Mst1: Function and Mechanism in Brain and Myocardial Ischemia Reperfusion Injury

Novel Protein Biomarkers and Therapeutic Targets for Type 1 Diabetes and Its Complications: Insights from Summary-Data-Based Mendelian Randomization and Colocalization Analysis

Millions of patients suffer from type 1 diabetes (T1D) and its associated complications. Nevertheless, the pursuit of a cure for T1D has encountered significant challenges, with a crucial impediment being the lack of biomarkers that can accurately predict the progression of T1D and reliable therapeutic targets for T1D. Hence, there is an urgent need to discover novel protein biomarkers and therapeutic targets, which holds promise for targeted therapy for T1D. In this study, we extracted summary-level data on 4907 plasma proteins from 35,559 Icelanders and 2923 plasma proteins from 54,219 UK participants as exposures. The genome-wide association study (GWAS) summary statistics on T1D and T1D with complications were obtained from the R9 release results from the FinnGen consortium. Summary-data-based Mendelian randomization (SMR) analysis was employed to evaluate the causal associations between the genetically predicted levels of plasma proteins and T1D-associated outcomes. Colocalization analysis was utilized to investigate the shared genetic variants between the exposure and outcome. Moreover, transcriptome analysis and a protein-protein interaction (PPI) network further illustrated the expression patterns of the identified protein targets and their interactions with the established targets of T1D. Finally, a Mendelian randomization phenome-wide association study evaluated the potential side effects of the identified core protein targets. In the primary SMR analysis, we identified 72 potential protein targets for T1D and its complications, and nine of them were considered crucial protein targets. Within the group were five risk targets and four protective targets. Backed by evidence from the colocalization analysis, the protein targets were classified into four tiers, with MANSC4, CTRB1, SIGLEC5 and MST1 being categorized as tier 1 targets. Delving into the DrugBank database, we retrieved 11 existing medications for T1D along with their therapeutic targets. The PPI network clarified the interactions among the identified potential protein targets and established ones. Finally, the Mendelian randomization phenome-wide association study corroborated MANSC4 as a reliable target capable of mitigating the risk of various forms of diabetes, and it revealed the absence of adverse effects linked to CTRB1, SIGLEC5 and MST1. This study unveiled many protein biomarkers and therapeutic targets for T1D and its complications. Such advancements hold great promise for the progression of drug development and targeted therapy for T1D.

Insulin-like growth factor-1 in myocardial ischemia-reperfusion injury: A review

Myocardial ischemia-reperfusion injury (MIRI) is a severe damage inflicted on the ischemic myocardium when blood flow is restored, and it commonly occurs in a wide range of cardiovascular diseases. Presently, no effective clinical treatment exists for MIRI. Accumulating evidence indicates that insulin-like growth factor-1 (IGF-1) plays a role in the intricate chain of cardiovascular events, in addition to its well-recognized growth-promoting and metabolic effects. IGF-1, a member of the insulin family, exhibits a broad spectrum of protective effects against ischemia/reperfusion injury in various tissues, especially the myocardium. In particular, earlier research has demonstrated that IGF-1 reduces cellular oxidative stress, improves mitochondrial function, interacts with noncoding RNAs, and activates cardiac downstream protective genes and protective signaling channels. This review aimed to summarize the role of IGF-1 in MIRI and elucidate its related mechanisms of action. In addition, IGF-1-related interventions for MIRI, such as ischemic preconditioning and post-conditioning, were discussed. The purpose of this review was to provide evidence supporting the activation of IGF-1 in MIRI and advocate its use as a therapeutic target.

Current animal models of extracorporeal cardiopulmonary resuscitation: A scoping review

Aim

Animal models of Extracorporeal Cardiopulmonary Resuscitation (ECPR) focusing on neurological outcomes are required to further the development of this potentially life-saving technology. The aim of this review is to summarize current animal models of ECPR.

