Increasing Regulatory T Cells With Interleukin-2 and Interleukin-2 Antibody Complexes Attenuates Lung Inflammation and Heart Failure Progression

Development and validation of a predictive model for pulmonary infection risk in patients with traumatic brain injury in the ICU: a retrospective cohort study based on MIMIC-IV

OBJECTIVE

To develop a nomogram for predicting occurrence of secondary pulmonary infection in patients with critically traumatic brain injury (TBI) during their stay in the intensive care unit, to further optimise personalised treatment for patients and support the development of effective, evidence-based prevention and intervention strategies.

DATA SOURCE

This study used patient data from the publicly available MIMIC-IV (Medical Information Mart for Intensive Care IV) database.

DESIGN

A population-based retrospective cohort study.

METHODS

In this retrospective cohort study, 1780 patients with TBI were included and randomly divided into a training set (n=1246) and a development set (n=534). The impact of pulmonary infection on survival was analysed using Kaplan-Meier curves. A univariate logistic regression model was built in training set to identify potential factors for pulmonary infection, and independent risk factors were determined in a multivariate logistic regression model to build nomogram model. Nomogram performance was assessed with receiver operating characteristic (ROC) curves, calibration curves and Hosmer-Lemeshow test, and predictive value was assessed by decision curve analysis (DCA).

RESULT

This study included a total of 1780 patients with TBI, of which 186 patients (approximately 10%) developed secondary lung infections, and 21 patients died during hospitalisation. Among the 1594 patients who did not develop lung infections, only 85 patients died (accounting for 5.3%). The survival curves indicated a significant survival disadvantage for patients with TBI with pulmonary infection at 7 and 14 days after intensive care unit admission (p<0.001). Both univariate and multivariate logistic regression analyses showed that factors such as race other than white or black, respiratory rate, temperature, mechanical ventilation, antibiotics and congestive heart failure were independent risk factors for pulmonary infection in patients with TBI (OR>1, p<0.05). Based on these factors, along with Glasgow Coma Scale and international normalised ratio variables, a training set model was constructed to predict the risk of pulmonary infection in patients with TBI, with an area under the ROC curve of 0.800 in the training set and 0.768 in the validation set. The calibration curve demonstrated the model's good calibration and consistency with actual observations, while DCA indicated the practical utility of the predictive model in clinical practice.

CONCLUSION

This study established a predictive model for pulmonary infections in patients with TBI, which may help clinical doctors identify high-risk patients early and prevent occurrence of pulmonary infections.

Unraveling the mechanisms of hepatogenous diabetes and its therapeutic perspectives

The review focused mainly on the pathogenesis of hepatogenous diabetes (HD) in liver cirrhosis (LC). This review reveals parallels between the mechanisms of metabolic dysfunction observed in LC and type II diabetes (T2DM), suggesting a shared pathway leading to HD. It underscores the role of insulin in HD pathogenesis, highlighting key factors such as insulin signaling, glucose metabolism, insulin resistance (IR), and the influence of adipocytes. Furthermore, the impact of adipose tissue accumulation, fatty acid metabolism, and pro-inflammatory cytokines like Tumor necrosis factor-α (TNF-α) on IR are discussed in the context of HD. Altered signaling pathways, disruptions in the endocrine system, liver inflammation, changes in muscle mass and composition, and modifications to the gut microbiota collectively contribute to the complex interplay linking cirrhosis and HD. This study highlights how important it is to identify and treat this complex condition in cirrhotic patients by thoroughly analyzing the link between cirrhosis, IR, and HD. It also emphasizes the vitality of targeted interventions. Cellular and molecular investigations into IR have revealed potential therapeutic targets for managing and preventing HD.

Alteration of the gut microbiome in patients with heart failure: A systematic review and meta-analysis

Recent research has revealed that alterations of the gut microbiome (GM) play a comprehensive role in the pathophysiology of HF. However, findings in this field remain controversial. In this study, we focus on differences in GM diversity and abundance between HF patients and non-HF people, based on previous 16 S ribosomal RNA (16rRNA) gene sequencing. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive search of PubMed, Web of Science, Embase, Cochrane Library, and Ovid databases using the keyword "Heart failure" and "Gastrointestinal Microbiome". A significant decrease in alpha diversity was observed in the HF patients (Chao1, I2 = 87.5 %, p < 0.001; Shannon index, I2 = 62.8 %, p = 0.021). At the phylum level, the HF group exhibited higher abundances of Proteobacteria (I2 = 92.0 %, p = 0.004) and Actinobacteria (I2 = 82.5 %, p = 0.010), while Bacteroidetes (I2 = 45.1 %, p = 0.017) and F/B ratio (I2 = 0.0 %, p＜0.001) were lower. The Firmicutes showed a decreasing trend but did not reach statistical significance (I2 = 82.3 %, p = 0.127). At the genus level, the relative abundances of Streptococcus, Bacteroides, Alistipes, Bifidobacterium, Escherichia-Shigella, Enterococcus and Klebsiella were increased in the HF group, whereas Ruminococcus, Faecalibacterium, Dorea and Megamona exhibited decreased relative abundances. Dialister, Blautia and Prevotella showed decreasing trends but without statistical significance. This observational meta-analysis suggests that GM changes are associated with HF, manifesting as alterations in GM abundance, disruptions in the production of short-chain fatty acids (SCFAs) bacteria, and an increase in trimethylamine N-oxide (TMAO) producing bacteria.

Tailoring Treatment in Cardiovascular Diseases: The Role of Targeted Therapies

Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality around the globe. To address this public health burden, innovative therapeutic agents are being developed to specifically target molecular and genetic markers. Various therapeutic modalities have been implemented, including vaccines, monoclonal or bispecific antibodies, and gene-based therapies. Such drugs precisely target the underlying disease pathophysiology, aiming at notable molecules such as lipid metabolism regulators, proinflammatory cytokines, and growth factors. This review focuses on the latest advancements in different targeted therapies. It provides an insightful overview of the current landscape of targeted cardiovascular therapies, highlighting promising strategies with potential to transform the treatment of CVDs into an era of precision medicine.

Mac-1 deficiency ameliorates pressure overloaded heart failure through inhibiting macrophage polarization and activation

Persistent pressure overload commonly leads to pathological cardiac hypertrophy and remodeling, ultimately leading to heart failure (HF). Cardiac remodeling is associated with the involvement of immune cells and the inflammatory response in pathogenesis. The macrophage-1 antigen (Mac-1) is specifically expressed on leukocytes and regulates their migration and polarization. Nonetheless, the involvement of Mac-1 in cardiac remodeling and HF caused by pressure overload has not been determined. The Mac-1-knockout (KO) and wild-type (WT) mice were subjected to transverse aortic constriction (TAC) for 6 weeks. Echocardiography and pressure-volume loop assessments were used to evaluate cardiac function, and cardiac remodeling and macrophage infiltration and polarization were estimated by histopathology and molecular techniques. The findings of our study demonstrated that Mac-1 expression was markedly increased in hearts subjected to TAC treatment. Moreover, compared with WT mice, Mac-1-KO mice exhibited dramatically ameliorated TAC-induced cardiac dysfunction, hypertrophy, fibrosis, oxidative stress and apoptosis. The potential positive impacts may be linked to the inhibition of macrophage infiltration and M1 polarization via reductions in NF-kB and STAT1 expression and upregulation of STAT6. In conclusion, this research reveals a new function of Mac-1 deficiency in reducing pathological cardiac remodeling and HF caused by pressure overload. Additionally, inhibiting Mac-1 could be a potential treatment option for patients with HF in a clinical setting.

