Post-hemorrhagic shock mesenteric lymph is an important contributor to cardiac dysfunction following hemorrhagic shock

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.

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.

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.