy, and VSMC phenotype were explored. Meanwhile, the effects of 3-MA on PHSML and RAPA on PHSML-SGB were observed. The results showed that PHSML, but not PHSML-SGB, incubation decreased VSMC contractility and induced autophagy activation and phenotype transformation. Importantly, 3-MA administration reversed the adverse effects of PHSML, and RAPA treatment attenuated the effects of PHSML-SGB incubation on VSMCs. Taken together, the protective effect of SGB on vascular reactivity is achieved by inhibiting excessive autophagy-mediated phenotypic transformation of VSMCs to maintain their contractile phenotype.

Analysis and Identification of Ferroptosis-Related Gene Signature for Acute Lung Injury.

BACKGROUND: Recent studies have shown that ferroptosis is involved in the evolution of acute lung injury (ALI), a serious respiratory pathological process leading to death. However, the regulatory mechanisms underlying ferroptosis in ALI remain largely unknown. The current study analyzed and identified a ferroptosis-related gene signature for ALI. METHODS: Key genes associated with ferroptosis in ALI were identified by bioinformatics analysis. GSE104214, GSE18341, and GSE17355 datasets were downloaded from the Gene Expression Omnibus database. The signature genes were screened by least absolute shrinkage and selection operator (LASSO) regression, and the key genes of ALI were screened by weighted correlation network analysis (WGCNA), followed by immune infiltration analysis and functional enrichment analysis. In addition, mRNA expression of key genes in the lungs of mice with hemorrhagic shock and sepsis was verified. RESULTS: A total of 2132 differential genes were identified by various analyses, and nine characteristic genes were detected using Lasso regression. We intersected nine signature genes with WGCNA module genes and finally determined four key genes (PROK2, IL6, TNF, SLC7A11). All four key genes were closely correlated with immune cells and regulatory genes of ALI, and the expression of the four genes was significantly different in the lung tissues of hemorrhagic shock and sepsis models. Besides, the ferroptosis related molecules GPX4 and ACSL4 showed remarkable difference in these models. CONCLUSION: These results indicate that PROK2, IL6, TNF, SLC7A11 may be key regulatory targets of ferroptosis during ALI. This study proved that ferroptosis is a common pathophysiological process in three ALI models.

ESTROGEN ALLEVIATES POSTHEMORRHAGIC SHOCK MESENTERIC LYMPH-MEDIATED LUNG INJURY THROUGH AUTOPHAGY INHIBITION.

ABSTRACT: Background: Hemorrhagic shock-induced acute lung injury (ALI) is commonly associated with the posthemorrhagic shock mesenteric lymph (PHSML) return. Whether excessive autophagy is involved in PHSML-mediated ALI remains unclear. The relationship between estrogen treatment and PHSML or autophagy needs to verify. The current study will clarify the role of estrogen in reducing PHSML-mediated ALI through inhibition of autophagy. Methods: First, a hemorrhagic shock model in conscious rats was used to observe the effects of 17ß-estradiol (E2) on intestinal blood flow, pulmonary function, intestinal and pulmonary morphology, and expression of autophagy marker proteins. Meanwhile, the effect of PHSML and autophagy agonist during E2 treatment was also investigated. Secondly, rat primary pulmonary microvascular endothelial cells were used to observe the effect of PHSML, PHSML plus E2, and E2-PHSML (PHSML obtained from rats treated by E2) on the cell viability. Results: Hemorrhagic shock induced intestinal and pulmonary tissue damage and increased wet/dry ratio, reduced intestinal blood flow, along with pulmonary dysfunction characterized by increased functional residual capacity and lung resistance and decreased inspiratory capacity and peak expiratory flow. Hemorrhagic shock also enhanced the autophagy levels in intestinal and pulmonary tissue, which was characterized by increased expressions of LC3 II/I and Beclin-1 and decreased expression of p62. E2 treatment significantly attenuated these adverse changes after hemorrhagic shock, which was reversed by PHSML or rapamycin administration. Importantly, PHSML incubation decreased the viability of pulmonary microvascular endothelial cells, while E2 coincubation or E2-treated lymph counteracted the adverse roles of PHSML. Conclusions: The role of estrogen reducing PHSML-mediated ALI is associated with the inhibition of autophagy.

