Progranulin ameliorates coxsackievirus-B3-induced viral myocarditis by downregulating Th1 and Th17 cells

Progression predictors of clinically isolated syndrome to multiple sclerosis: A prospective study in China

OBJECTIVES

Clinically isolated syndrome (CIS) is a preclinical phase of multiple sclerosis (MS). The progression rate of CIS to clinical definite MS (CDMS) varies significantly across different populations, and identifying predictors of progression is crucial for early diagnosis and treatment. We aimed to investigate predictors of progression from CIS to CDMS in a Chinese cohort.

METHODS

A single-center cohort study was conducted with newly diagnosed patients with CIS in China between 2018 and 2021. All patients underwent a comprehensive clinical evaluation, including neurological examination, magnetic resonance imaging, and laboratory tests. Follow-up assessments were conducted at regular intervals to monitor disease progression. Progression to CDMS was defined according to the 2017 McDonald criteria. Age, sex, Expanded Disability Status Scale (EDSS) score, number of patients with magnetic resonance imaging gadolinium-enhancing (Gd+) lesions, T2 lesions and Gd+ lesions count, CSF cell count, CSF total protein, CSF and serum neurofilament light chain (NfL), progranulin (PGRN) and Th17-related cytokines (IL-6, IL-17, IL-21, IL-22, IL-23 and TGF-β) were measured for association with risk of progression to CDMS.

RESULTS

A total of 96 CIS patients were recruited in the study. During the at least 24 months follow-up period, 57 (59.38 %) CIS patients progressed to CDMS, while 39 (40.62 %) patients without progression remained stable as CIS. Multivariate analysis revealed that younger age at onset (OR= 43.43, 95 % CI= 1.76-1071.68, p<0.021), higher CSF elevated protein (OR=58.64, 95 % CI=2.72-1264.51, p=0.009), higher CSF NfL levels (OR= 97.00, 95 % CI= 4.68-2012.99, p=0.003) and higher CSF IL-23 levels (OR= 412.02, 95 % CI=6.56-25869.60, p=0.004) were associated with high risk of progression to CDMS.

CONCLUSION

Younger age at onset, elevated CSF NfL, IL-23 and protein levels might be progression predictors of CIS to CDMS in Chinese population.

Immune mechanisms of group B coxsackievirus induced viral myocarditis

Viral myocarditis is known to be a primary cause of dilated cardiomyopathy (DCM) that can lead to heart failure and sudden cardiac death and is invariably caused by myocardial viral infection following active inflammatory destruction of the myocardium. Although acute viral myocarditis frequently recovers on its own, current chronic myocarditis therapies are unsatisfactory, where the persistence of viral or immunological insults to the heart may play a role. Cellular and mouse experimental models that utilized the most prevalent Coxsackievirus group B type 3 (CVB3) virus infection causing myocarditis have illustrated the pathophysiology of viral myocarditis. In this review, immunological insights into the different stages of development of viral myocarditis were discussed, concentrating on the mechanisms of innate and adaptive immunity in the development of CVB3-induced myocarditis.

Ruxolitinib ameliorated coxsackievirus B3-induced acute viral myocarditis by suppressing the JAK-STAT pathway

BACKGROUND

Accumulating evidences have demonstrated that overwhelming inflammation occurs in the process of Coxsackievirus B3 (CVB3)-induced acute viral myocarditis (AVM). No specific therapy is available. More than an effective Janus-associated kinase (JAK) inhibiter, ruxolitinib exerts a critical role in the inflammatory diseases. In this study, we investigated the potential effect of ruxolitinib on CVB3-induced acute viral myocarditis.

METHOD

In vivo, BALB/c mice were intraperitoneally injected of CVB3, treated of a successive gavage of ruxolitinib for seven days, and subjected to a series of analysis. In vitro, primary bone marrow-derived macrophages (BMDMs) and cardiac fibroblasts were isolated, cultured, treated, harvested and finally detected.

