Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury that induces cytokine hypersecretion. Receptor activity-modifying protein (RAMP) 1, a subunit of the calcitonin gene-related peptide (CGRP) receptor, regulates the production of cytokines. This study examined the role of RAMP1 signaling during lipopolysaccharide (LPS)-induced acute lung injury (ALI). LPS administration to wild-type (WT) mice depleted alveolar macrophages (AMs) and recruited monocyte-derived macrophages (MDMs) and neutrophils. RAMP1-deficient (RAMP1^−/−) mice exhibited higher lung injury scores, cytokine levels, and cytokine-producing neutrophil infiltration. RAMP1-deficient AMs produced more cytokines in response to LPS than WT AMs. Adoptive transfer of RAMP1-deficient AMs to RAMP1^−/− mice increased cytokine levels and neutrophil accumulation compared to the transfer of WT AMs. RAMP1^−/− mice had reduced MDM recruitment and lower pro-inflammatory and reparative macrophage profiles. Cultured bone marrow (BM)-derived RAMP1-deficient macrophages stimulated with LPS showed decreased expression of pro-inflammatory and pro-repairing genes. CGRP administration to WT mice reduced cytokine production and neutrophil accumulation. These findings indicate that RAMP1 signaling mitigates LPS-induced ALI by inactivating AMs and promoting inflammatory and repair activities of MDMs. Targeting RAMP1 signaling presents a potential therapeutic approach for the treatment of ARDS.

Background: Congenital myasthenia syndrome is a heterogeneous disease with impaired neuromuscular transmission. Case presentation: This report describes a 13-year-old child with congenital myasthenia syndrome who underwent surgery for scoliosis under general anesthesia. We used a small dose of rocuronium, neuromuscular transmission monitoring, and non-invasive positive pressure ventilation for postoperative respiratory management. There were no respiratory complications during the perioperative period. Conclusion: As there are only a few reports on the anesthetic management of patients with congenital myasthenia syndrome, we applied the principles of managing autoimmune myasthenia gravis. The postoperative management described herein can prevent respiratory complications in patients with congenital myasthenia syndrome.

Liver ischemia-reperfusion (IR) injury is a substantial form of damage that occurs during liver transplantation and resection surgeries. Steatotic livers are particularly susceptible to IR injury, but few strategies to effectively alleviate this issue in steatotic livers exist. Invariant natural killer T (iNKT) cells regulate IR injury in healthy livers as well as liver repair by interacting with macrophages. In this study, we explored the role of iNKT cell-macrophage crosstalk in IR injury in steatotic livers. High-fat diet (HFD)-fed macrophage-specific CD1d conditional knockout (Cd1d^△mac) and Cd1d^flox control (Cont) mice were subjected to liver IR. HFD-fed CD1d^△mac mice showed mitigation of IR-induced liver damages with reduction of hepatic necrosis and inflammation along with promotion of liver repair. Flow cytometric analysis revealed that HFD-fed Cd1d^△mac mice showed increased hepatic reparative macrophages and interleukin (IL)-13-positive iNKT cells but decreased pro-inflammatory macrophages with IL-1β. IL-13 administration to HFD-fed Cont mice attenuated IR injury and accelerated liver recovery, which was associated with accumulation of hepatic macrophages skewed to a reparative phenotype. IL-13 promoted reparative macrophage polarization in bone marrow (BM)-derived Cd1d-deficient macrophages in vitro. Blockade of IL-13 in HFD-fed Cd1d^△mac mice aggravated IR injury. Overall, inhibiting iNKT cell-macrophage crosstalk attenuates steatotic liver IR injury and facilitates liver repair via IL-13-mediated reparative macrophage polarization. These findings provide new insights into therapeutic strategies to regulate the vulnerability of the steatotic liver to IR injury.