POSTHEMORRHAGIC SHOCK MESENTERIC LYMPH IMPAIRS SPLENIC DENDRITIC CELL FUNCTION IN MICE.

ABSTRACT: Dendritic cell (DC)-mediated immune dysfunction is involved in the process of severe hemorrhagic shock that leads to sepsis. Although post-hemorrhagic shock mesenteric lymph (PHSML) induces immune organs injuries and apoptosis, whether PHSML exerts adverse effects on splenic DCs remains unknown. In this study, we established a hemorrhagic shock model (40 ± 2 mm Hg for 60 min) followed by fluid resuscitation with the shed blood and equal Ringer's solution and drained the PHSML after resuscitation. At 3 h after resuscitation, we harvested the splenic tissue to isolate DCs using anti-CD11c immunomagnetic beads and then detected the necrotic and apoptotic rates in splenocytes and splenic DCs. We also detected the levels of TNF-α, IL-10, and IL-12 in the culture supernatants and surface marker expressions of MHC-II, CD80, and CD86 of splenic DCs following LPS stimulation for 24 h. Second, we purified the DCs from splenocytes of normal mice to investigate the effects of PHSML treatment on cytokine production and surface marker expression following LPS stimulation. The results showed that PHSML drainage attenuated LPS-induced cell death of splenocytes and DCs. Meanwhile, PHSML drainage enhanced the DC percentage in splenocytes and increased the TNF-α and IL-12 production by DCs and the expressions of CD80, CD86, and MHCII of DCs treated by LPS. Furthermore, PHSML treatment reduced the productions of TNF-α, IL-10, and IL-12 and the expressions of CD80 and CD86 in normal DCs after treatment with LPS. In summary, the current investigation demonstrated that PHSML inhibited the cytokine production and surface marker expressions of DCs stimulated by LPS, suggesting that PHSML plays an important role in hemorrhagic shock-induced immunosuppression through the impairment of DC function and maturation.

Omega-3 polyunsaturated fatty acids alleviates lung injury mediated by post-hemorrhagic shock mesenteric lymph.

Severe hemorrhage-induced acute lung injury (ALI) remains the major contributor to critical patient mortality and is associated with posthemorrhagic shock mesenteric lymph (PHSML) return. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) play overall protection on acute hemorrhage, but a reliable mechanism needs to be identified. The aims of this study were to investigate the role of ω-3 PUFAs in alleviating ALI and whether is related to the endotoxin contained in PHSML. Mesenteric lymph was harvested from rats subjected to hemorrhagic shock (hemorrhage-induced hypotension of 40 ± 2 mmHg for 90 min plus by resuscitation) or sham shock. The effect of ω-3 PUFAs on pulmonary function, water content, morphology, and LBP, CD14, TNF-α, and IL-6 levels were observed in rats subjected to hemorrhagic shock, while the effect of PHSML intravenous infusion on the beneficial effect of ω-3 PUFAs also was investigated. In addition, the effect of ω-3 PUFAs on the endotoxin contents in mesenteric lymph were detected. Hemorrhagic shock-induced ALI was characterized by increased functional residual capacity (FRC), lung resistance (RI), inspiratory capacity (IC), respiratory frequency, water contents and structural damage, along with increases in LBP, IL-6, and TNF-α. ω-3 PUFAs treatment reduced FRC, RI, IC, frequency, water contents, LBP, IL-6, TNF-α, and alleviated morphological damage. In contrast, PHSML infusion abolished the advantageous effects of ω-3 PUFAs on the above indices and CD14. Furthermore, the endotoxin level of PHSML was significantly enhanced, but declined following ω-3 PUFAs administration. These findings together suggested that treatment with ω-3 PUFAs ameliorates hemorrhagic shock-induced ALI, which is associated with reduced endotoxin contained in PHSML.

TLR2/TLR4-Enhanced TIPE2 Expression Is Involved in Post-Hemorrhagic Shock Mesenteric Lymph-Induced Activation of CD4+T Cells.