RESULTS

In vivo, acute viral myocarditis was successfully induced by the injection of CVB3 characterized by impaired cardiac function, predominant infiltration of inflammatory cells, necroptosis of myocardium, great increase of cardiac troponin I (cTnI) and cytokine levels, replication of CVB3, and excessive activation of JAK-STAT pathways. Oral administration of ruxolitinib suppressed the activation of JAK-STAT pathway in a dosage-dependent way, lessened the infiltration of inflammatory cells and necroptosis of myocardium, reduced the levels of cTnI and cytokines, and finally alleviated CVB3-induced cardiac dysfunction, with the reduced production of type I interferon and no promising effect on the replication of CVB3. In vitro, the treatment of ruxolitinib inhibited the activation of JAK-STAT pathway and increase of multiple cytokines mRNA levels in BMDMs and had no protective effect against CVB3 replication in cardiac fibroblasts.

CONCLUSIONS

Our study suggested that ruxolitinib ameliorated CVB3-induced AVM by inhibiting the activation of JAK-STAT pathway, infiltration of inflammatory cells and necroptosis of myocardium, which may provide a novel strategy for AVM therapy.

Role of Coxsackievirus B3-Induced Immune Responses in the Transition from Myocarditis to Dilated Cardiomyopathy and Heart Failure

Dilated cardiomyopathy (DCM) is a cardiac disease marked by the stretching and thinning of the heart muscle and impaired left ventricular contractile function. While most patients do not develop significant cardiac diseases from myocarditis, disparate immune responses can affect pathological outcomes, including DCM progression. These altered immune responses, which may be caused by genetic variance, can prolong cytotoxicity, induce direct cleavage of host protein, or encourage atypical wound healing responses that result in tissue scarring and impaired mechanical and electrical heart function. However, it is unclear which alterations within host immune profiles are crucial to dictating the outcomes of myocarditis. Coxsackievirus B3 (CVB3) is a well-studied virus that has been identified as a causal agent of myocarditis in various models, along with other viruses such as adenovirus, parvovirus B19, and SARS-CoV-2. This paper takes CVB3 as a pathogenic example to review the recent advances in understanding virus-induced immune responses and differential gene expression that regulates iron, lipid, and glucose metabolic remodeling, the severity of cardiac tissue damage, and the development of DCM and heart failure.

Identification of Heterophilic Epitopes of H1N1 Influenza Virus Hemagglutinin

Our previous studies found that the H1-50 monoclonal antibody (mAb) of influenza A virus hemagglutinin (HA) cross-reacted with pancreatic tissue and islet β-cells, and further studies showed that H1-50 mAb binds to prohibitin (PHB) protein of islet β-cells. These suggest that there are heterophilic epitopes between influenza virus HA and pancreatic tissue, which may be involved in the pathogenesis of type 1 diabetes. To further investigate these heterophilic epitopes, we screened binding epitopes of H1-50 mAb using a phage 12-peptide library. DNA sequencing and comparative analysis were performed on specific positive phage clones, and the sequence of 12-peptide binding to H1-50 mAb was obtained. The binding epitopes of H1-50 mAb in influenza virus HA were determined by sequence analysis and experimental verification, and their distribution within the three-dimensional structure was assessed by PyMOL. The results showed that H1-50 mAb specifically binds to polypeptides (306-SLPFQNIHPITIGK-319) of influenza A virus HA, located in the stem of the HA protein. However, there is no specific binding sequence between H1-50 mAb and the PHB protein of islet β-cells in the primary structure, and we speculate that the binding of H1-50 mAb to islet β-cells may depend on the spatial conformation. The identification of the heterophilic epitopes of H1N1 influenza virus hemagglutinin provides a new perspective on type 1 diabetes that may be caused by influenza virus infection, which may contribute to the prevention and control of influenza.

Acute Viral Pericarditis Complicated by Cardiac Tamponade as a Result of COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) and coronavirus disease 2019 (COVID-19) predominantly cause respiratory symptoms but cardiovascular complications from COVID-19 have been documented in the literature. Acute pericarditis has been known to be caused by COVID-19 but severe cardiac complications, such as cardiac tamponade, have rarely been reported. Early diagnosis and treatment with pericardiocentesis are imperative, as this can improve patient outcomes. A 56-year-old female presented with chest pain and recurrent episodes of presyncope. The patient tested positive for SARS-Cov-2 through a polymerase chain reaction (PCR) test. The patient was hypotensive on arrival and the initial workup with electrocardiogram was significant for sinus tachycardia with low voltage QRS complexes in the precordial and limb leads. A transthoracic echocardiogram was also done and showed a large circumferential pericardial effusion with chamber collapse of the right atrium and right ventricle during diastole indicative of tamponade physiology. The patient's clinical course was complicated by pulseless electrical activity cardiac arrest during which a pericardiocentesis was done. One hundred (100) mL of serous pericardial fluid was drained and a return of spontaneous circulation was obtained after roughly 10 minutes of cardiopulmonary resuscitation. Further infectious and noninfectious workups, including malignant and rheumatologic etiologies for acute pericarditis, were negative. The patient was subsequently treated with high-dose non-steroidal anti-inflammatory drugs (NSAIDs) and colchicine for viral pericarditis. The patient's clinical course improved, and the patient was subsequently discharged after a prolonged hospital course to a subacute rehabilitation facility to undergo physical therapy.

