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With the increasing incidence of kidney diseases, there is an urgent need to develop therapeutic strategies to combat post-injury fibrosis. Immune cells, including platelets, play a pivotal role in this repair process, primarily through their released cytokines. However, the specific role of platelets in kidney injury and subsequent repair remains underexplored. Here, the detrimental role of platelets in renal recovery following ischemia/reperfusion injury and its contribution to acute kidney injury  to chronic kidney disease transition is aimed to investigated. In this study, it is shown that depleting platelets accelerates injury resolution and significantly reduces fibrosis. Employing advanced single-cell and spatial transcriptomic techniques, macrophages as the primary mediators modulated by platelet signals is identified. A novel subset of macrophages, termed cycling M2, which exhibit an M2 phenotype combined with enhanced proliferative activity is uncovered. This subset emerges in the injured kidney during the resolution phase and is modulated by platelet-derived thrombospondin 1 (THBS1) signaling, acquiring profibrotic characteristics. Conversely, targeted inhibition of THBS1 markedly downregulates the cycling M2 macrophage, thereby mitigating fibrotic progression. Overall, this findings highlight the adverse role of platelet THBS1-boosted cycling M2 macrophages in renal injury repair and suggest platelet THBS1 as a promising therapeutic target for alleviating inflammation and kidney fibrosis.

BackgroundIschemia-reperfusion injury (IRI) is a significant clinical concern in liver transplantation, with a key influence on short-term and long-term allograft and patient survival. Myeloid cells trigger and sustain tissue inflammation and damage associated with IRI, but the mechanisms regulating these activities are unknown. To address this, we investigated the molecular characteristics of intragraft myeloid cells present in biopsy-proven IRI- and IRI+ liver transplants.MethodsRNA-sequencing was performed on 80 pre-reperfusion and post-reperfusion biopsies from 40 human recipients of liver transplantation (23 IRI+, 17 IRI-). We used transcriptional profiling and computational approaches to identify specific gene coexpression network modules correlated with functional subsets of MPO+, lysozyme+, and CD68+ myeloid cells quantified by immunohistochemistry on sequential sections from the same patient biopsies.ResultsA global molecular map showed gene signatures related to myeloid activation in all patients regardless of IRI status; however, myeloid cell subsets differed dramatically in their spatial morphology and associated gene signatures. IRI- recipients were found to have a natural corticosteroid production and response profile from pre-reperfusion to post-reperfusion, particularly among monocytes/macrophages. The pre-reperfusion signature of IRI+ recipients included acute inflammatory responses in neutrophils and increased translation of adaptive immune-related genes in monocytes/macrophages coupled with decreased glucocorticoid responses. Subsequent lymphocyte activation at post-reperfusion identified transcriptional programs associated with the transition to adaptive immunity found only among IRI+ recipients.ConclusionsMyeloid subset-specific genes and related signaling pathways provide targets for the development of therapeutic strategies aimed at limiting IRI in the clinical setting of liver transplantation.