Purpose: Post hemorrhagic shock mesenteric lymph (PHSML) return contributes to CD4+ T cell dysfunction, which leads to immune dysfunction and uncontrolled inflammatory response. Tumor necrosis factor α induced protein 8 like-2 (TIPE2) is one of the essential proteins to maintain the immune homeostasis. This study investigated the role of TIPE2 in regulation of CD4+ T lymphocyte function in interaction of PHSML and TLR2/TLR4. Methods: The splenic CD4+ T cells were isolated from various mice (WT, TLR2-/-, TLR4-/-) by immunomagnetic beads, and stimulated with PHSML, normal lymphatic fluid (NML), respectively. Application of TIPE2-carrying interfering fragments of lentivirus were transfected to WT, TLR4-/-, and TLR2-/- CD4+ T cells, respectively. After interference of TIPE2, they were stimulated with PHSML and NML for the examinations of TIPE2, TLR2, and TLR4 mRNA expressions, proliferation, activation molecules on surface, and cytokine secretion function. Results: PHSML stimulation significantly upregulated TIPE2, TLR2, and TLR4 mRNA expressions, decreased proliferation, CD25 expression, and IFN-γ secretion, and increased the secretion ability of IL-4 in WT CD4+ T cells. TIPE2 silencing enhanced proliferative capacity, upregulated CD25 expression, and increased IFNγ secretion in CD4+ T cells. PHSML stimulated TLR2-/-CD4+ T or TLR4-/-CD4+ T cells of which TIPE2 were silenced. TLR2 or TLR4 knockout attenuated PHSML-induced CD4+ T cells dysfunction; PHSML stimulation of silent TIPE2-expressing TLR2-/-CD4+ T or TLR4-/-CD4+ T revealed that the coexistence of low TIPE2 expression with lack of TLR2 or TLR4 eliminated this beneficial effect. Conclusion: TIPE2 improves the PHSML-mediated CD4+T cells dysfunction by regulating TLR2/TLR4 pathway, providing a new intervention target following hemorrhagic shock-induced immune dysfunction.

Voluntary Exercise Prevents Hypertensive Response Sensitization Induced by Angiotensin II.

Exercise training has profound effects on the renin-angiotensin system, inflammatory cytokines and oxidative stress, all of which affect autonomic nervous system activity and regulate blood pressure (BP) in both physiological and pathophysiological states. Using the Induction-Delay-Expression paradigm, our previous studies demonstrated that various challenges (stressors) during Induction resulted in hypertensive response sensitization (HTRS) during Expression. The present study tested whether voluntary exercise would protect against subpressor angiotensin (ANG) II-induced HTRS in rats. Adult male rats were given access to either "blocked" (sedentary rats) or functional running (exercise rats) wheels for 12 weeks, and the Induction-Delay-Expression paradigm was applied for the rats during the last 4 weeks. A subpressor dose of ANG II given during Induction produced an enhanced hypertensive response to a pressor dose of ANG II given during Expression in sedentary rats in comparison to sedentary animals that received saline (vehicle control) during Induction. Voluntary exercise did not attenuate the pressor dose of ANG II-induced hypertension but prevented the expression of HTRS seen in sedentary animals. Moreover, voluntary exercise reduced body weight gain and feed efficiency, abolished the augmented BP reduction after ganglionic blockade, reversed the increased mRNA expression of pro-hypertensive components, and upregulated mRNA expression of antihypertensive components in the lamina terminalis and hypothalamic paraventricular nucleus, two key brain nuclei involved in the control of sympathetic activity and BP regulation. These results indicate that exercise training plays a beneficial role in preventing HTRS and that this is associated with shifting the balance of the brain prohypertensive and antihypertensive pathways in favor of attenuated central activity driving sympathetic outflow and reduced BP.

Controlled Hemorrhage Sensitizes Angiotensin II-Elicited Hypertension through Activation of the Brain Renin-Angiotensin System Independently of Endoplasmic Reticulum Stress.