Identification of key genes associated with heart failure based on bioinformatics analysis and screening of traditional Chinese medicines for the prevention and treatment of heart failure

Heart failure (HF) is the final stage of heart disease. An increasing number of experiments and clinical reports have shown that traditional Chinese medicine (TCM) has many therapeutic effects and advantages in treating HF. In this study, we used bioinformatics methods to screen key genes and predict the components of Chinese herbal medicines with preventive and therapeutic effects on HF. GSE120895 and GSE21610 HF chips were downloaded from the Gene Expression Omnibus database. We screened differentially expressed genes (DEGs). Weighted gene coexpression network analysis was performed to determine key modules. Genes in key modules were used for Gene Ontology and Kyoto Encyclopedia of Genes Genomes analysis to determine the biological functions. Finally, receiver operating characteristic curve analysis was used to screen out key genes, and single-sample GSEA was conducted to screen TCM compounds and effective ingredients of TCM compounds related to HF. We have selected a key module (MeTerquoise) and identified 489 DEGs, of which 357 are up regulated and 132 are down regulated. Gene Ontology and Kyoto Encyclopedia of Genes Genomes analyses indicated that the DEGs were associated with the extracellular matrix, fat metabolism and inflammatory response. We identified IL2, CXCR4, CCL5, THY1, CCN2, and IL7R as key genes. Single-sample GSEA showed that key genes were mainly related to energy metabolism, mitochondrial oxidative phosphorylation, extracellular matrix, and immunity. Finally, a total of 70 TCM compounds and 30 active ingredients of TCM compounds were identified. Bioinformatics methods were applied to preliminarily predict the key genes and TCM compounds involved in HF. These results provide theoretical support for the treatment of HF with TCM compounds and provide targets and research strategies for the development of related new Chinese medicines.

The immunostimulant effects of the rice ragged stunt virus genome on the growth and metastasis of breast cancer in mouse model

There are multiple treatment strategies that have been reported for breast cancer, while new and effective therapies against it are still necessary. Stimulating the immune system and its components against cancer cells is one of the unique treatment strategies of immunotherapy and long dsRNAs are immunostimulant in this regard. Based on bioinformatics approaches, a fragment of the Rice ragged stunt RNA virus genome was selected and synthesized according to its immunogenicity. Based on the in vitro transcription technique, dsRNA was synthesized and its binding ability to the PEI/PEI-Ac Polyethylenimine (PEI) or Acetylated polyethylenimine (PEI-Ac) was verified by the gel retardation assay. Then, the PEI-Ac was synthesized by adding acetyl groups to the PEI, and the results of the 1H NMR method indicated its successful synthesis. After cancer induction by 4 T1 cells in Balb/C mice, intraperitoneal (IP) and intratumoral (IT) treatment by the PEI/PEI-Ac-dsRNA were performed and the tumor growth inhibition was evaluated. Results demonstrated that PEI/PEI-Ac-dsRNA can lead to a decrease in tumor weight and volume in both the IP and IT routes. Also, by using macro-metastatic nodule counting and hematoxylin and eosin (H&E) staining we showed that PEI/PEI-Ac-dsRNA can prevent micro and macro-metastasis in the lung. Therefore, the PEI/PEI-Ac-dsRNA acts as an effective inhibitor of growth and metastasis of the breast cancer models. We showed that viral dsRNA can exert its antitumor properties by stimulating TNF-α and IFN-γ. In general, our results revealed that dsRNA derived from the plant virus genome stimulates the intrinsic immune system and can be a potential immune stimulant drug for cancer treatment.

The role of lung microbiota in primary graft dysfunction in lung transplant recipients

BACKGROUND

Recent studies have shown that the lung microbiota is altered in critically ill patients and predicts clinical outcomes. Primary graft dysfunction (PGD) is a common complication and a leading cause of death within 1 month of lung transplantation, but the clinical significance of changes in the lung bacterial community during PGD is unclear. The aim of this study was to determine the contribution of the lung microbiota to the development and course of severe PGD.

METHODS

We conducted a retrospective study to characterize the lung microbiota of 32 lung transplant patients with combined PGD using next-generation sequencing of bronchoalveolar lavage samples. The relationship between lung flora dysbiosis and lung immunity in PGD was assessed by quantification of alveolar cytokines. The contribution of microbiota characteristics to patient outcomes was assessed by estimating overall survival.

RESULTS

Patients diagnosed with PGD grade 3 showed a reduction in alpha diversity, driven by a significant increase in the abundance of the genera Modestobacter, Scardovia and Selenomonas, and a reduction in the proportion of the genera Klebsiella and Oribacterium. Alpha diversity of the lung microbiota in PGD3 patients was negatively correlated with BALF interleukin (IL)-2 (r = -.752, p < .05). In addition, bacterial diversity in the lung microbiota of non-survivors was lower than that of survivors (p = .041).

CONCLUSIONS

There is variation in the lung microbiota of PGD grade 3 patients and dysbiosis of the lung microbiota is associated with lung immunity. The lung microbiota has potential in the diagnosis and treatment of PGD grade 3.

Oxidation of hemoglobin in the lung parenchyma facilitates the differentiation of pneumococci into encapsulated bacteria

Pneumococcal pneumonia causes cytotoxicity in the lung parenchyma but the underlying mechanism involves multiple factors contributing to cell death. Here, we discovered that hydrogen peroxide produced by Streptococcus pneumoniae (Spn-H 2 O 2 ) plays a pivotal role by oxidizing hemoglobin, leading to its polymerization and subsequent release of labile heme. At physiologically relevant levels, heme selected a population of encapsulated pneumococci. In the absence of capsule and Spn-H 2 O 2 , host intracellular heme exhibited toxicity towards pneumococci, thus acting as an antibacterial mechanism. Further investigation revealed that heme-mediated toxicity required the ABC transporter GlnPQ. In vivo experiments demonstrated that pneumococci release H 2 O 2 to cause cytotoxicity in bronchi and alveoli through the non-proteolytic degradation of intracellular proteins such as actin, tubulin and GAPDH. Overall, our findings uncover a mechanism of lung toxicity mediated by oxidative stress that favor the growth of encapsulated pneumococci suggesting a therapeutic potential by targeting oxidative reactions.

Graphical abstract

Highlights

Oxidation of hemoglobin by Streptococcus pneumoniae facilitates differentiation to encapsulated pneumococci in vivo Differentiated S. pneumoniae produces capsule and hydrogen peroxide (Spn-H 2 O 2 ) as defense mechanism against host heme-mediated toxicity. Spn-H 2 O 2 -induced lung toxicity causes the oxidation and non-proteolytic degradation of intracellular proteins tubulin, actin, and GAPDH. The ABC transporter GlnPQ is a heme-binding complex that makes Spn susceptible to heme toxicity.

Searching for Intrinsic Causality between Colonic Dysbiosis and Non-Ischemic Cardiomyopathy: A Mendelian Randomization-Based Analysis

Objective: Little is known about gut microbiota (GM) and cardiomyopathy. Their causal relationship was explored using two-sample Mendelian randomization (TSMR) performed by R software. Methods: The single nucleotide polymorphisms (SNPs) were further screened based on the genome-wide association studies (GWAS) of gut microbiota and cardiomyopathy obtained from an open database. TSMR was performed using an MR-Egger regression, simple estimator based on mode, weighted median method, inverse variance weighted (IVW), weighted estimator and CML-MA-BIC to explore the causal association. And the sensitivity analysis was carried out using an MR-Egger regression and the leave-one-out sensitivity test. Results: As for 211 GM taxa, IVW results confirmed that the class Actinobacteria (OR = 0.81, p = 0.021) and genus Coprobacter (OR = 0.85, p = 0.033) were protective factors for cardiomyopathy. The phylum Firmicutes (OR = 0.87, p < 0.01), family Acidaminococcaceae (OR = 0.89, p < 0.01), genus Desulfovibrio (OR = 0.92, p = 0.030) and genus Prevotella9 (OR = 0.93, p = 0.029) were protective factors for ischemic cardiomyopathy. The family Rhodospirillaceae (OR = 1.06, p = 0.036) and genus Turicibacter (OR = 1.09, p = 0.019) were risk factors for ischemic cardiomyopathy. The genus Olsenella (OR = 0.91, p = 0.032) was a protective factor for non-ischemic cardiomyopathy. The order Rhodospirillales (OR = 1.14, p = 0.024), family Rikenellaceae (OR = 1.21, p = 0.012) and genus Gordonibacter (OR = 1.12, p = 0.019) were risk factors for non-ischemic cardiomyopathy. The robustness of MR results was reflected in the heterogeneity (p > 0.05) and pleiotropy (p > 0.05) analyses. Conclusions: A potential causal relationship of cardiomyopathy with some GM taxa has been confirmed in the current study.

