Decreased Mortality After Long-Term Treatment With Dipeptidyl Peptidase-4 Inhibitors: A Retrospective Study of U.S. Veterans With Type 2 Diabetes.

OBJECTIVE: The prevalence of chronic kidney disease (CKD) in the United States is 13% of the general population. Among those with CKD, diabetic nephropathy is the leading cause of end-stage renal disease. This is a retrospective study examining the effect of long-term use of dipeptidyl peptidase-4 (DPP-4) inhibitors on all-cause mortality and progression of renal disease in the veteran population. METHODS: Data was extracted using the Veterans Administration Informatics and Computing Infrastructure. A large cohort of veterans diagnosed with type 2 diabetes mellitus were used to identify patients on DPP-4 inhibitors and without DPP-4 inhibitors. Groups were compared to determine the effect of DPP-4 inhibitors on the progression of CKD and all-cause mortality. Data were analyzed using SAS. RESULTS: Subjects in the treatment group (n = 40 558) had baseline variables (age, body mass index, race) similar to the control group (n = 40 558). Diabetes control improved in the treatment group (HgbA1c, 8.3% [67 mmol/mol] to 7.8% [62 mmol/mol]; P < .001) but not in the control group (HgbA1c, 7.4% [57 mmol/mol] to 7.3% [56 mmol/mol]). New diagnoses of heart failure and coronary artery bypass grafts were clinically significant (odds ratios = 0.66 and 0.52). No change in progression of CKD was seen in either group. All-cause mortality was reduced by 59%. CONCLUSION: We conclude that DPP-4 inhibitors are associated with a significant reduction in all-cause mortality independent of glucose control, albeit with no clear cause, including obtainable cardiovascular outcomes. Our data is consistent with prior trials in that DPP-4 inhibitors did not show a significant change in serum creatinine or microalbuminuria.

In vivo treatment of HCV core-positive HepG2 cells with the transfer of recombinant caspase-3 using a 2'-5' OAS promoter.

Hepatitis C virus (HCV) is one of the most common pathogens causing liver-related morbidity and mortality, which affect 170 million individuals worldwide. There is no vaccine available, and current therapy is only partially effective. In a previous study, we constructed a recombinant caspase-3 expression vector under the 2'-5'-oligoadenylate synthetase gene (OAS) promoter (pGL3-OAS-re-caspase-3) and demonstrated that it is an effective gene therapy for HCV core-positive liver cells in vitro. In the present study, the human hepatoma cell line HepG2 was transfected with the pcDNA3.1-HCV-core-EGFP plasmid and selected by G418. Expression of HCV core protein was confirmed by RT-PCR and immunocytochemistry. Both HepG2-expressing HCV core protein and parental HepG2 cells were inoculated subcutaneously into BALB/c mice, respectively. Tumor-bearing mice were treated with an intratumoral injection of pGL3-OAS-re-caspase-3. The mice were sacrificed after 48 h. The correlation between HCV core and caspase-3 expression in tumor tissues was analyzed by immunohistochemical staining and double-label immunofluorescence staining. The subcutaneous hepatoma in vivo mouse models stably expressing HCV core protein and co-expressing HCV core protein and pGL3-OAS-re-caspase-3 were established. Double-label immunofluorescence staining showed that the percentage of co-expression of both HCV core and caspase-3 was 76 ± 6% in the group treated with pGL3-OAS-re-caspase-3. There was a significant increase in the number of apoptotic cells in the group treated with the pGL3-OAS-re-caspase-3 system by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and transmission electron microscopy. The results suggest that the pGL3-OAS-re-caspase-3 construct can effectively induce apoptosis in HCV core-positive hepatocytes in vivo. The results presented strongly suggest that the transfer of pGL3-OAS-re-caspase-3 is an effective and promising gene therapy strategy for HCV infection.