Citations

Background: Viral myocarditis presents a significant burden of disease, particularly among children and young adults. However, clinical guidelines and treatment strategies for pediatric patients are derived from those for adult patients due to a lack of pediatric data. Current animal models of viral myocarditis use adult mice, so conclusions from these models cannot necessarily be extrapolated to the pediatric population. We sought to develop a juvenile mouse model of myocarditis to examine differences between these two distinct clinical populations. Methods: Male and female BALB/c 3-4-week-old 'juvenile' and 8-week-old 'adult' mice were infected intraperitoneally with 103 PFU of heart-passaged coxsackievirus B3. Sera was used to evaluate testosterone and estradiol levels. Cardiac histological evaluations included overall inflammation, fibrosis, and specific cell-type infiltration. RNA was extracted from cardiac tissue and evaluated for changes in gene expression of cell-type markers, complement components, and NLRP3 inflammasome components. Results: Juvenile mice exhibited more severe inflammation than adult mice but no sex differences in overall inflammation. Juvenile mice demonstrated increased infiltration of CD11b+ cells, F4/80+ cells, and CD3+ T-cells vs. adults. Inflammasome genes NLRP3 and caspase-1 were significantly increased in juvenile compared with adult myocarditis. Conclusions: This paper is the first to describe a juvenile mouse model of coxsackievirus B3 myocarditis and provides a direct comparison to a translational adult mouse model. Juvenile mice had greater cardiac inflammation than adults. This model replicates clinical populations and provides a valuable tool to study age as a factor in the pathogenesis of myocarditis.

Abstract Background Radiation-induced heart disease (RIHD) may develop months to years following radiation therapy for cancers near the heart such as lung or breast cancer. Several mouse models of RIHD exist to study the pathogenesis of disease, but to our knowledge no studies have examined whether sex differences exist in RIHD in mice. Methods Female and male BALB/cJ mice received one whole heart dose of 22 Gray (Gy) radiation via a C5 collimator vs. sham controls that received 0 Gy, anesthesia and were placed in the X-ray machine for the same length of time. Mechanisms of cardiotoxicity were examined at 24 h (innate cardiotoxicity), day 10 (acute cardiotoxicity) and day 35 (chronic cardiotoxicity) post irradiation. Results Females and males developed dsDNA breaks from radiation at day 10 but females had more damage than males ( p < 0.001). Vessel area and cardiac hypertrophy were increased by radiation at day 10 and 35 but were higher in males than females at day 35 ( p < 0.001, p = 0.001, respectively). Bulk RNA sequencing of the heart at day 10 revealed that females and males developed similar gene pathway responses to radiation by upregulating cellular repair pathways and downregulated mitochondrial function. However, females upregulated the master regulator of mitochondrial function, Pgc1α ( p = 0.0001), suggesting improved mitochondrial repair in females. By day 35, males developed heart failure with reduced ejection fraction (HFrEF), inflammatory dilated cardiomyopathy (iDCM) and fibrosis while females developed heart failure with preserved ejection fraction (HFpEF) without inflammation or fibrosis. Conclusions We observed sex differences in nearly every cardiac parameter that we examined following radiation exposure. BALB/c males exposed to 22 Gy radiation developed HFrEF and iDCM by day 35 while females developed HFpEF. Further research is needed to better understand mechanisms driving sex differences in RIHD using translational animal models.