Xuebijing injection, a Chinese patent medicine, against severe pneumonia: Current research progress and future perspectives

Severe pneumonia is one of the most common infectious diseases and the leading cause of sepsis and septic shock. Preventing infection, balancing the patient's immune status, and anti-coagulation therapy are all important elements in the treatment of severe pneumonia. As multi-target agents, Xuebijing injection (XBJ) has shown unique advantages in targeting complex conditions and saving the lives of patients with severe pneumonia. This review outlines progress in the understanding of XBJ's anti-inflammatory, endotoxin antagonism, and anticoagulation effects. From the hundreds of publications released over the past few years, the key results from representative clinical studies of XBJ in the treatment of severe pneumonia were selected and summarized. XBJ was observed to effectively suppress the release of pro-inflammatory cytokines, counter the effects of endotoxin, and assert an anticoagulation effect in most clinical trials, which are consistent with experimental studies. Collectively, this evidence suggests that XBJ could play an important and expanding role in clinical medicine, especially for sepsis, septic shock and severe pneumonia. Please cite this article as: Zhang M, Zheng R, Liu WJ, Hou JL, Yang YL, Shang HC. Xuebijing injection, a Chinese patent medicine, against severe pneumonia: Current research progress and future perspectives. J Integr Med. 2023; 21(5): 413-422.

Inhibition of NK1.1 signaling attenuates pressure overload-induced heart failure, and consequent pulmonary inflammation and remodeling

Background

Inflammation contributes to heart failure (HF) development, the progression from left ventricular failure to pulmonary remodeling, and the consequent right ventricular hypertrophy and failure. NK1.1 plays a critical role in Natural killer (NK) and NK T (NKT) cells, but the role of NK1.1 in HF development and progression is unknown.

Methods

We studied the effects of NK1.1 inhibition on transverse aortic constriction (TAC)-induced cardiopulmonary inflammation, HF development, and HF progression in immunocompetent male mice of C57BL/6J background.

Results

We found that NK1.1+ cell-derived interferon gamma+ (IFN-γ+) was significantly increased in pulmonary tissues after HF. In addition, anti-NK1.1 antibodies simultaneously abolished both NK1.1+ cells, including the NK1.1+NK and NK1.1+NKT cells in peripheral blood, spleen, and lung tissues, but had no effect on cardiopulmonary structure and function under control conditions. However, systemic inhibition of NK1.1 signaling by anti-NK1.1 antibodies significantly rescued mice from TAC-induced left ventricular inflammation, fibrosis, and failure. Inhibition of NK1.1 signaling also significantly attenuated TAC-induced pulmonary leukocyte infiltration, fibrosis, vessel remodeling, and consequent right ventricular hypertrophy. Moreover, inhibition of NK1.1 signaling significantly reduced TAC-induced pulmonary macrophage and dendritic cell infiltration and activation.

Conclusions

Our data suggest that inhibition of NK1.1 signaling is effective in attenuating systolic overload-induced cardiac fibrosis, dysfunction, and consequent pulmonary remodeling in immunocompetent mice through modulating the cardiopulmonary inflammatory response.

Deficiency of Tregs in hypertension-associated left ventricular hypertrophy

Left ventricular hypertrophy (LVH) is the most common target organ damage in hypertension. Abnormal numbers or functions of CD4+ CD25+ Foxp3+ regulatory T lymphocytes (Tregs) can cause immune disorders, which participates in LVH. This study aimed to explore the role of Tregs in LVH by investigating circulating Tregs and associated cytokine levels in hypertensive patients with or without LVH. Blood samples were collected from 83 hypertensive patients without LVH (essential hypertension group, EH), 91 hypertensive patients with LVH (left ventricular hypertrophy group, LVH), and 69 normotensive controls without LVH (control group, CG). Tregs and cytokines were measured by flow cytometry and enzyme-linked immunosorbent assays. We found that circulating Tregs were significantly lower in hypertensive patients than in CG subjects. It was lower in LVH than in EH patients. No correlation between blood pressure regulation and Tregs was found in EH or LVH patients. Furthermore, Tregs in older females were lower than those in older males among LVH patients. Additionally, serum interleukin-10 (IL-10) and transforming growth factor beta 1 (TGFβ1) decreased in hypertensive patients, and interleukin-6 (IL-6) increased in LVH patients. Tregs were negatively correlated with creatine kinase, low-density lipoprotein cholesterol, apoprotein B, high-sensitivity C-reactive protein, and left ventricular mass index (LVMI) values. In general, our study demonstrates significantly decreased circulating Tregs in hypertensive LVH patients. Decreased circulating Tregs in LVH is independent of blood pressure regulation. IL-6, IL-10, and TGF-β1 are related with LVH in hypertension.

Regulatory T Cells in Pathological Cardiac Hypertrophy: Mechanisms and Therapeutic Potential

BACKGROUND

Pathological cardiac hypertrophy is linked to immune-inflammatory injury, and regulatory T cells (Tregs) play a crucial role in suppressing immune-inflammatory responses. However, the precise role of Tregs in pathological cardiac hypertrophy remains unclear.

OBJECTIVE

To summarize the current knowledge on the role and mechanisms of Tregs in pathological cardiac hypertrophy and explore their perspectives and challenges as a new therapeutic approach.

RESULTS

Treg cells may play an important protective role in pressure overload (hypertension, aortic stenosis), myocardial infarction, metabolic disorders (diabetes, obesity), acute myocarditis, cardiomyopathy (hypertrophic cardiomyopathy, storage diseases), and chronic obstructive pulmonary disease-related pathological cardiac hypertrophy. Although some challenges remain, the safety and efficacy of Treg-based therapies have been confirmed in some clinical trials, and engineered antigen-specific Treg cells may have better clinical application prospects due to stronger immunosuppressive function and stability.

CONCLUSION

Targeting the immune-inflammatory response via Treg-based therapies might provide a promising and novel future approach to the prevention and treatment of pathological cardiac hypertrophy.

Pathophysiological Effects of Various Interleukins on Primary Cell Types in Common Heart Disease

Myocardial infarction (MI), heart failure, cardiomyopathy, myocarditis, and myocardial ischemia-reperfusion injury (I/R) are the most common heart diseases, yet there is currently no effective therapy due to their complex pathogenesis. Cardiomyocytes (CMs), fibroblasts (FBs), endothelial cells (ECs), and immune cells are the primary cell types involved in heart disorders, and, thus, targeting a specific cell type for the treatment of heart disease may be more effective. The same interleukin may have various effects on different kinds of cell types in heart disease, yet the exact role of interleukins and their pathophysiological pathways on primary cell types remain largely unexplored. This review will focus on the pathophysiological effects of various interleukins including the IL-1 family (IL-1, IL-18, IL-33, IL-37), IL-2, IL-4, the IL-6 family (IL-6 and IL-11), IL-8, IL-10, IL-17 on primary cell types in common heart disease, which may contribute to the more precise and effective treatment of heart disease.

The link between immunity and hypertension in the kidney and heart

Hypertension is the primary cause of cardiovascular disease, which is a leading killer worldwide. Despite the prevalence of this non-communicable disease, still between 90% and 95% of cases are of unknown or multivariate cause ("essential hypertension"). Current therapeutic options focus primarily on lowering blood pressure through decreasing peripheral resistance or reducing fluid volume, but fewer than half of hypertensive patients can reach blood pressure control. Hence, identifying unknown mechanisms causing essential hypertension and designing new treatment accordingly are critically needed for improving public health. In recent years, the immune system has been increasingly implicated in contributing to a plethora of cardiovascular diseases. Many studies have demonstrated the critical role of the immune system in the pathogenesis of hypertension, particularly through pro-inflammatory mechanisms within the kidney and heart, which, eventually, drive a myriad of renal and cardiovascular diseases. However, the precise mechanisms and potential therapeutic targets remain largely unknown. Therefore, identifying which immune players are contributing to local inflammation and characterizing pro-inflammatory molecules and mechanisms involved will provide promising new therapeutic targets that could lower blood pressure and prevent progression from hypertension into renal or cardiac dysfunction.

