Tim-3 enhances brain inflammation by promoting M1 macrophage polarization following intracerebral hemorrhage in mice

Tim-3 Deficiency Ameliorates Motor Deficits and Neuroinflammation in MPP+/MPTP-Induced Parkinson's Disease Models via the NF-κB/NLRP3 Pathway

Parkinson's disease (PD) is a common neurodegenerative disorder, and neuroinflammation plays a pivotal role in its pathogenesis. T-cell immunoglobulin and mucin-domain-containing molecule 3 (Tim-3) is a crucial immunoregulatory mediator in various diseases; however, its roles and underlying molecular mechanisms in PD remain unclear. We established in vitro and in vivo 1-methyl-4-phenylpyridinium (MPP+)/1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD models in Tim-3-knockout BV2 cells and mice, respectively. Motor function was assessed through behavioral tests, including pole, traction, forced swimming, and open field tests. Immunofluorescence was used to examine dopaminergic neuron loss and glial activation. The expression levels of nuclear factor-kappa B (NF-κB)/nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) pathway components were evaluated by western blotting. Proinflammatory cytokines were measured via enzyme-linked immunosorbent assay (ELISA). Compared with the wild-type, Tim-3 expression was significantly increased in the PD model, and Tim-3 deficiency mitigated MPTP-induced motor deficits, dopaminergic neuron loss, and glial cell activation. Furthermore, Tim-3 deficiency suppressed neuroinflammation by negatively modulating the NF-κB/NLRP3 pathway, thereby downregulating the expression of the proinflammatory cytokines IL-1β, IL-18, IL-6, and TNF-α. These findings indicate that Tim-3 plays a proinflammatory role in PD by regulating the NF-κB/NLRP3 pathway, highlighting Tim-3 as a promising therapeutic target for PD.

miR-874-3p Alleviates Macrophage-Mediated Inflammatory Injury in Intracerebral Hemorrhage by Targeting HIPK2

Macrophages mediate secondary inflammatory injury after intracerebral hemorrhage (ICH). This study aimed to investigate the role and molecular mechanisms of miR-874-3p in macrophage polarization. A mice model of ICH was constructed by autologous blood injection. Macrophages were treated with erythrocyte lysates to construct an ICH cell model. Real-time quantitative reverse transcription PCR (RT-qPCR) was used to detect miR-874-3p levels. Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect macrophage polarization markers. Brain tissue water content and neurological deficit scores were used to assess the degree of inflammatory injury in ICH mice. RNA immunoprecipitation (RIP) and Dual-luciferase reporter (DLR) assays were used to analyze the targeting relationship between miR-874-3p and target mRNA. miR-874-3p levels were decreased in ICH mice and erythrocyte lysates-treated macrophages. miR-874-3p mimic alleviated inflammatory injury, decreased the levels of M1 macrophage markers, and increased the levels of M2 macrophage markers, suggesting that miR-874-3p is involved in ICH by regulating macrophage polarization. HIPK2 is the target mRNA of miR-874-3p and has the opposite expression pattern of miR-874-3p. Overexpression of HIPK2 attenuates the effect of elevated miR-874-3p levels on macrophage polarization and inflammatory brain injury in ICH mice. miR-874-3p regulates macrophage polarization in ICH by targeting HIPK2. Therefore, the miR-874-3p/HIPK2 axis may be a promising target for ICH treatment.

Crosstalk between ferroptosis and innate immune in diabetic kidney disease: mechanisms and therapeutic implications

