Circulating lumican as a potential biomarker for osteosarcopenia in older adults.

In vitro and animal experiments demonstrated that lumican exerts anabolic effects on bone and muscle by stimulating osteoblastogenesis, suppressing osteoclastogenesis and increasing myogenesis. However, the relationship between circulating lumican and musculoskeletal phenotypes in humans remains unclear. We aimed to analyze the relationship between serum lumican levels and osteosarcopenia in older adults. Blood samples were collected from 134 participants (age: 65 years and older) who underwent comprehensive assessment of bone and muscle phenotypes. Osteoporosis and sarcopenia were diagnosed based on World Health Organization and Asian consensus guidelines, respectively. Osteosarcopenia was defined as the simultaneous presence of osteoporosis and sarcopenia. After adjusting for sex, age, and body mass index, older adults with osteosarcopenia had 20.2 % lower serum lumican levels than those without (P = 0.010). The odds ratio (OR) for osteosarcopenia per standard deviation decrease in serum lumican level was 4.17 (P = 0.003). Consistently, higher serum lumican levels were correlated with higher bone mass at all measured sites (P = 0.004 to 0.045) and higher grip strength (P = 0.023). Furthermore, participants in the lowest tertile (T1) had 7.56-fold higher OR for osteosarcopenia (P = 0.024) than those in the highest lumican tertile (T3). In conclusion, these findings clinically validate previous experimental data showing the musculoskeletal protective effects of lumican and suggest that blood lumican levels could be used as a potential biomarker to assess the risk of not only osteosarcopenia but also osteoporosis or sarcopenia in older adults.

Hydrogen sulfide inhibits gene expression associated with aortic valve degeneration by inducing NRF2-related pro-autophagy effect in human aortic valve interstitial cells.

Aortic valve stenosis (AS) is the most common valvular heart disease but there are currently no effective medical treatments that can delay disease progression due to a lack of knowledge of the precise pathophysiology. The expression of sulfide: quinone oxidoreductase (SQOR) and nuclear factor erythroid 2-related factor 2 (NRF2) was decreased in the aortic valve of AS patients. However, the role of SQOR and NRF2 in the pathophysiology of AS has not been found. We investigated the effects of hydrogen sulfide (H2S)-releasing compounds on diseased aortic valve interstitial cells (AVICs) to explain the cellular mechanism of SQOR and elucidate the medical value of H2S for AS treatment. Sodium hydrosulfide (NaHS) treatment increased the expression of SQOR and NRF2 gene and consequently induced the NRF2 target genes, such as NAD(P)H quinone dehydrogenase 1 and cystathionine γ-lyase. In addition, NaHS dose-dependently decreased the expression level of fibrosis and inflammation-related genes (MMP9, TNF-α, IL6) and calcification-related genes (ALP, osteocalcin, RUNX2, COL1A1) in human AVICs. Furthermore, NaHS activated the AMPK-mTOR pathway and inhibited the PI3K-AKT pathway, resulting in a pro-autophagy effect in human AVICs. An NRF2 inhibitor, brusatol, attenuated NaHS-induced AMPK activation and decreased the autophagy markers Beclin-1 and LC3AB, suggesting that the mechanism of action of H2S is related to NRF2. In conclusion, H2S decreased gene expression levels related to aortic valve degeneration and activated AMPK-mTOR-mediated pro-autophagy function associated with NRF2 in human AVICs. Therefore, H2S could be a potential therapeutic target for the development of AS treatment.

Association of citrullination with the progression of aortic stenosis.