IL-12α deficiency attenuates pressure overload-induced cardiac inflammation, hypertrophy, dysfunction, and heart failure progression

IL-12α plays an important role in modulating inflammatory response, fibroblast proliferation and angiogenesis through modulating macrophage polarization or T cell function, but its effect on cardiorespiratory fitness is not clear. Here, we studied the effect of IL-12α on cardiac inflammation, hypertrophy, dysfunction, and lung remodeling in IL-12α gene knockout (KO) mice in response to chronic systolic pressure overload produced by transverse aortic constriction (TAC). Our results showed that IL-12α KO significantly ameliorated TAC-induced left ventricular (LV) failure, as evidenced by a smaller decrease of LV ejection fraction. IL-12α KO also exhibited significantly attenuated TAC-induced increase of LV weight, left atrial weight, lung weight, right ventricular weight, and the ratios of them in comparison to body weight or tibial length. In addition, IL-12α KO showed significantly attenuated TAC-induced LV leukocyte infiltration, fibrosis, cardiomyocyte hypertrophy, and lung inflammation and remodeling (such as lung fibrosis and vessel muscularization). Moreover, IL-12α KO displayed significantly attenuated TAC-induced activation of CD4+ T cells and CD8+ T cells in the lung. Furthermore, IL-12α KO showed significantly suppressed accumulation and activation of pulmonary macrophages and dendritic cells. Taken together, these findings indicate that inhibition of IL-12α is effective in attenuating systolic overload-induced cardiac inflammation, heart failure development, promoting transition from LV failure to lung remodeling and right ventricular hypertrophy.

Emerging epigenetic therapies of cardiac fibrosis and remodelling in heart failure: from basic mechanisms to early clinical development

Cardiovascular diseases and specifically heart failure (HF) impact global health and impose a significant economic burden on society. Despite current advances in standard of care, the risks for death and readmission of HF patients remain unacceptably high and new therapeutic strategies to limit HF progression are highly sought. In disease settings, persistent mechanical or neurohormonal stress to the myocardium triggers maladaptive cardiac remodelling, which alters cardiac function and structure at both the molecular and cellular levels. The progression and magnitude of maladaptive cardiac remodelling ultimately leads to the development of HF. Classical therapies for HF are largely protein-based and mostly are targeted to ameliorate the dysregulation of neuroendocrine pathways and halt adverse remodelling. More recently, investigation of novel molecular targets and the application of cellular therapies, epigenetic modifications, and regulatory RNAs has uncovered promising new avenues to address HF. In this review, we summarize the current knowledge on novel cellular and epigenetic therapies and focus on two non-coding RNA-based strategies that reached the phase of early clinical development to counteract cardiac remodelling and HF. The current status of the development of translating those novel therapies to clinical practice, limitations, and future perspectives are additionally discussed.

The Role of Gut Microbiota in Heart Failure: When Friends Become Enemies

Heart failure is a complex health issue, with important consequences on the overall wellbeing of patients. It can occur both in acute and chronic forms and, in the latter, the immune system appears to play an important role in the pathogenesis of the disease. In particular, in the forms with preserved ejection fraction or with only mildly reduced ejection fraction, some specific associations with chronic inflammatory diseases have been observed. Another interesting aspect that is worth considering is the role of microbiota modulation, in this context: given the importance of microbiota in the modulation of immune responses, it is possible that changes in its composition may somewhat influence the progression and even the pathogenesis of heart failure. In this narrative review, we aim to examine the relationship between immunity and heart failure, with a special focus on the role of microbiota in this pathological condition.

Tregs biomimetic nanoparticle to reprogram inflammatory and redox microenvironment in infarct tissue to treat myocardial ischemia reperfusion injury in mice

Background

At present, patients with myocardial infarction remain an increased risk for myocardial ischemia/reperfusion injury (MI/RI). There lacks effectively method to treat MI/RI in clinic. For the treatment of MI/RI, it is still a bottleneck to effectively deliver drug to ischemic myocardium. In this paper, a regulatory T cells (Tregs) biomimetic nanoparticle (CsA@PPTK) was prepared by camouflaging nanoparticle with platelet membrane.

Results

CsA@PPTK actively accumulated in ischemic myocardium of MI/RI mice. CsA@PPTK significantly scavenged reactive oxygen species (ROS) and increased the generation of Tregs and the ratio of M2 type macrophage to M1 type macrophage in ischemic myocardium. Moreover, CsA@PPTK significantly attenuated apoptosis of cardiomyocytes and reduced the infarct size and fibrosis area in ischemic myocardium. CsA@PPTK markedly decreased the protein expression of MMP-9 and increased the protein expression of CX43 in ischemic myocardium tissue. Subsequently, the remodeling of the left ventricle was significant alleviated, and heart function of MI/RI mice was markedly improved.

Conclusion

CsA@PPTK showed significant therapeutic effect on MI/RI, and it has great potential application in the treatment of MI/RI.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01445-2.

Sustained Elevated Circulating Activin A Impairs Global Longitudinal Strain in Pregnant Rats: A Potential Mechanism for Preeclampsia-Related Cardiac Dysfunction

Mediators of cardiac injury in preeclampsia are not well understood. Preeclamptic women have decreased cardiac global longitudinal strain (GLS), a sensitive measure of systolic function that indicates fibrosis and tissue injury. GLS is worse in preeclampsia compared to gestational hypertension, despite comparable blood pressure, suggesting that placental factors may be involved. We previously showed that Activin A, a pro-fibrotic factor produced in excess by the placenta in preeclampsia, predicts impaired GLS postpartum. Here, we hypothesized that chronic excess levels of Activin A during pregnancy induces cardiac dysfunction. Rats were assigned to sham or activin A infusion (1.25–6 µg/day) on a gestational day (GD) 14 (n = 6–10/group). All animals underwent blood pressure measurement and comprehensive echocardiography followed by euthanasia and the collection of tissue samples on GD 19. Increased circulating activin A (sham: 0.59 ± 0.05 ng/mL, 6 µg/day: 2.8 ± 0.41 ng/mL, p < 0.01) was associated with impaired GLS (Sham: −22.1 ± 0.8%, 6 µg/day: −14.7 ± 1.14%, p < 0.01). Activin A infusion (6 µg/day) increased beta-myosin heavy chain expression in heart tissue, indicating cardiac injury. In summary, our findings indicate that increasing levels of activin A during pregnancy induces cardiac dysfunction and supports the concept that activin A may serve as a possible mediator of PE-induced cardiac dysfunction.

The heart under pressure: immune cells in fibrotic remodeling

The complex syndrome of heart failure (HF) is characterized by increased left ventricular pressures. Cardiomyocytes increase in size, cardiac fibroblasts transform and make extracellular matrix, and leukocytes infiltrate the cardiac tissue and alter cardiomyocyte and cardiac fibroblast function. Here we review recent advances in our understanding of the cellular composition of the heart during homeostasis and in response to cardiac pressure overload, with an emphasis on immune cell communication with cardiac fibroblasts and its consequences in cardiac remodeling.

The additional value of lung cancer screening program in identifying unrecognized diseases

Background

A systematic examination of low-dose CT (LDCT) scan, beside lung nodules, may disclose the presence of undiagnosed diseases, improving the efficacy and the cost/efficacy of these programs. The study was aimed at evaluating the association between LDCT scan findings and non-oncologic and oncologic diseases.

Methods

The LDCT scan of participants to the “Un Respiro per la vita”^® lung cancer screening program were checked and abnormal findings, beside lung nodules, recorded. First admission to the acute care because of cardiovascular (CD), respiratory (RD) and oncological diseases (OD) in the following three years were retrieved. The association of LDCT scan abnormal findings with CD, RD and OD was assessed through univariable and multivariable logistic regression models.

Results

Mean age of 746 participants was 62 years (SD:5), 62% were male. 11 (1.5%) received a diagnosis of lung cancer. 16.1% participants were admitted to the acute care in the following three years: 8.6% for CD, 4.3% for RD and 5.2% for OD. Valve calcification (OR 2.02, p:0.02) and mucus plugs (OR 3.37, p:0.04) were positively associated with CD, while sub-pleural fibrosis had a protective role (OR 0.47, p:0.01). Lung nodules > 8 mm (OR 5.54, p: < 0.01), tracheal deviation (OR 6.04, p:0.01) and mucus plugs (OR 4.00, p:0.04) were positively associated with OD admissions. Centrilobular emphysema OR for RD admissions was 1.97 (p:0.06).

