Carvedilol and exercise combination therapy improves systolic but not diastolic function and reduces plasma osteopontin in Col4a3-/- Alport mice.

There are currently no Food and Drug Administration-approved treatments for heart failure with preserved ejection fraction (HFpEF). Here we compared the effects of exercise with and without α/ß-adrenergic blockade with carvedilol in Col4a3-/- Alport mice, a model of the phenogroup 3 subclass of HFpEF with underlying renal dysfunction. Alport mice were assigned to the following groups: no treatment control (n = 29), carvedilol (n = 11), voluntary exercise (n = 9), and combination carvedilol and exercise (n = 8). Cardiac function was assessed by echocardiography after 4-wk treatments. Running activity of Alport mice was similar to wild types at 1 mo of age but markedly reduced at 2 mo (1.3 ± 0.40 vs. 4.5 ± 1.02 km/day, P < 0.05). There was a nonsignificant trend for increased running activity at 2 mo by carvedilol in the combination treatment group. Combination treatments conferred increased body weight of Col4a3-/- mice (22.0 ± 1.18 vs. 17.8 ± 0.29 g in untreated mice, P < 0.01), suggesting improved physiology, and heart rates declined by similar increments in all carvedilol-treatment groups. The combination treatment improved systolic parameters; stroke volume (30.5 ± 1.99 vs. 17.8 ± 0.77 µL, P < 0.0001) as well as ejection fraction and global longitudinal strain compared with controls. Myocardial performance index was normalized by all interventions (P < 0.0001). Elevated osteopontin plasma levels in control Alport mice were significantly lowered only by combination treatment, and renal function of the Alport group assessed by urine albumin creatinine ratio was significantly improved by all treatments. The results support synergistic roles for exercise and carvedilol to augment cardiac systolic function of Alport mice with moderately improved renal functions but no change in diastole.NEW & NOTEWORTHY In an Alport mouse model of heart failure with preserved ejection fraction (HFpEF), exercise and carvedilol synergistically improved systolic function without affecting diastole. Carvedilol alone or in combination with exercise also improved kidney function. Molecular analyses indicate that the observed improvements in cardiorenal functions were mediated at least in part by effects on serum osteopontin and related inflammatory cytokine cascades. The work presents new potential therapeutic targets and approaches for HFpEF.

Osteopontin and LDLR Are Upregulated in Hearts of Sudden Cardiac Death Victims With Heart Failure With Preserved Ejection Fraction and Diabetes Mellitus.

Background: Diabetes mellitus (DM) is associated with increased risk of sudden cardiac death (SCD), particularly in patients with heart failure with preserved ejection fraction (HFpEF). However, there are no known biomarkers in the population with DM and HFpEF to predict SCD risk. Objectives: This study was designed to test the hypothesis that osteopontin (OPN) and some proteins previously correlated with OPN, low-density lipoprotein receptor (LDLR), dynamin 2 (DNM2), fibronectin-1 (FN1), and 2-oxoglutarate dehydrogenase-like (OGDHL), are potential risk markers for SCD, and may reflect modifiable molecular pathways in patients with DM and HFpEF. Methods: Heart tissues were obtained at autopsy from 9 SCD victims with DM and HFpEF and 10 age and gender-matched accidental death control subjects from a Finnish SCD registry and analyzed for the expression of OPN and correlated proteins, including LDLR, DNM2, FN1, and OGDHL by immunohistochemistry. Results: We observed a significant upregulation in the expression of OPN, LDLR, and FN1, and a marked downregulation of DNM2 in heart tissues of SCD victims with DM and HFpEF as compared to control subjects (p < 0.01). Conclusions: The dysregulated protein expression of OPN, LDLR, FN1, and DNM2 in patients with DM and HFpEF who experienced SCD provides novel potential modifiable molecular pathways that may be implicated in the pathogenesis of SCD in these patients. Since secreted OPN and soluble LDLR can be measured in plasma, these results support the value of further prospective studies to assess the predictive value of these plasma biomarkers and to determine whether tuning expression levels of OPN and LDLR alters SCD risk in patients with DM and HFpEF.

Critical Review: Propensity of Premise Plumbing Pipe Materials to Enhance or Diminish Growth of Legionella and Other Opportunistic Pathogens.

