Sodium-glucose co-transporter 2 inhibitor canagliflozin modulates myocardial metabolism and inflammation in a swine model for chronic myocardial ischemia.

BACKGROUND: Inflammation and disruption of cardiac metabolism are prevalent in the setting of myocardial ischemia. Canagliflozin, a sodium-glucose costransporter-2 inhibitor, has beneficial effects on the heart, though the precise mechanisms are unknown. This study investigated the effects of canagliflozin therapy on metabolic pathways and inflammation in ischemic myocardial tissue using a swine model of chronic myocardial ischemia. METHODS: Sixteen Yorkshire swine underwent placement of an ameroid constrictor to the left circumflex artery to induce chronic ischemia. Two weeks later, pigs received either no drug (n = 8) or 300 mg canagliflozin (n = 8) daily. Five weeks later, pigs underwent terminal harvest and tissue collection. RESULTS: Canagliflozin treatment was associated with a trend toward decreased expression of fatty acid oxidation inhibitor acetyl-CoA carboxylase and decreased phosphorylated/inactivated acetyl-CoA carboxylase, a promotor of fatty acid oxidation, compared with control ischemic myocardium (P = .08, P = .03). There was also a significant modulation in insulin resistance markers p-IRS1, p-PKCα, and phosphoinositide 3-kinase in ischemic myocardium of the canagliflozin group compared with the control group (all P < .05). Canagliflozin treatment was associated with a significant increase in inflammatory markers interleukin 6, interleukin 17, interferon-gamma, and inducible nitric oxide synthase (all P < .05). There was a trend toward decreased expression of the anti-inflammatory cytokines interleukin 10 (P = .16) and interleukin 4 (P = .31) with canagliflozin treatment. CONCLUSION: The beneficial effects of canagliflozin therapy appear to be associated with inhibition of fatty acid oxidation and enhancement of insulin signaling in ischemic myocardium. Interestingly, canagliflozin appears to increase the levels of several inflammatory markers, but further studies are required to better understand how canagliflozin modulates inflammatory signaling pathways.

Diabetic state of human coronary artery endothelial cells results in altered effects of bone mesenchymal stem cell-derived extracellular vesicles.

Human bone mesenchymal stem cell-derived extracellular vesicles (HBMSC-EV) have been used successfully in animal models of myocardial ischemia, yet have dampened effects in metabolic syndrome through unknown mechanisms. This study demonstrates the basal differences between non-diabetic human coronary artery endothelial cells (HCAEC) and diabetic HCAEC (DM-HCAEC), and how these cells respond to the treatment of HBMSC-EV. HCAEC and DM-HCAEC were treated with HBMSC-EV for 6 h. Proteomics, western blot analysis, and tube formation assays were performed. Key metabolic, growth, and stress/starvation cellular responses were significantly altered in DM-HCAEC in comparison to that of HCAEC at baseline. Proteomics demonstrated increased phosphorus metabolic process and immune pathways and decreased RNA processing and biosynthetic pathways in DM-HCAEC. Similar to previous in vivo findings, HCAEC responded to the HBMSC-EV with regenerative and anti-inflammatory effects through the upregulation of multiple RNA pathways and downregulation of immune cell activation pathways. In contrast, DM-HCAEC had a significantly diminished response to HBMSC-EV, likely due to the baseline abnormalities in DM-HCAEC. To achieve the full benefits of HBMSC-EV and for a successful transition of this potential therapeutic agent to clinical studies, the abnormalities found in DM-HCAEC will need to be further studied.

Intramyocardial injection of hypoxia-conditioned extracellular vesicles modulates apoptotic signaling in chronically ischemic myocardium.

Objective: Limited treatments exist for nonoperative chronic coronary artery disease. Previously, our laboratory has investigated extracellular vesicle (EV) therapy as a potential treatment for chronic coronary artery disease using a swine model and demonstrated improved cardiac function in swine treated with intramyocardial EV injection. Here, we seek to investigate the potential cardiac benefits of EVs by using hypoxia-conditioned EVs (HEV). Specifically, this study aims to investigate the effect of HEV on apoptosis in chronically ischemic myocardium in swine. Methods: Fourteen Yorkshire swine underwent placement of an ameroid constrictor on the left circumflex artery. Two weeks later, swine underwent redo left thoracotomy with injection of either saline (control, n = 7) or HEVs (n = 7). After 5 weeks, swine were euthanized for tissue collection. Terminal deoxynucleotidyl transferase dUTP nick end labeling was used to quantify apoptosis. Immunoblotting was used for protein quantification. Results: Terminal deoxynucleotidyl transferase dUTP nick end labeling staining showed a decrease in apoptosis in the HEV group compared with the control (P = .049). The HEV group exhibited a significant increase in the anti-apoptotic signaling molecule phospho-BAD (P = .005), a significant decrease in B-cell lymphoma 2 (P = .006) and an increase in the phospho-B-cell lymphoma to B-cell lymphoma 2 ratio (P < .001). Furthermore, the HEV group exhibited increased levels of prosurvival signaling markers including phosphoinositide 3-kinase, phosphor-extracellular signal-regulated kinase 1/2, phospho-forkhead box protein O1, and phospho-protein kinase B to protein kinase B ratio (all P < .05). Conclusions: In chronic myocardial ischemia, treatment with HEV results in a decrease in overall apoptosis, possibly through the activation of both pro-survival and anti-apoptotic signaling pathways.

