Effects of hypertonic saline on CD4+CD25+Foxp3+ regulatory T cells after hemorrhagic shock in relation to iNOS and cytokines

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.

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

The aim is to investigate that 17β-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-β 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-β, and associated with the attenuation of hemorrhagic shock-induced ERS.

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.

Higher Concentration of Hypertonic Saline Shows Better Recovery Effects on Rabbits with Uncontrolled Hemorrhagic Shock

Background

Our previous study found a novel fluid combination with better resuscitation effects under hypotensive condition at the early stage of uncontrolled hemorrhagic shock (UHS). However, the optimal recovery concentration of hypertonic saline in this fluid combination remains unknown. This experiment aimed to explore the optimal concentration.

Material/Methods

New Zealand white rabbits (n=40) were randomly divided into 5 groups, including a sham-operated group (SO), a shock non-treated group (SNT), a normal saline group (NS), and hypertonic saline groups (4.5% and 7.5%). We established an UHS model and administered various fluid combinations (dose-related sodium chloride solution+crystal-colloidal solution) to the groups followed by monitoring indexes of hemodynamic and renal function, measuring infusion volume and blood loss, and analyzing pathological morphology by hematoxylin and eosin staining.

Results

The hypertonic saline groups showed more stable hemodynamic indexes, reduced blood loss, fewer required infusions, and milder decreases in renal function than those of control groups (SNT and NS groups), and exhibited fewer pathological changes in the heart, lung, kidney, and liver. All indexes in the 4.5% and 7.5% groups were better than those of the NS group, and the hemodynamic indexes in the 7.5% group were more stable than those of the 4.5% group (P<0.05), with reduced blood loss and infusion volume and a milder decrease in renal function.

Conclusions

The novel fluid combination with 7.5% hypertonic saline group had a better recovery effect at the early stage of UHS before hemostasis compared to that of the 4.5% hypertonic saline group. This result may provide guidance for clinical fluid resuscitation.

Immune recovery after fluid resuscitation in rats with severe hemorrhagic shock

OBJECTIVE

To investigate the effects of resuscitation with normal saline (NS), hypertonic saline (HTS), and hydroxyethyl starch (HES) on regulatory T cells (Tregs), helper T 1 (Th1)/Th2 and cytotoxic T 1 (Tc1)/Tc2 profiles in the treatment of hemorrhagic shock.

METHODS

Rats subjected to severe hemorrhagic shock were resuscitated for 30 min with NS (n=8), HTS (n=8), or HES (n=8); sham (n=8) and naive control (n=8) groups were used for comparison. Following fluid resuscitation, the whole shed blood was reinfused for 30 min, and the rats were observed with continuous hemodynamic monitoring for 120 min. CD4⁺CD25⁺Foxp3⁺ Treg proportions, Th1/Th2 and Tc1/Tc2 profiles in spleen were analyzed by three-color flow cytometry.

RESULTS

The proportion of CD4⁺CD25⁺Foxp3⁺ Tregs and ratios of Th1/Th2 and Tc1/Tc2 did not differ among control, sham, and HTS groups, but were significantly lower in NS and HES groups (both P<0.05 vs. sham); NS and HES levels were similar. The level of Tc1 was significantly increased in HTS (P<0.05 vs. sham), and levels of Tc2 were increased in NS, HES, and HTS groups compared to sham (all P<0.05), but did not differ from each other.

CONCLUSIONS

HTS resuscitation has a greater impact on immune system recovery than NS or HES by preserving the proportion of Tregs and maintaining the balance between Th1/Th2 and Tc1/Tc2 cells in the spleen. Thus, HTS resuscitation provides potential immunomodulatory activity in the early stage after hemorrhagic shock.

Effects of aminoguanidine, a potent nitric oxide synthase inhibitor, on myocardial and organ structure in a rat model of hemorrhagic shock

Background:

Nitric oxide (NO) has been shown to increase following hemorrhagic shock (HS). Peroxynitrite is produced by the reaction of NO with reactive oxygen species, leads to nitrosative stress mediated organ injury. We examined the protective effects of a potent inhibitor of NO synthase, aminoguanidine (AG), on myocardial and multiple organ structure in a rat model of HS.

Materials and Methods:

Male Sprague Dawley rats (300-350 g) were assigned to 3 experimental groups (n = 6 per group): (1) Normotensive rats (N), (2) HS rats and (3) HS rats treated with AG (HS-AG). Rats were hemorrhaged over 60 min to reach a mean arterial blood pressure of 40 mmHg. Rats were treated with 1 ml of 60 mg/kg AG intra-arterially after 60 min HS. Resuscitation was performed in vivo by the reinfusion of the shed blood for 30 min to restore normo-tension. Biopsy samples were taken for light and electron microscopy.

Results:

Histological examination of hemorrhagic shocked untreated rats revealed structural damage. Less histological damage was observed in multiple organs in AG-treated rats. AG-treatment decreased the number of inflammatory cells and mitochondrial swollen in myocardial cells.

Conclusion:

AG treatment reduced microscopic damage and injury in multiple organs in a HS model in rats.

Hypertonic saline as a therapy for pediatric concussive pain: a randomized controlled trial of symptom treatment in the emergency department

OBJECTIVE

Three-percent hypertonic saline (HTS) is a hyperosmotic therapy used in pediatric traumatic brain injury to treat increased intracranial pressure and cerebral edema. It also promotes plasma volume expansion and cerebral perfusion pressure, immunomodulation, and anti-inflammatory response. We hypothesized that HTS will improve concussive symptoms of mild traumatic brain injury.