Diabetic kidney disease (DKD) is a prevalent complication of diabetes mellitus (DM), and its incidence is increasing alongside the number of diabetes cases. Effective treatment and long-term management of DKD present significant challenges; thus, a deeper understanding of its pathogenesis is essential to address this issue. Chronic inflammation and abnormal cell death in the kidney closely associate with DKD development. Recently, there has been considerable attention focused on immune cell infiltration into renal tissues and its inflammatory response's role in disease progression. Concurrently, ferroptosis-a novel form of cell death-has emerged as a critical factor in DKD pathogenesis, leading to increased glomerular filtration permeability, proteinuria, tubular injury, interstitial fibrosis, and other pathological processes. The cardiorenal benefits of SGLT2 inhibitors (SGLT2-i) in DKD patients have been demonstrated through numerous large clinical trials. Moreover, further exploratory experiments indicate these drugs may ameliorate serum and urinary markers of inflammation, such as TNF-α, and inhibit ferroptosis in DKD models. Consequently, investigating the interplay between ferroptosis and innate immune and inflammatory responses in DKD is essential for guiding future drug development. This review presents an overview of ferroptosis within the context of DKD, beginning with its core mechanisms and delving into its potential roles in DKD progression. We will also analyze how aberrant innate immune cells, molecules, and signaling pathways contribute to disease progression. Finally, we discuss the interactions between ferroptosis and immune responses, as well as targeted therapeutic agents, based on current evidence. By analyzing the interplay between ferroptosis and innate immunity alongside its inflammatory responses in DKD, we aim to provide insights for clinical management and drug development in this area.

Mechanisms and therapeutic targets of mitophagy after intracerebral hemorrhage

Mitochondria are dynamic organelles responsible for cellular energy production. In addition to regulating energy homeostasis, mitochondria are responsible for calcium homeostasis, clearance of damaged organelles, signaling, and cell survival in the context of injury and pathology. In stroke, the mechanisms underlying brain injury secondary to intracerebral hemorrhage are complex and involve cellular hypoxia, oxidative stress, inflammatory responses, and apoptosis. Recent studies have shown that mitochondrial damage and autophagy are essential for neuronal metabolism and functional recovery after intracerebral hemorrhage, and are closely related to inflammatory responses, oxidative stress, apoptosis, and other pathological processes. Because hypoxia and inflammatory responses can cause secondary damage after intracerebral hemorrhage, the restoration of mitochondrial function and timely clearance of damaged mitochondria have neuroprotective effects. Based on studies on mitochondrial autophagy (mitophagy), cellular inflammation, apoptosis, ferroptosis, the BNIP3 autophagy gene, pharmacological and other regulatory approaches, and normobaric oxygen (NBO) therapy, this article further explores the neuroprotective role of mitophagy after intracerebral hemorrhage.

Identification of a novel MYC target gene set signature for predicting the prognosis of osteosarcoma patients

Osteosarcoma is a primary malignant tumor found mainly in teenagers and young adults. Patients have very little long-term survival. MYC controls tumor initiation and progression by regulating the expression of its target genes; thus, constructing a risk signature of osteosarcoma MYC target gene set will benefit the evaluation of both treatment and prognosis. In this paper, we used GEO data to download the ChIP-seq data of MYC to obtain the MYC target gene. Then, a risk signature consisting of 10 MYC target genes was developed using Cox regression analysis. The signature indicates that patients in the high-risk group performed poorly. After that, we verified it in the GSE21257 dataset. In addition, the difference in tumor immune function among the low- and high-risk populations was compared by single sample gene enrichment analysis. Immunotherapy and prediction of response to the anticancer drug have shown that the risk signature of the MYC target gene set was positively correlated with immune checkpoint response and drug sensitivity. Functional analysis has demonstrated that these genes are enriched in malignant tumors. Finally, STX10 was selected for functional experimentation. STX10 silence has limited osteosarcoma cell migration, invasion, and proliferation. Therefore, these findings indicated that the MYC target gene set risk signature could be used as a potential therapeutic target and prognostic indicator in patients with osteosarcoma.