Methods

A comprehensive database search of PubMed, EMBASE, and Web of Science was undertaken. Full-text publications describing animal models of ECPR between January 1, 2000, and June 30, 2022, were identified and included in the review. Data describing the conduct of the animal models of ECPR, measured variables, and outcomes were extracted according to pre-defined definitions.

Results

The search strategy yielded 805 unique reports of which 37 studies were included in the final analysis. Most studies (95%) described using a pig model of ECPR with the remainder (5%) describing a rat model. The most common method for induction of cardiac arrest was a fatal ventricular arrhythmia through electrical stimulation (70%). 10 studies reported neurological assessment of animals using physical examination, serum biomarkers, or electrophysiological findings, however, only two studies described a multimodal assessment. No studies reported the use of brain imaging as part of the neurological assessment. Return of spontaneous circulation was the most reported primary outcome, and no studies described the neurological status of the animal as the primary outcome.

Conclusion

Current animal models of ECPR do not describe clinically relevant neurological outcomes after cardiac arrest. Further work is needed to develop models that more accurately mimic clinical scenarios and can test innovations that can be translated to the application of ECPR in clinical medicine.

A comprehensive review of stroke-related signaling pathways and treatment in western medicine and traditional Chinese medicine

This review provides insight into the complex network of signaling pathways and mechanisms involved in stroke pathophysiology. It summarizes the historical progress of stroke-related signaling pathways, identifying potential interactions between them and emphasizing that stroke is a complex network disease. Of particular interest are the Hippo signaling pathway and ferroptosis signaling pathway, which remain understudied areas of research, and are therefore a focus of the review. The involvement of multiple signaling pathways, including Sonic Hedgehog (SHH), nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE), hypoxia-inducible factor-1α (HIF-1α), PI3K/AKT, JAK/STAT, and AMPK in pathophysiological mechanisms such as oxidative stress and apoptosis, highlights the complexity of stroke. The review also delves into the details of traditional Chinese medicine (TCM) therapies such as Rehmanniae and Astragalus, providing an analysis of the recent status of western medicine in the treatment of stroke and the advantages and disadvantages of TCM and western medicine in stroke treatment. The review proposes that since stroke is a network disease, TCM has the potential and advantages of a multi-target and multi-pathway mechanism of action in the treatment of stroke. Therefore, it is suggested that future research should explore more treasures of TCM and develop new therapies from the perspective of stroke as a network disease.

The hippo kinases MST1/2 in cardiovascular and metabolic diseases: A promising therapeutic target option for pharmacotherapy

Cardiovascular diseases (CVDs) and metabolic disorders are major components of noncommunicable diseases, causing an enormous health and economic burden worldwide. There are common risk factors and developmental mechanisms among them, indicating the far-reaching significance in exploring the corresponding therapeutic targets. MST1/2 kinases are well-established proapoptotic effectors that also bidirectionally regulate autophagic activity. Recent studies have demonstrated that MST1/2 influence the outcome of cardiovascular and metabolic diseases by regulating immune inflammation. In addition, drug development against them is in full swing. In this review, we mainly describe the roles and mechanisms of MST1/2 in apoptosis and autophagy in cardiovascular and metabolic events as well as emphasis on the existing evidence for their involvement in immune inflammation. Moreover, we summarize the latest progress of pharmacotherapy targeting MST1/2 and propose a new mode of drug combination therapy, which may be beneficial to seek more effective strategies to prevent and treat CVDs and metabolic disorders.

Mst1 attenuates myocardial ischemia/reperfusion injury following heterotopic heart transplantation in mice through regulating Keap1/Nrf2 axis