Conclusions

The observed association between selected LDCT findings and ensuing CD, RD and OD suggests that the information potential of LCDT goes beyond the screening of lung cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01826-1.

Nigella sativa oil protects against cadmium-induced intestinal toxicity via promotion of anti-inflammatory mechanisms, mucin expression and microbiota integrity

Objective

This study examined the protective effects of Nigella sativa oil (NSO) on cadmium (Cd)-induced alterations affecting gut morphology and microbiota composition, as well as the involvement of mucus glycoprotein (MUC2) and immuno-inflammatory markers (TNFα and IL-2) in the colon of rats.

Materials and Methods

Male Wistar rats, randomized into four groups, were treated either with distilled water (control), CdCl₂ (100 mg/kg), CdCl₂+NSO (1 ml/kg) or NSO alone. After the experiments, faecal samples were processed for microbial culture on various selective media, while intestinal segments were prepared for histopathological examination and immunohistochemistry. The composition of NSO was analyzed using Gas Chromatography-Mass Spectrometry (GC-MS).

Results

Oral Cd administration provoked dramatic increases in faecal counts of potentially pathogenic bacteria (Staphylococci, Enterococci, Pseudomonas and Escherichia coli), while decreasing probiotic lactobacilli counts. Cadmium treatment caused down-regulation of colonic MUC2 (p=0.003) and IL-2 (p=0.03), but increased TNFα (p=0.034), along with reduced goblet cell counts and mucus production. Conversely, treatment with NSO significantly improved Lactobacilli counts (p=0.042), while reducing the levels of potentially pathogenic species. In addition, NSO significantly restored colonic expressions of MUC2 (p=0.001), TNFα (p=0.007) and IL-2 (p=0.025) to control levels. GC-MS analysis of NSO revealed the presence of the active ingredient, thymoquinone and a high content of unsaturated fatty acids, including trans-13-octadecenoic acid and oleic acid.

Conclusion

This study highlights the intestinal mucus, microbiota and immuno-inflammatory system as important protective targets of NSO against Cd-induced intestinal toxicity.

The Role of the Gut Microbiota in the Pathogenesis of Diabetes

Diabetes mellitus is a significant clinical and therapeutic problem because it can lead to serious long-term complications. Its pathogenesis is not fully understood, but there are indications that dysbiosis can play a role in the development of diabetes, or that it appears during the course of the disease. Changes in microbiota composition are observed in both type 1 diabetes (T1D) and type 2 diabetes (T2D) patients. These modifications are associated with pro-inflammation, increased intestinal permeability, endotoxemia, impaired β-cell function and development of insulin resistance. This review summarizes the role of the gut microbiota in healthy individuals and the changes in bacterial composition that can be associated with T1D or T2D. It also presents new developments in diabetes therapy based on influencing the gut microbiota as a promising method to alter the course of diabetes. Moreover, it highlights the lacking data and suggests future directions needed to prove the causal relationship between dysbiosis and diabetes, both T1D and T2D.

Therapeutic targeting of inflammation in hypertension: from novel mechanisms to translational perspective

Both animal models and human observational and genetic studies have shown that immune and inflammatory mechanisms play a key role in hypertension and its complications. We review the effects of immunomodulatory interventions on blood pressure, target organ damage, and cardiovascular risk in humans. In experimental and small clinical studies, both non-specific immunomodulatory approaches, such as mycophenolate mofetil and methotrexate, and medications targeting T and B lymphocytes, such as tacrolimus, cyclosporine, everolimus, and rituximab, lower blood pressure and reduce organ damage. Mechanistically targeted immune interventions include isolevuglandin scavengers to prevent neo-antigen formation, co-stimulation blockade (abatacept, belatacept), and anti-cytokine therapies (e.g. secukinumab, tocilizumab, canakinumab, TNF-α inhibitors). In many studies, trial designs have been complicated by a lack of blood pressure-related endpoints, inclusion of largely normotensive study populations, polypharmacy, and established comorbidities. Among a wide range of interventions reviewed, TNF-α inhibitors have provided the most robust evidence of blood pressure lowering. Treatment of periodontitis also appears to deliver non-pharmacological anti-hypertensive effects. Evidence of immunomodulatory drugs influencing hypertension-mediated organ damage are also discussed. The reviewed animal models, observational studies, and trial data in humans, support the therapeutic potential of immune-targeted therapies in blood pressure lowering and in hypertension-mediated organ damage. Targeted studies are now needed to address their effects on blood pressure in hypertensive individuals.

Gut Microbiota and Subclinical Cardiovascular Disease in Patients with Type 2 Diabetes Mellitus

Type 2 diabetes (T2D) is associated with an increased risk of cardiovascular disease (CVD). The gut microbiota may contribute to the onset and progression of T2D and CVD. The aim of this study was to evaluate the relationship between the gut microbiota and subclinical CVD in T2D patients. This cross-sectional study used echocardiographic data to evaluate the cardiac structure and function in T2D patients. We used a quantitative polymerase chain reaction to measure the abundances of targeted fecal bacterial species that have been associated with T2D, including Bacteroidetes, Firmicutes, Clostridium leptum group, Faecalibacterium prausnitzii, Bacteroides, Bifidobacterium, Akkermansia muciniphila, and Escherichia coli. A total of 155 subjects were enrolled (mean age 62.9 ± 10.1 years; 57.4% male and 42.6% female). Phyla Bacteroidetes and Firmicutes and genera Bacteroides were positively correlated with the left ventricular ejection fraction. Low levels of phylum Firmicutes were associated with an increased risk of left ventricular hypertrophy. High levels of both phylum Bacteroidetes and genera Bacteroides were negatively associated with diastolic dysfunction. A high phylum Firmicutes/Bacteroidetes (F/B) ratio and low level of genera Bacteroides were correlated with an increased left atrial diameter. Phyla Firmicutes and Bacteroidetes, the F/B ratio, and the genera Bacteroides were associated with variations in the cardiac structure and systolic and diastolic dysfunction in T2D patients. These findings suggest that changes in the gut microbiome may be the potential marker of the development of subclinical CVD in T2D patients.

Inflammatory Cytokines, Immune Cells, and Organ Interactions in Heart Failure

Despite mounting evidence demonstrating the significance of inflammation in the pathophysiological mechanisms of heart failure (HF), most large clinical trials that target the inflammatory responses in HF yielded neutral or even worsening outcomes. Further in-depth understanding about the roles of inflammation in the pathogenesis of HF is eagerly needed. This review summarizes cytokines, cardiac infiltrating immune cells, and extracardiac organs that orchestrate the complex inflammatory responses in HF and highlights emerging therapeutic targets.

Embryonic Stem Cell-Derived Exosomes Attenuate Transverse Aortic Constriction Induced Heart Failure by Increasing Angiogenesis

Background: Although there are concerns regarding their clinical use, embryonic stem cells (ESCs) hold a great promise for cardiac repair. Exosomes deriving from ESCs constitute a promising alternative for heart restoration. However, their effects in hypertension-induced heart failure are still unknown.

Objective and Methods: To investigate the effects of ESCs-derived exosomes on hypertension-induced heart failure and the underlying mechanisms, sustained transverse aortic constriction (TAC) was performed on 8-week-old C57BL/6 male mice. After 1 months, ESCs-derived exosomes were isolated and injected intravenously once a week for 6 weeks. Echocardiography, wheat germ agglutinin (WGA), Masson staining, immunohistochemistry, and tube formation assays were all involved in our study.

Results: Proteomics analyses revealed that ESC-derived exosomes contain FGF2 protein. Tube formation induced by these exosomes could be inhibited by FGF2R siRNA interference. ESCs-derived exosomes evidently attenuated TAC-induced heart failure, improving cardiac function and promoting myocardial angiogenesis which can be attenuated by selective FGF2 inhibitor AZD4547.

Conclusions: ESC-derived exosomes attenuate TAC-induced heart failure mostly by promoting myocardial angiogenesis. FGF2 signaling plays a vital role in the myocardial angiogenesis induced by ESC-derived exosomes.

