Obesity associated pro-fibrotic protein augments fibrosis in heart

 

Chronic sterile inflammation in visceral fat has causal roles for systemic metabolic disorders in obesity. Inflamed visceral adipose tissue secretes pro-inflammatory adipokines, and this contributes to tissue remodeling under a metabolically stressed condition. Various kinds of white adipokines are broadly studied, however, roles of brown adipose tissue (BAT) derived adipokines (BATokine) remain to be explored. In this project, we tried to characterize pathogenic role of BATokine in obesity related fibrotic disorders, especially focusing on heart failure with preserved ejection fraction (HFpEF). For this purpose, we analyzed two sets of DNA microarray data, and identified an obesity associated pro-fibrotic protein (OAFP) as a possible pathogenic BATokine. Our biobank studies showed OAFP increased in patients with diastolic dysfunction, and E/e' analyzed with cardiac echo increased in direct proportion to circulating OAFP level in humans. We generated dietary obese mice model, and found OAFP increased both in BAT and circulation. We generated a murine systemic or BAT specific OAFP knockout (KO) models, and found that obesity-induced diastolic dysfunction ameliorated in these models. Cardiac fibrosis was also suppressed by genetic depletion of OAFP. We found OAFP increased in circulation in aged humans and mice, and studies in chronologically aged mice showed this molecule increased in BAT with aging. Our results indicate that OAFP is secreted predominantly from BAT, and mediates pathogenic roles by augmenting cardiac fibrosis in dietary obesity or aging. Suppression of OAFP may become a therapy for HFpEF.

Funding Acknowledgement

Type of funding source: None

P2591Circulating pro fibrotic protein promotes fibrosis in liver and heart

Analyzing two sets of DNA micro array data with bioinformatics, we identified a secreted form pro-fibrotic protein (sPFP) expressed in dysfunctional brown adipose tissue (BAT) in mice. Testing our biobank samples, we found this protein increased in plasma of non-alcoholic steatohepatitis (NASH) patients or aged individuals. We generated a murine obese NASH model by imposing a high fat diet in C57BL/6NCr mice for 9–10 months since 4 weeks of age, and found that sPFP is produced predominantly by BAT. In this model, we also found that sPFP increased in plasma. We generated a murine systemic sPFP knockout (KO) model and found that liver fibrosis ameliorated in sPFP-KO model. We also suppressed circulating sPFP with a peptide vaccine targeting this molecule, and found that sPFP vaccination therapy inhibited liver fibrosis. Next, we generated sPFP gain of function (GOF) model by the administration of plasmid encoding sPFP into skeletal muscle. Liver fibrosis augmented in sPFP-GOF model, and these results suggested that sPFP has causal role for the progression of fibrotic response in liver. In the obese NASH model, we found that cardiac fibrosis also developed and it ameliorated in sPFP-KO model, indicating that sPFP may have pathological roles for heart failure with preserved ejection fraction (HFpEF) related with age-related disorders. In addition to an increase in circulating sPFP in aged individuals, we found that sPFP increased in BAT of chronological aged mice model. In vitro studies with differentiated brown adipocytes showed that c-Fos upregulated sPFP in transcript level. Our results suggest that sPFP contributes for the progression of fibrotic responses in obese or aged models. Inhibition of sPFP may become a therapy for NASH or HFpEF.

Multivariate analysis using a linear discriminant function for predicting the prognosis of congestive heart failure