Background and Purpose Experimental Approach Key Results Conclusions and Implications Ulinastatin has beneficial effects in patients undergoing coronary artery bypass grafting (CABG) surgery due to its anti‐inflammatory properties, but the underlying mechanism remains unclear.We used samples from patients undergoing CABG, a model of cardiac ischaemia–reperfusion injury (IRI) in mice and murine cardiac endothelial cell cultures to investigate links between ulinastatin, the kallikrein‐kinin system (KKS), endothelial dysfunction and cardiac inflammation in the response to ischaemia/reperfusion injury (IRI). These links were assessed using clinical investigations, in vitro and in vivo experiments and RNA sequencing analysis.Ulinastatin inhibited the activity of tissue kallikrein, a key enzyme of the KKS, at 24 h after CABG surgery, which was verified in our murine cardiac ischaemia–reperfusion model. Under normal conditions, ulinastatin only inhibited kallikrein activity but did not affect bradykinin (B1/B2) receptors. Ulinastatin protected against IRI, in vivo and in vitro, by suppressing activation of the kallikrein‐kinin system and down‐regulating B1/B2 receptor‐related signalling pathways including ERK/ iNOS, which resulted in enhanced endothelial barrier function, mitigation of inflammation and oedema, decreased infarct size, improved cardiac function and decreased mortality. Inhibition of kallikrein and knockdown of B1, but not B2 receptors prevented ERK translocation into the nucleus, reducing reperfusion‐induced injury in murine cardiac endothelial cells.Treatment with ulinastatin exerts a protective influence on cardiac reperfusion by suppressing activation of the kallikrein‐kinin system. Our findings highlight the potential of targeting kallikrein /bradykinin receptors to alleviate endothelial dysfunction, thus improving cardiac IRI. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions Normothermic machine perfusion (NMP) aims to reduce ischemia–reperfusion injury in donor livers and its clinical manifestation, early allograft dysfunction (EAD) by maintaining perfusion and oxygenation. However, there is limited data on which NMP perfusate biomarkers might be associated with such EAD and the role of perfusate hemoglobin has not been assessed.We performed a pilot retrospective analysis of adult donor livers undergoing NMP between 2020 and 2022 at our center. NMP was commenced at the recipient hospital after initial static cold storage. All NMP circuits were primed in the same manner according to the manufacturer's instructions. Livers were stratified by initial perfusate hemoglobin below (≤5.2 mmol/L) or above (>5.2 mmol/L) the median. The association between hemoglobin levels and EAD or recipient peak transaminase levels was assessed.Among 23 livers, eight were considered unsuitable for transplantation, leaving 15 livers for assessment. Higher initial hemoglobin was associated with a lower risk of EAD (0% vs. 55.6%, p = 0.04). Perfusate hemoglobin decreased after NMP initiation (p = 0.003) and negatively correlated with recipient peak transaminase levels (ALT: ρ = −0.72, p = 0.002; AST: ρ = −0.79, p < 0.001). Consistently, higher hemoglobin livers also demonstrated lower perfusate liver enzymes.Perfusate hemoglobin levels decreased during NMP, and lower perfusate hemoglobin levels were associated with a higher incidence of EAD and higher levels of liver injury markers. Maintaining higher hemoglobin levels during NMP may help reduce ischemia–reperfusion injury and prevent or attenuate EAD. Larger prospective studies are needed to validate the findings of this pilot study. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the protective efficacy of remifentanil against testicular ischemia-reperfusion injury.The study included 24 male rats. The rats were randomized into three groups: Group 1 was the control group. Group 2 was subjected to a testicular torsion/detorsion model. Group 3 underwent similar procedures and additionally received remifentanil (0.6 μg/kg/min) intravenously for the first 20 min of reperfusion. Blood samples were taken for biochemical analyses, and orchiectomy was performed for histopathologic examination.Biochemical analysis of blood samples showed a significant increase in antioxidant enzyme activity, including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in Group 3 compared to Group 2 (p:0.004 and p:0.002, respectively). There was a dramatic decrease in the levels of proinflammatory cytokines, including interleukin-1 beta (IL-1 Beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) in Group 3 compared to Group 2 (p:0.001, p:0.046, and p:0.004, respectively). Similarly, malondialdehyde (MDA) levels decreased in Group 3 compared to Group 2 (p:0.004). Histopathologic examination of Group 3 rats showed positive changes in inflammation, hemorrhage, edema, and congestion levels compared to Group 2 (p<0.001). Similarly, there was a positive effect on the Johnsen and Cosentino score in Group 3 compared to Group 2 (p:0.001 and p<0.001, respectively).In our study, it has been documented that remifentanil protects against testicular ischemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

Proliferation of renal tubular epithelial cells (TEC) is essential for restoring tubular integrity and thereby to support renal functional recovery from kidney ischemia/reperfusion (KI/R) injury. Activation of transcriptional factor c-Myc promotes TEC proliferation following KI/R; however, the mechanism regarding c-Myc activation in TEC is incompletely known. Heat shock protein A12A (HSPA12A) is an atypic member of HSP70 family. In this study, we found that KI/R decreased HSPA12A expression in mouse kidneys and TEC, while ablation of HSPA12A in mice impaired TEC proliferation and renal functional recovery following KI/R. Gain-of-functional studies demonstrated that HSPA12A promoted TEC proliferation upon hypoxia/reoxygenation (H/R) through directly interacting with c-Myc and enhancing its nuclear localization to upregulate expression of its target genes related to TEC proliferation. Notably, c-Myc was lactylated in TEC after H/R, and this lactylation was enhanced by HSPA12A overexpression. Importantly, inhibition of c-Myc lactylation attenuated the HSPA12A-induced increases of c-Myc nuclear localization, proliferation-related gene expression, and TEC proliferation. Further experiments revealed that HSPA12A promoted c-Myc lactylation via increasing the glycolysis-derived lactate generation in a Hif1α-dependent manner. The results unraveled a role of HSPA12A in promoting TEC proliferation and facilitating renal recovery following KI/R, and this role of HSPA12A was achieved through increasing lactylation-mediated c-Myc activation. Therefore, targeting HSPA12A in TEC might be a viable strategy to promote renal functional recovery from KI/R injury in patients. HSPA12A facilitated renal functional recovery from kidney ischemia/reperfusion (KI/R) injury. This protective effect of HSPA12A was mediated through directly interacting with c-Myc as well as upregulating the Hif1α-mediated lactate generation, thereby increasing c-Myc lactylation and nuclear localization to drive expression of genes related to cell proliferation, and ultimately promoting TEC proliferation. [ABSTRACT FROM AUTHOR]

