Clinical and ultrasound features of difficult-to-treat rheumatoid arthritis: A multicenter RA ultrasound cohort study

OBJECTIVE

The optimal strategy for difficult-to-treat (D2T) rheumatoid arthritis (RA) has not been identified, and the ultrasound characteristics of D2T RA have not been reported. We investigated the clinical characteristics and factors contributing to the outcome in D2T RA in a multicentre RA ultrasound observational cohort.

METHOD

We reviewed 307 Japanese patients diagnosed with RA who underwent treatment with biological and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs). We compared the differences in patient characteristics between the D2T RA and non-D2T RA groups. We examined the factors contributing to a good response [defined as b/tsDMARD continuation and Clinical Disease Activity Index (CDAI) ≤ 10 at 12 months] in the D2T RA patient group.

RESULTS

Forty-three patients (14%) were categorized as D2T RA and the remaining 264 (86%) as non-D2T RA at baseline. The grey-scale (GS) score, disease duration, and CDAI at the initiation of treatment were significantly higher in the D2T RA group than in the non-D2T RA group. In contrast, the power Doppler (PD) score was not significantly different between the two groups. Of the 43 D2T RA patients, 20 achieved a good response. The introduction of CTLA4-Ig (n = 5) was significantly associated with a good response in analysis based on inverse probability weighting with propensity score. GS and PD scores at baseline were not significantly associated with therapeutic response at 12 months in D2T RA patients.

CONCLUSIONS

Patients with D2T RA had high clinical and ultrasound activity and poor responses to treatment with b/tsDMARDs. CTLA4-Ig was associated with a good response at 12 months in D2T RA patients.

VNAR development through antigen immunization of Japanese topeshark (Hemitriakis japanica)

The VNAR (Variable New Antigen Receptor) is the smallest single-domain antibody derived from the variable domain of IgNAR of cartilaginous fishes. Despite its biomedical and diagnostic potential, research on VNAR has been limited due to the difficulties in obtaining and maintaining immune animals and the lack of research tools. In this study, we investigated the Japanese topeshark as a promising immune animal for the development of VNAR. This shark is an underutilized fishery resource readily available in East Asia coastal waters and can be safely handled without sharp teeth or venomous stingers. The administration of Venus fluorescent protein to Japanese topesharks markedly increased antigen-specific IgM and IgNAR antibodies in the blood. Both the phage-display library and the yeast-display library were constructed using RNA from immunized shark splenocytes. Each library was enriched by biopanning, and multiple antigen-specific VNARs were acquired. The obtained antibodies had affinities of 1 × 10-8 M order and showed high plasticity, retaining their binding activity even after high-temperature or reducing-agent treatment. The dissociation rate of a low-affinity VNAR was significantly improved via dimerization. These results demonstrate the potential utility of the Japanese topeshark for the development of VNAR. Furthermore, we conducted deep sequencing analysis to reveal the quantitative changes in the CDR3-coding sequences, revealing distinct enrichment bias between libraries. VNARs that were primarily enriched in the phage display had CDR3 coding sequences with fewer E. coli rare codons, suggesting translation machinery on the selection and enrichment process during biopanning.

Recommendations for the use of next-generation sequencing in patients with metastatic cancer in the Asia-Pacific region: a report from the APODDC working group

INTRODUCTION

Next-generation sequencing (NGS) diagnostics have shown clinical utility in predicting survival benefits in patients with certain cancer types who are undergoing targeted drug therapies. Currently, there are no guidelines or recommendations for the use of NGS in patients with metastatic cancer from an Asian perspective. In this article, we present the Asia-Pacific Oncology Drug Development Consortium (APODDC) recommendations for the clinical use of NGS in metastatic cancers.