Growth of Legionella pneumophila and other opportunistic pathogens (OPs) in drinking water premise plumbing poses an increasing public health concern. Premise plumbing is constructed of a variety of materials, creating complex environments that vary chemically, microbiologically, spatially, and temporally in a manner likely to influence survival and growth of OPs. Here we systematically review the literature to critically examine the varied effects of common metallic (copper, iron) and plastic (PVC, cross-linked polyethylene (PEX)) pipe materials on factors influencing OP growth in drinking water, including nutrient availability, disinfectant levels, and the composition of the broader microbiome. Plastic pipes can leach organic carbon, but demonstrate a lower disinfectant demand and fewer water chemistry interactions. Iron pipes may provide OPs with nutrients directly or indirectly, exhibiting a high disinfectant demand and potential to form scales with high surface areas suitable for biofilm colonization. While copper pipes are known for their antimicrobial properties, evidence of their efficacy for OP control is inconsistent. Under some circumstances, copper's interactions with premise plumbing water chemistry and resident microbes can encourage growth of OPs. Plumbing design, configuration, and operation can be manipulated to control such interactions and health outcomes. Influences of pipe materials on OP physiology should also be considered, including the possibility of influencing virulence and antibiotic resistance. In conclusion, all known pipe materials have a potential to either stimulate or inhibit OP growth, depending on the circumstances. This review delineates some of these circumstances and informs future research and guidance towards effective deployment of pipe materials for control of OPs.

Chlorine Disinfection of Legionella spp., L. pneumophila, and Acanthamoeba under Warm Water Premise Plumbing Conditions.

Premise plumbing conditions can contribute to low chlorine or chloramine disinfectant residuals and reactions that encourage opportunistic pathogen growth and create risk of Legionnaires' Disease outbreaks. This bench-scale study investigated the growth of Legionella spp. and Acanthamoeba in direct contact with premise plumbing materials-glass-only control, cross-linked polyethylene (PEX) pipe, magnesium anode rods, iron pipe, iron oxide, pH 10, or a combination of factors. Simulated glass water heaters (SGWHs) were colonized by Legionella pneumophila and exposed to a sequence of 0, 0.1, 0.25, and 0.5 mg/L chlorine or chloramine, at two levels of total organic carbon (TOC), over 8 weeks. Legionella pneumophila thrived in the presence of the magnesium anode by itself and or combination with other factors. In most cases, 0.5 mg/L Cl2 caused a significant rapid reduction of L. pneumophila, Legionella spp., or total bacteria (16S rRNA) gene copy numbers, but at higher TOC (>1.0 mg C/L), a chlorine residual of 0.5 mg/L Cl2 was not effective. Notably, Acanthamoeba was not significantly reduced by the 0.5 mg/L chlorine dose.

Nuclear Osteopontin Is a Marker of Advanced Heart Failure and Cardiac Allograft Vasculopathy: Evidence From Transplant and Retransplant Hearts.

BACKGROUND: Heart transplant is the gold standard therapy for patients with advanced heart failure. Over 5,500 heart transplants are performed every year worldwide. Cardiac allograft vasculopathy (CAV) is a common complication post-heart transplant which reduces survival and often necessitates heart retransplantation. Post-transplant follow-up requires serial coronary angiography and endomyocardial biopsy (EMB) for CAV and allograft rejection screening, respectively; both of which are invasive procedures. This study aims to determine whether osteopontin (OPN) protein, a fibrosis marker often present in chronic heart disease, represents a novel biomarker for CAV. METHODS: Expression of OPN was analyzed in cardiac tissue obtained from patients undergoing heart retransplantation using immunofluorescence imaging (n = 20). Tissues from native explanted hearts and three serial follow-up EMB samples of transplanted hearts were also analyzed in five of these patients. RESULTS: Fifteen out of 20 patients undergoing retransplantation had CAV. 13/15 patients with CAV expressed nuclear OPN. 5/5 patients with multiple tissue samples expressed nuclear OPN in both 1 st and 2 nd explanted hearts, while 0/5 expressed nuclear OPN in any of the follow-up EMBs. 4/5 of these patients had an initial diagnosis of dilated cardiomyopathy (DCM). CONCLUSION: Nuclear localization of OPN in cardiomyocytes of patients with CAV was evident at the time of cardiac retransplant as well as in patients with DCM at the time of the 1 st transplant. The results implicate nuclear OPN as a novel biomarker for severe CAV and DCM.

Osteopontin Expression in Cardiomyocytes Is Increased in Pediatric Patients With Sepsis or Pneumonia.