(I/R) injury. Homeobox-containing 1 (Hmbox1), a homeobox family member, has been identified as a putative transcriptional repressor and is downregulated in the exercised heart. However, its roles in exercise-induced physiological cardiac growth and its potential protective effects against cardiac I/R injury remain largely unexplored. METHODS: We studied the function of Hmbox1 in exercise-induced physiological cardiac growth in mice after 4 weeks of swimming exercise. Hmbox1 expression was then evaluated in human heart samples from deceased patients with myocardial infarction and in the animal cardiac I/R injury model. Its role in cardiac I/R injury was examined in mice with adeno-associated virus 9 (AAV9) vector-mediated Hmbox1 knockdown and in those with cardiac myocyte--specific Hmbox1 ablation. We performed RNA sequencing, promoter prediction, and binding assays and identified glucokinase (Gck) as a downstream effector of Hmbox1. The effects of Hmbox1 together with Gck were examined in cardiomyocytes to evaluate their cell size, proliferation, apoptosis, mitochondrial respiration, and glycolysis. The function of upstream regulator of Hmbox1, ETS1, was investigated through ETS1 overexpression in cardiac I/R mice in vivo. RESULTS: We demonstrated that Hmbox1 downregulation was required for exercise-induced physiological cardiac growth. Inhibition of Hmbox1 increased cardiomyocyte size in isolated neonatal rat cardiomyocytes and human embryonic stem cell--derived cardiomyocytes but did not affect cardiomyocyte proliferation. Under pathological conditions, Hmbox1 was upregulated in both human and animal postinfarct cardiac tissues. Furthermore, both cardiac myocyte--specific Hmbox1 knockout and AAV9-mediated Hmbox1 knockdown protected against cardiac I/R injury and heart failure. Therapeutic effects were observed when sh-Hmbox1 AAV9 was administered after I/R injury. Inhibition of Hmbox1 activated the Akt/ mTOR/P70S6K pathway and transcriptionally upregulated Gck, leading to reduced apoptosis and improved mitochondrial respiration and glycolysis in cardiomyocytes. ETS1 functioned as an upstream negative regulator of Hmbox1 transcription, and its overexpression was protective against cardiac I/R injury. CONCLUSIONS: Our studies unravel a new role for the transcriptional repressor Hmbox1 in exercise-induced physiological cardiac growth. They also highlight the therapeutic potential of targeting Hmbox1 to improve myocardial survival and glucose metabolism after I/R injury. [ABSTRACT FROM AUTHOR]

Myocardial ischemia-reperfusion injury (MIRI) is a significant complication following reperfusion therapy after myocardial infarction. Mitochondrial oxidative stress is a critical factor in MIRI, and Sirtuin 3 (SIRT3), as a major mitochondrial deacetylase, plays a key protective role, with its activity potentially regulated by O-GlcNAcylation. This study used the H9C2 cell line to establish a simulated ischemia/reperfusion (SI/R) model, we utilized co-immunoprecipitated to validate the relationship between O-GlcNAc transferase (OGT) and SIRT3, demonstrated SIRT3 O-GlcNAcylation sites through LC–MS/MS, and performed site mutations using CRISPR/Cas9 technology. The results were validated using immunoblotting. SIRT3 and superoxide dismutase 2 (SOD2) activities were detected using a fluorometric assay, while mitochondrial reactive oxygen species (MROS) levels and cellular apoptosis were assessed using immunofluorescence. We have identified an interaction between SIRT3 and OGT, where SIRT3 undergoes dynamic O-GlcNAcylation at the S190 site, facilitating SIRT3 deacetylase activity. During SI/R, elevated levels of O-GlcNAcylation activate SOD2 by promoting SIRT3 enzyme activity, thereby inhibiting excessive MROS production. This significantly mitigates the occurrence of malignant autophagy in myocardial cells during reperfusion, promoting their survival. Conversely, blocking SIRT3 O-GlcNAcylation at the S190 site exacerbates SI/R injury. We demonstrate that O-GlcNAcylation is a crucial post-translational modification (PTM) of SIRT3 during SI/R, shedding light on a promising mechanism for future therapeutic approaches. [ABSTRACT FROM AUTHOR]

Background: At present, hepatic ischemia-reperfusion injury (IRI) is an important complication of partial hepatectomy and liver transplantation, and it is an important cause of poor prognosis. Spleen tyrosine kinase(SYK) plays an important role in a variety of signaling pathways in the liver, but its role in hepatic IRI is still unclear. This study aims to investigate the role and mechanism of SYK in hepatic IRI and tumor recurrence. Methods: We first observed the activation of SYK in the liver of mice in response to hepatic IRI. Subsequently, Pharmacological inhibitions of SYK were used to evaluated the effect of SYK on neutrophil recruitment and NETosis, and further explored the effect of SYK on IRI and tumor recurrence. Results: Our study shows that SYK is activated in response to hepatic IRI and aggravates liver injury. On the one hand, neutrophils SYK during the early stage of liver reperfusion increases neutrophil extracellular traps (NETs) production by promoting Pyruvate kinase M2(PKM2) nuclear translocation leading to upregulation of phosphorylated STAT3, thereby exacerbating liver inflammation and tumor recurrence. On the other hand, macrophages SYK can promote the recruitment of neutrophils and increase the activation of NLRP3 inflammasome and IL1β, which further promotes the formation of NETs. Conclusions: Our study demonstrates that neutrophil and macrophage SYK synergistically promote hepatic IRI and tumor recurrence, and SYK may be a potential target to improve postoperative hepatic IRI and tumor recurrence. [ABSTRACT FROM AUTHOR]