METHODS

The study was a prospective, double-blind, randomized controlled trial. Children, 4 to 7 years of age with a Glasgow Coma Scale score greater than 13, were enrolled from a pediatric emergency department following closed-head injury upon meeting Acute Concussion Evaluation criteria with head pain. Patients were randomized to receive 10 mL/kg of HTS or normal saline (NS) over 1 hour. Self-reported pain values were obtained using the Wong-Baker FACES Pain Rating Scale initially, immediately following fluids, and at 2 to 3 days of discharge. The primary outcome measure was change in self-reported pain following fluid administration. Secondary outcome measures were a change in pain and postconcussive symptoms within 2 to 3 days of fluid administration. We used an intention-to-treat analysis.

RESULTS

Forty-four patients, ranging from 7 to 16 years of age with comparable characteristics, were enrolled in the study; 23 patients (52%) received HTS, and 21 (48%) received NS. There was a significant difference (P < 0.001) identified in the self-reported improvement of pain following fluid administration between the HTS group (mean improvement = 3.5) and the NS group (mean improvement = 1.1). There was a significant difference (P = 0.01) identified in the self-reported improvement of pain at 2 to 3 days after treatment between the HTS group (mean improvement = 4.6) and the NS group (mean improvement = 3.0). We were unable to determine a difference in other postconcussive symptoms following discharge.

CONCLUSIONS

Three-percent HTS is more effective than NS in acutely reducing concussion pain in children.

Effect of 200 mEq/L Na+ hypertonic saline resuscitation on systemic inflammatory response and oxidative stress in severely burned rats

BACKGROUND

Excessive release of inflammatory mediators and oxidative stress play important roles in the increased vascular permeability and systemic edema during the early stage of severe burn. This study investigates the effect of 200 mEq/L Na(+) hypertonic saline (HS) on systemic inflammatory response and oxidative stress in severely burned rats.

MATERIALS AND METHODS

Sprague-Dawley rats were divided into three groups: sham group, burn plus lactated Ringer's group, and burn plus HS group. Lung edema was assessed in terms of wet-weight-to-dry-weight ratio. Tumor necrosis factor α and interleukin 6 concentrations in serum were examined by enzyme-linked immunosorbent assay. Peripheral blood mononuclear cells were isolated and the expression of p38 mitogen-activated protein kinase was determined by Western blot analysis. The lung and intestinal concentrations of malondialdehyde, an indicator of oxidative stress, were also measured.

RESULTS

Resuscitation with 200 mEq/L Na(+) HS significantly decreased the lung wet-weight-to-dry-weight ratio and abolished hyponatremia induced by burn injury. HS treatment also prevented the increases of myeloperoxidase activity and malondialdehyde content in the lung and intestine of severely burned rats. However, there were no significant differences, either in serum tumor necrosis factor α and interleukin 6 concentrations or with respect to the p38 mitogen-activated protein kinase expression in peripheral blood mononuclear cells, between the burn plus lactated Ringer's group and burn plus HS group (P > 0.05).

CONCLUSIONS

Initial resuscitation with 200 mEq/L Na(+) HS after severe burn injury decreases pulmonary edema, prevents hyponatremia, and attenuates oxidative stress, but is not capable of inhibiting the systemic inflammatory response.

Inducible nitric oxide synthase contributes to immune dysfunction following trauma

Trauma results in a persistent depression in adaptive immunity, which contributes to patient morbidity and mortality. This state of immune paralysis following trauma is characterized by a change in cell-mediated immunity, specifically a depression in T-cell function and a shift toward TH2 T-cell phenotype. Upregulation of inducible nitric oxide synthase (iNOS) is well recognized after injury and contributes to the inflammatory response and organ damage early after trauma. However, it is unknown whether iNOS plays a role in adaptive immune dysfunction after trauma. This study utilized a murine model of severe peripheral tissue injury to show that iNOS is rapidly upregulated in macrophages and a (Gr-1-CD11b) myeloid-derived suppressor cell subpopulation in the spleen. Through the use of iNOS knockout mice, a specific iNOS inhibitor, and a nitric oxide (NO) scavenger, this study demonstrates that iNOS-derived NO is required for the depression in T-lymphocyte proliferation, interferon γ, and interleukin 2 production within the spleen at 48 h after trauma. These findings support the hypothesis that iNOS regulates immune suppression following trauma and suggest that targeting the sustained production of NO by iNOS may attenuate posttraumatic immune depression.

The regulation of interleukin-6 implicates skeletal muscle as an integrative stress sensor and endocrine organ

Skeletal muscle has been identified as an endocrine organ owing to its capacity to produce and secrete a variety of cytokines (myokines) and other proteins. To date, myokines have primarily been studied in response to exercise or metabolic challenges; however, numerous observations suggest that skeletal muscle may also release myokines in response to certain categories of internal or external stress exposure. Internal stress signals include oxidative or nitrosative stress, damaged or unfolded proteins, hyperthermia or energy imbalance. External stress signals, which act as indicators of organismal stress or injury in other cells, employ mediators such as catecholamines, endotoxin, alarmins, ATP and pro-inflammatory cytokines, such as tumour necrosis factor-α and interleukin-1β. External stress signals generally induce cellular responses through membrane receptor systems. In this review, we focus on the regulation of interleukin-6 (IL-6) as a prototypical stress response myokine and highlight evidence that IL-6 gene regulation in muscle is inherently organized to respond to a wide variety of internal and external stressors. Given that IL-6 can initiate protective, anti-inflammatory or restorative processes throughout the organism during life-threatening conditions, we present the argument that skeletal muscle has a physiological function as a sensor and responder to stress. Furthermore, we hypothesize that it may comprise a fundamental component of the organism's acute stress response.