Evaluation of capillary leakage after vasopressin resuscitation in a hemorrhagic shock model

A COMPARATIVE ANALYSIS TO DETERMINE THE OPTIMUM HISTONE DEACETYLASE INHIBITORS AND ADMINISTRATION ROUTE FOR IMPROVING SURVIVAL AND ORGAN INJURY IN RATS AFTER HEMORRHAGIC SHOCK

ABSTRACT

Objective: Histone deacetylase inhibitors (HDACIs) have been reported to improve survival in rats with hemorrhagic shock (HS). However, no consensus exists on the most effective HDACIs and their administration routes. We herein aimed to determine the optimal HDACIs and administration route in rats with HS. Methods: Survival analysis: In experiment I, male Sprague-Dawley rats were subjected to HS (mean arterial pressure [MAP] was maintained at 30-40 mm Hg for 20 min), and intravenously injected with the following agents (n = 8 per group): (1) no treatment, (2) vehicle (VEH), (3) entinostat (MS-275), (4) [ N -((6-(Hydroxyamino)-6-oxohexyl)oxy)-3,5-dimethylbenzamide] (LMK-235), (5) tubastatin A, (6) trichostatin A (TSA), and (7) sirtinol. In experiment II, rats were intraperitoneally injected with TSA. Mechanism research: In experiments I and II, rats were observed for 3 h, after which blood samples and liver, heart, and lung tissues were harvested. Results: In experiment I, 75% rats in the VEH group but only 25% rats in the LMK-235 and sirtinol groups died within ≤5 h of treatment, whereas the survival of rats in the MS-275, tubastatin A, and TSA groups was significantly prolonged. MS-275, LMK-235, tubastatin A, and TSA significantly reduced histopathological scores, apoptosis cell numbers, and inflammatory cytokine levels. In experiment II, the survival was longer after i.v. TSA treatment than after i.p. TSA treatment, and the IL-6 levels in the heart were significantly lower in rat who received i.p. TSA treatment than in those who received i.v. TSA treatment. Conclusions: The i.v. effect was superior to the i.p. effect, while nonselective and isoform-specific classes I and IIb HDACIs had similar effects.

PTPRO knockdown protects against inflammation in hemorrhage shock-induced lung injury involving the NF-κB signaling pathway

Background

Hemorrhage shock (HS) is characterized by decreased tissue oxygenation and organ damage due to severe blood loss. Protein tyrosine phosphatase receptor type O (PTPRO) is abnormally up-regulated in the rat lungs after trauma/HS.

Methods

To elucidate the regulatory mechanism of PTPRO in lung inflammation following HS, we established a rat model of HS via withdrawing blood by a catheter inserted into the femoral artery followed by resuscitation. The rats were infected with lentivirus harboring short hairpin RNA (shRNA) targeting PTPRO by intratracheal instillation.

Results

PTPRO was significantly up-regulated in rat lungs after HS. PTPRO knockdown enhanced epithelial integrity and reduced capillary leakage by up-regulating tight junction proteins zonula occludens-1 (ZO-1) and occludin (OCC) in the lungs. Besides, HS-induced myeloperoxidase activity and inflammatory cell infiltration was mitigated by PTPRO knockdown. The expression of inflammatory cytokines/chemokines (TNF-α, IL-6, MIP-2, MCP-1, and KC) in the lungs and bronchoalveolar lavage fluid was regressed after PTPRO knockdown. The nuclear factor kappa B (NF-κB) pathway was involved in HS-induced lung inflammation. PTPRO down-regulation inhibited the NF-κB pathway activation by suppressing the phosphorylation of NF-κB and its translocation from the cytoplasm into the nucleus in HS.

Conclusion

Taken together, we demonstrated that PTPRO knockdown may contribute to attenuating inflammation in HS-induced lung injury via inhibiting NF-κB pathway activation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02118-2.

Treatment with ddAVP improves platelet-based coagulation in a rat model of traumatic hemorrhagic shock

Objectives

Trauma-induced hemorrhagic shock is characterized by increased endothelial permeability and coagulopathy. Vasopressin analog ddAVP (desmopressin) acts by reorganizing and redistributing adhesive and tight junction molecules, enhancing endothelial barrier function. Furthermore, ddAVP increases von Willebrand factor (vWF) plasma levels and thereby potentially enhances platelet-based coagulation. The objective of this study was to assess whether the use of ddAVP results in improvement of both endothelial barrier function and platelet-based coagulation, thereby improving shock reversal and reduce organ failure in a rat model of trauma and transfusion.