Uncovering the pharmacological mechanisms of Xijiao Dihuang decoction combined with Yinqiao powder in treating influenza viral pneumonia by an integrative pharmacology strategy

Xijiao Dihuang decoction combined with Yinqiao powder (XDD-YQP) is a classical combination formula; however, its therapeutic effects in treating influenza viral pneumonia and the pharmacological mechanisms remain unclear. The therapeutic effect of XDD-YQP in influenza viral pneumonia was evaluated in mice. Subsequently, an everted gut sac model coupled with UPLC/Q-TOF MS were used to screen and identify the active compounds of XDD-YQP. Furthermore, network pharmacological analysis was adopted to probe the mechanisms of the active compounds. Lastly, we verified the targets predicted from network pharmacological analysis by differential bioinformatics analysis. Animal experiments showed that XDD-YQP has a therapeutic effect on influenza viral pneumonia. Moreover, 113 active compounds were identified from intestinal absorbed solutions of XDD-YQP. Using network pharmacological analysis, 90 major targets were selected as critical in the treatment of influenza viral pneumonia through 12 relevant pathways. Importantly, the MAPK signaling pathway was found to be closely associated with the other 11 pathways. Moreover, seven key targets, EGFR, FOS, MAPK1, MAP2K1, HRAS, NRAS, and RELA, which are common targets in the MAPK signaling pathway, were investigated. These seven key targets were identified as differentially expressed genes (DEGs) between influenza virus-infected and uninfected individuals. Hence, the seven key targets in the MAPK signaling pathway may play a vital role in the treatment of influenza viral pneumonia with XDD-YQP. This research may offer an integrative pharmacology strategy to clarify the pharmacological mechanisms of traditional Chinese medicines. The results provide a theoretical basis for a broader clinical application of XDD-YQP.

Targeted Therapy in Cardiovascular Disease: A Precision Therapy Era

Targeted therapy refers to exploiting the specific therapeutic drugs against the pathogenic molecules (a protein or a gene) or cells. The drug specifically binds to disease-causing molecules or cells without affecting normal tissue, thus enabling personalized and precision treatment. Initially, therapeutic drugs included antibodies and small molecules, (e.g. nucleic acid drugs). With the advancement of the biology technology and immunotherapy, the gene editing and cell editing techniques are utilized for the disease treatment. Currently, targeted therapies applied to treat cardiovascular diseases (CVDs) mainly include protein drugs, gene editing technologies, nucleic acid drugs and cell therapy. Although targeted therapy has demonstrated excellent efficacy in pre-clinical and clinical trials, several limitations need to be recognized and overcome in clinical application, (e.g. off-target events, gene mutations, etc.). This review introduces the mechanisms of different targeted therapies, and mainly describes the targeted therapy applied in the CVDs. Furthermore, we made comparative analysis to clarify the advantages and disadvantages of different targeted therapies. This overview is expected to provide a new concept to the treatment of the CVDs.

Biological drug and drug delivery-mediated immunotherapy

The initiation and development of major inflammatory diseases, i.e., cancer, vascular inflammation, and some autoimmune diseases are closely linked to the immune system. Biologics-based immunotherapy is exerting a critical role against these diseases, whereas the usage of the immunomodulators is always limited by various factors such as susceptibility to digestion by enzymes in vivo, poor penetration across biological barriers, and rapid clearance by the reticuloendothelial system. Drug delivery strategies are potent to promote their delivery. Herein, we reviewed the potential targets for immunotherapy against the major inflammatory diseases, discussed the biologics and drug delivery systems involved in the immunotherapy, particularly highlighted the approved therapy tactics, and finally offer perspectives in this field.

Inflammation, immunity and potential target therapy of SARS-COV-2: A total scale analysis review

Coronavirus disease-19 (COVID-19) is a complex disease that causes illness ranging from mild to severe respiratory problems. It is caused by a novel coronavirus SARS-CoV-2 (Severe acute respiratory syndrome coronavirus-2) that is an enveloped positive-sense single-stranded RNA (+ssRNA) virus belongs to coronavirus CoV family. It has a fast-spreading potential worldwide, which leads to high mortality regardless of lows death rates. Now some vaccines or a specific drug are approved but not available for every country for disease prevention and/or treatment. Therefore, it is a high demand to identify the known drugs and test them as a possible therapeutic approach. In this critical situation, one or more of these drugs may represent the only option to treat or reduce the severity of the disease, until some specific drugs or vaccines will be developed and/or approved for everyone in this pandemic. In this updated review, the available repurpose immunotherapeutic treatment strategies are highlighted, elucidating the crosstalk between the immune system and SARS-CoV-2. Despite the reasonable data availability, the effectiveness and safety of these drugs against SARS-CoV-2 needs further studies and validations aiming for a better clinical outcome.

Immunomodulation in Heart Failure with Preserved Ejection Fraction: Current State and Future Perspectives

The heart failure (HF) epidemic is growing and approximately half of the HF patients have heart failure with preserved ejection fraction (HFpEF). HFpEF is a heterogeneous syndrome, characterized by a preserved left ventricular ejection fraction (LVEF ≥ 50%) with diastolic dysfunction, and is associated with high morbidity and mortality. Underlying comorbidities of HFpEF, i.e., hypertension, type 2 diabetes mellitus, obesity, and renal failure, lead to a systemic pro-inflammatory state, thereby affecting normal cardiac function. Increased inflammatory biomarkers predict incident HFpEF and are higher in patients with HFpEF as compared with heart failure with reduced ejection fraction (HFrEF). Randomized trials in HFpEF patients using traditional HF medication failed to demonstrate a clear benefit on hard endpoints (mortality and/or HF hospitalization). Therefore, therapies targeting underlying comorbidities and systemic inflammation in early HFpEF may provide better opportunities. Here, we provide an overview of the current state and future perspectives of immunomodulatory therapies for HFpEF.

Regulatory T cell heterogeneity and therapy in autoimmune diseases

Regulatory T (Treg) cells are a group of CD4⁺ T cell with high expression of CD25 and cell linage specific transcription factor forkhead box P3 (Foxp3) and play a vital role in maintaining immune homeostasis. In the last two decades, researchers have shown that Treg cells involved in the occurrence, development and prognosis of many diseases, especially in autoimmune diseases. Treg targeted therapies, such as low-dose interleukin-2 (IL-2) treatment and Treg infusion therapy, which are aimed at restoring the number or function of Treg cells, have become a hot topic in clinical trials of these diseases. It is believed that Treg cells are heterogeneous. Different subsets of Treg cells have various functions and play different parts in immunomodulatory. Gaining insights into Treg heterogeneity will help us further understand the function of Treg cells and provide news ideas for the selective therapeutic manipulation of Treg cells. In this review, we mainly summarize the heterogeneity of Treg cells and their potential therapeutic value in autoimmune diseases.

Regulatory T cells in ischemic cardiovascular injury and repair

Ischemic injury triggers a heightened inflammatory response that is essential for tissue repair, but excessive and chronic inflammatory responses contribute to the pathogenesis of ischemic cardiovascular disease. Regulatory T cells (Tregs), a major regulator of self-tolerance and immune suppression, control innate and adaptive immune responses, modulate specific immune cell subsets, prevent excessive inflammation, and participate in tissue repair after ischemia. Herein, we summarize the multiple potential mechanisms by which Tregs exert suppressor functions including modulation of cytokine production, alteration of cell-cell interactions, and disruption of metabolic pathways. Furthermore, we review the role of Tregs implicated in ischemic injury and repair including myocardial, limb, and cerebral ischemia. We conclude with a perspective on the therapeutic opportunities and future challenges of Treg biology in understanding the pathogenesis of ischemic cardiovascular disease states.