Background Objectives Materials and Methods Results Discussion and Conclusion Testicular torsion/detorsion can cause testis loss and infertility. Aloperine is a major active alkaloid extracted from Sophora alopecuroides Linn. It has been shown to have organ‐protective effects. However, the effects of aloperine on the testis and its underlying mechanisms remain unclear.This study investigated the effect of aloperine on testicular torsion/detorsion injury in rats.Male Sprague‐Dawley rats were randomized to the sham‐operated (sham), testicular I/R (TI/R), or aloperine preconditioning (ALOPre) or postconditioning (ALOPost) groups. All rats except for the sham‐operated rats were subjected to 3 h of right spermatic cord torsion (720°, clockwise), followed by 3 h of detorsion. Aloperine (10 mg/kg) was intravenously administered before testicular torsion (ALOPre) or at the onset of testicular detorsion (ALOPost). The therapeutic efficacy of aloperine was evaluated by histological analysis, oxidative stress evaluation, inflammatory response examination, apoptosis analysis, protein analysis, and immunohistological assessment.Compared with TI/R, aloperine protected both the ipsilateral and contralateral testes against unilateral testicular I/R, as evidenced by a reduced testicular weight to body weight (TW/BW) ratio (ALOPre: p = 0.0037; ALOPost: p = 0.0021) and volume (ALOPre: p = 0.0020; ALOPost: p = 0.0009), less structural damage with better Johnsen (ALOPre: p = 0.0013; ALOPost: p = 0.0021), and Cosentino scores (ALOPre: p < 0.0001; ALOPost: p < 0.0001), increased mean seminiferous tubule diameter and mean seminiferous tubule epithelial height, decreased testicular apoptosis, and less oxidative stress and inflammatory response. In addition, aloperine significantly stimulated the phosphorylation of signal transducer and activator of transcription (STAT)‐3 in the ipsilateral testes following detorsion. Administration of Ag490 suppressed STAT‐3 phosphorylation, thereby abrogating the protective effects exerted by aloperine on the ipsilateral testis.Aloperine has a strong testicular protective effect on the ipsilateral and contralateral testes after testicular torsion/detorsion. This aloperine‐induced ipsilateral testicular protection is mediated via the STAT‐3 signaling pathway. [ABSTRACT FROM AUTHOR]

The article discusses the past, present, and future of the ESC Working Group on Cellular Biology of the Heart. The group aims to deliver knowledge and raise awareness on the basic cellular mechanisms regulating normal heart function and disease. They provide education, facilitate exchange of advancements in cardiology, and have a strong focus on trainees. The COVID-19 pandemic has posed challenges for the group, but they have adapted by shifting to virtual formats and publishing COVID-19-related projects. The current nucleus of the group consists of experts in various research areas, and they collaborate with other ESC groups and associations. In the future, the group aims to integrate basic science into cardiology education and training, create research networks, and promote joint research endeavors. Overall, the group is continuously evolving and adapting to new challenges in order to fight heart disease. [Extracted from the article]

Background: Myocardial ischemia/reperfusion (I/R) injury is a common pathological process in clinical practice. Developing effective therapeutic strategies to reduce or prevent this injury is crucial. The article aimed to investigate the role and mechanism of mesencephalic astrocyte-derived neurotrophic factor (MANF) and its key subdomains in modulating myocardial I/R-induced cardiomyocyte apoptosis. Methods: MANF stable knockout cell line and MANF mutant overexpression plasmids were constructed. The effects of MANF and mutants on apoptosis and endoplasmic reticulum (ER) stress related proteins were evaluated in hypoxia/reoxygenation-induced HL-1 cardiomyocytes by western blot, immunofluorescence, Tunel and flow cytometry. Echocardiography, ELISA, TTC and Masson were used to observe the effects of recombinant MANF protein (rMANF) on cardiac function in myocardial I/R mice. Results: This study observed increased expression of MANF in both myocardial infarction patients and I/R mice. MANF overexpression in cardiomyocytes decreased ER stress-induced apoptosis, while MANF knockout exacerbated it. rMANF improved cardiac function in I/R mice by reducing injury and inflammation. This study specifically demonstrates that mutations in the α-helix of MANF were more effective in reducing ER stress and cardiomyocyte apoptosis. Mechanistically, MANF and the α-helix mutant attenuated I/R injury by inhibiting the JAK1/STAT1/NF-κB signaling pathway in addition to reducing ER stress-induced apoptosis. Conclusion: These findings highlight MANF and its subdomains as critical regulators of myocardial I/R injury, offering promising therapeutic targets with significant clinical implications for I/R-related diseases. [ABSTRACT FROM AUTHOR]

Ischemic heart disease is the most prevalent cause of death worldwide affecting both the gender of all age groups. The high mortality rate is due to damage of myocardial tissue that emanates at the time of myocardial ischemia and re-oxygenation, thus averting reperfusion injury is recognized as a potential way to reduce acute cardiac injury and subsequent mortality. Flavonoids are polyphenol derivatives of plant origin and empirical shreds of evidence substantiate their numerous activities such as antioxidant, anti-inflammatory, anti-apoptotic, and anti-thrombotic activity, leading to their role in cardio protection. Recent investigations have unveiled the capacity of flavonoids to impede pivotal regulatory enzymes, signaling molecules, and transcription factors that orchestrate the mediators participating in the inflammatory cascade. The present comprehensive review, dwells on the preclinical studies on the effectiveness of flavonoids from the year 2007 to 2023, for the prevention and therapeutics for myocardial ischemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