Effect of FoxO1 on Cardiomyocyte Apoptosis and Inflammation in Viral Myocarditis via Modultion of the TLR4/NF-κB Signaling Pathway

To investigate the possible effect of FoxO on coxsackievirus B3 (CVB3) -induced cardiomyocyte inflammation and apoptosis via modulation of the TLR4/NF-κB signaling pathway.Viral myocarditis (VMC) models were establied via CVB3 infection both in vivo and in vitro. Western blotting was adopted to detect FoxO1 and TLR4 expressions in myocardial tissues and cells. Cardiomyocytes of suckling mouse were divided into the control, CVB3, CVB3 + pcDNA, CVB3 + pcDNA-FoxO1, CVB3 + TLR4 siRNA, and CVB3 + pcDNA-FoxO1 + TLR4 siRNA groups. Flow cytometry was employed to evaluate cell apoptosis. The expressions of inflammatory factors including TNF-α, IL-1β, and IL-6 were detected via quantitative reverse transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. Then, TLR4/NF-κB pathway-related proteins were determined via Western blotting.VMC mice had increased FoxO1 and TLR4 expressions in myocardial tissues. Cardiomyocytes with CVB3 infection also had upregulated protein expressions of p-FoxO1/FoxO1 and TLR4. Compared with those in the control group, the cardiomyocytes in the CVB3 group were increased in LDH and CK-MB levels, cell apoptosis rate and inflammatory factors (TNF-α, IL-1β and IL-6), as well as protein expressions of TLR4 and p-p65/p65. Compared with those in the CVB3 group, the cardiomyocytes in the CVB3 + pcDNA-FoxO1 group were further upregulated whereas those in the CVB3 +TLR4 siRNA group were downregulated in the aforementioned indicators. Furthermore, TLR4 siRNA can reverse the effect of pcDNA-FoxO1 on the aggravation of cardiomyocyte injury induced by CVB3 infection.FoxO1 can upregulate the TLR4/NF-κB signaling pathway to promote cardiomyocyte apoptosis and inflammatory injury in CVB3-induced VMC.

Targeting regulatory T cells for cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of death and disability worldwide. The CVDs are accompanied by inflammatory progression, resulting in innate and adaptive immune responses. Regulatory T cells (Tregs) have an immunosuppressive function and are one of the subsets of CD4⁺T cells that play a crucial role in inflammatory diseases. Whether using Tregs as a biomarker for CVDs or targeting Tregs to exert cardioprotective functions by regulating immune balance, suppressing inflammation, suppressing cardiac and vascular remodeling, mediating immune tolerance, and promoting cardiac regeneration in the treatment of CVDs has become an emerging research focus. However, Tregs have plasticity, and this plastic Tregs lose immunosuppressive function and produce toxic effects on target organs in some diseases. This review aims to provide an overview of Tregs' role and related mechanisms in CVDs, and reports on the research of plasticity Tregs in CVDs, to lay a foundation for further studies targeting Tregs in the prevention and treatment of CVDs.

Progranulin from different gliocytes in the nucleus accumbens exerts distinct roles in FTD- and neuroinflammation-induced depression-like behaviors

BACKGROUND

Neuroinflammation in the nucleus accumbens (NAc) is well known to influence the progression of depression. However, the molecular mechanisms triggering NAc neuroinflammation in depression have not been fully elucidated. Progranulin (PGRN) is a multifunctional growth factor that is linked to the innate immune response and inflammation, and PGRN plays a key role in neurodegenerative diseases such as frontotemporal dementia (FTD). Here, the purpose of this study was to validate whether PGRN was involved in the NAc neuroinflammation-promoted depressive-like phenotype.