Ischemia reperfusion (I/R) injury remains a frequent adverse event that accompanies heart transplantation. Oxidative stress and aberrant production of free radicals were regarded as the culprit of cell death and tissue damage in post-transplant IR injury. Mst1 has been identified as a mediator of oxidative stress and Nrf2 regulates anti-oxidative enzymes, however, the interaction between Mst1 and Nrf2 anti-oxidative stress pathway remains to be clarified in the event of cardiac IR injury. Herein, the model of ischemia-reperfusion injury in heterotopic heart transplantation mice was firstly established.. We observed that cardiac IR induced upregulation of Mst1 and activation of Nrf2/HO-1pathway in mice receiving heterotopic heart transplantation. Further Cobalt dichloride-induced oxidative stress model of RAW264.7 macrophage cells were then established to mimic cardiac I/R injury, results showed that exposure to CoCl₂ induced the upregulation of Mst1 and activation of Keap1/Nrf2 pathway, and genetic ablation of Mst-1 and inhibition of Keap1/Nrf2 pathway aggravated oxidative damage in those cells. Additional in vivo study showed that transfection of Mst1 shRNA spurred ROS generation and worsened cardiac damage in IR mice. Meanwhile, Mst1-KD mice receiving heart transplantation showed markedly downregulation of Nrf2, HO-1 yet upregulation of Keap1, indicating diminished protective effect against tissue damage caused by IR probably owing to the frustration of Keap1/Nrf2 pathway. Taken together, our findings demonstrated the protective effect of Mst1 from cardiac IR injury via triggering Keap1/Nrf2 axis and suppressing ROS generation, which shed light on the promising role of Mst1 in transitional management of IR injury resulted from cardiac transplantation.

Melatonin attenuates manganese-induced mitochondrial fragmentation by suppressing the Mst1/JNK signaling pathway in primary mouse neurons

Manganese (Mn) toxicity is mainly caused by excessive Mn content in drinking water and occupational exposure. Moreover, overexposure to Mn can impair mental, cognitive, memory, and motor capacities. Although melatonin (Mel) can protect against Mn-induced neuronal damage and mitochondrial fragmentation, the underlying mechanism remains elusive. Here, we examined the related molecular mechanisms underlying Mel attenuating Mn-induced mitochondrial fragmentation through the mammalian sterile 20-like kinase-1 (Mst1)/JNK signaling path. To test the role of Mst1 in mitochondrial fragmentation, we treated mouse primary neurons overexpressing Mst1 with Mel and Mn stimulation. In normal neurons, 10 μM Mel reduced the effects of Mn (200 μM) on Mst1 expression at the mRNA and protein levels and on phosphorylation of JNK and Drp1, Drp1 mitochondrial translocation, and mitochondrial fragmentation. Conversely, overexpression of Mst1 hindered the protective effect of Mel (10 μM) against Mn-induced mitochondrial fragmentation. Anisomycin (ANI), an activator of JNK signaling, was similarly found to inhibit the protective effect of Mel on mitochondria, while Mst1 levels were not significantly changed. Thus, our results demonstrated that 10 μM Mel negatively regulated the Mst1-JNK pathway, thereby reducing excessive mitochondrial fission, maintaining the mitochondrial network, and alleviating Mn-induced mitochondrial dysfunction.

Knockout of circRNA single stranded interacting protein 1 (circRBMS1) played a protective role in myocardial ischemia-reperfusion injury though inhibition of miR-2355-3p/Mammalian Sterile20-like kinase 1 (MST1) axis

Evidence suggests circRBMS1 regulates mRNA to mediate cell apoptosis, inflammation, and oxidative stress in different diseases. MST1 is reported to be the target and activator of apoptosis-related molecules and signaling pathways. Hence, the present study aims to investigate the role of circ-RBMS1/miR-2355-3p/MST1 in the development of I/R injury. In vitro experiments showed increased circ-RBMS1 and decreased miR-2355-3p in H/R-induced HCMs. CircRBMS1 served as a sponge for miR-2355-3p and miR-2355-3p targeted MST1. Furthermore, knockout of circRBMS1 attenuated cell apoptosis, oxidized stress, and inflammation in H/R-induced HCMs. In vivo experiments indicated circRBMS1 knockdown attenuated cardiac function damage, cell apoptosis, oxidative stress injury and inflammatory response through miR-2355-3p/MST1 axis in mice. In summary, these results demonstrated circRBMS1 played a protective role in myocardial I/R injury though inhibition of miR-2355-3p/MST1 axis. It might provide a new therapeutic target for cardiac I/R injury.