Role of Inflammatory Processes in Hemorrhagic Stroke

Hemorrhagic stroke is the deadliest form of stroke and includes the subtypes of intracerebral hemorrhage and subarachnoid hemorrhage. A common cause of hemorrhagic stroke in older individuals is cerebral amyloid angiopathy. Intracerebral hemorrhage and subarachnoid hemorrhage both lead to the rapid collection of blood in the central nervous system and generate inflammatory immune responses that involve both brain resident and infiltrating immune cells. These responses are complex and can contribute to both tissue recovery and tissue injury. Despite the interconnectedness of these major subtypes of hemorrhagic stroke, few reviews have discussed them collectively. The present review provides an update on inflammatory processes that occur in response to intracerebral hemorrhage and subarachnoid hemorrhage, and the role of inflammation in the pathophysiology of cerebral amyloid angiopathy-related hemorrhage. The goal is to highlight inflammatory processes that underlie disease pathology and recovery. We aim to discuss recent advances in our understanding of these conditions and identify gaps in knowledge with the potential to develop effective therapeutic strategies.

Prognostic Role of Serum Soluble Tim-3 in Severe Traumatic Brain Injury: A Prospective Observational Study

OBJECTIVE

T cell immunoglobulin and mucin domain-3 (Tim-3) may be implicated in neuroinflammation. Herein, we attempted to discern the role of serum soluble (s) Tim-3 as an inflammatory prognostic biomarker of severe traumatic brain injury (sTBI).

METHODS

In this prospective observational study of 112 sTBI patients and 112 controls, serum sTim-3 levels were determined, Rotterdam computed tomography (CT) classification and Glasgow coma scale (GCS) were selected as the two severity indicators, serum C-reactive protein (CRP) was regarded as an inflammatory biomarker, and poor prognosis was referred to as extended Glasgow outcome scale (GOSE) scores 1-4 at 180 days after trauma.

RESULTS

Serum sTim-3 levels were markedly higher in patients than in controls (median, 4.2 ng/mL versus 0.7 ng/mL; P<0.001). Serum sTim-3 levels of patients were independently related to Rotterdam CT scores (β=1.126), GCS scores (β=-0.589), serum CRP levels (β=0.155) and GOSE scores (β=-0.211). Serum sTim-3 appeared as an independent predictor of post-traumatic 180-day mortality (odds ratio=1.289), overall survival (hazard ratio=1.208) and poor prognosis (odds ratio=1.293). Serum sTim-3 levels discriminated patients at risk of post-injury 180-day mortality and poor prognosis with areas under curve (AUCs) at 0.753 and 0.782, respectively. Serum sTim-3 levels combined with GCS scores and Rotterdam CT scores (AUC=0.869) exhibited significantly higher AUC than Rotterdam CT scores (P=0.026), but not than GCS scores (P=0.181) for death prediction and their combination (AUC=0.895) had significantly higher AUC than GCS scores (P=0.036) or Rotterdam CT scores (P=0.005) for outcome prediction.

CONCLUSION

Elevated serum sTim-3 levels, in close correlation with traumatic severity and inflammation, are substantially associated with long-term death and poor outcome, indicating that serum sTim-3, as an inflammatory biomarker, may be of clinical significance in severity assessment and prediction of prognosis following sTBI.

The potential for immune checkpoint modulators in cerebrovascular injury and inflammation

Introduction: Neuroinflammation has been linked to poor neurologic and functional outcomes in many cerebrovascular disorders. Immune checkpoints are upregulated in the setting of traumatic brain injury, intracerebral hemorrhage, ischemic stroke, central nervous systems vasculitis, and post-hemorrhagic vasospasm, and are potential mediators of pathologic inflammation. Burgeoning evidence suggests that immune checkpoint modulation is a promising treatment strategy to decrease immune cell recruitment, cytokine secretion, brain edema, and neurodegeneration.Areas covered: This review discusses the role of immune checkpoints in neuroinflammation, and the potential for therapeutic immune checkpoint modulation in inflammatory cerebrovascular disorders. A search of Pubmed and clinicaltrials.gov was performed to find relevant literature published within the last 50 years.Expert opinion: The clinical success of immune-activating checkpoint modulators in human cancers has shown the immense clinical potential of checkpoint-based immunotherapy. Given that checkpoint blockade can also precipitate a pathologic pro-inflammatory or autoimmune response, it is plausible that these pathways may also be targeted to quell aberrant inflammation. A limited but growing number of studies suggest that immune checkpoints play a critical role in regulating the immune response in the central nervous system in a variety of contexts, and that immune-deactivating checkpoint modulators may be a promising treatment strategy for acute and chronic neuroinflammation in cerebrovascular disorders.