METHODS

A NAc neuroinflammation-relevant depression-like model was established using wild-type (WT) and PGRN-knockout (KO) mice after NAc injection with lipopolysaccharide (LPS), and various behavioral tests related to cognition, social recognition, depression and anxiety were performed with WT and PGRNKO mice with or without NAc immune challenge. RT‒PCR, ELISA, western blotting and immunofluorescence staining were used to determine the expression and function of PGRN in the neuroinflammatory reaction in the NAc after LPS challenge. The morphology of neurons in the NAc from WT and PGRNKO mice under conditions of NAc neuroinflammation was analyzed using Golgi-Cox staining, followed by Sholl analyses. The potential signaling pathways involved in NAc neuroinflammation in PGRNKO mice were investigated by western blotting.

RESULTS

Under normal conditions, PGRN deficiency induced FTD-like behaviors in mice and astrocyte activation in the NAc, promoted the release of the inflammatory cytokines interleukin (IL)-6 and IL-10 and increased dendritic complexity and synaptic protein BDNF levels in the NAc. However, NAc neuroinflammation enhanced PGRN expression, which was located in astrocytes and microglia within the NAc, and PGRN deficiency in mice alleviated NAc neuroinflammation-elicited depression-like behaviors, seemingly inhibiting astrocyte- and microglia-related inflammatory reactions and neuroplasticity complexity in the NAc via the p38 and nuclear factor of kappa (NF-κB) signaling pathways present in the NAc after neuroinflammation.

CONCLUSIONS

Our results suggest that PGRN exerts distinct function on different behaviors, showing protective roles in the FTD-like behavior and detrimental effects on the neuroinflammation-related depression-like behavior, resulting from mediating astrocyte and microglial functions from the NAc in different status.

Progranulin aggravates lethal Candida albicans sepsis by regulating inflammatory response and antifungal immunity

Candida albicans is the most frequent pathogen of fungal sepsis associated with substantial mortality in critically ill patients and those who are immunocompromised. Identification of novel immune-based therapeutic targets from a better understanding of its molecular pathogenesis is required. Here, we reported that the production of progranulin (PGRN) levels was significantly increased in mice after invasive C.albicans infection. Mice that lacked PGRN exhibited attenuated kidney injury and increased survival upon a lethal systemic infection with C. albicans. In mice, PGRN deficiency protected against systemic candidiasis by decreasing aberrant inflammatory reactions that led to renal immune cell apoptosis and kidney injury, and by enhancing antifungal capacity of macrophages and neutrophils that limited fungal burden in the kidneys. PGRN in hematopoietic cell compartment was important for this effect. Moreover, anti-PGRN antibody treatment limited renal inflammation and fungal burden and prolonged survival after invasive C. albicans infection. In vitro, PGRN loss increased phagocytosis, phagosome formation, reactive oxygen species production, neutrophil extracellular traps release, and killing activity in macrophages or neutrophils. Mechanistic studies demonstrated that PGRN loss up-regulated Dectin-2 expression, and enhanced spleen tyrosine kinase phosphorylation and extracellular signal-regulated kinase activation in macrophages and neutrophils. In summary, we identified PGRN as a critical factor that contributes to the immunopathology of invasive C.albicans infection, suggesting that targeting PGRN might serve as a novel treatment for fungal infection.

Dapagliflozin Alleviates Coxsackievirus B3-induced Acute Viral Myocarditis by Regulating the Macrophage Polarization Through Stat3-related Pathways

Viral myocarditis (VMC), which is most prevalently caused by Coxsackievirus B3 (CVB3) infection, is a serious clinical condition characterized by cardiac inflammation. Dapagliflozin, a kind of sodium glucose co-transporters 2(SGLT-2) inhibitor, exhibited protective effects on plenty of inflammatory diseases, while its effect on viral myocarditis has not been studied. Recently, we found the protective effect of dapagliflozin on VMC. After CVB3 infection, dapagliflozin and STATTIC (a kind of stat3 inhibitor) were given to Balb/c male mice for 8 days, and then the severity of myocarditis was assessed. Our results indicated that dapagliflozin significantly alleviated the severity of viral myocarditis, elevated the survival rate, and ameliorated cardiac function. Besides, dapagliflozin can decrease the level of pro-inflammatory cytokines including IL-1β, IL-6, and TNF-α. Furthermore, dapagliflozin can inhibit macrophages differentiate to classically activated macrophages (M1) in cardiac tissue and activate the Stat3 signal pathway which is reported to promote polarization of the alternatively activated macrophage (M2). And STATTIC can reverse these changes caused by dapagliflozin. In conclusion, we found that dapagliflozin treatment increased anti-inflammatory macrophage polarization and reduced cardiac injury following VMC via activating Stat3 signal pathway.