Hemorrhagic shock is associated with activation of renin-angiotensin system (RAS) and endoplasmic reticulum stress (ERS). Previous studies demonstrated that central RAS activation produced by various challenges sensitizes angiotensin (Ang) II-elicited hypertension and that ERS contributes to the development of neurogenic hypertension. The present study investigated whether controlled hemorrhage could sensitize Ang II-elicited hypertension and whether the brain RAS and ERS mediate this sensitization. Results showed that hemorrhaged (HEM) rats had a significantly enhanced hypertensive response to a slow-pressor infusion of Ang II when compared to sham HEM rats. Treatment with either angiotensin-converting enzyme (ACE) 1 inhibitor, captopril, or ACE2 activator, diminazene, abolished the HEM-induced sensitization of hypertension. Treatment with the ERS agonist, tunicamycin, in sham HEM rats also sensitized Ang II-elicited hypertension. However, blockade of ERS with 4-phenylbutyric acid in HEM rats did not alter HEM-elicited sensitization of hypertension. Either HEM or ERS activation produced a greater reduction in BP after ganglionic blockade, upregulated mRNA and protein expression of ACE1 in the hypothalamic paraventricular nucleus (PVN), and elevated plasma levels of Ang II but reduced mRNA expression of the Ang-(1-7) receptor, Mas-R, and did not alter plasma levels of Ang-(1-7). Treatment with captopril or diminazene, but not phenylbutyric acid, reversed these changes. No treatments had effects on PVN protein expression of the ERS marker glucose-regulated protein 78. The results indicate that controlled hemorrhage sensitizes Ang II-elicited hypertension by augmenting RAS prohypertensive actions and reducing RAS antihypertensive effects in the brain, which is independent of ERS mechanism.

Autophagy Is Involved in Stellate Ganglion Block Reversing Posthemorrhagic Shock Mesenteric Lymph-Mediated Vascular Hyporeactivity.

Objective: The aim of this study was to clarify the role of autophagy in stellate ganglion block (SGB) reversing posthemorrhagic shock mesenteric lymph (PHSML)-mediated vascular hyporeactivity. Methods: Hemorrhagic shock model in conscious rats was employed to observe the effects of SGB (0.2 ml of 0.25% ropivacaine hydrochloride hydrate) and autophagy inhibitor 3-methyladenine (3-MA; 30 mg/kg) on the vascular reactivity of second-order rat mesenteric arteries in vitro, while the effects of PHSML (1 ml/kg) and autophagy agonist rapamycin (Rapa, 10 mg/kg) on the beneficial effect of SGB were investigated. The cellular viability, contractility, and autophagy-related protein expressions in vascular smooth muscle cells (VSMCs) were detected following treatments of PHSML, PHSML obtained from the rats that underwent hemorrhagic shock plus SGB (PHSML-SGB), and PHSML plus 3-MA (5 mM), respectively. Results: Hemorrhagic shock significantly decreased the vascular reactivity to gradient norepinephrine (NE), which is reversed by the SGB treatment and 3-MA administration. On the contrary, PHSML intravenous infusion and Rapa administration inhibited the vascular contractile responses in rats that underwent hemorrhagic shock plus SGB treatment. PHSML treatment significantly inhibited the cellular viability and contractility in VSMCs, increased the expressions of LC3-II and Beclin 1, and decreased the expression of p62, along with opposite appearances in these indices following PHSML-SGB treatment. In addition, 3-MA counteracted the adverse roles of PHSML in these indices in VSMCs. Conclusion: SGB inhibits PHSML-mediated vascular hyporeactivity by reducing the excessive autophagy in VSMCs.

Stellate Ganglion Block Improves the Proliferation and Function of Splenic CD4 + T Cells Through Inhibition of Posthemorrhagic Shock Mesenteric Lymph-Mediated Autophagy.

Severe hemorrhagic shock leads to excessive inflammation and immune dysfunction, which results in high mortality related to mesenteric lymph return. A recent study showed that stellate ganglion block (SGB) increased the survival rate in rats suffering hemorrhagic shock. However, whether SGB ameliorates immune dysfunction induced by hemorrhagic shock remains unknown. The aim of the present study was to verify the favorable effects of SGB on the proliferation and function of splenic CD4 + T cells isolated from rats that underwent hemorrhagic shock and to investigate the mechanism related to the SGB interaction with autophagy and posthemorrhagic shock mesenteric lymph (PHSML). Male rats underwent SGB or sham SGB and conscious acute hemorrhage followed by resuscitation and multiple treatments. After 3 h of resuscitation, splenic CD4 + T cells were isolated to measure proliferation and cytokine production following stimulation with ConA in vitro. CD4 + T cells isolated from normal rats were treated with PHSML drained from SBG-treated rats, and proliferation, cytokine production, and autophagy biomarkers were detected. Hemorrhagic shock reduced CD4 + T cell proliferation and production of interleukin (IL)-2, IL-4, and tumor necrosis factor-α-induced protein 8-like 2 (TIPE2). SGB or administration of the autophagy inhibitor 3-methyladenine (3-MA) normalized these indicators. In contrast, administration of rapamycin (RAPA) autophagy agonist or intravenous injection of PHSML inhibited the beneficial effects of SGB on CD4 + T cells from hemorrhagic shocked rats. Furthermore, PHSML incubation decreased proliferation and cytokine production, increased LC3 II/I and Beclin-1 expression, and reduced p-PI3K and p-Akt expression in normal CD4 + T cells. These adverse effects of PHSML were also abolished by 3-MA administration, as well as incubation with PHSML obtained from SGB-treated rats. SGB improves splenic CD4 + T cell function following hemorrhagic shock, which is related to the inhibition of PHSML-mediated autophagy.

