Encapsulated Hsp70 decreases endotoxin-induced production of ROS and TNFα in human phagocytes

Preventive Administration of the Heat Shock Protein Hsp70 Relieves Endotoxemia-Induced Febrile Reaction in Pigeons ( ) and Rats

The stress-inducible 70 kDa heat shock protein (Hsp70) can exert a protective effect on endotoxemia and sepsis due to its ability to interact with immune cells and modulate the immune response. However, it remains unknown whether Hsp70 is able to relieve endotoxemia-induced fever. We carried out a comparative study of the effects of preventive administration of the human recombinant Hsp70 (HSPA1A) on lipopolysaccharide (LPS)-induced endotoxemia in pigeons and rats with preimplanted electrodes and thermistors for recording the thermoregulation parameters (brain temperature, peripheral vasomotor reaction, muscular contractile activity). Additionally, we analyzed the dynamics of the white blood cell (WBC) count in rats under the same conditions. It was found that preventive administration of Hsp70 relieves the LPS-induced febrile reaction in pigeons and rats and accelerates the restoration of the WBC count in rats. The data obtained suggest that these warm-blooded animals share a common physiological mechanism that underlies the protective effect of Hsp70.

H2S counteracts proinflammatory effects of LPS through modulation of multiple pathways in human cells

BACKGROUND

Hydrogen sulfide donors reduce inflammatory signaling in vitro and in vivo. The biological effect mediated by H₂S donors depends on the kinetics of the gas release from the donor molecule. However, the molecular mechanisms of H₂S-induced immunomodulation were poorly addressed. Here, we studied the effect of two different hydrogen sulfide (H₂S)-producing agents on the generation of the LPS-induced inflammatory mediators. Importantly, we investigated the transcriptomic changes that take place in human cells after the LPS challenge, combined with the pretreatment with a slow-releasing H₂S donor-GYY4137.

METHODS

We investigated the effects of GYY4137 and sodium hydrosulfide on the release of proinflammatory molecules such as ROS, NO and TNF-α from LPS-treated human SH-SY5Y neuroblastoma and the THP-1 promonocytic cell lines. Transcriptomic and RT-qPCR studies using THP-1 cells were performed to monitor the effects of the GYY4137 on multiple signaling pathways, including various immune-related and proinflammatory genes after combined action of LPS and GYY4137.

RESULTS

The GYY4137 and sodium hydrosulfide differed in the ability to reduce the production of the LPS-evoked proinflammatory mediators. The pre-treatment with GYY4137 resulted in a drastic down-regulation of many TNF-α effectors that are induced by LPS treatment in THP-1 cells. Furthermore, GYY4137 pretreatment of LPS-exposed cells ameliorates the LPS-mediated induction of multiple pro-inflammatory genes and decreases expression of immunoproteasome genes. Besides, in these experiments we detected the up-regulation of several important pathways that are inhibited by LPS.

CONCLUSION

Based on the obtained results we believe that our transcriptomic analysis significantly contributes to the understanding of the molecular mechanisms of anti-inflammatory and cytoprotective activity of hydrogen sulfide donors, and highlights their potential against LPS challenges and other forms of inflammation.

Heat stress combined with lipopolysaccharide alter the activity and superficial molecules of peripheral monocytes

The purpose of this study was to focus on the underlying relationship between the hyperactivity for the peripheral monocytes and heat stroke by investigating the inflammatory oxidative activity of and the expression of superficial molecules. Peripheral blood samples were collected from 10 healthy adult volunteers. Human blood monocytes were isolated by density gradient centrifugation and sequent adherent culture. The objectives were divided into four groups: 43°C heat stress combined with lipopolysaccharide (LPS) group, 43°C heat stress group, LPS group, and control group. There were 10 cases in each group. An enzyme-linked immunosorbent assay (ELISA) test was used to measure the concentrations of supernatant inflammatory mediators (tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-10 (IL-10)). After loaded by 2,7-Dichlorodi-hydrofluorescein-diacetate (DCFHDA) fluorescent probe, intracellular reactive oxygen species (ROS) levels were determined by a flow cytometry. After fluorescent microspheres incubation, the phagocytosis of monocytes was observed under a fluorescent microscope. Respectively, the flow cytometry and Western blot were used to evaluate the level of triggering receptor expressed on myeloid cells-1 (TREM-1) and Toll-like receptor-4 (TLR-4) on the monocytes. Furthermore, the mRNA expression of TREM-1 and TLR-4 was detected by real-time polymerase chain reaction (RT-PCR). The heat stress combined with LPS stimulation promoted the peripheral monocytes to produce inflammatory mediators (TNF-α, IL-1β, and IL-10) and release ROS. Otherwise, such complex strike significantly suppressed the phagocytic activity of monocytes in peripheral blood. Moreover, the expression of TREM-1, TLR-4 and CD86 was measured by the flow cytometry on peripheral monocytes which were respectively promoted by the union of heat stress and LPS. The results of Western blot and RT-PCR demonstrated the similar kinetics on these superficial molecules (TREM-1, TLR-4, and CD86) stimulated by the combination of heat stress and LPS. The underlying mechanism of the dysfunction for the peripheral monocytes may be related to the abnormal expression of superficial molecules TREM-1, TLR-4, and CD86 on the monocytes induced by heat stress and LPS.