Derivation and validation of a type 2 diabetes treatment selection algorithm for SGLT2-inhibitor and DPP4-inhibitor therapies based on glucose-lowering efficacy: cohort study using trial and routine clinical data

Objective: To establish whether clinical patient characteristics routinely measured in primary care can identify people with differing short-term benefits and risks for SGLT2-inhibitor and DPP4-inhibitor therapies, and to derive and validate a treatment selection algorithm to identify the likely optimal therapy for individual patients. Design: Prospective cohort study. Setting: Routine clinical data from United Kingdom general practice (Clinical Practice Research Datalink [CPRD]), and individual-level clinical trial data from 14 multi-country trials of SGLT2-inhibitor and DPP4-inhibitor therapies. Participants: 26,877 new users of SGLT2-inhibitor and DPP4-inhibitor therapy in CPRD over 2013-2019, and 10,414 participants randomised to SGLT2-inhibitor or DPP4-inhibitor therapy in 14 clinical trials, including 3 head-to-head trials of the two therapies (n=2,499). Main outcome measures: The primary outcome was achieved HbA1c 6 months after initiating therapy. Clinical features associated with differential HbA1c outcomes with SGLT2-inhibitor and DPP4-inhibitor therapies were identified in routine clinical data, with associations then tested in trial data. A multivariable treatment selection algorithm to predict differential HbA1c outcomes was developed in a CPRD derivation cohort (n=14,069), with validation in a CPRD validation cohort (n=9,376) and the head-to-head trials. In CPRD, we further explored the relationship between model predictions and secondary outcomes of weight loss and treatment discontinuation. Results: The final treatment selection algorithm included HbA1c, eGFR, ALT, age, and BMI, which were identified as predictors of differential HbA1c outcomes with SGLT2-inhibitor and DPP4-inhibitor therapies using both routine and trial data. In validation cohorts, patient strata predicted to have a ≥5 mmol/mol HbA1c reduction with SGLT2-inhibitor therapy compared with DPP4-inhibitor therapy (38.8% of CPRD validation sample) had an observed greater reduction of 8.8 mmol/mol [95%CI 7.8-9.8] in the CPRD validation sample, a 5.8 mmol/mol (95%CI 3.9-7.7) greater reduction in the Cantata D/D2 trials, and a 6.6 mmol/mol [95%CI 2.2-11.0]) greater reduction in the BI1245.20 trial. In CPRD, there was a greater weight reduction with SGLT2-inhibitor therapy regardless of predicted glycaemic benefit. Strata predicted to have greater reduction in HbA1c on SGLT2-inhibitor therapy had a similar risk of discontinuation as on DPP4-inhibitor therapy. In contrast, strata predicted to have greater reduction in HbA1c with DPP4-inhibitor therapy were half as likely to discontinue DPP4-inhibitor therapy than SGLT2-inhibitor therapy. Conclusions: Routinely measured clinical features are robustly associated with differential glycaemic responses to SGLT2-inhibitor and DPP4-inhibitor therapies. Combining features into a treatment selection algorithm can inform clinical decisions concerning optimal type 2 diabetes treatment choices.

Linagliptin Ameliorates Pulmonary Fibrosis in Systemic Sclerosis Mouse Model via Inhibition of Endothelial to Mesenchymal Transition

Systemic sclerosis (SSc) is a connective tissue disease that often causes pulmonary fibrosis. Dipeptidyl peptidase 4 (DPP4) inhibitor, has shown anti-fibrotic properties in various fibrotic diseases. However, only two studies have reported its anti-fibrosis effects in pulmonary fibrosis, and the mechanism is not completely clear. In the present study, we further investigated the protective effects of linagliptin, a highly specific DPP4 inhibitor, on pulmonary fibrosis in SSc mouse model and the potential mechanisms. The results showed that linagliptin ameliorated pulmonary fibrosis in SSc mouse model, as evidenced by improved pathological changes of lung and body weight loss induced by BLM. Linagliptin also reduced BLM-induced oxidative stress, inflammation in lung in vivo. We revealed that linagliptin attenuated BLM-induced endothelial to mesenchymal transition (EndMT) in vitro and in vivo. BLM-induced enhanced migration ability of endothelial cells was also alleviated by linagliptin. Moreover, we confirmed that the Akt/mammalian target of rapamycin (mTOR) pathway was involved in BLM-induced EndMT in vivo, which was suppressed by linagliptin. In summary, we further confirmed the therapeutic effects of linagliptin on pulmonary fibrosis in SSc mouse model, which is based on its inhibitory effects on EndMT, oxidative stress and inflammation.