Mechanosensing and the Hippo Pathway in Microglia: A Potential Link to Alzheimer's Disease Pathogenesis?

The activation of microglia, the inflammatory cells of the central nervous system (CNS), has been linked to the pathogenesis of Alzheimer’s disease and other neurodegenerative diseases. How microglia sense the changing brain environment, in order to respond appropriately, is still being elucidated. Microglia are able to sense and respond to the mechanical properties of their microenvironment, and the physical and molecular pathways underlying this mechanosensing/mechanotransduction in microglia have recently been investigated. The Hippo pathway functions through mechanosensing and subsequent protein kinase cascades, and is critical for neuronal development and many other cellular processes. In this review, we examine evidence for the potential involvement of Hippo pathway components specifically in microglia in the pathogenesis of Alzheimer’s disease. We suggest that the Hippo pathway is worth investigating as a mechanosensing pathway in microglia, and could be one potential therapeutic target pathway for preventing microglial-induced neurodegeneration in AD.

Down-regulation of MST1 in hippocampus protects against stress-induced depression-like behaviours and synaptic plasticity impairments

Depression is a common mental disorder, and its main environmental risk factor is chronic stress. The activation of mammalian STE20-like kinase 1 (MST1), a key factor involved in the underlying pathophysiology of stress, can trigger synaptic plasticity impairment, neuronal dysfunction and neuroinflammation. However, it is unclear whether down-regulation of MST1 in the hippocampus protects against stress-induced behavioural dysfunctions. In this study, three mouse models were used to assess the role of MST1 in stress. Various behavioural tests, in vivo electrophysiological recordings, Western blotting, Golgi staining and immunofluorescence assay were used. The data showed that the level of phospho-MST1 (T183) was significantly increased in the hippocampus of mice subjected to chronic unpredictable mild stress (CUMS) and that mice with MST1 overexpression showed depression-like behaviours. Importantly, the impairment of cognitive functions and the hippocampal synaptic plasticity induced by CUMS were significantly improved by MST1 knockdown, suggesting that MST1 down-regulation effectively protected against stress-induced behavioural dysfunctions. Moreover, MST1 knockdown suppressed CUMS-induced microglial activation, reduced the abnormal expression of inflammatory cytokines and impeded the activation of p38, implying that the antidepressant-like effects of MST1 knockdown were associated with inhibiting the p38 pathway. These findings suggest that hippocampal MST1 is an essential regulator of stress, which can be an ideal target for the development of antidepressants in the future.

HIF‑1α in myocardial ischemia‑reperfusion injury (Review)

Myocardial ischemia-reperfusion injury (MIRI) is a severe injury to the ischemic myocardium following the recovery of blood flow. Currently, there is no effective treatment for MIRI in clinical practice. Over the past two decades, biological studies of hypoxia and hypoxia-inducible factor-1α (HIF-1α) have notably improved understanding of oxygen homeostasis. HIF-1α is an oxygen-sensitive transcription factor that mediates adaptive metabolic responses to hypoxia and serves a pivotal role in MIRI. In particular, previous studies have demonstrated that HIF-1α improves mitochondrial function, decreases cellular oxidative stress, activates cardioprotective signaling pathways and downstream protective genes and interacts with non-coding RNAs. The present review summarizes the roles and associated mechanisms of action of HIF-1α in MIRI. In addition, HIF-1α-associated MIRI intervention, including natural compounds, exosomes, ischemic preconditioning and ischemic post-processing are presented. The present review provides evidence for the roles of HIF-1α activation in MIRI and supports its use as a therapeutic target.