Some of cases of congestive heart failure (CHF) are intractable or refractory and respond poorly to conventional treatment. We have examined factors which may influence the clinical course and prognosis. The subjects were 114 hospitalized patients with CHF. Of these, 77 had a good response to treatment and were classified as the curative group (Group C) while the remaining 37 who were difficult to treat, including those with poor prognosis, were designated the refractory group (Group R). Of the various clinical background factors including the findings of laboratory and other examinations, the following 8 variables made a significant contribution to differentiation between the 2 groups: 1) heart rate (X1), 2) hemoglobin content (X2), 3) serum K (X3), 4) serum total protein (X4), 5) A/G (X5), 6) BUN (X6), 7) grade of hepatomegaly (X7), and 8) number of previous CHF episodes (X8). The linear discriminant function represented by the following equation using these 8 variables showed an excellent result in differentiating the 2 groups. Y = - 9.64 - 0.0686X1 + 0.345X2 + 1.351X3 + 1.513X4 + + 1.988X5 - 0.0876X6 - 0.792X7 - 0.737X8. When Y value is over 0, Group C is judged. When Y value is under 0, group R is judged. We concluded that the discriminant equation covering these 8 factors is a useful means of predicting the prognosis in CHF and the response to treatment.

Clinical study on the hypotensive effect of diltiazem hydrochloride

Diltiazem HCl was administered p.o. at a fixed daily dose level of 180 mg to patients with essential hypertension, and the hypotensive effect of the drug was investigated. The following results were obtained: diltiazem HCl given alone exhibited a hypotensive effect on systolic pressure in 88.9% of the patients and on diastolic pressure in 66.7% of the patients. The concurrent use of diltiazem HCl with trichlormethiazide exerted a hypotensive effect on patients who were nonresponsive to diltiazem HCl alone. As regards side effects, one patient complained of gastric fullness and one of dizziness. However, the symptoms were so mild that further continuation of diltiazem HCl therapy was possible. From the results obtained, it is concluded that diltiazem HCl can effectively be used clinically as a hypotensive drug.

Treatment of angina pectoris patients with niludipine a new calcium antagonistic drug

The antianginal effectivity of niludipine (Bay a 7168), a new calcium antagonistic drug, was investigated in angina pectoris patients, selected for admission to the trials by pre-determined strict criteria. Oral administration of from 60--120 mg niludipine daily for 4--8 weeks, resulted in the following: 1. Number of anginal attacks significantly reduced. 2. Nitrate consumption markedly lowered. 3. Investigating physicians assessed globally the clinical results of niludipine treatment on the basis of the reduction of the number of anginal attacks, nitrate consumption, improved physical ability and reports by the patients as to their subjective evaluation of the test drug. Niludipine was judged clinically effective in 21 out of 27 patients (77.8%). 4. Full records of ECGs, a necessary item for assessment, were obtained from 24 out of 27 patients. Ischemic ECGs were improved or normalized in 6 out of 24 patients (25%). 5. In the investigators' final overall assessment, including the evaluation of ECG changes, niludipine was rated effective for 20 out of 27 patients (74.1%). 6. Tolerance to the test drug was excellent. Only one patient complained of transient, mild nausea. After reduction of the daily dose, the patient completed the trial without any further appearance or complaints of side effects. Results suggest that niludipine is a useful antianginal drug in the management of coronary artery disease patients. Further clinical investigations with a larger number of patients should be conducted.

A study on vectorcardiographic criteria for evaluating right ventricular hypertrophy in chronic obstructive pulmonary disease

Vectorcardiographic analysis was mainly made on the basis of hemodynamic findings through right heart catheterization in COPD. From the results obtained in the present study, the authors proposed the following quantitative VCG criteria as a mean for clinical recognition of right ventricular overload in patients with COPD. (I) Individual parameters of the criteria are: i) The QRS loop; (a) P/A (posterior force/anterior force) greater than or equal to 2.8 (b) R/L (rightward force/leftward force) greater than or equal to 0.6 (c) P/6 (posterior force/leftward force) greater than or equal to 1.8 ii) The P loop; Ap/Pp (anterior force/posterior force) greater than or equal to 1.8 (II) Criteria i) "RVH (right ventricular hypertrophy)" should satisfy more than 3 of the above individual parameters. ii) "RVH suspected" should satisfy 1 or 2 of them. iii) "RVH negative" should not satisfy any of them. The recognition rate for RVH by the present VCG criteria was higher than the conventional ECG criteria and there was good correspondence with autopsy findings.