Abstract Objectives Patients with hypermobile Ehlers–Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD) experience a wide array of symptoms and system disorders. This study aimed to identify whether differences occurred in 115 self-reported symptoms and comorbidities in patients diagnosed with hEDS or HSD. Methods In this study we analysed self-reported data from an EDS Clinic intake questionnaire in patients diagnosed with hEDS, HSD or no hypermobile conditions. Results From 1 November 2019 to 7 March 2024, the EDS Clinic saw 2088 patients. Using the 2017 diagnostic criteria, 66.5% were diagnosed with HSD (n = 1389), 20.3% with hEDS (n = 423), 10.6% with historic HSD (H-HSD) or localized HSD (L-HSD) (n = 256) (hypermobile controls) and 2.6% were not diagnosed with hEDS, HSD, H-HSD or L-HSD (n = 55) (controls). Symptoms/comorbidities that occurred with high prevalence in both hEDS and HSD included joint pain (hEDS 82.0%, HSD 88.9%), allergy (hEDS 77.0%, HSD 77.0%), subluxations (hEDS 71.2%, HSD 72.6%), brain fog (hEDS 70.0%, HSD 74.7%), headache (hEDS 68.1%, HSD 69.1%), anxiety (hEDS 60.3%, HSD 69.3%), depression (hEDS 52.2%, HSD 58.0%), migraine (hEDS 53.7%, HSD 52.5%), nausea (hEDS 54.6%, HSD 59.5%) and constipation (hEDS 53.0%, HSD 57.2%). In contrast, 9/115 (8%) symptoms/comorbidities were self-reported significantly more often in hEDS but 42/115 (37%) in HSD. hEDS patients reported more symptoms that suggest a defect in collagen, such as dislocation, hernias and rectal prolapse, while HSD patients reported more joint, muscle, allergy, neurological, gastrointestinal, sleep and psychological symptoms/comorbidities. Conclusion Although we found an overlap in some symptoms and comorbidities self-reported by hEDS/HSD patients, such as allergy/atopy, headache/migraine and gastrointestinal symptoms, our findings suggest key differences exist between the two diagnoses, suggesting that hEDS and HSD may be distinct conditions.

Abstract Background Myocarditis is an inflammation of the heart muscle most often caused by an immune response to viral infections. Sex differences in the immune response during myocarditis have been well described but upstream mechanisms in the heart that might influence sex differences in disease are not completely understood. Methods Male and female BALB/c wild type mice received an intraperitoneal injection of heart-passaged coxsackievirus B3 (CVB3) or vehicle control. Bulk-tissue RNA-sequencing was conducted to better understand sex differences in CVB3 myocarditis. We performed enrichment analysis to understand sex differences in the transcriptional landscape of myocarditis and identify candidate transcription factors that might drive sex differences in myocarditis. Results The hearts of male and female mice with myocarditis were significantly enriched for pathways related to an innate and adaptive immune response compared to uninfected controls. When comparing females to males with myocarditis, males were enriched for inflammatory pathways and gene changes that suggested worse mitochondrial transcriptional support (e.g., mitochondrial electron transport genes). In contrast, females were enriched for pathways related to mitochondrial respiration and bioenergetics, which were confirmed by higher transcript levels of master regulators of mitochondrial function including peroxisome proliferator-activated receptor gamma coactivator 1 (PGC1α), nuclear respiratory factor 1 (NRF1) and estrogen-related receptor alpha (ERRα). TRANSFAC analysis identified ERRa as a transcription factor that may mediate sex differences in mitochondrial function during myocarditis. Conclusions Master regulators of mitochondrial function were elevated in females with myocarditis compared to males and may promote sex differences in mitochondrial respiratory transcript expression during viral myocarditis resulting in less severe myocarditis in females following viral infection.

AbstractPatients with viral myocarditis are at risk of sudden death and may progress to dilated cardiomyopathy (DCM). Currently, no disease‐specific therapies exist to treat viral myocarditis. Here it is examined whether reconstituted, lyophilized extracellular vesicles (EVs) from platelets from healthy men and women reduce acute or chronic myocarditis in male mice. Human‐platelet‐derived EVs (PEV) do not cause toxicity, damage, or inflammation in naïve mice. PEV administered during the innate immune response significantly reduces myocarditis with fewer epidermal growth factor (EGF)‐like module‐containing mucin‐like hormone receptor‐like 1 (F4/80) macrophages, T cells (cluster of differentiation molecules 4 and 8, CD4 and CD8), and mast cells, and improved cardiac function. Innate immune mediators known to increase myocarditis are decreased by innate PEV treatment including Toll‐like receptor (TLR)4 and complement. PEV also significantly reduces perivascular fibrosis and remodeling including interleukin 1 beta (IL‐1β), transforming growth factor‐beta 1, matrix metalloproteinase, collagen genes, and mast cell degranulation. PEV given at days 7–9 after infection reduces myocarditis and improves cardiac function. MicroRNA (miR) sequencing reveals that PEV contains miRs that decrease viral replication, TLR4 signaling, and T‐cell activation. These data show that EVs from the platelets of healthy individuals can significantly reduce myocarditis and improve cardiac function.