Background: Open partial nephrectomy (OPN) has previously been considered the gold standard procedure for treatment of T1 localized renal tumors. After introduction of robot assisted partial nephrectomy (RAPN) as an alternative method to OPN, OPN was gradually abandoned at our department. The aim of the study was to retrospectively compare the results of patients treated with either OPN or RAPN for suspected renal carcinoma. Methods: Patients who underwent either open or robotic assisted partial nephrectomy between January 1st 2010 and December 31st 2020 were retrospectively included in the study. Each tumor subjected to surgery was scored preoperatively by the RENAL nephrometry score. Complications within 30 days were assessed according to the Clavien-Dindo classification system. Results: A total of 197 patients who underwent partial nephrectomy were identified; 75 were subjected to OPN and 122 were treated with RAPN. There were no significant differences between the groups with respect to age (OPN: 63 years ± 11, RAPN: 62 years ± 10), gender (OPN: 71/29%, RAPN: 67/33%), body mass index (OPN: 28 ± 5, RAPN: 28 ± 5), ASA score (OPN: 2.4 ± 0.6, RAPN: 2.2 ± 0.5), or nephrometry score (OPN: 6.6 ± 1.7, RAPN: 6.9 ± 1.7, p = 0.2). The operative time was significantly shorter in the OPN group (81 min) compared to the RAPN group (144.5 min, p < 0.001). Mean perioperative blood loss was 227 ± 162 ml in the OPN group compared to 189 ± 152 ml in the RAPN group (p = 0.1). Mean length of stay was shorter in the RAPN group (3 days) compared to the OPN group (6, days, p < 0.001). Positive surgical margin rate was significantly higher in the OPN group (21.6%) compared to the RAPN group (4.2%, p < 0.001). There were no differences in the number of Clavien-Dindo graded complications between the groups (p = 0.6). Conclusions: The introduction of RAPN at our department resulted in shorter length of stay and fewer positive surgical margins, without increasing complications. [ABSTRACT FROM AUTHOR]

G protein-coupled receptors' conformational landscape can be affected by their local, microscopic interactions within the cell plasma membrane. We employ here a pleiotropic stimulus, namely osmotic swelling, to alter the cortical environment within intact cells and monitor the response in terms of receptor function and downstream signaling. We observe that in osmotically swollen cells the β2-adrenergic receptor, a prototypical GPCR, favors an active conformation, resulting in cAMP transient responses to adrenergic stimulation that have increased amplitude. The results are validated in primary cell types such as adult cardiomyocytes, a model system where swelling occurs upon ischemia-reperfusion injury. Our results suggest that receptors' function is finely modulated by their biophysical context, and specifically that osmotic swelling acts as a potentiator of downstream signaling, not only for the β2-adrenergic receptor, but also for other receptors, hinting at a more general regulatory mechanism. Osmotic swelling alters the local membrane environment, activating several GPCRs. Here the authors show that osmotic swelling enhances ligand-dependent signalling of β2-AR: this suggests regulatory mechanisms for GPCRs via their biophysical context. [ABSTRACT FROM AUTHOR]

Introduction: The administration of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) in the treatment of acute ischemic stroke (AIS) has been a subject of debate, and its potential benefits remain uncertain. This retrospective study aimed to investigate the effect of preoperative IVT on glycocalyx damage in patients with cerebral ischemia-reperfusion injury (IRI). Methods: A cohort of 106 patients with acute large vessel occlusion in the anterior circulation treated with mechanical thrombectomy was enrolled. The levels of the glycocalyx damage marker, syndecan-1, were measured in the peripheral blood of these patients to assess glycocalyx damage during IRI, and clinical outcomes were compared between patients receiving MT alone vs. combined IVT and MT. Results: The study results indicate that thrombolytic drugs have a significant impact on syndecan-1 levels in the blood. Compared to patients who underwent direct MT, those who received preoperative IVT had significantly lower levels of syndecan-1 in their blood. Although preoperative IVT did not alter the final clinical outcomes, the levels of syndecan-1 shedding reflect the extent of damage to the endothelial glycocalyx. Discussion: This suggests that using thrombolytic drugs before mechanical thrombectomy may reduce endothelial glycocalyx damage in patients with ischemia-reperfusion injury. These findings provide indirect clinical evidence supporting the preoperative use of intravenous thrombolysis in such patients. [ABSTRACT FROM AUTHOR]

The article explores the potential use of restoring organelles to treat ischemic cardiomyopathy, a common cause of heart failure. The authors focus on the protein DEPP1, which is found in high levels in patients with ischemic cardiomyopathy. They demonstrate that DEPP1 plays a role in myocardial remodeling and cellular pathology caused by sustained cardiomyocyte HIF activation. The authors propose that targeting DEPP1 could improve outcomes in ischemic cardiomyopathy by restoring organelle function. However, more research is needed to fully understand the mechanisms and potential benefits of inhibiting autophagy in this context. The article also discusses the role of HIF signaling in mitophagy and pexophagy, processes that remove damaged mitochondria and peroxisomes from cells. The proteins BNIP3 and NIX are identified as important factors in these processes. The article suggests that restoring the function of mitochondria and peroxisomes may be a promising approach for treating ischemic cardiomyopathy, but further research is necessary to develop targeted therapies and fully comprehend the underlying mechanisms. [Extracted from the article]