Canagliflozin improves coronary microvascular vasodilation and increases absolute blood flow to the myocardium independent of angiogenesis.

OBJECTIVES: Sodium-glucose cotransporter-2 inhibitor, canagliflozin, improves myocardial perfusion to ischemic territory without accompanying changes in vascular density. We aimed to (1) characterize effects on angiogenic pathways, (2) use multiomics to identify gene expression and metabolite profiles relevant to regulation of myocardial blood flow, and (3) investigate drug effect on coronary microvascular reactivity. METHODS: A nondiabetic swine model of chronic myocardial ischemia and nondiabetic rat model were used to study functional and molecular effects of canagliflozin on myocardium and in vitro microvascular reactivity. RESULTS: Canagliflozin resulted in increased coronary microvascular vasodilation and decreased vasoconstriction (P < .05) without changes in microvascular density (P > .3). Expression of the angiogenic modulator, endostatin, increased (P = .008), along with its precursor, collagen 18 (P < .001), and factors that increase its production, including cathepsin L (P = .004). Endostatin and collagen 18 levels trended toward an inverse correlation with blood flow to ischemic territory at rest. Proangiogenic fibroblast growth factor receptor was increased (P = .03) and matrix metalloproteinase-9 was decreased (P < .001) with canagliflozin treatment. Proangiogenic vascular endothelial growth factor A (P = .13), Tie-2 (P = .10), and Ras (P = .18) were not significantly altered. Gene expression related to the cardiac renin-angiotensin system was significantly decreased. CONCLUSIONS: In chronic myocardial ischemia, canagliflozin increased absolute blood flow to the myocardium without robustly increasing vascular density or proangiogenic signaling. Canagliflozin resulted in altered coronary microvascular reactivity to favor vasodilation, likely through direct effect on vascular smooth muscle. Downregulation of cardiac renin-angiotensin system demonstrated local regulation of perfusion. VIDEO ABSTRACT.

Ischemic myocardial inflammatory signaling in starvation versus hypoxia-derived extracellular vesicles: A comparative analysis.

Background: Coronary artery disease remains a leading cause of death worldwide. Bone mesenchymal stem cell-derived extracellular vesicles (EVs) have shown promise in the setting of myocardial ischemia. Furthermore, the properties of the EVs can be modified via preconditioning of progenitor cells. Previous research from our lab demonstrated a significant decrease in proinflammatory signaling following treatment with EVs derived from starvation preconditioning of human bone mesenchymal stem cells (MVM EVs) in a porcine model of chronic myocardial ischemia. However, rodent models have demonstrated that the use of EVs derived from hypoxia preconditioning of bone mesenchymal stem cells (HYP EVs) may have extended benefits compared to MVM EVs. This study evaluated the effect of HYP EVs on inflammation in a swine model of chronic myocardial ischemia. We hypothesized that HYP EVs would have a greater anti-inflammatory effect than MVM EVs or saline (CON). Methods: Yorkshire swine fed a standard diet underwent placement of an ameroid constrictor to the left circumflex artery. Two weeks later, the animals received intramyocardial injection of saline (CON; n = 6), starvation-derived EVs (MVM; n = 10), or hypoxia-derived EVs (HYP; n = 7). After 5 weeks, myocardial perfusion was assessed, and left ventricular myocardial tissue was harvested. Protein expression was measured using immunoblotting. Data were analyzed via the Kruskal-Wallis test or one-way analysis of variance based on the results of a Shapiro-Wilk test. Coronary perfusion was plotted against relative cytokine concentration and analyzed with the Spearman rank-sum test. Results: HYP EV treatment was associated with decreased expression of proinflammatory markers interleukin (IL)-6 (P = .03), Pro-IL-1ß (P = .01), IL-17 (P < .01), and NOD-like receptor protein 3 (NLRP3; P < .01) compared to CON. Ischemic tissue from the MVM group showed significantly decreased expression of pro-inflammatory markers NLRP3 (P < .01), IL-17 (P < .01), and HLA class II histocompatibility antigen (P < .01) compared to CON. The MVM group also had decreased expression of anti-inflammatory IL-10 (P = .01) compared to CON counterparts. There were no significant differences in expression of tumor necrosis factor-α, interferon-γ, IL-12, Toll-like receptor-2, and nuclear factor kappa-light-chain-enhancer of activated B cells in either group . There was no correlation between coronary perfusion and cytokine concentration in the MVM or HYP groups, either at rest or with pacing. Conclusions: HYP EVs and MVM EVs appear to result in relative decreases in the degree of inflammation in chronically ischemic swine myocardium, independent of coronary perfusion. It is possible that this observed decrease may partially explain the myocardial benefits seen with both HYP and MVM EV treatment.