Despite its clinical importance, biomarkers of disease activity in aortic stenosis (AS) are lacking. We investigated the association between anti-cyclic citrullinated peptide (CCP) antibodies and AS. All 678 patients who underwent echocardiography and anti-CCP antibody testing were analysed. Anti-CCP antibody status was categorized as negative, low-positive, and high-positive. In addition, aortic valve (AV) tissues were obtained from the patients with and without AS to analyze the presence of citrullinated proteins. At baseline, 241 (35.5%) subjects with AV degeneration had a higher rate of anti-CCP antibody positivity (42.7% versus 34.6%, p = 0.035) than those without AV degeneration. Out of the 331 (48.8%) subjects who underwent echocardiographic follow-up, progression of AS was observed in 34 (10.3%) patients, with a higher incidence in the high-positive group compared to the low-positive or negative group (19.0% vs. 11.3% vs. 8.4%, respectively; p = 0.041). On multivariable analysis, high anti-CCP antibody positivity was independently associated with progression to AS (odds ratio: 2.312; 95% confidence interval: 1.006-5.310; p = 0.048). Furthermore, immunohistochemistry and Western blotting revealed increased citrullination in diseased AV compared to normal AV tissue. This study demonstrated that a high positive anti-CCP antibody result is associated with AV degeneration and may be an independent factor for AS progression.

Effect of Neprilysin Inhibition for Ischemic Mitral Regurgitation after Myocardial Injury.

Angiotensin receptor neprilysin inhibitor (ARNI) treatment reduces functional mitral regurgitation (MR) to a greater extent than angiotensin receptor blocker (ARB) treatment alone, but the mechanism is unclear. We evaluated the mechanisms of how ARNI has an effect on functional MR. After inducing functional MR by left circumflex coronary artery occlusion, male Sprague Dawley rats (n = 31) were randomly assigned to receive the ARNI LCZ696, the ARB valsartan, or corn oil only (MR control). Excised mitral leaflets and left ventricle (LV) were analyzed, and valvular endothelial cells were evaluated focusing on molecular changes. LCZ696 significantly attenuated LV dilatation after 6 weeks when compared with the control group (LV end-diastolic volume, 461.3 ± 13.8 µL versus 525.1 ± 23.6 µL; p < 0.05), while valsartan did not (471.2 ± 8.9 µL; p > 0.05 to control). Histopathological analysis of mitral leaflets showed that LCZ696 strongly reduced fibrotic thickness compared to the control group (28.2 ± 2.7 µm vs. 48.8 ± 7.5 µm; p < 0.05). Transforming growth factor-ß and downstream phosphorylated extracellular-signal regulated kinase were also significantly lower in the LCZ696 group. Consequently, excessive endothelial-to-mesenchymal transition (EndoMT) was mitigated in the LCZ696 group compared to the control group and leaflet area was higher (11%) in the LCZ696 group than in the valsartan group. Finally, the MR extent was significantly lower in the LCZ696 group and functional improvement was observed. In conclusion, neprilysin inhibitor has positive effects on LV reverse remodeling and also attenuates fibrosis in MV leaflets and restores adaptive growth by directly modulating EndoMT.

Antibody-Based Therapeutics for Atherosclerosis and Cardiovascular Diseases.

Cardiovascular disease is the leading cause of death worldwide, and its prevalence is increasing due to the aging of societies. Atherosclerosis, a type of chronic inflammatory disease that occurs in arteries, is considered to be the main cause of cardiovascular diseases such as ischemic heart disease or stroke. In addition, the inflammatory response caused by atherosclerosis confers a significant effect on chronic inflammatory diseases such as psoriasis and rheumatic arthritis. Here, we review the mechanism of action of the main causes of atherosclerosis such as plasma LDL level and inflammation; furthermore, we review the recent findings on the preclinical and clinical effects of antibodies that reduce the LDL level and those that neutralize the cytokines involved in inflammation. The apolipoprotein B autoantibody and anti-PCSK9 antibody reduced the level of LDL and plaques in animal studies, but failed to significantly reduce carotid inflammation plaques in clinical trials. The monoclonal antibodies against PCSK9 (alirocumab, evolocumab), which are used as a treatment for hyperlipidemia, lowered cholesterol levels and the incidence of cardiovascular diseases. Antibodies that neutralize inflammatory cytokines (TNF-α, IL-1ß, IL-6, IL-17, and IL-12/23) have shown promising but contradictory results and thus warrant further research.