METHODS

The APODDC set up a group of experts in the field of clinical cancer genomics to (i) understand the current NGS landscape for metastatic cancers in the Asia-Pacific (APAC) region; (ii) discuss key challenges in the adoption of NGS testing in clinical practice; and (iii) adapt/modify the European Society for Medical Oncology guidelines for local use. Nine cancer types [breast cancer (BC), gastric cancer (GC), nasopharyngeal cancer (NPC), ovarian cancer (OC), prostate cancer, lung cancer, and colorectal cancer (CRC) as well as cholangiocarcinoma and hepatocellular carcinoma (HCC)] were identified, and the applicability of NGS was evaluated in daily practice and/or clinical research. Asian ethnicity, accessibility of NGS testing, reimbursement, and socioeconomic and local practice characteristics were taken into consideration.

RESULTS

The APODDC recommends NGS testing in metastatic non-small-cell lung cancer (NSCLC). Routine NGS testing is not recommended in metastatic BC, GC, and NPC as well as cholangiocarcinoma and HCC. The group suggested that patients with epithelial OC may be offered germline and/or somatic genetic testing for BReast CAncer gene 1 (BRCA1), BRCA2, and other OC susceptibility genes. Access to poly (ADP-ribose) polymerase inhibitors is required for NGS to be of clinical utility in prostate cancer. Allele-specific PCR or a small-panel multiplex-gene NGS was suggested to identify key alterations in CRC.

CONCLUSION

This document offers practical guidance on the clinical utility of NGS in specific cancer indications from an Asian perspective.

Effect of Blonanserin on the Proliferation and Migration of Glioblastoma Cells

Glioblastoma is a highly malignant and invasive brain tumor, and there is an urgent need to establish a treatment option that prevents its growth and metastasis. Blonanserin is an antipsychotic drug widely used in the treatment of schizophrenia. It has recently been reported to inhibit the growth of breast cancer cells. In this study, we investigated the effect of blonanserin on the proliferation and migration of glioblastoma cells. The anti-proliferative activity of blonanserin was evaluated in terms of cell viability, competition, and cell death pathways in glioblastoma. Cell viability studies showed that blonanserin had growth inhibitory ability regardless of the malignancy of glioblastoma cells, but at concentrations close to its IC₅₀, it only had a slight cell death-inducing effect. Blonanserin showed growth inhibitory activity without D₂ antagonism following an independent competition analysis using blonanserin and D₂ antagonists. When the anti-migration activity of U251 cells was measured, blonanserin was found to attenuate cell migration. Furthermore, treatment with blonanserin at concentrations close to its IC₅₀ value inhibited extensive filament actin formation. In conclusion, blonanserin inhibited the proliferation and migration of glioblastoma cells independent of D₂ antagonism. The present study shows that blonanserin may serve as a seed compound for the discovery of new glioblastoma therapeutics to prevent the growth and metastasis of glioblastoma.

Prevention of end-stage renal disease with percutaneous endoscopic gastrojejunostomy tubes in a patient with recurrent episodes of binge eating and purging

Background

Bulimia nervosa (BN) and the binge-eating/purging subtype of anorexia nervosa (b/p AN) are characterized by binge eating and unsafe compensatory behaviors, such as laxatives or diuretic abuse, self-induced vomiting, and excessive exercise. BN often causes miscellaneous physical complications that can lead to death. However, there have been very few prior reports on the physical complications of chronic BN.

Case Presentation

We report a case of chronic BN of over 10 years. Her compensatory behaviors caused dehydration more easily than before. Repeated dehydration may result in end-stage renal disease (ESRD). Therefore, we had to prevent dehydration by placing a percutaneous endoscopic gastrojejunostomy (PEG-J) tube. After PEG-J placement, dehydration did not reoccur, thereby protecting her renal involvement from progressing to ESRD.

Conclusion

Chronic BN exposure may cause repeated dehydration with time. Therefore, the PEG-J tube would be effective in preventing dehydration, which leads to ESRD.

The DPP4 inhibitor linagliptin exacerbated heart failure due to energy deficiency via downregulation of glucose absorption and utilization in mice

Background

It was reported that glucagon-like peptide-1 has cardio-protective effects, however, the occurrence of heart failure was increased with DPP4 inhibitor in some large clinical trials.