Mesenteric Lymph Drainage Improves Cardiac Papillary Contractility and Calcium Sensitivity in Rats with Hemorrhagic Shock.

BACKGROUND: Myocardial dysfunction is an important adverse factor of hemorrhagic shock that induces refractory hypotension, and post-hemorrhagic shock mesenteric lymph (PHSML) return is involved in this adverse effect. This study investigated whether mesenteric lymph drainage (MLD) improves PHSML return-induced cardiac contractile dysfunction via the restoration of cardiomyocyte calcium sensitivity. MATERIALS AND METHODS: A hemorrhage shock model was established by using a controlled hemorrhage through the femoral artery that maintained a mean arterial pressure of 40 ± 2 mmHg for 3 h. MLD and mesenteric lymph duct ligation (MLDL) were performed from 1 to 3 h during hypotension. The papillary muscles of the heart were collected for measurement of calmodulin expression and for determining contractile responses to either isoprenaline or calcium. RESULTS: The results showed that either MLD or MLDL reversed the hemorrhagic shock-induced downregulation of calmodulin expression, a marker protein of cardiomyocyte calcium sensitization, in papillary muscles. MLD also improved the decreased contractile response and ±df/dt of the papillary muscle strip to gradient isoprenaline or calcium caused by hemorrhagic shock. CONCLUSION: These findings indicate that increased cardiac contractibility may be associated with the restoration of calcium sensitivity produced by PHSML drainage.

Therapeutic mechanisms of mesenchymal stem cells in acute respiratory distress syndrome reveal potentials for Covid-19 treatment.

The mortality rate of critically ill patients with acute respiratory distress syndrome (ARDS) is 30.9% to 46.1%. The emergence of the coronavirus disease 2019 (Covid-19) has become a global issue with raising dire concerns. Patients with severe Covid-19 may progress toward ARDS. Mesenchymal stem cells (MSCs) can be derived from bone marrow, umbilical cord, adipose tissue and so on. The easy accessibility and low immunogenicity enable MSCs for allogeneic administration, and thus they were widely used in animal and clinical studies. Accumulating evidence suggests that mesenchymal stem cell infusion can ameliorate ARDS. However, the underlying mechanisms of MSCs need to be discussed. Recent studies showed MSCs can modulate immune/inflammatory cells, attenuate endoplasmic reticulum stress, and inhibit pulmonary fibrosis. The paracrine cytokines and exosomes may account for these beneficial effects. In this review, we summarize the therapeutic mechanisms of MSCs in ARDS, analyzed the most recent animal experiments and Covid-19 clinical trial results, discussed the adverse effects and prospects in the recent studies, and highlight the potential roles of MSC therapy for Covid-19 patients with ARDS.

Estradiol-induced inhibition of endoplasmic reticulum stress normalizes splenic CD4 + T lymphocytes following hemorrhagic shock.