Sepsis and pneumonia are major causes of death in the United States, and their pathophysiology includes infection with inflammation and immune dysfunction. Both sepsis and pneumonia cause cardiovascular dysfunction. The expression of Osteopontin (OPN) in cardiomyocytes of patients with sepsis or pneumonia, and its role the induced cardiac dysfunction have not been thoroughly investigated. OPN is a matricellular protein synthesized by multiple diseased tissues and cells including cardiomyocytes. Here, we studied the expression of OPN protein using immunofluorescence in human myocardial autopsy tissues from pediatric and mid age or elderly patients with sepsis and/or pneumonia. Fourteen human myocardial tissues from six pediatric patients and eight mid-age or elderly patients were studied. Immunofluorescence was used to investigate the expression of OPN in paraffin-embedded heart sections co-stained with the myocyte markers Actin Alpha 1 (ACTA1) and Myosin Light Chain 2 (MLC2). A quantitative analysis was performed to determine the number of ACTA1 and MLC2 positive cardiomyocytes that express OPN. The results showed that OPN expression was significantly increased in cardiomyocytes in the hearts from pediatric patients with sepsis and/or pneumonia (N = 3) relative to pediatric patients without sepsis/pneumonia (N = 3), or adult to elderly patients with sepsis/pneumonia (N = 5). Among the older septic hearts, higher levels of cardiomyocyte OPN expression was seen only in conjunction with severe coronary arterial occlusion. This is the first study to document increased OPN expression in cardiomyocytes of pediatric subjects with sepsis or pneumonia. Our findings highlight a potentially important role for OPN in sepsis- or pneumonia-mediated cardiac dysfunction in pediatric patients.

Overlap between Parkinson disease and Alzheimer disease in ABCA7 functional variants.

OBJECTIVE: Given their reported function in phagocytosis and clearance of protein aggregates in Alzheimer disease (AD), we hypothesized that variants in ATP-binding cassette transporter A7 (ABCA7) might be involved in Parkinson disease (PD). METHODS: ABCA7 variants were identified using whole-exome sequencing (WES) on 396 unrelated patients with PD and 222 healthy controls. In addition, we used the publicly available WES data from the Parkinson's Progression Markers Initiative (444 patients and 153 healthy controls) as a second, independent data set. RESULTS: We observed a higher frequency of loss-of-function (LOF) variants and rare putative highly functional variants (Combined Annotation Dependent Depletion [CADD] >20) in clinically diagnosed patients with PD than in healthy controls in both data sets. Overall, we identified LOF variants in 11 patients and 1 healthy control (odds ratio [OR] 4.94, Fisher exact p = 0.07). Four of these variants have been previously implicated in AD risk (p.E709AfsX86, p.W1214X, p.L1403RfsX7, and rs113809142). In addition, rare variants with CADD >20 were observed in 19 patients vs 3 healthy controls (OR 2.85, Fisher exact p = 0.06). CONCLUSION: The presence of ABCA7 LOF variants in clinically defined PD suggests that they might be risk factors for neurodegeneration in general, especially those variants hallmarked by protein aggregation. More studies will be needed to evaluate the overall impact of this transporter in neurodegenerative disease.

Relationship between Organic Carbon and Opportunistic Pathogens in Simulated Glass Water Heaters.

Controlling organic carbon levels in municipal water has been hypothesized to limit downstream growth of bacteria and opportunistic pathogens in premise plumbing (OPPPs). Here, the relationships between influent organic carbon (0-15,000 µg ozonated fulvic acid /L) and the number of total bacteria [16S rRNA genes and heterotrophic plate counts (HPCs)] and a wide range of OPPPs (gene copy numbers of Acanthamoeba polyphaga, Vermamoeba vermiformis, Legionella pneumophila, and Mycobacterium avium) were examined in the bulk water of 120-mL simulated glass water heaters (SGWHs). The SGWHs were operated at 32-37 °C, which is representative of conditions encountered at the bottom of electric water heaters, with water changes of 80% three times per week to simulate low use. This design presented advantages of controlled and replicated (triplicate) conditions and avoided other potential limitations to OPPP growth in order to isolate the variable of organic carbon. Over seventeen months, strong correlations were observed between total organic carbon (TOC) and both 16S rRNA gene copy numbers and HPC counts (avg. R2 > 0.89). Although M. avium gene copies were occasionally correlated with TOC (avg. R2 = 0.82 to 0.97, for 2 out of 4 time points) and over a limited TOC range (0-1000 µg/L), no other correlations were identified between other OPPPs and added TOC. These results suggest that reducing organic carbon in distributed water is not adequate as a sole strategy for controlling OPPPs, although it may have promise in conjunction with other approaches.

