HSP-70-Mediated Hyperbaric Oxygen Reduces Brain and Pulmonary Edema and Cognitive Deficits in Rats in a Simulated High-Altitude Exposure

Abstract

High-mountain sickness is characterized by brain and pulmonary edema and cognitive deficits. The definition can be fulfilled by a rat model of high-altitude exposure (HAE) used in the present study. This study aimed to investigate the protective effect of hyperbaric oxygen therapy (HBO2T) and to determine the underlying mechanisms. Rats were subjected to an HAE (9.7% O2 at 0.47 absolute atmosphere of 6,000 m for 3 days). Immediately after termination of HAE, rats were treated with HBO2T (100% O2 at 2.0 absolute atmosphere for 1 hour per day for 5 consecutive days) or non-HBO2T (21% O2 at 1.0 absolute atmosphere for 1 hour per day for 5 consecutive days). As compared to non-HAE+non-HBO2T controls, the HAE+non-HBO2T rats exhibited brain edema and resulted in cognitive deficits, reduced food and water consumption, body weight loss, increased cerebral inflammation and oxidative stress, and pulmonary edema. HBO2T increased expression of both hippocampus and lung heat shock protein (HSP-70) and also reversed the HAE-induced brain and pulmonary edema, cognitive deficits, reduced food and water consumption, body weight loss, and brain inflammation and oxidative stress. Decreasing the overexpression of HSP-70 in both hippocampus and lung tissues with HSP-70 antibodies significantly attenuated the beneficial effects exerted by HBO2T in HAE rats. Our data provide in vivo evidence that HBO2T works on a remodeling of brain/lung to exert a protective effect against simulated high-mountain sickness via enhancing HSP-70 expression in HAE rats.

B2M is a Biomarker Associated With Immune Infiltration In High Altitude Pulmonary Edema

“…These studies showed that compared with the control group, the metabolism, oxidative stress, and apoptosis of the HAPE group were enhanced, the antigen presentation ability involved in MCH I molecules decreased, and there may be activation of infection pathways. Studies have shown that HAPE is associated with increased oxidative stress, metabolism and apoptosis, and is also prone to secondary infection, which is consistent with our findings [ 44 , 45 ].…”

Posterior reversible encephalopathy syndrome secondary to acute post-streptococcal glomerulonephritis in a child: a case report from the Tibetan plateau

“…HBO therapy has been shown to decrease cerebral oedema, attenuate inflammation, decrease apoptotic cell death, and promote neural regeneration in a variety of animal models [ 19 ]. In rats exposed to a high altitude, HBO therapy significantly inhibited the upregulation of IL-1β, IL-6, TNF-α, and IF-γ in brain tissue, and HBO therapy attenuated brain and pulmonary oedema by inducing HSP-70 expression [ 20 ]. Another study in minipigs with intracerebral haemorrhage (ICH) at high altitude demonstrated that HBO therapy mitigated blood–brain barrier disruption and suppressed the progression of brain oedema [ 21 ].…”

The Effect of Hemoglobin Concentration on Hyperbaric Oxygen and Non-hyperbaric Oxygen in the Treatment of Hypertensive Intracerebral Hemorrhage After Operation at the High Altitude

“…However, the hemoglobin concentration increases at high altitudes, and the pathophysiology is different from that at low altitudes ( Yu et al, 2014 ; Cavalcante and Ormond, 2018 ). HBO treatment can transport oxygen to hypoxic tissue through higher-than-normal atmospheric pressure, reduce brain edema, improve oxygen diffusion ability and ameliorate nerve cell function ( Wu et al, 2018 ). In addition, studies have shown that intracerebral hemorrhage is essentially an inflammatory reaction ( Weng et al, 2015 ).…”