Background: Post-cardiac arrest syndrome (PCAS) presents a multifaceted challenge in clinical practice, characterized by severe neurological injury and high mortality rates despite advancements in management strategies. One of the important critical aspects of PCAS is post-arrest lung injury (PALI), which significantly contributes to poor outcomes. PALI arises from a complex interplay of pathophysiological mechanisms, including trauma from chest compressions, pulmonary ischemia–reperfusion (IR) injury, aspiration, and systemic inflammation. Despite its clinical significance, the pathophysiology of PALI remains incompletely understood, necessitating further investigation to optimize therapeutic approaches. Methods: This review comprehensively examines the existing literature to elucidate the epidemiology, pathophysiology, and therapeutic strategies for PALI. A comprehensive literature search was conducted to identify preclinical and clinical studies investigating PALI. Data from these studies were synthesized to provide a comprehensive overview of PALI and its management. Results: Epidemiological studies have highlighted the substantial prevalence of PALI in post-cardiac arrest patients, with up to 50% of survivors experiencing acute lung injury. Diagnostic imaging modalities, including chest X-rays, computed tomography, and lung ultrasound, play a crucial role in identifying PALI and assessing its severity. Pathophysiologically, PALI encompasses a spectrum of factors, including chest compression-related trauma, pulmonary IR injury, aspiration, and systemic inflammation, which collectively contribute to lung dysfunction and poor outcomes. Therapeutically, lung-protective ventilation strategies, such as low tidal volume ventilation and optimization of positive end-expiratory pressure, have emerged as cornerstone approaches in the management of PALI. Additionally, therapeutic hypothermia and emerging therapies targeting mitochondrial dysfunction hold promise in mitigating PALI-related morbidity and mortality. Conclusion: PALI represents a significant clinical challenge in post-cardiac arrest care, necessitating prompt diagnosis and targeted interventions to improve outcomes. Mitochondrial-related therapies are among the novel therapeutic strategies for PALI. Further clinical research is warranted to optimize PALI management and enhance post-cardiac arrest care paradigms. [ABSTRACT FROM AUTHOR]

Ischemic stroke (IS) is a severe cerebrovascular disease with high disability and mortality rates, where the inflammatory response is crucial to its progression and prognosis. Efferocytosis, the prompt removal of dead cells, can reduce excessive inflammation after IS injury. While electroacupuncture (EA) has been shown to decrease inflammation post-ischemia/reperfusion (I/R), its link to efferocytosis is unclear. Our research identified ATP-binding cassette transporter A1 (Abca1) as a key regulator of the engulfment process of efferocytosis after IS by analyzing public datasets and validating findings in a mouse model, revealing its close ties to IS progression. We demonstrated that EA can reduce neuronal cell death and excessive inflammation caused by I/R. Furthermore, EA treatment increased Abca1 expression, prevented microglia activation, promoted M2 microglia polarization, and enhanced their ability to phagocytose injured neurons in I/R mice. This suggests that EA's modulation of efferocytosis could be a potential mechanism for reducing cerebral I/R injury, making regulators of efferocytosis steps a promising therapeutic target for EA benefits. [ABSTRACT FROM AUTHOR]

AbstractObjectiveMaterials and methodsResultsDiscussion and conclusionThis study aimed to investigate the mechanism of emulsified isoflurane in reducing myocardial ischemia-reperfusion injury (MIRI).Forty-eight healthy male Sprague-Dawley rats were randomly divided into four groups (n = 12). In the sham group (group S) and ischemia-reperfusion group (group I/R), saline (4 ml/kg/h) was administered intravenously for 30 min. In intralipid group (group L), intralipid (4 ml/kg/h) was administered intravenously. In the emulsified isoflurane group (group EI), emulsified isoflurane (4 ml/kg/h) was administered intravenously. The infusion was then discontinued for 15 min during the washout period. Apart from group S, ischemia was produced by occlusion of the left anterior descending artery (LADA) for 30 min. After 30 min of occlusion, all groups received reperfusion for two hours.Creatine kinase MB (CK-MB), cardiac troponin I (cTnI), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). Myocardial infarct size was measured using triphenyl tetrazolium chloride staining. According to the result, pretreatment with emulsified isoflurane attenuated CK-MB and cTnI concentrations (p < 0.05). And serum TNF-α and IL-6 levels and infarct size in the emulsified isoflurane group obviously decreased. An obvious decrease in the expression of the toll-like receptor-4 (TLR-4) mRNA in group EI was observed compared with group I/R.Emulsified isoflurane precondition had a potent cardioprotective effect against myocardial ischemia-reperfusion injury. The mechanisms involved may be related to the decrease in the expression of TLR-4 and the reduced inflammatory response. [ABSTRACT FROM AUTHOR]