Tim-3 deteriorates neuroinflammatory and neurocyte apoptosis after subarachnoid hemorrhage through the Nrf2/HMGB1 signaling pathway in rats

Inflammation is known to play an important role in early brain injury (EBI) after subarachnoid hemorrhage (SAH). T cell immunoglobulin and mucin domain-3 (Tim-3) has emerged as a critical regulator of adaptive and innate immune responses, and has been identified to play a vital role in certain inflammatory diseases; The present study explored the effect of Tim-3 on inflammatory responses and detailed mechanism in EBI following SAH. We investigated the effects of Tim-3 on SAH models established by endovascular puncture method in Sprague–Dawley rats. The present studies revealed that SAH induced a significant inflammatory response and significantly increased Tim-3 expression. Tim-3-AAV administration aggravated neurocyte apoptosis, brain edema, blood-brain barrier permeability, and neurological dysfunction; significantly inhibited Nrf2 expression; and increased HMGB1 expression and secretion of pro-inflammatory cytokines, such as tumor necrosis factor alpha, interleukin (IL)-1 beta, IL-17, and IL-18. However, Tim-3 siRNA or NK252 administration abolished the pro-inflammatory effects of Tim-3. Our results indicate a function for Tim-3 as a molecular player that links neuroinflammation and brain damage after SAH. We reveal that Tim-3 overexpression deteriorates neuroinflammatory and neurocyte apoptosis after subarachnoid hemorrhage through the Nrf2/HMGB1 signaling pathway in rats.

miR-330-5p inhibits NLRP3 inflammasome-mediated myocardial ischaemia-reperfusion injury by targeting TIM3

BACKGROUND/AIMS

The Nod-like receptor protein-3 (NLRP3) inflammasome signalling pathway is involved in the inflammatory reaction of myocardial ischaemia-reperfusion (I/R) injury. Our previous study showed that miR-330-5p was differentially expressed in both cerebral and myocardial I/R injury, and thus might be a biomarker for I/R injury-related diseases. Another study also indicated that miR-330-5p could promote NLRP3 inflammasome activation in renal IRI. However, the role of miR-330-5p in myocardial I/R injury-induced inflammatory responses is unknown. This study aimed to investigate the role of miR-330-5p in NLRP3 inflammasome-mediated myocardial I/R injury.

METHODS

Myocardial I/R injury was induced in mice by occlusion of the left anterior descending coronary artery for 45 min followed by reperfusion. For NLRP3 inflammasome stimulation in vitro, cardiomyocytes were treated with 2 h of oxygen and glucose deprivation (OGD) or LPS (100 ng/ml). Myocardial miR-330-5p expression was examined by PCR at different treatment times. A miR-330-5p antagomir and an agomir were used to regulate miR-330-5p expression. To evaluate the role of miR-330-5p in myocardial I/R injury, 2,3,5-triphenyltetrazolium chloride (TTC) staining, echocardiography, and immunoblotting were used to assess infarct volume, cardiac function, and NLRP3 inflammasome activation respectively. A luciferase binding assay was used to examine whether miR-330-5p could directly bind to the T cell immunoglobulin domain and mucin domain-containing molecule-3 (TIM3). Finally, the role of the miR-330-5p/TIM3 axis in regulating apoptosis and NLRP3 inflammasome formation was evaluated with flow cytometry assays and immunofluorescence staining.