The aim is to investigate that 17ß-estradiol (E2)/estrogen receptors (ERs) activation normalizes splenic CD4 + T lymphocytes proliferation and cytokine production through inhibition of endoplasmic reticulum stress (ERS) following hemorrhage. The results showed that hemorrhagic shock (hemorrhage through femoral artery, 38-42 mmHg for 90 min followed by resuscitation of 30 min and subsequent observation period of 180 min) decreased the CD4+ T lymphocytes proliferation and cytokine production after isolation and incubation with Concanavalin A (5 µg/mL) for 48 h, induced the splenic injury with evidences of missed contours of the white pulp, irregular cellular structure, and typical inflammatory cell infiltration, upregulated the expressions of ERS biomarkers 78 kDa glucose-regulated protein (GRP78) and activating transcription factor 6 (ATF6). Either E2, ER-α agonist propyl pyrazole triol (PPT) or ERS inhibitor 4-Phenylbutyric acid administration normalized these parameters, while ER-ß agonist diarylpropionitrile administration had no effect. In contrast, administrations of either ERs antagonist ICI 182,780 or G15 abolished the salutary effects of E2. Likewise, ERS inducer tunicamycin induced an adverse effect similarly to that of hemorrhagic shock in sham rats, and aggravated shock-induced effects, also abolished the beneficial effects of E2 and PPT, respectively. Together, the data suggest that E2 produces salutary effects on CD4+ T lymphocytes function, and these effects are mediated by ER-α and GPR30, but not ER-ß, and associated with the attenuation of hemorrhagic shock-induced ERS.

Estrogen Enhances the Microvascular Reactivity Through RhoA-ROCK Pathway in Female Mice During Hemorrhagic Shock.

ABSTRACT: Vascular hypo-reactivity plays a critical role inducing organ injury during hemorrhagic shock. 17ß-estradiol (E2) can induce vasodilation to increase blood flow in various vascular beds. This study observed whether E2 can restore vascular hypo-reactivity induced by hemorrhagic shock, and whether E2 effects are associated with RhoA-Rho kinase (ROCK)-myosin light chain kinase phosphatase (MLCP) pathway. The hemorrhagic shock model (40 ±â€Š2 mm Hg for 1 h, resuscitation for 4 h) was established in ovary intact sham operation (OVI), ovariectomized (OVX), and OVX plus E2 supplement female mice. Intestinal microvascular loop was used to assess blood flow in vivo, mRNA expression and vascular reactivity in vitro. Hemorrhagic shock significantly reduced norepinephrine microvascular reactivity. Decreased microvascular reactivity was exacerbated by OVX and reversed by E2 supplement. U-46619 (RhoA agonist) increased microvascular reactivity, and C3 transferase (an ADP ribosyl transferase that selectively induces RhoA ribosylation) or Y-27632 (ROCK inhibitor) inhibited sham mice microvascular reactivity. Similarly, U-46619 increased microvascular reactivity in OVI and OVX mice following hemorrhagic shock, which was abolished by Y-27632 or concomitant incubation of okadaic acid (OA) (MLCP inhibitor) and Y-27632. In OVX plus E2 supplement mice with hemorrhagic shock, Y-27632 inhibited microvascular reactivity, which was abolished by concomitant U-46619 application. Lastly, hemorrhagic shock remarkably decreased intestinal loop blood flow, RhoA and ROCK mRNA expressions in vascular tissues in OVX females, but not in OVI females, which were reversed by E2 supplement. These results indicate that estrogen improves microvascular reactivity during hemorrhagic shock, and RhoA-ROCK signaling pathway may mediate E2 effects.

Transcriptome Analysis Revealed Inflammation Is Involved in the Impairment of Human Umbilical Vein Endothelial Cells Induced by Post-hemorrhagic Shock Mesenteric Lymph.

Vascular endothelial injury caused by post-hemorrhagic shock mesenteric lymph (PHSML) return is an important manifestation during refractory hemorrhagic shock. Using human umbilical vein endothelial cells (HUVECs) and transcriptome analysis, this study sought to investigate the molecular mechanism underlying the adverse effect of PHSML on vascular endothelium. Post-hemorrhagic shock mesenteric lymph was collected from male rats after they underwent hemorrhagic shock and following resuscitation, while normal mesenteric lymph (NML) was harvested from sham rats. Human umbilical vein endothelial cells were incubated with the culture medium containing either 10% phosphate buffered saline (Control), NML, or PHSML for 3 h, and then were harvested for RNA sequencing. In comparison with NML treated cells, 37 genes were differentially expressed in PHSML-treated HUVECs, including 32 upregulated genes and five downregulated genes. These differentially expressed genes were mainly enriched in inflammatory pathways, including signaling pathways for activation of the NOD-like receptors, NF-κB, and TNF. Furthermore, we found that C-C motif chemokine ligand 2 (CCL2) was increased significantly after PHSML treatment, and Bindarit, a CCL2 production inhibitor, attenuated the damage of HUVECs induced by PHSML. The results provide molecular evidence on vascular endothelium damage caused by PHSML. C-C motif chemokine ligand 2 might represent a new target for reducing vascular injury after severe hemorrhagic shock.