Purpose

The purpose of the present work was to clarify whether DPP4 inhibitor had any effects on chronic, dilated heart failure and to identify the mechanisms.

Methods

Heart / Muscle-specific Manganese superoxide dismutase (Mn-SOD)-deficient mice, (H/M-Sod−/−) which exert dilated cardiomyopathy were randomized to receive low dose (1 mg/kg) linagliptin, HF-L group; high dose (10 mg/kg) linagliptin, HF-H group; mixed with food, or normal food, HF group; for eight weeks. Then, evaluation was performed in cardiac function and pathophysiological changes.

Result

Interestingly, the mice treated with linagliptin treatment exhibited shorter life span and greater heart/body weight ratio. Echocardiographic studies showed decreased contractility in the HF-H group with compared to the HF control group. In Sirius Red staining, severer fibrosis was also observed in the linagliptin groups. HbA1c levels did not change among three groups, however, glycogen content in the liver was significantly decreased in the linagliptin groups. Similarly, indirect calorimetry showed decreased carbohydrate consumption in the HF-H group compared to the HF control group, suggesting worsening of heart failure was due to unavailability of carbohydrates as an energy source. Therefore, we fed a diet containing 33 wt% glucose to the HF-H group as complementary experiments. As a result, adequate glucose supplementation reduced cardiac fibrosis and cardiac function, while worsened life span, HbA1c levels and CHO consumption were not changed. Therefore, we hypothesized that there might be a change in the absorption of glucose in intestine or utilization ability of glucose in body another experiments were performed. 13C, which was released from mice after the oral administration of 13C glucose and measured by respiratory gas analysis, was significantly reduced in HF-H mice. The measurements the amount of 13C in feces revealed increased levels of unabsorbed glucose by linagliptin treatment in HF. In addition, GLUT2, a glucose transporter, in small intestine, was downregulated in the HF-H and the HF-HG groups. On the other hand, the cardiac uptake of Deoxy-D-glucose, 2-[1,2-3H(N)] (3H-2DG), which was injected from mice tail vein, was not different between in the HF-H group and in the HF control group. Taken together, linagliptin treatment may inhibit glucose transport in intestine in HF.

Conclusions

Linagliptin treatment exacerbated heart failure, resulting in shortened life span, worsened cardiac function, and fibrosis of the myocardium. DPP4 inhibitor may promote the cardiac cachexia and exacerbate heart failure at least, in part, through modification of glucose absorption and utilization.

Funding Acknowledgement

Type of funding sources: None.

The impact of right atrium and left atrium reverse remodeling for functional regurgitation of atrioventricular valve among patients who were underwent ablation for atrial fibrillation

Background

Atrial fibrillation (AF) is a risk factor of Regurgitation of Atrioventricular Valve and Regurgitation of Atrioventricular Valve is improved after ablation for AF. However, Mechanism of improvement of Tricuspid regurgitation (TR) and Mitral regurgitation (MR) after ablation for AF were unclear.

Methods

The one hundred fifty-seven cases consecutive patients who were underwent ablation for persistent AF were examined in this study. These patients were performed Holter ECG and Echocardiography 6 months after ablation for persistent AF. The area of the Right Atrium (RA), Left Atrium (LA), diameter of the tricuspid valve anulus and Mitral valve annulus, were measured by echocardiography at before and 6 months after ablation for AF. The reverse remodeling index (RRI) was defined as divided post area of RA and LA by pre area of RA and LA. The Improved group was defined as one or more than regurgitation grade improvements.