Knockdown of LncRNA MALAT1 Alleviates Coxsackievirus B3-Induced Acute Viral Myocarditis in Mice via Inhibiting Th17 Cells Differentiation

Acute viral myocarditis (AVMC), most often caused by coxsackievirus B3 (CVB3) infection, is characterized by myocardial inflammation associated with high morbidity and mortality. A pathogenic role for T helper (Th) 17 cells in AVMC is well established. Long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been shown to play a key role in various inflammatory diseases. However, the expression of MALAT1 and its impact on Th17 cells differentiation in AVMC remain unclear. In the present study, we found that MALAT1 was highly expressed in mice with AVMC, and the expression was correlated positively with cardiac pathological scores, cardiac IL-17 mRNA expression, and the percentages of splenic Th17 cells. We further demonstrated that MALAT1 knockdown could significantly alleviate the severity of disease and inhibit the differentiation of Th17 cells, accompanying the reduced mRNA expression of RORγt and productions of Th17-related pro-inflammatory cytokines in vivo. Additionally, in vitro analysis showed that MALAT1 knockdown suppressed naïve CD4⁺ T cells differentiation towards Th17 cells. In conclusion, our results suggest that MALAT1 knockdown alleviates CVB3-induced AVMC in mice, which may be partially attributable to the decline in Th17 cells responses. MALAT1 may serve as a novel therapeutic option in AVMC.

Progranulin as a Potential Therapeutic Target in Immune-Mediated Diseases

Progranulin (PGRN), a secretory glycoprotein consisting of 593 amino acid residues, is a key actor and regulator of multiple system functions such as innate immune response and inflammation, as well as tissue regeneration. Recently, there is emerging evidence that PGRN is protective in the development of a variety of immune-mediated diseases, including rheumatoid arthritis (RA), inflammatory bowel disease (IBD), type 1 diabetes mellitus (T1DM) and multiple sclerosis (MS) by regulating signaling pathways known to be critical for immunology, particularly the tumor necrosis factor alpha/TNF receptor (TNF-α/TNFR) signaling pathway. Whereas, the role of PGRN in psoriasis, systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) is controversial. This review summarizes the immunological functions of PGRN and its role in the pathogenesis of several immune-mediated diseases, in order to provide new ideas for developing therapeutic strategies for these diseases.

Neutralization of interleukin-38 exacerbates coxsackievirus B3-induced acute myocarditis in mice

Background

Interleukin (IL)-38, a novel member of the IL-1 family, has been reported to be involved in several diseases associated with viral infection. However, the expression and functional role of IL-38 in acute viral myocarditis (AVMC) have not been investigated.

Methods

Male BALB/c mice were treated with intraperitoneal (i.p.) injection of coxsackievirus B3 (CVB3) for establishing AVMC models. On day 7 post-injection, the expression of IL-38 and IL-36R (IL-36 receptor) were measured. Mice were then treated with i.p. injection of mouse Anti-IL-38 Antibodies (Abs) for neutralization of IL-38. The survival, bodyweight loss, cardiac function, and myocarditis severity of mice were recorded. The percentages of splenic Th1 and Th17 cells, the expression levels of Th1/Th17-related master transcription factors (T-bet and RORγt) and cytokines were determined by flow cytometry, RT-qPCR, and ELISA, respectively. Cardiac viral replication was further detected.