Stellate Ganglion Blockade repairs Intestinal Mucosal Barrier through suppression of Endoplasmic Reticulum Stress following Hemorrhagic Shock.

Background: Hemorrhagic shock-induced ischemia and hypoxia elicit endoplasmic reticulum stress (ERS) that leads to cell apoptosis, tissue structural damage and organ dysfunction and failure. Stellate ganglion blockade (SGB) has been demonstrated to improve intestinal barrier dysfunction induced by hemorrhagic shock. The present study sought to investigate whether the beneficial effect of SGB on the intestinal mucosal barrier function is via suppression of ERS. Materials and methods: A conscious rat model of hemorrhagic shock (40 ±2 mmHg for 1 hour, followed by resuscitation) was established. The parameters reflecting intestinal morphology and intestinal mucosal barrier function including wet-dry ratio (W/D), intestinal permeability, D-lactic acid (D-LA) and intestinal fatty acid binding protein (I-FABP) in plasma, and expressions of ATF6α, PERK, and IRE1α in intestinal tissues were then observed. Furthermore, the effects of either SGB or ERS inhibitor, 4-phenylbutyric acid (4-PBA), on these parameters in rats with hemorrhagic shock were assessed. The effect of ERS agonist tunicamycin (TM) on the rats subjected with both SGB and hemorrhagic shock was also determined. Results: Either SGB or administration of ERS inhibitor, 4-PBA, alleviated hemorrhagic shock-induced adverse effects such as intestinal mucosal barrier dysfunction and excessive autophagy, which were characterized by damaged intestinal tissue, enhanced intestinal permeability and D-LA and I-FABP levels in plasma, and increased expressions of ATF6α, PERK, IRE1α in intestinal tissue. In contrast, administration of ERS agonist, TM, suppressed the beneficial effects of SGB on intestinal tissue and function during hemorrhagic shock. Conclusion: The SGB repairs intestinal mucosal barrier through suppression of ERS following hemorrhagic shock.

Interaction of Estradiol and Endoplasmic Reticulum Stress in the Development of Esophageal Carcinoma.

Gender differences in esophageal cancer patients indicate that estradiol may have antitumor effects on esophageal cancer. The initiation of endoplasmic reticulum stress (ERS) can induce apoptosis in esophageal cancer cells. However, it is still unknown whether estradiol inhibits the development of esophageal cancer by activating ERS pathway. In this study, the gender difference in the development of esophageal cancer was observed by analyzing clinical data and the experimental tumor xenografts in mice. Meanwhile, we investigated the mechanism of ERS in estradiol-mediated inhibition of esophageal cancer using esophageal squamous cell carcinoma cell line EC109. The proportion of male patients with esophageal cancer was significantly higher than female patients. Meanwhile, male patients were prone to have adventitial invasion. The weight of transplanted tumors in female mice was significantly smaller than that in male mice. In vitro experiments showed estradiol inhibits the viability and migration of EC109 cells by increasing the expression of ERS-related proteins, whereas ERS inhibitor 4-PBA abolished the effects of estradiol. In conclusion, our data demonstrate that sex difference exists in the occurrence of esophageal cancer. Estradiol can inhibit the viability and migration of esophageal cancer cells through the activation of ERS, providing a novel insight for esophageal cancer development, treatment, and prevention.

Engagement of Posthemorrhagic Shock Mesenteric Lymph on CD4+ T Lymphocytes In Vivo and In Vitro.