Results

TR improved in 56 cases (35.7%) of 157 cases and MR improved in 25 (16.6%) cases of 157 cases. The ratio of improved TR was significantly higher than ratio of improved MR (p<0.01). The difference in tricuspid annulus diameter before and after ablation for AF was significantly longer in TR improved group than in TR non-improved group. (4.9±5.3 mm vs 1.6±5.4 mm, p<0.01). The RRI of RA in TR improved group was significantly smaller than in TR non-improved group (0.73±0.19 vs 0.89±0.26 p<0.01). The difference in mitral annulus diameter before and after ablation for AF was not significant differences between MR improved group and MR non-improved group. The RRI of LA in MR improved group was significantly smaller than in MR non-improved group (0.79±0.22 vs 0.90±0.25 p<0.01). The RRI of RA was significantly smaller than RRI of LA among patients who were able to maintain sinus rhythm after ablation for persistent AF (0.79±0.23 vs 0.85±0.24 p=0.04).

Conclusion

Reverse remodeling of RA was higher than Reverse remodeling of LA among patients who were able to maintain sinus rhythm after ablation for persistent AF and Reverse remodeling of RA and LA were important factors of improvement of TR and MR after ablation for persistent AF. These results considered to be the cause why the improvement rate of TR was higher than the Improvement rate of MR after persistent AF.

Funding Acknowledgement

Type of funding sources: None.

AB0157 EFFICACY AND SAFETY OF FILGOTINIB IN ACTIVE RHEUMATOID ARTHRITIS PATIENTS WITH INADEQUATE RESPONSE TO METHOTREXATE: COMPARATIVE STUDY WITH FILGOTINIB AND TOCILIZUMAB EXAMINED BY CLINICAL INDEX AS WELL AS MUSCULOSKELETAL ULTRASOUND ASSESSMENT (TRANSFORM STUDY): STUDY PROTOCOL

Background

The administration of Janus kinase (JAK) inhibitors as well as biological disease-modifying anti-rheumatic drugs has dramatically improved even the clinical outcomes in rheumatoid arthritis (RA) patients with inadequate response to methotrexate (MTX). The dysregulation of JAK- signal transducer and activator of transcription (STAT) pathways via overproduction of cytokines, such as interleukin-6 (IL-6) is involved in the pathogenesis of RA (1). Filgotinib, a preferential JAK1 inhibitor, is effective in suppressing disease activity and preventing the progression of joint destruction due to inhibition of the JAK-STAT pathway. IL-6 inhibitors such as tocilizumab also inhibit the JAK-STAT pathways due to inhibition of IL-6 signaling. Thus, it should be desirable to investigate whether the effectiveness of filgotinib monotherapy is non-inferior to those of tocilizumab monotherapy in RA patients with inadequate response to MTX. In addition, it is important to accurately evaluate disease activity at the joint level by using musculoskeletal ultrasound (MSUS) and clinical disease activity indices, including subjective parameters (2).

Objectives

This study’s principal objective is to evaluate the effects of filgotinib monotherapy is non-inferior to those of tocilizumab monotherapy in RA patients with inadequate response to MTX. In addition, we will evaluate changes in patients’ parameters, including clinical disease activity indices, MSUS scores, serum biomarkers, patient-reported outcome (PRO), and modified total Sharp score (mTSS) after the administration of filgotinib or tocilizumab. Herein, we describe the study protocol for this study.

Methods

This study is an interventional, multicenter, randomized, open-label, parallel-group and non-inferiority clinical trial with a 52-week follow-up. In total, 400 RA patients with at least moderate disease activity during treatment with MTX will be included. Patients will be randomized in a 1:1 ratio to administration of filgotinib 200mg/day monotherapy or subcutaneous tocilizumab 162mg/biweekly monotherapy switched from MTX (Figure 1). We will evaluate disease activity by measuring clinical disease activity indices and by using MSUS. The primary endpoint is the proportion of patients who achieve an American College of Rheumatology 50 response at week 12. Important secondary endpoints are the changes from the baseline of the MSUS scores, PRO, and mTSS. We will also comprehensively analyze the serum levels of multiple biomarkers such as cytokines and chemokines.

Figure 1.

Results

Although the study results cannot be shown because the research entry is in progress, they are expected to show the non-inferiority of filgotinib monotherapy to tocilizumab monotherapy in RA patients with inadequate response to MTX.