Goal Directed Perfusion Is Not Associated with a Decrease in Acute Kidney Injury in Patients Predicted to Be at High Risk for Acute Renal Failure after Cardiac Surgery.

Small increases in serum creatinine postoperatively reflect an acute kidney injury (AKI) that likely occurred during cardiopulmonary bypass (CPB). Maintaining adequate oxygen delivery (DO2) during CPB, known as GDP (goal-directed perfusion), improves outcomes. Whether GDP improves outcomes of patients at high risk for acute renal failure (ARF) is unknown. Forty-seven adult patients undergoing cardiac surgery with CPB utilizing GDP with Cleveland Clinic Acute Renal Failure Score of 3 or greater were compared with a matched cohort of patients operated upon using a flow-directed strategy. CPB flow in the GDP cohort was based on a DO2 goal of 260 mL/min/m2. Serum creatinine values were used to determine whether postoperative AKI occurred according to AKIN (Acute Kidney Injury Network) guidelines. We examined the distribution of all variables using proportions for categorical variables and means (standard deviations) for continuous variables and compared treatment groups using t tests for categorical variables and tests for differences in distributions for continuous and count variables. We used inverse probability of treatment weighting to adjust for treatment selection bias. In adjusted models, GDP was not associated with a decrease in AKI (odds ratio [OR]: .97; confidence interval [CI]: .62, 1.52), but was associated with higher odds of ARF (OR: 3.13; CI: 1.26, 7.79), mortality (OR: 3.35; CI: 1.14, 9.89), intensive care unit readmission (OR: 2.59; CI: 1.31, 5.15), need for intraoperative red blood cell transfusion (OR: 2.02; CI: 1.26, 3.25), and postoperative platelet transfusion (OR: 1.78; CI: 1.05, 3.01) when compared with the historic cohort. In patients who are at high risk for postoperative renal failure, GDP was not associated with a decrease in AKI when compared to the historical cohort managed traditionally by determining CPB flows based on body surface area. Surprisingly, the GDP cohort performed significantly worse than the retrospective control group in terms of ARF, mortality, intensive care unit readmission, and RBC and platelet transfusions.

Comparison of intraoperative tranexamic acid and epsilon-aminocaproic acid in cardiopulmonary bypass patients.

Objective: To compare tranexamic acid (TXA) and epsilon-aminocaproic acid (EACA) in patients undergoing cardiac surgery with cardiopulmonary bypass. Methods: Over a consecutive 2-year period, 824 adult cardiac surgery patients who received TXA during an EACA shortage were compared with 778 patients who received EACA postshortage. Patient characteristics and process and outcome variables were collected through chart review and database queries. This retrospective analysis used inverse probability of treatment weighting to control for confounding by indication, and propensity scores were calculated using a logistic regression model. Results: In adjusted models, overall transfusion rates for the TXA cohort (odds ratio [OR], 0.94; 95% confidence interval [95% CI], 0.81-1.10) and administration of platelets (OR, 1.04; 95% CI, 0.85-1.27), red blood cells (OR, 0.93; 95% CI, 0.80-1.09), fresh frozen plasma (OR, 1.00; 95% CI, 0.79-1.25), and cryoprecipitate (OR, 1.08; 95% CI, 0.71-1.64) were equivalent to the EACA cohort. In addition, there was no statistical difference with respect to stroke, seizure, mortality, reoperation for bleeding, chest tube drainage, and acute kidney injury. Patients who received TXA had shorter ventilator times (difference in medians -1.33 hours [95% CI, -1.86 to -0.80]) and lower postsurgical charges (difference of medians -$2913 [95% CI, -5147 to -679]). Conclusions: Substituting TXA for EACA during cardiac surgery with cardiopulmonary bypass did not change transfusion rate or amount, nor was there a significant difference in chest tube drainage. Patients who received TXA had a statistically significant but not clinically significant lower postoperative ventilator times and charges without an increase in mortality, stroke, reoperation for bleeding, acute kidney injury, or seizures.