Regeneration of Little Ice Age bryophytes emerging from a polar glacier with implications of totipotency in extreme environments.

Across the Canadian Arctic Archipelago, widespread ice retreat during the 20th century has sharply accelerated since 2004. In Sverdrup Pass, central Ellesmere Island, rapid glacier retreat is exposing intact plant communities whose radiocarbon dates demonstrate entombment during the Little Ice Age (1550-1850 AD). The exhumed bryophyte assemblages have exceptional structural integrity (i.e., setae, stem structures, leaf hair points) and have remarkable species richness (60 of 144 extant taxa in Sverdrup Pass). Although the populations are often discolored (blackened), some have developed green stem apices or lateral branches suggesting in vivo regrowth. To test their biological viability, Little Ice Age populations emerging from the ice margin were collected for in vitro growth experiments. Our results include a unique successful regeneration of subglacial bryophytes following 400 y of ice entombment. This finding demonstrates the totipotent capacity of bryophytes, the ability of a cell to dedifferentiate into a meristematic state (analogous to stem cells) and develop a new plant. In polar ecosystems, regrowth of bryophyte tissue buried by ice for 400 y significantly expands our understanding of their role in recolonization of polar landscapes (past or present). Regeneration of subglacial bryophytes broadens the concept of Ice Age refugia, traditionally confined to survival of land plants to sites above and beyond glacier margins. Our results emphasize the unrecognized resilience of bryophytes, which are commonly overlooked vis-a-vis their contribution to the establishment, colonization, and maintenance of polar terrestrial ecosystems.

Repeat expansions in the C9ORF72 gene contribute to Alzheimer's disease in Caucasians.

Recently, a hexanucleotide repeat expansion in the C9ORF72 gene has been identified to account for a significant portion of Caucasian families affected by frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Given the clinical overlap of FTD with Alzheimer's disease (AD), we hypothesized that C9ORF72 expansions might contribute to AD. In Caucasians, we found C9ORF72 expansions in the pathogenic range of FTD/ALS (>30 repeats) at a proportion of 0.76% in AD cases versus 0 in control subjects (p = 3.3E-03; 1182 cases, 1039 controls). In contrast, no large expansions were detected in individuals of African American ethnicity (291 cases, 620 controls). However, in the range of normal variation of C9ORF72 expansions (0-23 repeat copies), we detected significant differences in distribution and mean repeat counts between Caucasians and African Americans. Clinical and pathological re-evaluation of identified C9ORF72 expansion carriers revealed 9 clinical and/or autopsy confirmed AD and 2 FTD final diagnoses. Thus, our results support the notion that large C9ORF72 expansions lead to a phenotypic spectrum of neurodegenerative disease including AD.

The application of amplicon length heterogeneity PCR (LH-PCR) for monitoring the dynamics of soil microbial communities associated with cadaver decomposition.

The placement of cadavers in shallow, clandestine graves may alter the microbial and geochemical composition of the underlying and adjacent soils. Using amplicon length heterogeneity-PCR (LH-PCR) the microbial community changes in these soils can be assessed. In this investigation, nine different grave sites were examined over a period of 16weeks. The results indicated that measurable changes occurred in the soil bacterial community during the decomposition process. In this study, amplicons corresponding to anaerobic bacteria, not indigenous to the soil, were shown to produce differences between grave sites and control soils. Among the bacteria linked to these amplicons are those that are most often part of the commensal flora of the intestines, mouth and skin. In addition, over the 16week sampling interval, the level of indicator organisms (i.e., nitrogen fixing bacteria) dropped as the body decomposed and after four weeks of environmental exposure they began to increase again; thus differences in the abundance of nitrogen fixing bacteria were also found to contribute to the variation between controls and grave soils. These results were verified using primers that specifically targeted the nifH gene coding for nitrogenase reductase. LH-PCR provides a fast, robust and reproducible method to measure microbial changes in soil and could be used to determine potential cadaveric contact in a given area. The results obtained with this method could ultimately provide leads to investigators in criminal or missing person scenarios and allow for further analysis using human specific DNA assays to establish the identity of the buried body.