Conclusion

The strength of this study is its prospective evaluation of therapeutic efficacy using not only clinical disease activity indices but also MSUS, which accurately and objectively evaluate disease activity at the joint level among patients drawn from multiple centers with a standardized evaluation by MSUS. In addition, we will evaluate the effectiveness of both drugs by integrating multilateral assessments, i.e., clinical disease activity indices, MSUS findings, and serum biomarkers.

References

[1]Gadina M, Le MT, Schwartz DM, Silvennoinen O, Nakayamada S, Yamaoka K, et al. Janus kinases to jakinibs: from basic insights to clinical practice. Rheumatology (Oxford). 2019;58(Suppl 1):i4-i16.

[2]Colebatch AN, Edwards CJ, Ostergaard M, van der Heijde D, Balint PV, D’Agostino MA, et al. EULAR recommendations for the use of imaging of the joints in the clinical management of rheumatoid arthritis. Ann Rheum Dis. 2013;72(6):804-14.

Disclosure of Interests

Toshimasa Shimizu: None declared, Shin-ya Kawashiri: None declared, Shimpei Morimoto: None declared, Yurika Kawazoe: None declared, Shohei Kuroda: None declared, Rina Kawasaki: None declared, Yasuko Ito: None declared, Shuntaro Sato: None declared, Hiroshi Yamamoto: None declared, Atsushi Kawakami Grant/research support from: Gilead Sciences, Inc.

OP0090 PRECLINICAL STUDIES OF A NOVEL CATHEPSIN C INHIBITOR IN MPO-ANCA-ASSOCIATED VASCULITIS MODEL

Background

MPO-ANCA-associated vasculitis (MPO-AAV) is a systemic small vessel vasculitis with the production of MPO-ANCA in the serum. This disease develops necrotizing and crescent glomerulonephritis (NCGN) and peritubular capillaritis-mediated interstitial damages in the kidneys, and pulmonary hemorrhage due to capillaritis in the lungs. Recent studies have revealed that neutrophil extracellular traps (NETs) induced by MPO-ANCA are critically involved in its pathogenesis,1 and neutrophil elastase (NE) plays an essential role in the formation of NETs.2 Cathepsin C (CatC) functions as a key enzyme in the activation process of several neutrophil serine proteases (NSPs) such as NE, proteinase 3 and cathepthin G by converting the inactive forms of the NSPs to the active forms by digesting dipeptides at the N-terminus of the enzymes.3

Objectives

Although glucocorticoids and immunosuppressive drugs used as the standard of cares can lead remission in MPO-AAV patients, there are remaining unmet medical needs such as severe side effects, resistance to the treatment and relapse. Therefore, development of new therapeutic strategies is awaited. The aim of this study is to demonstrate the efficacy of MOD06051, a novel CatC inhibitor, against MPO-AAV, using an MPO-AAV rat model established previously.4

Methods

In vitro studies: Cathpsins and NE inhibitory activity was measured using recombinant enzymes and fluorescent substrates. Cellular NE activity in the granulocytes differentiated from the primary human bone marrow-derived hematopietic stem cells under the presence or absence of MOD06051 was determined using fluorescent substrates.

In vivo studies: 4-week-old Wistar Kyoto (WKY) rats were immunized with human MPO according to Little’s protocol.4 The rats were divided into three groups (n=8 in each group), and vehicle (0.5% methylcellulose) or MOD06051 (0.3 or 3 mg/kg bid) was orally administered every day for 42 days. All rats were euthanized at the end of the study for serological and histological evaluations.

Results

In vitro studies: MOD06051 inhibited the enzymatic activity of human recombinant CatC with an IC50 value of 1.5 nM, and no other cathepsins nor NE inhibition was observed at 10 μM. The NE activity in primary human granulocytes was suppressed by MOD06051 with an IC50 value of 18 nM.