Results

The mRNA and protein expression levels of IL-38 in myocardium and serum, as well as cardiac IL-36R mRNA levels were significantly elevated in mice with AVMC. Increased IL-38 levels were negatively correlated with the severity of AVMC. Neutralization of IL-38 exacerbated CVB3-induced AVMC, as verified by the lower survival rate, impaired cardiac function, continuous bodyweight loss, and higher values of HW/BW and cardiac pathological scores. In addition, neutralization of IL-38 suppressed Th1 cells differentiation while promoted Th17 cells differentiation, accompanied by decreased T-bet mRNA expression and increased RORγt expression. Down-regulation of IFN-γ and up-regulation of IL-17, TNF-α, and IL-6 mRNA and protein expression levels in myocardium and serum were also observed in the IL-38 neutralization group. Furthermore, neutralization of IL-38 markedly promoted cardiac viral replication.

Conclusions

Neutralization of IL-38 exacerbates CVB3-induced AVMC in mice, which may be attributable to the imbalance of Th1/Th17 cells and increased CVB3 replication. Thus, IL-38 can be considered as a potential therapeutic target for AVMC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01687-w.

Viruses in the Heart: Direct and Indirect Routes to Myocarditis and Heart Failure

Viruses are an underappreciated cause of heart failure. Indeed, several types of viral infections carry cardiovascular risks. Understanding shared and unique mechanisms by which each virus compromises heart function is critical to inform on therapeutic interventions. This review describes how the key viruses known to lead to cardiac dysfunction operate. Both direct host-damaging mechanisms and indirect actions on the immune systems are discussed. As viral myocarditis is a key pathologic driver of heart failure in infected individuals, this review also highlights the role of cytokine storms and inflammation in virus-induced cardiomyopathy.

Progranulin Regulates Inflammation and Tumor

Progranulin (PGRN) mediates cell cycle progression and cell motility as a pleiotropic growth factor and acts as a universal regulator of cell growth, migration and transformation, cell cycle, wound healing, tumorigenesis, and cytotoxic drug resistance as a secreted glycoprotein. PGRN overexpression can induce the secretion of many inflammatory cytokines, such as IL-8, -6,-10, TNF-α. At the same time, this protein can promote tumor proliferation and the occurrence and development of many related diseases such as gastric cancer, breast cancer, cervical cancer, colorectal cancer, renal injury, neurodegeneration, neuroinflammatory, human atherosclerotic plaque, hepatocarcinoma, acute kidney injury, amyotrophic lateral sclerosis, Alzheimer’s disease and Parkinson’s disease. In short, PGRN plays a very critical role in injury repair and tumorigenesis, it provides a new direction for succeeding research and serves as a target for clinical diagnosis and treatment, thus warranting further investigation. Here, we discuss the potential therapeutic utility and the effect of PGRN on the relationship between inflammation and cancer.

CD11b is involved in coxsackievirus B3-induced viral myocarditis in mice by inducing Th17 cells

Viral myocarditis (VMC) caused by coxsackievirus B3 (CVB3) infection is a life-threatening disease. The cardiac damage during VMC is not mainly due to the direct cytotoxic effect of the virus on cardiomyocytes but mostly involves the induction of immune responses. Integrin CD11b plays an important role in immune response, for instance, in the induction of Th17 cells. However, the role of CD11b in the pathogenesis of VMC remains largely unknown. In the present study, a mouse model of VMC was established by CVB3 infection and CD11b was knocked down in the VMC mice by transfection with siRNA-CD11b. The expression of CD11b and IL-17 in heart tissues, frequency of Th17 cells in spleen tissues and serum IL-17 levels were measured using quantitative RT-PCR, Western blot, immunohistochemistry, flow cytometry and ELISA. Results showed that CVB3 infection caused the pathological changes in heart tissues with the increases in the following indexes: expression of CD11b and IL-17 in heart tissues, frequency of Th17 cells in spleen tissues and serum IL-17 levels. The expression of CD11b was positively correlated with IL-17 expression in heart tissues. Depletion of CD11b attenuated the damage caused by CVB3 and decreased the frequency of Th17 cells in spleen tissues as well as in IL-17, IL-23 and STAT3 expression in heart tissues. In summary, our findings reveal that disruption of CD11b function reduced CVB3-induced myocarditis, suggesting that CD11b may be a novel therapeutic target for VMC.

