Melatonin modulates the aggravation of pyroptosis, necroptosis, and neuroinflammation following cerebral ischemia and reperfusion injury in obese rats

PRDM1 promotes nucleus pulposus cell pyroptosis leading to intervertebral disc degeneration via activating CASP1 transcription

Intervertebral disc degeneration (IVDD) is a primary contributor to low back pain and poses a considerable burden to society. However, the molecular mechanisms underlying IVDD remain to be elucidated. PR/SET domain 1 (PRDM1) regulates cell proliferation, apoptosis, and inflammatory responses in various diseases. Despite these regulatory functions, the mechanism of action of PRDM1 in IVDD remains unexplored. In this study, we investigated the role and underlying mechanisms of action of PRDM1 in IVDD progression. The expression of PRDM1 in nucleus pulposus (NP) tissues and NP cells (NPCs) was assessed using western blotting, immunohistochemistry, and immunofluorescence. The effects of PRDM1 on IVDD progression were investigated in vitro and in vivo. Mechanistically, mRNA sequencing, chromatin immunoprecipitation, and dual-luciferase reporter assays were performed to confirm that PRDM1 triggered CASP1 transcription. Our study demonstrated for the first time that PRDM1 expression was substantially upregulated in degenerated NP tissues and NPCs. PRDM1 overexpression promoted NPCs pyroptosis by inhibiting mitophagy and exacerbating IVDD progression, whereas PRDM1 silencing exerted the opposite effect. Furthermore, PRDM1 activated CASP1 transcription, thereby promoting NPCs pyroptosis in vitro. Notably, CASP1 silencing reversed the effects of PRDM1 on the NPCs. To the best of our knowledge, this study is the first to demonstrate that PRDM1 silencing inhibits NPCs pyroptosis by repressing CASP1 transcription, which may be a promising new therapeutic target for IVDD.

β-Hydroxybutyrate and melatonin suppress maladaptive UPR, excessive autophagy and pyroptosis in Aβ 1-42 and LPS-Induced SH-SY5Y cells

BACKGROUND

Alzheimer's disease is a neurological disease characterized by the build-up of amyloid beta peptide (Aβ) and lipopolysaccharide (LPS), which causes synapse dysfunction, cell death, and neuro-inflammation. A maladaptive unfolded protein response (UPR), excessive autophagy, and pyroptosis aggravate the disease. Melatonin (MEL) and hydroxybutyrate (BHB) have both shown promise in terms of decreasing Aβ pathology. The goal of this study was to see how BHB and MEL affected the UPR, autophagy, and pyroptosis pathways in Aβ1-42 and LPS-induced SH-SY5Y cells.

MATERIALS AND METHODS

Human neuroblastoma SH-SY5Y cells were treated with BHB, MEL, or a combination of the two after being exposed to A β1-42 and LPS. Cell viability was determined using the MTT test, and gene expression levels of UPR (ATF6, PERK, and CHOP), autophagy (Beclin-1, LC3II, P62, and Atg5), and pyroptosis-related markers (NLRP3, TXNIP, IL-1β, and NFκB1) were determined using quantitative Real-Time PCR (qRT-PCR). For statistical analysis, one-way ANOVA was employed, followed by Tukey's post hoc test.

RESULTS

BHB and MEL significantly increased SH-SY5Y cell viability in the presence of A β1-42 and LPS. Both compounds inhibited the expression of maladaptive UPR and autophagy-related genes, as well as inflammatory and pyroptotic markers caused by Aβ1-42 and LPS-induced SH-SY5Y cells.

CONCLUSION

BHB and MEL rescue neurons in A β1-42 and LPS-induced SH-SY5Y cells by reducing maladaptive UPR, excessive autophagy, and pyroptosis. More research is needed to fully comprehend the processes behind their beneficial effects and to discover their practical applications in the treatment of neurodegenerative disorders.

Curcumin-primed olfactory mucosa-derived mesenchymal stem cells mitigate cerebral ischemia/reperfusion injury-induced neuronal PANoptosis by modulating microglial polarization

BACKGROUND

Cerebral ischemia-reperfusion (I/R) injury often leads to neuronal death through persistent neuroinflammatory responses. Recent research has unveiled a unique inflammatory programmed cell death mode known as PANoptosis. However, direct evidence for PANoptosis in ischemic stroke-induced neuronal death has not been established. Although it is widely thought that modulating the balance of microglial phenotypic polarization in cerebral I/R could mitigate neuroinflammation-mediated neuronal death, it remains unknown whether microglial polarization influences PANoptotic neuronal death triggered by cerebral I/R. Our prior study demonstrated that curcumin (CUR) preconditioning could boost the neuroprotective properties of olfactory mucosa-derived mesenchymal stem cells (OM-MSCs) in intracerebral hemorrhage. Yet, the potential neuroprotective capacity of curcumin-pretreated OM-MSCs (CUR-OM-MSCs) on reducing PANoptotic neuronal death during cerebral I/R injury through modulating microglial polarization is uncertain.