In vivo studies: MPO-ANCA was induced in all groups at the same level. The percentage of affected glomeruli including those with NCGN, NET-forming neutrophils in the peripheral blood and glomeruli, and glomerular neutrophil counts were significantly suppressed by MOD06051 treatment in a dose-dependent manner. Furthermore, hematuria score, urinary NGAL (Neutrophil Gelatinase-Associated Lipocalin), tubular erythrocyte cast counts, and pulmonary hemorrhage foci were significantly decreased in the 3 mg/kg of MOD06051 treated group with the similar trends in 0.3 mg/kg group.

Conclusion

MOD06051 showed sepcific inhibition of CatC activity. This compound suppressed the serine proteases activation in primary human neutrophils and NET formation in the MPO-AAV model rats, resulting in amelioration of MPO-ANCA-induced tissue destruction, including NCGN and tubular interstitial damages in the kidneys, and disorder of alveolar septal capillaries in the lungs. MOD06051 appears to be a promising agent for treatment of MPO-AAV patients.

References

[1]Nakazawa D, et al. Nat Rev Rheumatol 15: 91-101, 2019.

[2]Papayannopoulos V, et al. J Cell Biol 191: 677-691, 2010.

[3]Korkmaz B, et al. Pharmacol Ther 190: 202-236, 2018.

[4]Little MA, et al. Am J Pathol 174: 1212-1220, 2009.

Disclosure of Interests

Akihiro Ishizu Grant/research support from: Modulus Discovery, Inc., Mai Taniguchi: None declared, Suishin Arai: None declared, Yuka Nishibata Grant/research support from: Modulus Discovery, Inc., Sakiko Masuda Grant/research support from: Modulus Discovery, Inc., Utano Tomaru: None declared, Takafumi Shimizu Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc., William Sinko Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc., Tadashi Nagakura Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc., Yoh Terada Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc.

Assessment of anthracycline-induced cardiotoxicity in patients with childhood cancer survivor for long-term follow-up

Funding Acknowledgements

Type of funding sources: None.

Background

 Anthracycline cardiotoxicity is an important prognostic determinant in childhood cancer survivors (CCSs). That has been reported to improve with early therapeutic intervention, and because it is dose-dependent and progressive, early diagnosis and long-term follow-up are important. In adult survivors of cancer, the longitudinal strain (LS) is useful as a sensitive index of cardiac function. In childhood cancer survivors, strain abnormalities are also observed at both short-term and long-term follow-up. Global longitudinal strain (GLS) abnormalities are common during or early after chemotherapy, whereas changes in global circumferential strain (GCS) are more significant and consistent on long-term follow-up.

Purpose

 In this study, we aimed to conduct a cross-sectional study using strain analysis in childhood cancer survivors of a wide age range to clarify the mode of progression of anthracycline-induced cardiotoxicity and to identify useful indicators for long-term follow-up.

Methods

 In total, 116 patients (median age: 15.5 [range: 4.7-40.2] years) with childhood cancer who had passed at least 1 year after chemotherapy with anthracycline, and 116 control patients of similar age. Strain measurements were assessed for longitudinal strain (LS) and circumferential strain at the apical, papillary and basal levels using speckle tracking imaging. Estimated value at 5, 15, 25 and 35 years old were mathematically calculated.

Results

 Results were shown in tables and figures. Most of conventional echocardiographic parameters were not significantly different between CCCs and controls. LS, papillary CS and basal CS in CCCs decreased compared to normal controls at all age. The difference of estimated value between CCCs and normal controls in LS at all age were relatively constant. However, those in basal CS tended to increase with aging. Furthermore, basal CS in CCCs decreased with aging (r = 0.212, p < 0.001) and the duration after completion of anthracycline treatment (r = -0.244, p < 0.008).