Progranulin Administration Attenuates β-Amyloid Deposition in the Hippocampus of 5xFAD Mice Through Modulating BACE1 Expression and Microglial Phagocytosis

Loss of function mutations in the progranulin (PGRN) gene is a risk factor for Alzheimer’s disease (AD). Previous works reported that the deficiency of PGRN accelerates β-amyloid (Aβ) accumulation in AD transgenic mouse brains while overexpression of PGRN could restrain disease progression. However, mechanisms of PGRN in protecting against Aβ deposition remains unclear. Here, using the 5xFAD AD mouse model, we show that intrahippocampal injection of PGRN protein leads to a reduction of Aβ plaques, downregulation of beta-secretase 1 (BACE1), and enhanced microglia Aβ phagocytosis in the mouse hippocampus. Furthermore, PGRN treatment inhibited BACE1 expression in N2a cells and primary culture neurons and improved the phagocytic capacity of microglia isolated from 5xFAD mouse brains. Collectively, our results provide further evidence that enhancing progranulin could be a promising option for AD therapy.

Cardiac manifestations of COVID-19 in Shenzhen, China

Purpose

The coronavirus disease 2019 (COVID-19) outbreak has become a global public health concern; however, relatively few detailed reports of related cardiac injury are available. The aims of this study were to compare the clinical and echocardiographic characteristics of inpatients in the intensive-care unit (ICU) and non-ICU patients.

Methods

We recruited 416 patients diagnosed with COVID-19 and divided them into two groups: ICU (n = 35) and non-ICU (n = 381). Medical histories, laboratory findings, and echocardiography data were compared.

Results

The levels of myocardial injury markers in ICU vs non-ICU patients were as follows: troponin I (0.029 ng/mL [0.007–0.063] vs 0.006 ng/mL [0.006–0.006]) and myoglobin (65.45 μg/L [39.77–130.57] vs 37.00 μg/L [26.40–53.54]). Echocardiographic findings included ventricular wall thickening (12 [39%] vs 1 [4%]), pulmonary hypertension (9 [29%] vs 0 [0%]), and reduced left-ventricular ejection fraction (5 [16%] vs 0 [0%]). Overall, 10% of the ICU patients presented with right heart enlargement, thickened right-ventricular wall, decreased right heart function, and pericardial effusion. Cardiac complications were more common in ICU patients, including acute cardiac injury (21 [60%] vs 13 [3%]) (including 2 cases of fulminant myocarditis), atrial or ventricular tachyarrhythmia (3 [9%] vs 3 [1%]), and acute heart failure (5 [14%] vs 0 [0%]).

Conclusion

Myocardial injury marker elevation, ventricular wall thickening, pulmonary artery hypertension, and cardiac complications including acute myocardial injury, arrhythmia, and acute heart failure are more common in ICU patients with COVID-19. Cardiac injury in COVID-19 patients may be related more to the systemic response after infection rather than direct damage by coronavirus.

Analysis of factors of pulmonary fungal infection in mice in respiratory medicine department based on logistic regression analysis model and Progranulin

The objective of this research is to solve the current medical problems of a high incidence of fungal infections in the lungs, high misdiagnosis rate, and high mortality. In this study, firstly, the logistic regression model was used to conduct. Risk factors of pulmonary fungal infection in respiratory department were analyzed. Then a model of pulmonary fungal infection in mice was constructed, and the expression difference of Progranulin (PGRN) in serum was detected by enzyme-linked immuno sorbent assay (ELISA). The expression of PGRN in lung tissues of mice infected by pulmonary fungi was detected by Western bolt method and quantitative polymerase chain reaction (PCR). The PGRN protein and mRNA expression in the lung epithelial cells of mice were detected after the infection. Results logistic regression model was used to analyze the main risk factors affecting pulmonary infection in mice. The risk factors of pulmonary fungal infection were indent catheter, hypoproteinemia, long-term use of glucocorticoid and long-term use of antibiotics. The PGRN content in serum was obviously higher than that before pulmonary fungal infection (P < 0.01). The expression of PGRN mRNA and protein in lung tissue was obviously higher than that before infection (P < 0.01). The expression of PGRN mRNA and protein in lung tissues of the infected group was obviously higher than that of the non-infected group (P < 0.01). The expression of PGRN protein in the lung epithelial cells of mice was obviously higher at 24 h after infection than before infection (P < 0.01), and the expression of PGRN mRNA was obviously higher at 12 h after infection than before infection (P < 0.01), indicating that PGRN is highly expressed in fungal pulmonary infection and is involved in disease progression. Therefore, this study provides a new idea for the diagnosis and treatment of fungal pulmonary infection in the later stage and has a good guiding significance for the diagnosis and treatment of fungal pulmonary infection.

