METHODS: Expression of TRAIL and TRAIL receptor in response to insulin and glucose was determined by polymerase chain reaction. Transcriptional activity was assessed using wild-type and site-specific mutations of the TRAIL promoter. Chromatin immunoprecipitation studies were performed. VSMC proliferation and apoptosis was measured.
RESULTS: Insulin and glucose exposure to VSMC for 24 h stimulated TRAIL mRNA expression. This was also evident at the transcriptional level. Both insulin- and glucose-inducible TRAIL transcriptional activity was blocked by dominant-negative specificity protein-1 (Sp1) overexpression. There are five functional Sp1-binding elements (Sp1-1, Sp1-2, Sp-5/6 and Sp1-7) on the TRAIL promoter. Insulin required the Sp1-1 and Sp1-2 sites, but glucose needed all Sp1-binding sites to induce transcription. Furthermore, insulin (but not glucose) was able to promote VSMC proliferation over time, associated with increased decoy receptor-2 (DcR2) expression. In contrast, chronic 5-day exposure of VSMC to 1 µg/mL insulin repressed TRAIL and DcR2 expression, and reduced Sp1 enrichment on the TRAIL promoter. This was associated with increased cell death.
CONCLUSIONS: The findings of the present study provide a new mechanistic insight into how TRAIL is regulated by insulin. This may have significant implications at different stages of diabetes-associated cardiovascular disease. Thus, TRAIL may offer a novel therapeutic solution to combat insulin-induced vascular pathologies.
METHODS: In this investigator-initiated, single-arm, open-label, pilot study, nine biopsy-proven NASH patients with T2DM were given empagliflozin 25 mg daily for 24 weeks. Liver biopsy was repeated at the end of treatment. The histological outcomes were compared with the placebo group of a previous 48-week clinical trial.
RESULTS: There was a significant reduction in body mass index (median change, Δ = -0.7 kg per m2, p = 0.011), waist circumference (Δ = -3 cm, p = 0.033), systolic blood pressure (Δ = -9 mmHg, p = 0.024), diastolic blood pressure (Δ = -6 mmHg, p = 0.033), fasting blood glucose (Δ = -1.7 mmol/L, p = 0.008), total cholesterol (Δ = -0.5 mmol/L, p = 0.011), gamma glutamyl transpeptidase (Δ = -19 U/L, p = 0.013), volumetric liver fat fraction (Δ = -7.8%, p = 0.017), steatosis (Δ = -1, p = 0.014), ballooning (Δ = -1, p = 0.034), and fibrosis (Δ = 0, p = 0.046). All histological components either remained unchanged or improved, except in one patient who had worsening ballooning. Empagliflozin resulted in significantly greater improvements in steatosis (67% vs. 26%, p = 0.025), ballooning (78% vs. 34%, p = 0.024), and fibrosis (44% vs. 6%, p = 0.008) compared with historical placebo.
CONCLUSION: This pilot study provides primary histological evidence that empagliflozin may be useful for the treatment of NASH. This preliminary finding should prompt larger clinical trials to assess the effectiveness of empagliflozin and other SGLT2 inhibitors for the treatment of NASH in T2DM patients. Trial registry number ClincialTrials.gov number, NCT02964715.
AREAS COVERED: We discussed various aspects of pharmacotherapeutic management in hospitalized patients with COVID-19: (i) susceptibility and severity of COVID-19 among individuals with diabetes, (ii) glycemic goals for hospitalized patients with COVID-19 and concurrent diabetes, (iii) pharmacological treatment considerations for hospitalized patients with COVID-19 and concurrent diabetes.
EXPERT OPINION: The glycemic goals in patients with COVID-19 and concurrent type 1 (T1DM) or type 2 diabetes (T2DM) are to avoid disruption of stable metabolic state, maintain optimal glycemic control, and prevent adverse glycemic events. Patients with T1DM require insulin therapy at all times to prevent ketosis. The management strategies for patients with T2DM include temporary discontinuation of certain oral antidiabetic agents and consideration for insulin therapy. Patients with T2DM who are relatively stable and able to eat regularly may continue with oral antidiabetic agents if glycemic control is satisfactory. Hyperglycemia may develop in patients with systemic corticosteroid treatment and should be managed upon accordingly.