Methods

Blood products were prepared from syngeneic rat blood according to blood bank standards. Polytrauma was induced in Sprague Dawley rats by a fractured femur and crush injury to the intestines and liver. The rats were hemorrhaged until a mean arterial pressure of 40 mm Hg and transfused with RBCs, fresh frozen plasmas and platelets in a 1:1:1 ratio, and randomized to receive a single dose of ddAVP (n=7 per group). Blood samples were taken up to 6 hours after trauma to assess biochemistry, markers of endothelial injury and coagulation status by rotational thromboelastometry (ROTEM). Organ damage was assessed by histopathology.

Results

Rats receiving ddAVP showed significantly better shock reversal compared with controls. Also, coagulation parameters remained stable in the ddAVP treated group, whereas rats in the control group showed deterioration of coagulation parameters, including decreased clot strength and decreased platelet functioning (89% (IQR 82% to 92%) of baseline values). Platelet count and vWF antigen levels at exsanguination did not differ between groups. ddAVP did not reduce markers of endothelial dysfunction nor markers of organ injury.

Conclusions

The use of ddAVP in a rat trauma-transfusion model improved shock parameters and ROTEM parameters of clot formation. However, this did not abrogate the amount of organ failure.

Level of evidence

Level III.

Therapeutically Targeting Microvascular Leakage in Experimental Hemorrhagic SHOCK: A Systematic Review and Meta-Analysis

BACKGROUND

Microvascular leakage is proposed as main contributor to disturbed microcirculatory perfusion following hemorrhagic shock and fluid resuscitation, leading to organ dysfunction and unfavorable outcome. Currently, no drugs are available to reduce or prevent microvascular leakage in clinical practice. We therefore aimed to provide an overview of therapeutic agents targeting microvascular leakage following experimental hemorrhagic shock and fluid resuscitation.

METHODS

PubMed, EMBASE.com, and Cochrane Library were searched in January 2021 for preclinical studies of hemorrhagic shock using any therapeutic agent on top of standard fluid resuscitation. Primary outcome was vascular leakage, defined as edema, macromolecule extravasation, or glycocalyx degradation. Drugs were classified by targeting pathways and subgroup analyses were performed per organ.

RESULTS

Forty-five studies, published between 1973 and 2020, fulfilled eligibility criteria. The included studies tested 54 different therapeutics mainly in pulmonary and intestinal vascular beds. Most studies induced trauma besides hemorrhagic shock. Forty-four therapeutics (81%) were found effective to reduce microvascular leakage, edema formation, or glycocalyx degradation in at least one organ. Targeting oxidative stress and apoptosis was the predominantly effective strategy (SMD: -2.18, CI [-3.21, -1.16], P < 0.0001). Vasoactive agents were found noneffective in reducing microvascular leakage (SMD: -0.86, CI [-3.07, 1.36], P = 0.45).

CONCLUSION

Pharmacological modulation of pathways involved in cell metabolism, inflammation, endothelial barrier regulation, sex hormones and especially oxidative stress and apoptosis were effective in reducing microvascular leakage in experimental hemorrhagic shock with fluid resuscitation. Future studies should investigate whether targeting these pathways can restore microcirculatory perfusion and reduce organ injury following hemorrhagic shock.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42018095432.

Tyrosine kinase nonreceptor 1 (TNK1) knockdown ameliorates hemorrhage shock-induced kidney injury via inhibiting macrophage M1 polarization

Hemorrhage shock (HS) is a major threat to patients with trauma and spontaneous bleeding, resulting in multi-organ failure including the kidney. Tyrosine kinase nonreceptor 1 (TNK1) has been shown to be upregulated in the kidney of experimental HS and patients with severe trauma. The study aims to investigate the role of TNK1 and the underlying mechanism in HS-induced kidney injury. A model of HS was established with femoral artery bloodletting, followed by resuscitation in Sprague-Dawley rats. Renal expression of TNK1 was abnormally induced by HS in rats. Knockdown of TNK1 alleviated HS-induced cell apoptosis and the level of proinflammatory cytokines (TNF-α, IL-6 and IL-1β) in the kidney. The expression of M1 macrophage markers (CD86 and iNOS) and the activation of STAT1 were inhibited by TNK1 knockdown in HS rats. In vitro, human monocyte THP-1 cells were treated with 20 ng/mL interferon-gamma plus 100 ng/mL lipopolysaccharide to induce M1 polarization. TNK1 knockdown exerted inhibitory effect on macrophage M1 polarization, M1-type inflammatory cytokine production and STAT1 activation in THP-1 cells. In conclusion, downregulation of TNK1 alleviates HS-induced kidney injury by suppressing macrophage M1 polarization, inflammation and kidney cell apoptosis, in which the deactivation of STAT1 signaling may be involved.