Comparative Effectiveness of Treatment Strategies for Squamous Cell Carcinoma of the Bladder.

BACKGROUND: While there is established evidence supporting the use of radical cystectomy (RC) and perioperative chemotherapy for muscle-invasive urothelial carcinoma of the bladder, such evidence does not exist for squamous cell carcinoma. OBJECTIVE: We present the largest study to date of patients with squamous cell carcinoma and compare the effectiveness of possible treatment regimens for overall survival. DESIGN, SETTING, AND PARTICIPANTS: The National Cancer Data Base was queried for cases of localized, muscle-invasive pure squamous cell bladder cancer, classified as clinical stage T2/3N0M0. Permutations of surgery (RC), chemotherapy, and external beam radiation were selected. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: A multinomial propensity score method was used to create treatment weights based on clinical characteristics predicting the probability of treatment receipt. These were then applied in weighted Cox proportional hazards models to assess the comparative effectiveness of treatments for overall survival, adjusting for age, TNM clinical stage, Charlson comorbidity index, race, sex, and facility and county level variables. RESULTS AND LIMITATIONS: A total of 828 cases were included, comprising 465 RC alone, 53 neoadjuvant chemotherapy+RC, 48 RC+adjuvant chemotherapy, 72 chemotherapy alone, 88 radiation alone, and 102 chemoradiation cases. On weighted regression, RC treatment with or without perioperative chemotherapy was associated with significantly better overall survival compared to the other treatment modalities; chemotherapy alone, radiation alone, and chemoradiation were associated with a hazard ratio (HR) of death of 2.43 (95% confidence interval [CI] 1.65-3.59), 4.78 (95% CI 3.33-6.86), and 1.61 (95% CI 1.16-2.25), respectively, compared to RC alone (all p<0.005). A combination of RC and neoadjuvant chemotherapy was comparable to RC alone, with HR of death 1.33 (95% CI 0.89-1.98). The combination of RC and adjuvant chemotherapy was also similar to RC alone (HR 1.11, 95% CI 0.66-1.85). These findings are limited by small numbers and the retrospective nature of the study. CONCLUSIONS: RC with or without perioperative chemotherapy should be considered an upfront therapy for squamous cell carcinoma of the bladder. PATIENT SUMMARY: Using a national database, we compared treatments for muscle-invasive squamous cell bladder cancer. Patients undergoing radical cystectomy with or without chemotherapy had longer survival. Radical cystectomy with or without chemotherapy should be the standard of care for this disease.

Outcomes of a urethroplasty algorithm for fossa navicularis strictures.

INTRODUCTION: There is no standardized treatment algorithm for isolated fossa navicularis strictures and treatment modality often falls to surgeon preference. We evaluated the outcomes of a standardized algorithm for fossa navicularis strictures based on stricture etiology, lumen size, and glans size to minimize the number of patients requiring a two-stage urethral reconstruction. MATERIALS AND METHODS: We retrospectively reviewed a prospectively maintained urethral reconstruction database by a single surgeon from 2011-2018. A treatment algorithm was applied and patients underwent one of three treatment modalities: a two-stage buccal mucosa graft (BMG), a single-stage dorsal inlay BMG, or a single-stage dorsal inlay BMG and ventral fasciocutaneous flap repair. Stricture recurrence was measured by inability to pass 17 Fr flexible cystoscope. Patient sexual function and satisfaction were evaluated by the International Index of Erectile Function (IIEF) and a patient perception questionnaire. RESULTS: Forty-two patients met inclusion criteria with a mean follow up of 12.3 months. Urethroplasty success rate was 92%. There was no change in IIEF scores pre and postoperatively between single stage BMG, two-stage BMG, and combined BMG and flap repairs (+ 0.4; p = 0.88, 0.0; p = 1.00, and -0.3; p = 0.74). Ninety-four percent of patients reported being very satisfied or satisfied with their reconstruction. CONCLUSION: An algorithmic approach to the treatment of fossa navicularis strictures is an appropriate method for reconstructive intervention with a high rate of success and patient satisfaction with no significant impact on erectile function.