ObjectiveThe aim was to study laryngological complaints in patients with hypermobile Ehlers‐Danlos syndrome (hEDS) or hypermobility spectrum disorders (HSD).MethodsA total of 363 patients met inclusion for the study by completing questions related to voice, upper airway, and swallowing between July 7, 2020 and July 13, 2022. Demographic data, voice‐related questions, and hypermobility diagnosis were analyzed retrospectively. From those, 289 patients were diagnosed with hEDS or HSD with 74 that did not meet the diagnostic criteria for either diagnosis serving as controls.ResultsThere were no statistically significant differences between patients with hEDS and HSD regarding Voice Handicap Index (VHI‐10) scores, voice, upper airway, or swallow complaints. However, more hEDS/HSD patients answered positively to the laryngeal dysfunction question versus controls (p = 0.031). 22.5% of hEDS/HSD patients (n = 65) reported hoarseness, of which 52.3% reported hoarseness >2 days/month. 33.9% (n = 98) with hEDS/HSD reported symptoms of dysphagia, and 27.0% (n = 78) reported laryngeal dysfunction symptoms. Controls demonstrated 20.3% prevalence of hoarseness, of which 46.7% reported hoarseness >2 days/month. 24.3% of controls had dysphagia and 14.9% laryngeal dysfunction symptoms. Of the 363 patients, VHI‐10 scores >11 were more likely in patients reporting >2 days of hoarseness/month (p = 0.001) versus those with <2 days of hoarseness/month. There was an increased prevalence of voice, upper airway, and dysphagia symptoms in hEDS/HSD patients compared with previously reported prevalence data in the general population.ConclusionA significant proportion of patients diagnosed with hypermobility due to hEDS or HSD were found to have voice, upper airway, and dysphagia symptoms. These rates are higher than those previously reported in the general population.Level of Evidence3 Laryngoscope, 134:773–778, 2024

As survival in breast cancer patients from newer therapies increases, concerns for chemotherapy-induced cardiotoxicity (CIC) have offset some of these benefits, manifesting as a decline in left ventricular ejection fraction (LVEF). Patients receiving anthracycline-based chemotherapy followed by trastuzumab are at risk for CIC. Previous research evaluating whether clinical biomarkers predict cardiotoxicity has been inconsistent. Recently, angiotensin II type 1 receptor (ATR1) and endothelin 1 (ET1) have been shown to play a role in breast tumor growth. We evaluated ATR1 and ET1 expression in breast cancer tissue and its association with CIC. A total of 33 paraffin-embedded breast tissue specimens from women with breast cancer treated with anthracycline-based chemotherapy and trastuzumab were analyzed by immunohistochemistry (IHC) and qRT-PCR. We found that ET1 expression was increased in patients with an LVEF ≤ 50% (p = 0.032) with a lower LVEF correlating with higher ET1 expression (r = 0.377, p = 0.031). In patients with a change in LVEF of greater than 10%, greater ET1 expression was noted compared to those without a change in LVEF (p = 0.017). Increased ET1 expression in breast tumor tissue is associated with reduced LVEF. Future studies need to examine whether ET1 may be a tissue biomarker that helps predict the risk of developing CIC in women with breast cancer.

Background: Myocarditis is an inflammatory heart disease caused by viral infections that can lead to heart failure, and occurs more often in men than women. Since animal studies have shown that myocarditis is influenced by sex hormones, we hypothesized that endocrine disruptors, which interfere with natural hormones, may play a role in the progression of the disease. The human population is exposed to the endocrine disruptor bisphenol A (BPA) from plastics, such as water bottles and plastic food containers. Methods: Male and female adult BALB/c mice were housed in plastic versus glass caging, or exposed to BPA in drinking water versus control water. Myocarditis was induced with coxsackievirus B3 on day 0, and the endpoints were assessed on day 10 post infection. Results: We found that male BALB/c mice that were exposed to plastic caging had increased myocarditis due to complement activation and elevated numbers of macrophages and neutrophils, whereas females had elevated mast cell activation and fibrosis. Conclusions: These findings show that housing mice in traditional plastic caging increases viral myocarditis in males and females, but using sex-specific immune mechanisms.