Systolic overload-induced pulmonary inflammation, fibrosis, oxidative stress and heart failure progression through interleukin-1β

Chronic heart failure is associated with increased interleukin-1β (IL-1β), leukocyte infiltration, and fibrosis in the heart and lungs. Here we further studied the role of IL-1β in the transition from left heart failure to pulmonary hypertension and right ventricular hypertrophy in mice with existing left heart failure produced by transverse aortic constriction. We demonstrated that transverse aortic constriction-induced heart failure was associated with increased lung inflammation and cleaved IL-1β, and inhibition of IL-1β signaling using blocking antibodies of clone B122 effectively attenuated further decrease of left ventricular systolic function in mice with existing heart failure. We found that inhibition of IL-1β attenuated lung inflammation, inflammasome activation, fibrosis, oxidative stress, and right ventricular hypertrophy. IL-1β blocking antibodies of clone B122 also significantly attenuated lung T cell activation. Together, these data indicate that IL-1β signaling exerts a causal role for heart failure progression, or the transition from left heart failure to lung remodeling and right heart hypertrophy.

2019 ATVB Plenary Lecture: Interleukin-2 Therapy in Cardiovascular Disease: The Potential to Regulate Innate and Adaptive Immunity

Regulatory T cells and type-2 innate lymphoid cells represent 2 subsets of immune cells, which have been shown in preclinical models to be important in atherosclerosis and myocardial repair. Regulatory T cells play a crucial role in immune homeostasis and tolerance via their interactions with effector T cells, dendritic cells, and monocytes/macrophages. They also utilize and secrete inhibitory cytokines, including interleukin 10 and transforming growth factor β, to regulate or suppress pathogenic immune responses. Type-2 innate lymphoid cells have an important role in type-2 immune responses and tissue repair through secreting interleukins 5 and 13, as well as a variety of biological mediators and growth factors. Intriguingly, interleukin-2 has emerged as a common cytokine, which can be harnessed to upregulate both cell types, and also has important translational consequences as clinical trials are ongoing for its use in cardiovascular disease. Here, we briefly review the biology of these regulatory immune cell types, discuss the preclinical and clinical evidence for their functions in cardiovascular disease, examine the prospects for clinical translation and current ongoing trials, and finally, postulate how overlap in the mechanisms of upregulation may be leveraged in future treatments for patients.

The Quest for Antiinflammatory and Immunomodulatory Strategies in Heart Failure

Intensive research over the last 3 decades has unequivocally demonstrated the relevance of inflammation in heart failure (HF). Despite our current and ever increasing knowledge about inflammation, the clinical success of antiinflammatory and immunomodulatory therapies in HF is still limited. This review outlines the complexity and diversity of inflammation, its reciprocal interaction with HF, and addresses future perspectives, calling for immunomodulatory therapies that are specific for factors that activate the immune system without the risk of nonspecific immune suppression.

Interleukin-2 induces extracellular matrix synthesis and TGF-β2 expression in retinal pigment epithelial cells

Macular fibrosis is a vital obstacle of vision acuity improvement of age‐related macular degeneration patients. This study was to investigate the effects of interleukin 2 (IL‐2) on epithelial‐mesenchymal transition (EMT), extracellular matrix (ECM) synthesis and transforming growth factor β2 (TGF‐β2) expression in retinal pigment epithelial (RPE) cells. 10 μg/L IL‐2 was used to induce fibrosis in RPE cells for various times. Western blot was used to detect the EMT marker α‐smooth muscle actin (α‐SMA), ECM markers fibronectin (Fn) and type 1 collagen (COL‐1), TGF‐β2, and the activation of the JAK/STAT3 and NF‐κB signaling pathway. Furthermore, JAK/STAT3 and NF‐κB signaling pathways were specifically blocked by WP1066 or BAY11‐7082, respectively, and the expression of α‐SMA, COL‐1, Fn and TGF‐β2 protein were detected. Wound healing and Transwell assays were used to measure cell migration ability of IL‐2 with or without WP1066 or BAY11‐7082. After induction of IL‐2, the expressions of Fn, COL‐1, TGF‐β2 protein were significantly increased, and this effect was correlated with IL‐2 treatment duration, while α‐SMA protein expression did not change significantly. Both WP1066 and BAY11‐7082 could effectively downregulate the expression of Fn, COL‐1 and TGF‐β2 induced by IL‐2. What's more, both NF‐κB and JAK/STAT3 inhibitors could suppress the activation of the other signaling pathway. Additionally, JAK/STAT3 inhibitor WP1066 and NF‐κB inhibitor BAY 11‐7082 could obviously decrease RPE cells migration capability induced by IL‐2. IL‐2 promotes cell migration, ECM synthesis and TGF‐β2 expression in RPE cells via JAK/STAT3 and NF‐κB signaling pathways, which may play an important role in proliferative vitreoretinopathy.

Can intestinal microbiota and circulating microbial products contribute to pulmonary arterial hypertension?

Pulmonary arterial hypertension (PAH) is a fatal disease with a median survival of only 5-7 yr. PAH is characterized by remodeling of the pulmonary vasculature causing reduced pulmonary arterial compliance (PAC) and increased pulmonary vascular resistance (PVR), ultimately resulting in right ventricular failure and death. Better therapies for PAH will require a paradigm shift in our understanding of the early pathophysiology. PAC decreases before there is an increase in the PVR. Unfortunately, present treatment has little effect on PAC. The loss of compliance correlates with extracellular matrix remodeling and fibrosis in the pulmonary vessels, which have been linked to chronic perivascular inflammation and immune dysregulation. However, what initiates the perivascular inflammation and immune dysregulation in PAH is unclear. Alteration of the gut microbiota composition and function underlies the level of immunopathogenic involvement in several diseases, including atherosclerosis, obesity, diabetes mellitus, and depression, among others. In this review, we discuss evidence that raises the possibility of an etiologic role for changes in the gut and circulating microbiome in the initiation of perivascular inflammation in the early pathogenesis of PAH.

Isolevuglandin scavenger attenuates pressure overload-induced cardiac oxidative stress, cardiac hypertrophy, heart failure and lung remodeling

Increased levels of reactive isolevuglandins (IsoLGs) are associated with vascular inflammation and hypertension, two important factors affect heart failure (HF) development. The role of IsoLGs in HF development is unknown. Here we studied the role of IsoLG scavenger 2-hydroxybenzylamine (2-HOBA) in transverse aortic constriction (TAC) induced heart failure. We observed that TAC caused a significant increase of IsoLG protein adducts in cardiac and lung tissues in mice. Both IsoLG scavenger 2-hydroxybenzylamine (2-HOBA) and its less reactive isomer 4-hydroxybenzylamine (4-HOBA) significantly attenuated the left ventricular (LV) and lung IsoLGs in mice after TAC. 2-HOBA and 4-HOBA attenuated TAC-induced LV hypertrophy, heart failure, and the increase of lung weight in mice, and also improved TAC-induced LV dysfunction. Moreover, both 2-HOBA and 4-HOBA effectively attenuated LV cardiomyocyte hypertrophy, lung inflammation, lung fibrosis. These findings suggest that methods to reduce IsoLGs may be useful for HF therapy.

Dietary Factors and Modulation of Bacteria Strains of Akkermansia muciniphila and Faecalibacterium prausnitzii: A Systematic Review

Akkermansia muciniphila and Faecalibacterium prausnitzii are highly abundant human gut microbes in healthy individuals, and reduced levels are associated with inflammation and alterations of metabolic processes involved in the development of type 2 diabetes. Dietary factors can influence the abundance of A. muciniphila and F. prausnitzii, but the evidence is not clear. We systematically searched PubMed and Embase to identify clinical trials investigating any dietary intervention in relation to A. muciniphila and F. prausnitzii. Overall, 29 unique trials were included, of which five examined A. muciniphila, 19 examined F. prausnitzii, and six examined both, in a total of 1444 participants. A caloric restriction diet and supplementation with pomegranate extract, resveratrol, polydextrose, yeast fermentate, sodium butyrate, and inulin increased the abundance of A. muciniphila, while a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols decreased the abundance of A. muciniphila. For F. prausnitzii, the main studied intervention was prebiotics (e.g. fructo-oligosaccharides, inulin type fructans, raffinose); seven studies reported an increase after prebiotic intervention, while two studies reported a decrease, and four studies reported no difference. Current evidence suggests that some dietary factors may influence the abundance of A. muciniphila and F. prausnitzii. However, more research is needed to support these microflora strains as targets of microbiome shifts with dietary intervention and their use as medical nutrition therapy in prevention and management of chronic disease.