Introduction Continuous extracorporeal perfusion (ECP), or machine perfusion, holds promise for prolonged skeletal muscle preservation in limb ischemia-reperfusion injury. This study aimed to extend the amputation-to-replantation time window from currently 6 hours to 33 hours using a 24-hour ECP approach. Materials and Methods Six large white pigs underwent surgical forelimb amputation under general anesthesia. After amputation, limbs were kept for 9 hours at room temperature and then perfused by 24-hour ECP with a modified histidine-tryptophan-ketoglutarate (HTK) solution. After ECP, limbs were orthotopically replanted and perfused in vivo for 12 hours. Clinical data, blood, and tissue samples were collected and analyzed. Results All 6 forelimbs could be successfully replanted and in vivo reperfused for 12 hours after 9 hours of room temperature ischemia followed by 24 hours ECP. Adequate limb perfusion was observed after replantation as shown by thermography and laser Doppler imaging. All pigs survived without severe organ failure, and no significant increase in inflammatory cytokines was found. Macroscopy and histology showed marked interstitial muscular edema of the limbs, whereas myofiber necrosis was not evident, implying the preservation of muscular integrity. Conclusions The use of a 24-hour ECP has successfully extended limb preservation to 33 hours. The modified histidine-tryptophan-ketoglutarate perfusate demonstrated its ability for muscle protection. This innovative approach not only facilitates limb replantation after combat injuries, surmounting geographical barriers, but also broadens the prospects for well-matched limb allotransplants across countries and continents. [ABSTRACT FROM AUTHOR]

The given text is a collection of abstracts from the European Journal of Immunology, covering a wide range of topics related to immunology research. The abstracts discuss the role of complement activation in various diseases, such as lupus nephritis and MPGN, and suggest potential therapeutic strategies. They also explore genetic factors influencing disease susceptibility and the development of therapies targeting the complement system. These abstracts provide valuable insights into the current research and understanding of the complement system and its implications in different biological processes and medical conditions. [Extracted from the article]

There are diverse pathophysiological mechanisms involved in acute kidney injury (AKI). Among them, overactivity of the renin-angiotensin system (RAS) has been described. Angiotensin-converting enzyme 2 (ACE2) is a tissue RAS enzyme expressed in the apical border of proximal tubules. Given the important role of ACE2 in the metabolism of angiotensin II, this study aimed to characterize kidney and urinary ACE2 in a mouse model of AKI. Ischemia-reperfusion injury (IRI) was induced in C57BL/6 mice by clamping of the left renal artery followed by removal of the right kidney. In kidneys harvested 48 h after IRI, immunostaining revealed a striking maldistribution of ACE2 including spillage into the tubular lumen and the presence of ACE2-positive luminal casts in the medulla. In cortical membranes, ACE2 protein and enzymatic activity were both markedly reduced (37 ± 4 vs. 100 ± 6 ACE2/β-actin, P = 0.0004, and 96 ± 14 vs. 152 ± 6 RFU/μg protein/h, P = 0.006). In urine, full-length membrane-bound ACE2 protein (100 kDa) was markedly increased (1,120 ± 405 vs. 100 ± 46 ACE2/µg creatinine, P = 0.04), and casts stained for ACE2 were recovered in the urine sediment. In conclusion, in AKI caused by IRI, there is a marked loss of ACE2 from the apical tubular border with deposition of ACE2-positive material in the medulla and increased urinary excretion of full-length membrane-bound ACE2 protein. The deficiency of tubular ACE2 in AKI suggests that provision of this enzyme could have therapeutic applications and that its excretion in the urine may also serve as a diagnostic marker of severe proximal tubular injury. NEW & NOTEWORTHY: This study provides novel insights into the distribution of kidney ACE2 in a model of AKI by IRI showing a striking detachment of apical ACE2 from proximal tubules and its loss in urine and urine sediment. The observed deficiency of kidney ACE2 protein and enzymatic activity in severe AKI suggests that administration of forms of this enzyme may mitigate AKI and that urinary ACE2 may serve as a potential biomarker for tubular injury. [ABSTRACT FROM AUTHOR]

We recently reported in a rat model of kidney transplantation that the addition of sodium thiosulfate (STS) to organ preservation solution improved renal graft quality and prolonged recipient survival. The present study investigates whether STS pre-treatment would produce a similar effect. In vitro, rat kidney epithelial cells were treated with 150 μM STS before and/or during exposure to hypoxia followed by reoxygenation. In vivo, donor rats were treated with PBS or 2.4 mg/kg STS 30 min before donor kidneys were procured and stored in UW or UW+150 μM STS solution at 4 °C for 24 h. Renal grafts were then transplanted into bilaterally nephrectomised recipient rats which were then sacrificed on post-operative day 3. STS pre-treatment significantly reduced cell death compared to untreated and other treated cells in vitro (p < 0.05), which corresponded with our in vivo result (p < 0.05). However, no significant differences were observed in other parameters of tissue injury. Our results suggest that STS pre-treatment may improve renal graft function after transplantation. [ABSTRACT FROM AUTHOR]

Nicotinamide adenine dinucleotide (NAD+) is an essential metabolite that plays a crucial role in diverse biological processes, including energy metabolism, gene expression, DNA repair, and mitochondrial function. An aberrant NAD+ level mediates the development of cardiovascular dysfunction and diseases. Both in vivo and in vitro studies have demonstrated that nicotinamide mononucleotide (NMN), as a NAD+ precursor, alleviates the development of cardiovascular diseases such as heart failure, atherosclerosis, and myocardial ischemia/reperfusion injury. Importantly, NMN has suggested pharmacological activities mostly through its involvement in NAD+ biosynthesis. Several clinical studies have been conducted to investigate the efficacy and safety of NMN supplementation, indicating its potential role in cardiovascular protection without significant adverse effects. In this review, we systematically summarize the impact of NMN as a nutraceutical and potential therapeutic drug on cardiovascular diseases and emphasize the correlation between NMN supplementation and cardiovascular protection. [ABSTRACT FROM AUTHOR]

