N6022 attenuates cerebral ischemia/reperfusion injury-induced microglia ferroptosis by promoting Nrf2 nuclear translocation and inhibiting the GSNOR/GSTP1 axis.

Stroke poses a significant risk of mortality, particularly among the elderly population. The pathophysiological process of ischemic stroke is complex, and it is crucial to elucidate its molecular mechanisms and explore potential protective drugs. Ferroptosis, a newly recognized form of programmed cell death distinct from necrosis, apoptosis, and autophagy, is closely associated with the pathophysiology of ischemic stroke. N6022, a selective inhibitor of S-nitrosoglutathione reductase (GSNOR), is a "first-in-class" drug for asthma with potential therapeutic applications. However, it remains unclear whether N6022 exerts protective effects in ischemic stroke, and the precise mechanisms of its action are unknown. This study aimed to investigate whether N6022 mitigates cerebral ischemia/reperfusion (I/R) injury by reducing ferroptosis and to elucidate the underlying mechanisms. Accordingly, we established an oxygen-glucose deprivation/reperfusion (OGD/R) cell model and a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model to mimic cerebral I/R injury. Our data, both in vitro and in vivo, demonstrated that N6022 effectively protected against I/R-induced brain damage and neurological deficits in mice, as well as OGD/R-induced BV2 cell damage. Mechanistically, N6022 promoted Nrf2 nuclear translocation, enhancing intracellular antioxidant capacity of SLC7A11-GPX4 system. Furthermore, N6022 interfered with the interaction of GSNOR with GSTP1, thereby boosting the antioxidant capacity of GSTP1 and attenuating ferroptosis. These findings provide novel insights, showing that N6022 attenuates microglial ferroptosis induced by cerebral I/R injury through the promotion of Nrf2 nuclear translocation and inhibition of the GSNOR/GSTP1 axis.

Therapeutic strategies targeting the NLRP3­mediated inflammatory response and pyroptosis in cerebral ischemia/reperfusion injury (Review).

Ischemic stroke poses a major threat to human health. Therefore, the molecular mechanisms of cerebral ischemia/reperfusion injury (CIRI) need to be further clarified, and the associated treatment approaches require exploration. The NOD­like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome serves an important role in causing CIRI, and its activation exacerbates the underlying injury. Activation of the NLRP3 inflammasome triggers the maturation and production of the inflammatory molecules IL­1ß and IL­18, as well as gasdermin­D­mediated pyroptosis and CIRI damage. Thus, the NLRP3 inflammasome may be a viable target for the treatment of CIRI. In the present review, the mechanisms of the NLRP3 inflammasome in the intense inflammatory response and pyroptosis induced by CIRI are discussed, and the therapeutic strategies that target the NLRP3­mediated inflammatory response and pyroptosis in CIRI are summarized. At present, certain drugs have already been studied, highlighting future therapeutic perspectives.

SLC18A3 promoted renal cancer development through acetylcholine/cAMP signaling.

Renal cancer displays a high metastatic potential and a poor response to chemotherapy. However, the critical contributors to renal cancer development remain elusive. This study focused on acetylcholine (ACh) signaling. We identified the vesicular acetylcholine transporter (SLC18A3) that upregulates in patients with renal cancer. We further discovered that SLC18A3 enhanced the uptake of ACh, a classical neurotransmitter mediating synaptic transmission. The elevated ACh activated the protein kinase A (PKA)/cAMP-response element binding protein (CREB) pathway, which contributed to renal cancer cell proliferation and invasive migration. Consistently, SLC18A3 overexpression caused sustained tumor growth and increased lung metastases in A489-bearing mice. In summary, our study demonstrated that SLC18A3 contributed to cancer spread in an ACh/PKA/CREB-dependent manner, which may drive the design of efficacious treatment strategies.

Multiple-biomarkers provide powerful prediction of early acute renal allograft rejection by combination of serum fractalkine, IFN-γ and IP-10.

Biomarkers are urgently required for predicting rejection so that anti-rejection treatment can be taken early to protect the allograft from irreversible damage. We hypothesized that the combination of circulating fractalkine, IFN-γ and IP-10 might serve as effective biomarkers for predicting early acute renal allograft rejection. We conducted a retrospective study of 87 subjects, who were classified into acute rejection group (ARG; n = 38) and non-rejection group (NRG; n = 49). Serum fractalkine, IFN-γ and IP-10 levels were measured by Luminex. The levels of fractalkine on day 0 and 7th day, IP-10 on 4th and 7th day, and IFN-γ on 7th day in ARG was significantly higher than that in NRG. Kaplan-Meier survival analysis highlighted the higher-levels groups of fractalkine on day 0, 4th and 7th day, IFN-γ on day 0, 1st, 4th, and 7th day and IP-10 on the 4th and 7th day in rejection-free survival probability were significantly lower than low-levels groups. ROC analyses highlight the superiority of fractalkine on day 0, IP-10 on day 0, 4th and 7th day, and IFN-γ on day 0, 1st and 7th day in prediction of acute rejection. We found the combination of fractalkine on day 0, IP-10 on 7th day and IFN-γ on 7th day had the highest AUC (0.866) for predicting rejection with a sensitivity of 86.8% and a specificity of 89.8%. Our findings demonstrated a more powerful prediction of early acute renal allograft rejection during the first month after transplantation by combination of multiple-biomarkers of fractalkine, IFN-γ and IP-10, and the results might help stratify the immunologic risk of acute allograft rejection in recipients.

Kidney injury molecule-1 and osteopontin: new markers for prediction of early kidney transplant rejection.

BACKGROUND: Kidney injury molecule-1 (KIM-1) and osteopontin (OPN) play important roles in immune regulation. We hypothesized that serum KIM-1 and OPN might serve as biomarkers for predicting early acute rejection after kidney transplantation (KTx). METHODS: We conducted a single-center study of 155 subjects, who were classified into acute rejection group (ARG, n=32), non-rejection group (NRG, n=45) and healthy controls (HC, n=78). Serum KIM-1 and OPN levels were measured by Luminex. RESULTS: The pre-transplant levels of serum KIM-1 and OPN in all KTx recipients were higher than those of HC (P<0.01). Compared with NRG, ARG showed significantly high serum levels of KIM-1 on day 0 (pre-KTx) and on the 1st, 4th, and 7th post-KTx days, and significantly high OPN levels on day 0 and the 7th day. Kaplan-Meier survival analysis showed that the higher levels of KIM-1 on day 0, the 1st and 4th days and OPN on day 0 and the 7th day were significantly associated with the lower probabilities of rejection-free survival. ROC analyses highlight the superiority of KIM-1 on the 1st day and OPN on the 7th day over those on other post-KTx days in prediction of acute rejection episodes. Multivariate logistic analysis revealed that the serum KIM-1 levels on the 1st post-KTx day and the OPN level on the 7th day were independent and powerful predictors of acute rejection episodes. An optimal predictive model was built by combining KIM-1 on the 1st day and OPN on the 7th day, and this model had the highest AUC (0.922). CONCLUSIONS: This study was the first to demonstrate that serum KIM-1 and OPN may be the promising and elegant markers for prediction of early acute kidney allograft rejection.