METHODS

To mimic cerebral I/R injury, We established in vivo models of reversible middle cerebral artery occlusion (MCAO) in C57BL/6 mice and in vitro models of oxygen-glucose deprivation/reoxygenation (OGD/R) in HT22 neurons and BV2 microglia.

RESULTS

Our findings indicated that cerebral I/R injury caused PANoptotic neuronal death and triggered microglia to adopt an M1 (pro-inflammatory) phenotype both in vivo and in vitro. Curcumin pretreatment enhanced the proliferation and anti-inflammatory capacity of OM-MSCs. The CUR-OM-MSCs group experienced a more pronounced reduction in PANoptotic neuronal death and a better recovery of neurological function than the OM-MSCs group. Bioinformatic analysis revealed that microRNA-423-5p (miRNA-423-5p) expression was obviously upregulated in CUR-OM-MSCs compared to OM-MSCs. CUR-OM-MSCs treatment induced the switch to an M2 (anti-inflammatory) phenotype in microglia by releasing miRNA-423-5p, which targeted nucleotide-binding oligomerization domain 2 (NOD2), an upstream regulator of NF-kappaB (NF-κB) and Mitogen-Activated Protein Kinase (MAPK) signaling pathways, to attenuate PANoptotic neuronal death resulting from cerebral I/R.

CONCLUSION

This results provide the first demonstration of the existence of PANoptotic neuronal death in cerebral I/R conditions. Curcumin preconditioning enhanced the ameliorating effect of OM-MSCs on neuroinflammation mediated by microglia polarization via upregulating the abundance of miRNA-423-5p. This intervention effectively alleviates PANoptotic neuronal death resulting from cerebral I/R. The combination of curcumin with OM-MSCs holds promise as a potentially efficacious treatment for cerebral ischemic stroke in the future.

Systematic review of melatonin in cerebral ischemia-reperfusion injury: critical role and therapeutic opportunities

Cerebral ischemia-reperfusion (I/R) injury is the predominant causes for the poor prognosis of ischemic stroke patients after reperfusion therapy. Currently, potent therapeutic interventions for cerebral I/R injury are still very limited. Melatonin, an endogenous hormone, was found to be valid in preventing I/R injury in a variety of organs. However, a systematic review covering all neuroprotective effects of melatonin in cerebral I/R injury has not been reported yet. Thus, we perform a comprehensive overview of the influence of melatonin on cerebral I/R injury by collecting all available literature exploring the latent effect of melatonin on cerebral I/R injury as well as ischemic stroke. In this systematic review, we outline the extensive scientific studies and summarize the beneficial functions of melatonin, including reducing infarct volume, decreasing brain edema, improving neurological functions and attenuating blood-brain barrier breakdown, as well as its key protective mechanisms on almost every aspect of cerebral I/R injury, including inhibiting oxidative stress, neuroinflammation, apoptosis, excessive autophagy, glutamate excitotoxicity and mitochondrial dysfunction. Subsequently, we also review the predictive and therapeutic implications of melatonin on ischemic stroke reported in clinical studies. We hope that our systematic review can provide the most comprehensive introduction of current advancements on melatonin in cerebral I/R injury and new insights into personalized diagnosis and treatment of ischemic stroke.

Emerging diagnostic markers and therapeutic targets in post-stroke hemorrhagic transformation and brain edema

Stroke is a devastating condition that can lead to significant morbidity and mortality. The aftermath of a stroke, particularly hemorrhagic transformation (HT) and brain edema, can significantly impact the prognosis of patients. Early detection and effective management of these complications are crucial for improving outcomes in stroke patients. This review highlights the emerging diagnostic markers and therapeutic targets including claudin, occludin, zonula occluden, s100β, albumin, MMP-9, MMP-2, MMP-12, IL-1β, TNF-α, IL-6, IFN-γ, TGF-β, IL-10, IL-4, IL-13, MCP-1/CCL2, CXCL2, CXCL8, CXCL12, CCL5, CX3CL1, ICAM-1, VCAM-1, P-selectin, E-selectin, PECAM-1/CD31, JAMs, HMGB1, vWF, VEGF, ROS, NAC, and AQP4. The clinical significance and implications of these biomarkers were also discussed.