Conclusions

 In childhood cancer survivors, strain analysis is a more sensitive indicators of cardiac function than conventional parameters. In addition, basal CS may decrease most markedly over time and could be useful indicator in long-term follow-up. Longitudinal studies should be conducted in the future to improve the accuracy of predicting anthracycline cardiotoxicity. These are new findings regarding the decline in cardiac function in childhood cancer survivors. Abstract Figure. Relationship between age and strains  Abstract Figure. Estimated values for each age group

Temperature dependence of sequential chlorinated ethenes dechlorination and the dynamics of dechlorinating microorganisms

Thermally enhanced bioremediation is a promising approach to shorten the bioremediation period of tetrachloroethene (PCE) and trichloroethene (TCE). To clarify the influence that temperature has on stepwise PCE dechlorination and associated microorganisms, this study conducted dechlorination experiments using contaminated soil and groundwater under five distinct temperature conditions (i.e., 15, 20, 25, 30, and 35 °C). PCE and TCE were dechlorinated most rapidly at 25-35 °C, whereas the preferable temperatures for the dechlorination of cis-1,2- dichloroethene (cis-1,2-DCE) and vinyl chloride (VC) were 25-30 °C and 25 °C, respectively. Microbial community analysis revealed that Sulfurospirillum and Geobacter may have a dominant contribution to the dechlorination of PCE to cis-1,2-DCE, whereas Dehalococcoides harboring VC reductase genes are likely major contributors to the dechlorination of cis-1,2-DCE and VC. These results suggest that temperature influences various microbial groups, including major dechlorinating microorganisms, resulting in the different extent of PCE dechlorination. In addition, the microbial community structure greatly changed after the onset of the experiment, whereas the temperature influence of 15-30 °C on the microbial community structure was minor; however, the microbial community was significantly impacted at 35 °C. Collectively, these results suggest that thermally enhanced anaerobic dechlorination at 25 °C is useful for successful dechlorination of chlorinated ethenes in a short period.

Empagliflozin improves prognosis and energetic properties through modulating mitochondrial function in failing murine hearts

Background/Introduction

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been reported to have beneficial effects on heart failure in large clinical trials; however, the underlying mechanism is still unclear.

Purpose

The purpose of this study is to elucidate the mechanism of cardioprotective effect of empagliflozin in heart failure.

Methods

Eight-week-old mice deficient in cardiac and skeletal muscle-specific manganese superoxide dismutase, a mouse model of dilated cardiomyopathy (MnSOD-cKO mice), were given food mixed with or without 10 mg/kg empagliflozin for seven weeks and evaluated. Mitochondrial function in the cardiac muscle were measured by a high-resolution respirometer, Oxygraph-2K. Respiratory gas analysis were performed by indirect calorimetry (ARCO 2000) to estimate the energy consumption and energetic substrates.

Results

The survival rate (P=0.015) and cardiac fibrosis (P=0.036) were significantly improved in the empagliflozin group. The capacity of oxidative phosphorylation in cardiac mitochondria was significantly improved by empagliflozin. Blood lactate levels were decreased in the empagliflozin group, indicating that energy such as ATP could be produced without resorting to anaerobic metabolism.

Respiratory gas analysis revealed significant improvement in energy expenditure along with increase in food intake. Respiratory quotient was not different between the two groups, showing the consumption of the carbohydrate to fat rate was not changed by empagliflozin in this study. Ketone levels in blood and HbA1c were neither significantly different between the two groups. Although a moderate amount glucose was excreted in urine in the empagliflozin group (128.3±20.4 mg/day, 0.51±0.08 kcal/day), the available energy substrates in the whole body nonetheless expanded because of the increased caloric intake (10.58±0.72 in control group vs. 13.55±0.08 kcal/day in empagliflozin group, P=0.018).

Conclusion(s)

We have shown that empagliflozin improved myocardial mitochondrial function and increased energy metabolism, which was accompanied by adequate energy intake and uptake, even in heart failure. Empagliflozin decreased myocardial fibrosis and improved prognosis in failing murine hearts through positive energetical properties including mitochondrial function. The finding that empagliflozin modulates cardiac metabolism in a positive way provides a novel mechanism for the cardioprotective effect of SGLT2 inhibitors in heart failure.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Boehringer Ingelheim Empa improved prognosis in HFEmpa improved mitochondrial function