Progranulin as a novel biomarker in diagnosis of early-onset neonatal sepsis

BACKGROUND

Infections are leading causes of morbidity and mortality in neonates and may also have severe long-term consequences. As early diagnosis of neonatal sepsis improves prognosis, identification of new or complementary biomarkers is of great importance. In this study, we have evaluated the diagnostic value of progranulin (PGRN) in early-onset neonatal sepsis (EOS) and compare its effectiveness with other commonly used biomarkers, such as procalcitonin (PCT) and C-reactive protein (CRP).

METHODS

A total of 121 infants with gestational age of >34 weeks admitted with suspected EOS were included in this study. Before initiating therapy, blood samples for whole blood count, CRP, PCT and PGRN were obtained from all neonates. Receiver-operating characteristic (ROC) curve and multivariate logistic regression analyses were performed.

RESULTS

Serum PGRN level of infected group was significantly higher than uninfected group (median 47.72 vs. 37.86 ng/ml, respectively; Mann-Whitney p < 0.0001). The ROC area under the curve (AUC) was 0.786 [95% confidence interval (CI) 0.706-0.867; p < 0.0001] for PGRN, 0.699 (95% CI 0.601-0.797; p = 0.0001) for age adjusted PCT, and 0.673 (95% CI 0.573-0.773; p = 0.0007) for CRP. With a cut-off value of 37.89 ng/ml, the diagnostic sensitivity and negative predictive value of PGRN were 94.34% and 91.7%, respectively. PGRN could significantly predict EOS independently of PCT (p < 0.0001), and the combined use of PGRN and PCT could significantly improve diagnostic performance for EOS (0.806; 95% CI 0.73-0.88; p < 0.0001), with a specificity of 89.06% and a positive predictive value of 81.10%.

CONCLUSIONS

PGRN may be used as a promising biomarker for the diagnosis of EOS, and the combined use of PGRN and PCT could improve the diagnosis of sepsis.

The role of viral infections in the development of autoimmune diseases

The exact aetiology of most autoimmune diseases remains unknown, nonetheless, several factors contributing to the induction or exacerbation of autoimmune reactions have been suggested. These include the genetic profile and lifestyle of the affected individual in addition to environmental triggers such as bacterial, parasitic, fungal and viral infections. Infections caused by viruses usually trigger a potent immune response that is necessary for the containment of the infection; however, in some cases, a failure in the regulation of this immune response may lead to harmful immune reactions directed against the host's antigens. The autoimmune attack can be carried out by different arms and components of the immune system and through different possible mechanisms including molecular mimicry, bystander activation, and epitope spreading among others. In this review, we examine the data available for the involvement of viral infections in triggering or exacerbating autoimmune diseases in addition to discussing the mechanisms by which these viral infections and the immune pathways they trigger possibly contribute to the development of autoimmunity.

Progranulin: A conductor of receptors orchestra, a chaperone of lysosomal enzymes and a therapeutic target for multiple diseases

Progranulin (PGRN), a widely expressed glycoprotein with pleiotropic function, has been linked to a host of physiological processes and diverse pathological states. A series of contemporary preclinical disease models and clinical trials have evaluated various therapeutic strategies targeting PGRN, highlighting PGRN as a promising therapeutic target. Herein we summarize available knowledge of PGRN targeting in various kinds of diseases, including common neurological diseases, inflammatory autoimmune diseases, cancer, tissue repair, and rare lysosomal storage diseases, with a focus on the functional domain-oriented drug development strategies. In particular, we emphasize the role of extracellular PGRN as a non-conventional, extracellular matrix bound, growth factor-like conductor orchestrating multiple membrane receptors and intracellular PGRN as a chaperone/co-chaperone that mediates the folding and traffic of its various binding partners.

Roles of Host Immunity in Viral Myocarditis and Dilated Cardiomyopathy

The pathogenesis of viral myocarditis includes both the direct damage mediated by viral infection and the indirect lesion resulted from host immune responses. Myocarditis can progress into dilated cardiomyopathy that is also associated with immunopathogenesis. T cell-mediated autoimmunity, antibody-mediated autoimmunity (autoantibodies), and innate immunity, working together, contribute to the development of myocarditis and dilated cardiomyopathy.