BACKGROUND: Immune dysfunction is associated with posthemorrhagic shock mesenteric lymph (PHSML) return. To determine the proliferation and cytokine production capacity of CD4+ T lymphocytes, the effect of PHSML drainage on spleen CD4+ T lymphocytes in a mouse model of hemorrhagic shock was assessed. METHODS: The normal spleen CD4+ T lymphocytes were in vitro incubated with either drained normal mesenteric lymph (NML), PHSML during hypotension (PHSML-H), or PHSML from 0 h to 3 h after resuscitation (PHSML-R) to verify direct proliferation effects of PHSML. RESULTS: Hemorrhagic shock led to reduction of proliferation and mRNA expression of interleukin 2 (IL-2) and IL-2 receptor in CD4+ T lymphocytes and to decrease in IL-2 and interferon γ (IFN-γ) levels in supernatants. In contrast, the interleukin-4 levels were increased. These effects were reversed by PHSML drainage. Moreover, NML incubation promoted CD4+ T lymphocyte proliferation, whereas both PHSML-H and PHSML-R treatment had a biphasic effects on CD4+ T lymphocyte proliferation, exhibiting an enhanced effect at early stages and an inhibitory effect at later stages. Compared with NML, PHSML-H increased IL-2 expression at 12 h, but decreased expression of both IL-2 and IFN-γ at 24 h. By contrast, PHSML-R induced significant increases in IL-2 and IFN-γ levels at 24 h. Interleukin-4 expression in CD4+ T lymphocytes was reduced at 12 h, but augmented at 24 h after incubation with either PHSML-H or PHSML-R. CONCLUSIONS: The results indicate that PHSML has a direct inhibitory effect on CD4+ T lymphocyte proliferation that induces an inflammatory response, which is associated with cellular immune dysfunction.

Mesenteric lymph drainage alleviates hemorrhagic shock-induced spleen injury and inflammation.

PURPOSE: To investigate the effect of mesenteric lymph drainage on the spleen injury and the expressions of inflammatory cytokines in splenic tissue in mice following hemorrhagic shock. METHODS: Male C57 mice were randomly divided into the sham shock, shock and shock+drainage groups. The mice in both shock and shock+drainage groups suffered femoral artery bleeding, maintained mean arterial pressure (MAP) of 40±2 mmHg for 90 min, and were resuscitated. And mesenteric lymph drainage was performed in the shock+drainage group at the time of resuscitation. After three hours of resuscitation, the splenic tissues were harvested for the histological observation and protein and mRNA expression analysis of cytokines. RESULTS: The spleen in the shock group revealed a significantly structural damage and increased mRNA expressions of MyD88 and TRAF6 and protein expressions of TIPE2, MyD88, TRIF and TRAF3 compared to the sham group. By contrast, the splenic pathological injury in the shock+drainage group was alleviated significantly, and the mRNA and protein expressions of TIPE2, MyD88, TRIF, TRAF3 and TRAF6 were significantly lower than those in the shock group. CONCLUSION: These results indicate that post-hemorrhagic shock mesenteric lymph drainage alleviates hemorrhagic shock-induced spleen injury and the expressions of inflammatory cytokines.

Blockade of Stellate Ganglion Remediates Hemorrhagic Shock-Induced Intestinal Barrier Dysfunction.

BACKGROUND: Acute hemorrhage-induced excessive excitation of sympathetic-adrenal-medullary system (SAS) leads to gut hypoperfusion and barrier dysfunction, which is a critical event during hemorrhagic shock-induced multiple organ injury. Stellate ganglion blockade (SGB) has been widely used for suppression of sympathetic-adrenal-medullary system in the clinical practice. However, whether SGB improves intestinal barrier function after hemorrhagic shock remains unclear. Here, we hypothesized that the implementation of SGB restores intestinal barrier function and reduces gut injury. MATERIALS AND METHODS: Male rats received the SGB pretreatment and underwent hemorrhagic shock followed by resuscitation. The 96-h survival rate, intestinal permeability and morphology, D-lactic acid concentration and diamine oxidase activity in plasma, and expressions of F-actin, Claudin-1, and E-cadherin in intestinal tissues were observed. RESULTS: Pretreatment with SGB significantly enhances the 96-h survival rate in rats subjected to hemorrhagic shock (from 8.3% to 66.7%). Hemorrhagic shock reduced the coverage scale of intestinal mucus and intestinal villus width and height, enhanced the intestinal permeability to fluorescein isothiocyanate-dextran 4 and D-lactic acid concentration in plasma, and decreased the expressions of F-actin, Claudin-1, and E-Cadherin in intestinal tissue. These hemorrhagic shock-induced adverse effects were abolished by SGB treatment. CONCLUSIONS: SGB treatment has a beneficial effect during hemorrhagic shock, which is associated with the improvement of intestine barrier function. SGB may be considered as a new therapeutic strategy for treatment of hemorrhagic shock.