RESULTS

Compared to that in the model group, the inhibition of miR-330-5p significantly aggravated myocardial I/R injury, resulting in increased infarct volume and more severe cardiac dysfunction. Moreover, inhibition of miR-330-5p significantly increased the levels of NLRP3 inflammasome-related proteins, including caspase-1, IL-1β, IL-18 and TNF-α, in both in-vivo and in-vitro models. Furthermore, TIM3 was confirmed as a potential target of miR-330-5p. As predicted, suppression of TIM3 by siRNA ameliorated the anti-miR-330-5p-mediated activation of the NLRP3 inflammasome induced by OGD and LPS, thus decreasing cardiomyocyte apoptosis.

CONCLUSIONS

Our study indicated that the miR-330-5p/TIM3 axis was involved in the regulatory mechanism of NLRP3 inflammasome-mediated myocardial inflammation.

Emerging therapeutic targets associated with the immune system in patients with intracerebral haemorrhage (ICH): From mechanisms to translation

Intracranial haemorrhage (ICH) is a life-threatening type of stroke with high mortality, morbidity, and recurrence rates. However, no effective treatment has been established to improve functional outcomes in patients with ICH to date. Strategies targeting secondary brain injury are of great interest in both experimental and translational studies. The immune system is increasingly considered to be a crucial contributor to ICH-induced brain injury because it participates in multiple phases of ICH, from the early vascular rupture events to brain recovery. Various pathobiological processes that contribute to secondary brain injury closely interact with the immune system, such as brain oedema, neuroinflammation, and neuronal damage. Hence, we summarize the immune response to ICH and recent progress in treatments targeting the immune system in this review. The emerging therapeutic strategies that target the immune system after ICH are a particular focus and have been summarized.

Tim-3 aggravates podocyte injury in diabetic nephropathy by promoting macrophage activation via the NF-κB/TNF-α pathway

Objective

Macrophage-mediated inflammation plays a significant role in the development and progression of diabetic nephropathy (DN). However, the underlying mechanisms remain unclear. Studies suggest that T cell immunoglobulin domain and mucin domain-3 (Tim-3) has complicated roles in regulating macrophage activation, but its roles in the progression of DN are still completely unknown.

Methods

We downregulated Tim-3 expression in kidney (intrarenal injection of Tim-3 shRNA expressing lentivirus or global Tim-3 knockout mice) and induced DN by streptozotocin (STZ). We analyzed the degree of renal injury, especially the podocyte injury induced by activated macrophages in vitro and in vivo. Then, we transferred different bone marrow derived macrophages (BMs) into STZ-induced Tim-3 knockdown mice to examine the effects of Tim-3 on macrophages in DN.

Results

First, we found that Tim-3 expression on renal macrophages was increased in patients with DN and in two diabetic mouse models, i.e. STZ-induced diabetic mice and db/db mice, and positively correlated with renal dysfunction of DN patients. Tim-3 deficiency ameliorated renal damage in STZ-induced diabetes with concurrent increase in protein levels of Nephrin and WT-1. Similar effects were observed in mice with Tim-3 knockdown diabetic mice. Second, adoptive transfer of Tim-3-expressing macrophages, but not Tim-3 knockout macrophages, accelerated diabetic renal injury in DN mice, suggesting a key role for Tim-3 on macrophages in the development of DN. Furthermore, we found NF-κB activation and TNF-α excretion were upregulated by Tim-3 in diabetic kidneys, and podocyte injury was associated with the Tim-3-mediated activation of the NF-κB/TNF-α signaling pathway in DN macrophages both in vivo and in vitro.

Conclusions

These results suggest that Tim-3 functions as a key regulator in renal inflammatory processes and serves as a potential therapeutic target for renal injury in DN.

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Tim-3 aggravates the progression of diabetic nephropathy (DN) by triggering the NF-κB/TNF-α pathway in renal macrophages.

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Tim-3 highly expresses on renal macrophages has positive correlation with bad renal function of DN patients.

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Tim-3 expressed on macrophages accelerates podocyte injury in vitro and in vivo.

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Tim-3 functions as a key regulator in renal inflammatory processes and serves as a potential therapeutic target in DN.