Hederagenin Attenuates Cerebral Ischaemia/Reperfusion Injury by Regulating MLK3 Signalling

Cerebral ischaemia/reperfusion (CI/R) injury is a major challenge due to the lack of effective neuroprotective drugs. Hederagenin (HE) is the aglycone part of saponins extracted from Hedera helix Linné that has exhibited anti-apoptotic and anti-inflammatory effects; however, the role of HE in CI/R has not been elucidated. In this study, mice were intraperitoneally (i.p.) injected with HE (26.5, 53, or 106 μmol/kg body weight) for 3 days after middle cerebral artery occlusion (MCAO). Neural function and brain infarct volume were evaluated. HE treatment attenuated CI/R-induced apoptosis and inflammatory cytokine expression within the infarcted areas. HE treatment also decreased the activation of the MLK3 signalling pathway, which potentiates CI/R damage via the MAPK and NFκB pathways. Due to HE's safety profile, it has potential to be used for the clinical treatment of ischaemic stroke.

The Role of VPS35 in the Pathobiology of Parkinson's Disease

The vacuolar protein sorting 35 (VPS35) gene located on chromosome 16 has recently emerged as a cause of late-onset familial Parkinson's disease (PD) (PARK17). The gene encodes a 796-residue protein nearly ubiquitously expressed in human tissues. The protein localizes on endosomes where it assembles with other peripheral membrane proteins to form the retromer complex. How VPS35 mutations induce dopaminergic neuron degeneration in humans is still unclear. Because the retromer complex recycles the receptors that mediate the transport of hydrolase to lysosome, it has been suggested that VPS35 mutations lead to impaired lysosomal and autophagy function. Recent studies also demonstrated that VPS35 and the retromer complex influence mitochondrial homeostasis, suggesting that VPS35 mutations elicit mitochondrial dysfunction. More recent studies have identified a key role of VPS35 in neurotransmission, whilst others reported a functional interaction between VPS35 and other genes associated with familial PD, including α-SYNUCLEIN-PARKIN-LRRK2. Here, we review the biological role of VPS35 protein, the VPS35 mutations identified in human PD patients, and the potential molecular mechanism by which VPS35 mutations can induce progressive neurodegeneration in PD.

FTY720 inhibits colon cancer cell survival and increases their sensitivity to gemcitabine through the miR-494/MST1 pathway

BACKGROUND

Colon cancer ranks 5th in both incidence and mortality among malignant tumors in China. Chemotherapy is the main treatment method. Studies have shown that immunosuppressive agent FTY720 has a certain inhibitory effect on cancer cell proliferation. Inhibitors combined with chemotherapy drugs can improve the therapeutic effect of cancer. In this study, immunosuppressive agent FTY720 and gemcitabine were used together to treat colon cancer cells, and the role of miR-494/mammalian Ste20-like kinase 1 (MST1) in the proliferation and apoptosis of colon cancer cells was explored, with an aim to provide a new treatment for colon cancer.

AIM

To investigate the effects of FTY720 and gemcitabine on the survival and apoptosis of colon cancer cells and the potential molecular mechanisms involved.

METHODS

Colon cancer SW1116 cells were treated with gemcitabine at concentrations of 0.0001 μg/mL, 0.001 μg/mL, 0.01 μg/mL, 0.1 μg/mL, and 1 μg/mL and FTY720 at concentrations of 2.5 μmol/L, 5 μmol/L, 7.5 μmol/L, 10 μmol/L, and 12.5 μmol/L. CCK8 assay and flow cytometry were applied to detect the survival rate and apoptosis rate of SW1116 cells. Quantitative real-time polymerase chain reaction was used to measure the levels of miR-494 and MST1 mRNA. Western blot was carried out to detect the expression levels of MST1, p21, and Caspase-3 proteins. Dual-luciferase reporter assay was performed to verify the relationship between miR-494 and MST1.

RESULTS

Gemcitabine and FTY720 reduced the survival rate of colon carcinoma SW1116 cells in a concentration dependent manner. According to the results, 0.1 μg/mL gemcitabine and 10 μmol/L FTY720 with an inhibition rate of about 50% were selected for subsequent experiments. Gemcitabine and FTY720 both inhibited cell survival and promoted cell apoptosis, and their combined use was better than the single use. Overexpression of miR-494 reversed the effects of FTY720 and gemcitabine on survival and apoptosis in SW1116 cells. MiR-494 targeted and regulated MST1. Inhibition of MST1 reversed the effects of FTY720 and gemcitabine on the survival and apoptosis in SW1116 cells.