Therapeutic interventions to restore microcirculatory perfusion following experimental hemorrhagic shock and fluid resuscitation: A systematic review

Objective

Microcirculatory perfusion disturbances following hemorrhagic shock and fluid resuscitation contribute to multiple organ dysfunction and mortality. Standard fluid resuscitation is insufficient to restore microcirculatory perfusion; however, additional therapies are lacking. We conducted a systematic search to provide an overview of potential non‐fluid‐based therapeutic interventions to restore microcirculatory perfusion following hemorrhagic shock.

Methods

A structured search of PubMed, EMBASE, and Cochrane Library was performed in March 2020. Animal studies needed to report at least one parameter of microcirculatory flow (perfusion, red blood cell velocity, functional capillary density).

Results

The search identified 1269 records of which 48 fulfilled all eligibility criteria. In total, 62 drugs were tested of which 29 were able to restore microcirculatory perfusion. Particularly, complement inhibitors (75% of drugs tested successfully restored blood flow), endothelial barrier modulators (100% successful), antioxidants (66% successful), drugs targeting cell metabolism (83% successful), and sex hormones (75% successful) restored microcirculatory perfusion. Other drugs consisted of attenuation of inflammation (100% not successful), vasoactive agents (68% not successful), and steroid hormones (75% not successful).

Conclusion

Improving mitochondrial function, inhibition of complement inhibition, and reducing microvascular leakage via restoration of endothelial barrier function seem beneficial to restore microcirculatory perfusion following hemorrhagic shock and fluid resuscitation.

Time to epinephrine treatment is associated with the risk of mortality in children who achieve sustained ROSC after traumatic out-of-hospital cardiac arrest

Background

The benefits of early epinephrine administration in pediatric with nontraumatic out-of-hospital cardiac arrest (OHCA) have been reported; however, the effects in pediatric cases of traumatic OHCA are unclear. Since the volume-related pharmacokinetics of early epinephrine may differ obviously with and without hemorrhagic shock (HS), beneficial or harmful effects of nonselective epinephrine stimulation (alpha and beta agonists) may also be enhanced with early administration. In this study, we aimed to analyze the therapeutic effect of early epinephrine administration in pediatric cases of HS and non-HS traumatic OHCA.

Methods

This was a multicenter retrospective study (2003–2014). Children (aged ≤ 19 years) who experienced traumatic OHCA and were administered epinephrine for resuscitation were included. Children were classified into the HS (blood loss > 30% of total body fluid) and non-HS groups. The demographics, outcomes, postresuscitation hemodynamics (the first hour) after the sustained return of spontaneous circulation (ROSC), and survival durations were analyzed and correlated with the time to epinephrine administration (early < 15, middle 15–30, late > 30 min) in the HS and non-HS groups. Cox regression analysis was used to adjust for risk factors of mortality.

Results

A total of 509 children were included. Most of them (n = 348, 68.4%) had HS OHCA. Early epinephrine administration was implemented in 131 (25.7%) children. In both the HS and non-HS groups, early epinephrine administration was associated with achieving sustained ROSC (both p < 0.05) but was not related to survival or good neurological outcomes (without adjusting for confounding factors). However, early epinephrine administration in the HS group increased cardiac output but induced metabolic acidosis and decreased urine output during the initial postresuscitation period (all p < 0.05). After adjusting for confounding factors, early epinephrine administration was a risk factor of mortality in the HS group (HR 4.52, 95% CI 2.73–15.91).

Conclusion

Early epinephrine was significantly associated with achieving sustained ROSC in pediatric cases of HS and non-HS traumatic OHCA. For children with HS, early epinephrine administration was associated with both beneficial (increased cardiac output) and harmful effects (decreased urine output and metabolic acidosis) during the postresuscitation period. More importantly, early epinephrine was a risk factor associated with mortality in the HS group.