IL-2 therapy preferentially expands adoptively transferred donor-specific Tregs improving skin allograft survival

Regulatory T cells (Tregs) have unique immunosuppressive properties and are essential to ensure effective immunoregulation. In animal models, Tregs have been shown to prevent autoimmune disorders and establish transplantation tolerance. Therefore, the prospect of harnessing Tregs, either by increasing their frequency or by conferring allospecificity, has prompted a growing interest in the development of immunotherapies. Here, employing a well-established skin transplant model with a single major histocompatibility complex mismatch, we compared the therapeutic efficacy of adoptively transfer Treg with or without donor specificity and the administration of IL-2 to promote in vivo expansion of Treg. We showed that IL-2 treatment preferentially enhances the proliferation of the allospecific Tregs adoptively transferred in an antigen-dependent manner. In addition, donor-specific Tregs significantly increased the expression of regulatory-related marker, such as CTLA4 and inducible costimulator (ICOS), in the skin allograft and draining lymph nodes compared to endogenous and polyclonal transferred Tregs. Importantly, by combining IL-2 with donor-specific Tregs, but not with polyclonal Tregs, a synergistic effect in prolonging skin allograft survival was observed. Altogether, our data suggest that this combination therapy could provide the appropriate conditions to enhance the immunoregulation of alloimmune responses in clinical transplantation.

Hypertension: a new treatment for an old disease? Targeting the immune system

Arterial hypertension represents a serious public health problem, being a major cause of morbidity and mortality worldwide. The availability of many antihypertensive therapeutic strategies still fails to adequately treat around 20% of hypertensive patients, who are considered resistant to conventional treatment. In the pathogenesis of hypertension, immune system mechanisms are activated and both the innate and adaptive immune responses play a crucial role. However, what, when and how the immune system is triggered during hypertension development is still largely undefined. In this context, this review highlights scientific advances in the manipulation of the immune system in order to attenuate hypertension and end-organ damage. Here, we discuss the potential use of immunosuppressants and immunomodulators as pharmacological tools to control the activation of the immune system, by non-specific and specific mechanisms, to treat hypertension and improve end-organ damage. Nevertheless, more clinical trials should be performed with these drugs to establish their therapeutic efficacy, safety and risk-benefit ratio in hypertensive conditions. LINKED ARTICLES: This article is part of a themed section on Immune Targets in Hypertension. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.12/issuetoc.

Y75B8A.8 (HC8) protein of Haemonchus contortus: A functional inhibitor of host IL-2

Interleukin 2 (IL-2) is an important immune regulatory factor in the immune response of the host. However, little is known about the inhibitor of host IL-2 in Haemonchus contortus infection. In this study, we found that globin domain-containing protein (HCGB) and Protein Y75B8A.8 (HC8) from H contortus excretory and secretory products are two binding proteins of IL-2 in goats. The yeast two-hybrid screening further validated the positive interactions of IL-2 with HCGB and HC8. Meanwhile, we found that HC8 had inhibitory effects on IL-2-induced peripheral blood mononuclear cell (PBMC) proliferation, while HCGB did not. Furthermore, transcriptional analysis revealed that HC8 could block the IL-2-activated signalling pathway. Our results showed that HC8 was a functional inhibitor of goat IL-2.

Short term Pm2.5 exposure caused a robust lung inflammation, vascular remodeling, and exacerbated transition from left ventricular failure to right ventricular hypertrophy

Heart failure (HF) is the single largest cause for increased hospitalization after fine particulate matter (PM2.5) exposure. Patients with left HF often progress to right ventricular (RV) failure even with optimal medical care. An increase of PM2.5 of 10 μg per cubic meter was associated with a 76% increase in the risk of death from cardiovascular disease in 4 years' period. However, the role and mechanism of PM2.5 in HF progression are not known. Here we investigated the role of PM2.5 exposure in mice with existing HF mice produced by transverse aortic constriction (TAC). TAC-induced HF caused lung inflammation, vascular remodeling and RV hypertrophy. We found increased PM2.5 profoundly exacerbated lung oxidative stress in mice with existing left HF. To our surprise, PM2.5 exposure had no effect on LV hypertrophy and function, but profoundly exacerbated lung inflammation, vascular remodeling, and RV hypertrophy in mice with existing left HF. These striking findings demonstrate that PM2.5 and/or air pollution is a critical factor for overall HF progression by regulating lung oxidative stress, inflammation and remodeling as well as RV hypertrophy. Improving air quality may save HF patients from a dismal fate.

Profound Increase of Lung Airway Resistance in Heart Failure: a Potential Important Contributor for Dyspnea

Dyspnea is a major symptom of heart failure (HF). Here, we have studied the lung remodeling and airway resistance in HF mice. We demonstrated that aortic banding-induced HF caused a dramatic decrease of lung compliance and an increase of lung airway resistance. The decrease of lung compliance was correlated with the increased lung weight in a linear fashion (γ² = 0.824). An HF-induced increase of lung airway resistance and a decrease of lung compliance were almost identical in anesthetized mice and in the isolated lungs from these mice. HF caused profound lung fibrosis in mice with increased lung weight. Moreover, HF patients of NYHA class III-IV showed increased lung density as revealed by high-resolution CT scanning. These data indicate that lung compliance and lung airway resistance may be useful in determining lung remodeling after HF, and lung structure changes may contribute to dyspnea in HF.

In Vivo Expansion of Regulatory T Cells with IL-2/IL-2 Antibody Complex Protects against Transient Ischemic Stroke

Regulatory T cells (Tregs) are known to protect against ischemic stroke. However, the low frequency of Tregs restricts their clinical utility. This study investigated whether expanding the number of Tregs in vivo with the IL-2/IL-2 antibody complex (IL-2/IL-2Ab) could improve stroke outcomes and further elaborated the mechanisms of protection in male mice. C57BL/6 mice received IL-2/IL-2Ab or isotype IgG (IsoAb) intraperitoneally for 3 d before (pretreatment) or starting 2 h after (posttreatment) 60 min middle cerebral artery occlusion (MCAO). IL-2/IL-2Ab selectively increased the number of Tregs in the blood, spleen, and lymph nodes. The IL-2/IL-2Ab treatment significantly reduced infarct volume, inhibited neuroinflammation, and improved sensorimotor functions, as manifested by rotarod test and foot fault test, compared with IsoAb-treated stroke mice. Treg depletion was then achieved by diphtheria toxin (DT) injection into transgenic mice expressing the DT receptor under the control of the Foxp3 promoter (DTR mice). The depletion of Tregs completely eliminated IL-2/IL-2Ab-afforded neuroprotection. Interestingly, adoptive transfer of Tregs collected from IL-2/IL-2Ab-treated mice demonstrated more potent neuroprotection than an equal number of Tregs prepared from IsoAb-treated mice, suggesting that IL-2/IL-2Ab not only elevated Treg numbers, but also boosted their functions. Mechanistically, IL-2/IL-2Ab promoted the expression of CD39 and CD73 in expanded Tregs. CD73 deficiency diminished the protective effect of IL-2/IL-2Ab-stimulated Tregs in stroke mice. The results show that IL-2/IL-2Ab expands Tregs in vivo and boosts their immunomodulatory function. The activation of CD39/CD73 signaling in Tregs may participate as a potential mechanism underlying IL-2/IL-2Ab-afforded neuroprotection against ischemic brain injury.SIGNIFICANCE STATEMENT Regulatory T cells (Tregs) are known to protect against ischemic stroke. However, the low frequency of Tregs restricts their clinical utility. This study reported that systemic administration of the IL-2/IL-2 antibody complex (IL-2/IL-2Ab) robustly and selectively expanded the number of Tregs after stroke. IL-2/IL-2Ab pretreatment or posttreatment significantly improved stroke outcomes in a rodent model of ischemic stroke. We further discovered that IL-2/IL-2Ab not only elevated Treg numbers, but also boosted their functions and enhanced the expression of CD39 and CD73. Using CD73-deficient mice, we confirmed the importance of CD73 in the protective effect of IL-2/IL-2Ab-stimulated Tregs in stroke mice. These results shed light on IL-2/IL-2Ab as a clinically feasible immune therapy to boost endogenous Treg responses and ameliorate ischemic brain injury.