CONCLUSION

FTY720 and gemcitabine inhibit SW1116 cell survival and promote apoptosis through the miR-494/MST1 pathway. The combination of FTY720 and gemcitabine has more significantly inhibitory effects on the survival and apoptosis of SW1116 cells.

Differential Levels of Hippo Signaling in Selected Brain and Peripheral Tissues in Streptozotocin-Induced Cognitive Dysfunction in Mice

Increasing studies have revealed that metabolic disorders, especially diabetes, are high risk factors for the development of Alzheimer's disease (AD) and other neurodegenerative diseases. It has been reported that patients with diabetes are prone to suffer from cognitive dysfunction (CD). Although abnormal glucose metabolism and deposition of amyloid β (Aβ) are proven to have a closely relationship with diabetes-induced CD, its exact mechanism is still undetermined. In this study, a total of 14 mice were intraperitoneally injected with streptozotocin for 5 consecutive days to mimic diabetic models, and then hierarchical cluster analysis was adopted to classify the diabetic mice into CD and Non-CD phenotypes by the results of Morris water maze test (MWMT). Furthermore, we detected Hippo signaling including mammalian sterile 20-like protein kinases1 (MST1), large tumor suppressors 1 (LATS1), Yes-associated protein (YAP) and phosphorylation of YAP (p-YAP) in brain and peripheral tissues. As compared with control mice, the levels of MST1, LATS1 and p-YAP/YAP ratio were increased in medial prefrontal cortex (mPFC), striatum and hippocampus of CD mice, while these proteins were decreased in gut tissue of CD mice. Additionally, there were significant positive correlations between escape latency and p-YAP/YAP ratio in mPFC, anterior cingulate cortex (ACC) and hippocampus, as well as the level of LATS1 in liver, kidney and gut tissues. In conclusion, alterations in Hippo signaling may contribute to CD induced by diabetes. Therefore, therapeutic interventions improving Hippo signaling might be beneficial to the treatment of diabetes-induced CD and other neurodegenerative diseases.

Novel Aspects of Cardiac Ischemia and Reperfusion Injury Mechanisms

Introduction.The present article, in which a contemporary analysis of the literature on the pathophysiology of ischemic and reperfusion injury (IRI) of the myocardium is presented, focuses on the possible role played by of the calpain system and oxidative stress. Several process development options were proposed, including cytosolic and mitochondrial Ca2+ overload, reactive oxygen stress release, acute inflammatory response and metabolic degradation. The combined effect of all of the above factors produces irreversible ischemic and reperfused damage of cardiomyocytes.Materials and methods.The role of the calpain system in the creation of myocardial IRI was experimentally investigated. It was found that active calpain substrates play a significant role in the processes of cell cycle, apoptosis and differentiation, adversely affecting cardiomyocyte functionality. The calpain system is part of an integrated proteolytic system that is critical to the relationship between the structure and function of the cardiac sarcomere. Uncontrolled activation of calpain is indicated in the pathophysiology of many cardiovascular disorders. As shown by research, inhibitor calpain reduces the size of the zone of infarction following ischemia reperfusion and thus lessens the risk of “stunning” the myocardium. As is known, a consequence of IRI is acute myocardial infarction (AMI), which is a central factor in cardiovascular disease (CVD) and is one of the primary causes of mortality. Understanding the exact pathophysiological mechanisms remains an urgent problem for clinical physicians. To date, the mechanisms of IRI are not fully known, which creates certain difficulties in further treatment and prevention tactics. In addition, myocardial IRI is also an important issue for pathoanatomical service, since sudden coronary death can occur despite timely reperfusion therapy following AMI.Conclusion.The development of strategies for creating conditions that limit the degree of damage to myocardial tissues significantly increases the ability of the heart to withstand ischemic damage.