Remote ischemic preconditioning (RIPC) reduces ischemia-reperfusion injury in aortocoronary bypass surgery, potentially via extracellular vesicles (EVs) and their micro-RNA content. Clinical data implicate that propofol might inhibit the cardioprotective RIPC effect. This prospective, randomized study investigated the influence of different anesthetic regimes on RIPC efficacy and EV micro-RNA signatures. We also assessed the impact of propofol on cell protection after hypoxic conditioning and EV-mediated RIPC in vitro. H9c2 rat cardiomyoblasts were subjected to hypoxia, with or without propofol, and subsequent simulated ischemia-reperfusion injury. Apoptosis was measured by flow cytometry. Blood samples of 64 patients receiving anesthetic maintenance with propofol or isoflurane, along with RIPC or sham procedures, were analyzed, and EVs were enriched using a polymer-based method. Propofol administration corresponded with increased Troponin T levels (4669 ± 435.6 pg/mL), suggesting an inhibition of the cardioprotective RIPC effect. RIPC leads to a notable rise in miR-21 concentrations in the group receiving propofol anesthesia (fold change 7.22 ± 6.6). In vitro experiments showed that apoptosis reduction was compromised with propofol and only occurred in an EV-enriched preconditioning medium, not in an EV-depleted medium. Our study could clinically and experimentally confirm propofol inhibition of RIPC protection. Increased miR-21 expression could provide evidence for a possible inhibitory mechanism. [ABSTRACT FROM AUTHOR]

Background: Exercise can promote sustainable protection against cold and warm liver ischemia–reperfusion injury (IRI) and tumor metastases. We have shown that this protection is by the induction of hepatic mitochondrial biogenesis pathway. In this study, we hypothesize that ZLN005, a PGC-1α activator, can be utilized as an alternative therapeutic strategy. Methods: Eight-week-old mice were pretreated with ZLN005 and subjected to liver warm IRI. To establish a liver metastatic model, MC38 cancer cells (1 × 106) were injected into the spleen, followed by splenectomy and liver IRI. Results: ZLN005-pretreated mice showed a significant decrease in IRI-induced tissue injury as measured by serum ALT/AST/LDH levels and tissue necrosis. ZLN005 pretreatment decreased ROS generation and cell apoptosis at the site of injury, with a significant decrease in serum pro-inflammatory cytokines, innate immune cells infiltration, and intrahepatic neutrophil extracellular trap (NET) formation. Moreover, mitochondrial mass was significantly upregulated in hepatocytes and maintained after IRI. This was confirmed in murine and human hepatocytes treated with ZLN005 in vitro under normoxic and hypoxic conditions. Additionally, ZLN005 preconditioning significantly attenuated tumor burden and increased the percentage of intratumoral cytotoxic T cells. Conclusions: Our study highlights the effective protection of ZLN005 pretreatment as a therapeutic alternative in terms of acute liver injury and tumor metastases. [ABSTRACT FROM AUTHOR]

Ischemia-reperfusion injury (IRI) is an intrinsic risk associated with liver transplantation. Ex vivo hepatic machine perfusion (MP) is an emerging organ preservation technique that can mitigate IRI, especially in livers subjected to prolonged warm ischemia time (WIT). However, a method to quantify the biological response to WIT during MP has not been established. Previous studies used physiologically based pharmacokinetic (PBPK) modeling to demonstrate that a decrease in hepatic transport and biliary excretion of the tracer molecule sodium fluorescein (SF) could correlate with increasing WIT in situ. Furthermore, these studies proposed intracellular sequestration of the hepatocyte canalicular membrane transporter multidrug resistance-associated protein 2 (MRP2) leading to decreased MRP2 activity (maximal transport velocity; Vmax) as the potential mechanism for decreased biliary SF excretion. We adapted an extant PBPK model to account for ex vivo hepatic MP and fit a six-parameter version of this model to control time-course measurements of SF in MP perfusate and bile. We then identified parameters whose values were likely insensitive to changes in WIT and fixed them to generate a reduced model with only three unknown parameters. Finally, we fit the reduced model to each individual biological replicate SF time course with differing WIT, found the mean estimated value for each parameter, and compared them using a one-way ANOVA. We demonstrated that there was a significant decrease in the estimated value of Vmax for MRP2 at the 30-min WIT. These studies provide the foundation for future studies investigating real-time assessment of liver viability during ex vivo MP. NEW & NOTEWORTHY: We developed a computational model of sodium fluorescein (SF) biliary excretion in ex vivo machine perfusion and used this model to assess changes in model parameters associated with the activity of MRP2, a hepatocyte membrane transporter, in response to increasing warm ischemia time. We found a significant decrease in the parameter value describing MRP2 activity, consistent with a role of decreased MRP2 function in ischemia-reperfusion injury leading to decreased secretion of SF into bile. [ABSTRACT FROM AUTHOR]