RETRACTED: Cerebral ischemia-induced elevation of hepatic inflammatory factors accompanied by glucose intolerance suppresses hypothalamic orexin-A-mediated vagus nerve activation

Interactions between the Autonomic Nervous System and the Immune System after Stroke

Acute stroke is one of the leading causes of morbidity and mortality worldwide. Stroke-induced immune-inflammatory response occurs in the perilesion areas and the periphery. Although stroke-induced immunosuppression may alleviate brain injury, it hinders brain repair as the immune-inflammatory response plays a bidirectional role after acute stroke. Furthermore, suppression of the systemic immune-inflammatory response increases the risk of life-threatening systemic bacterial infections after acute stroke. Therefore, it is essential to explore the mechanisms that underlie the stroke-induced immune-inflammatory response. Autonomic nervous system (ANS) activation is critical for regulating the local and systemic immune-inflammatory responses and may influence the prognosis of acute stroke. We review the changes in the sympathetic and parasympathetic nervous systems and their influence on the immune-inflammatory response after stroke. Importantly, this article summarizes the mechanisms on how ANS regulates the immune-inflammatory response through neurotransmitters and their receptors in immunocytes and immune organs after stroke. To facilitate translational research, we also discuss the promising therapeutic approaches modulating the activation of the ANS or the immune-inflammatory response to promote neurologic recovery after stroke. © 2022 American Physiological Society. Compr Physiol 12:3665-3704, 2022.

Interleukin-13 ameliorates postischemic hepatic gluconeogenesis and hyperglycemia in rat model of stroke

Hyperglycemia is a well-known indicator of stroke prognosis, and one-third of nondiabetic patients develop postischemic hyperglycemia during the acute phase of stroke; this is related to relatively poor prognosis, high mortality, and impaired neurological recovery. Interleukin-13 (IL-13), a member of the Th2 cytokine family, is involved in both the regulation of immune response and glucose metabolism. Thus, we investigated the mechanism of postischemic hyperglycemia and the role of IL-13 by using a permanent middle cerebral artery occlusion (MCAO) rat model. Our results indicated that postischemic hyperglycemia was accompanied with hyperinsulinemia and increased HOMA-IR, elevated hepatic gluconeogenesis, and suppressed insulin signaling. A shift towards inflammatory response was evident with results of elevated proinflammatory cytokines and increased expression of negative regulatory proteins, suggesting an ongoing vicious cycle of inflammatory-induced insulin-resistant hyperglycemia. IL-13 treatment counteracted the proinflammatory states and abolished the vicious cycle through enhancing STAT6 and STAT3, which mediated the immune and metabolic pathways respectively; these effects resolved the formerly described pathological changes of postischemic hyperglycemia and reduced infarction size in the MCAO rats. Our findings demonstrated the importance of Th1-Th2 balance in the peripheral glucose metabolism affected by acute ischemic stroke, which provides a new perspective for the prevention and control of postischemic hyperglycemia.