Contribution of Dipeptidyl peptidase 4 to Nontypeable H. influenzae-induced lung inflammation in COPD

Dipeptidyl peptidase 4 (DPP4) expression is increased in the lungs of chronic obstructive pulmonary disease (COPD). DPP4 is known to be associated with inflammation in various organs, including LPS-induced acute lung inflammation. Since non-typeable H. influenzae (NTHi) causes acute exacerbations in COPD patients, we examined the contribution of DPP4 in NTHi-induced lung inflammation in COPD. Pulmonary macrophages isolated from COPD patients showed higher expression of DPP4 than the macrophages isolated from normal subjects. In response to NTHi infection, COPD, but not normal macrophages show a further increase in the expression DPP4. COPD macrophages also showed higher expression of IL-1β, and CCL3 responses to NTHi than normal, and treatment with DPP4 inhibitor, diprotin A attenuated this response. To examine the contribution of DPP4 in NTHi-induced lung inflammation, COPD mice were infected with NTHi, treated with diprotin A or PBS intraperitoneally, and examined for DPP4 expression, lung inflammation and cytokine expression. Mice with COPD phenotype showed increased expression of DPP4, which increased further following NTHi infection. DPP4 expression was primarily observed in the infiltrated inflammatory cells. NTHi-infected COPD mice also showed sustained neutrophilic lung inflammation and expression of CCL3, and this was inhibited by DPP4 inhibitor. These observations indicate that enhanced expression of DPP4 in pulmonary macrophages may contribute to sustained lung inflammation in COPD following NTHi infection. Therefore, inhibition of DPP4 may reduce the severity of NTHi-induced lung inflammation in COPD.

Repurposing DPP-4 Inhibitors for Colorectal Cancer: A Retrospective and Single Center Study

Background: There have been studies reporting the crucial roles of Dipeptidyl-peptidase 4 (DPP4) in colorectal cancer (CRC) initiation and progression, whereas DPP4-inhibitors are safe Food and Drug Association (FDA)-approved drugs for treating diabetes. This study aims to investigate the association between DPP4-inhibitor treatment and the prognosis of CRC patients. Methods: Clinical data of CRC patients with diabetes and the prescription of DPP4-inhibitors who had undergone curative surgery in our hospital between January 2006 and December 2015 were retrieved. Their survival data and immune cell population in circulatory blood were compared to those treated with metformin. Results: The DPP4-inhibitor patient group showed a significantly better 5-year disease-free survival (median DFS = 1733 days, 95% CI = 1596 to 1870 days) when compared to the metformin group (p = 0.030, median DFS = 1382 days, 95% CI = 1246 to 1518 days). 33 out of the 92 patients in the metformin group showed recurrence whereas only 3 of the 26 patients in the DPP4-inhibitor group showed recurrence (p = 0.033). Cox regression analysis demonstrated that DPP4-inhibitor application is a favorable factor associated with a lower risk of recurrence (Hazard ratio = 0.200, p = 0.035). Furthermore, our results suggested that the immune cell profile of CRC patients is a potential biomarker for response to DPP4-inhibitor treatment. Conclusion: This study demonstrated the association of DPP4-inhibitor treatment with a better prognosis of CRC patients.

The effect of dipeptidyl peptidase IV on disease-associated microglia phenotypic transformation in epilepsy

Background Accumulating evidence suggests that disease-associated microglia (DAM), a recently discovered subset of microglia, plays a protective role in neurological diseases. Targeting DAM phenotypic transformation may provide new therapeutic options. However, the relationship between DAM and epilepsy remains unknown. Methods Analysis of public RNA-sequencing data revealed predisposing factors (such as dipeptidyl peptidase IV; DPP4) for epilepsy related to DAM conversion. Anti-epileptic effect was assessed by electroencephalogram recordings and immunohistochemistry in a kainic acid (KA)-induced mouse model of epilepsy. The phenotype, morphology and function of microglia were assessed by qPCR, western blotting and microscopic imaging. Results Our results demonstrated that DPP4 participated in DAM conversion and epilepsy. The treatment of sitagliptin (a DPP4 inhibitor) attenuated KA-induced epilepsy and promoted the expression of DAM markers (Itgax and Axl) in both mouse epilepsy model in vivo and microglial inflammatory model in vitro. With sitagliptin treatment, microglial cells did not display an inflammatory activation state (enlarged cell bodies). Furthermore, these microglia exhibited complicated intersections, longer processes and wider coverage of parenchyma. In addition, sitagliptin reduced the activation of NF-κB signaling pathway and inhibited the expression of iNOS, IL-1β, IL-6 and the proinflammatory DAM subset gene CD44. Conclusion The present results highlight that the DPP4 inhibitor sitagliptin can attenuate epilepsy and promote DAM phenotypic transformation. These DAM exhibit unique morphological features, greater migration ability and better surveillance capability. The possible underlying mechanism is that sitagliptin can reduce the activation of NF-κB signaling pathway and suppress the inflammatory response mediated by microglia. Thus, we propose DPP4 may act as an attractive direction for DAM research and a potential therapeutic target for epilepsy.

Analysis of the Relationship Between Learning and Synaptophysin in Obese Rats Treated With DPP4 Inhibitor

In this study, it is aimed to investigate possible changes in cognitive functions in obesity by using targeted treatment hypothesis. Accordingly, the effects of DPP4 inhibitor, which is actively used in the clinic in the treatment of diabetes, and the effect of exercise, which has been proven to be effective in the treatment of obesity, on the change of learning performance and the relationship of these effects with the synaptophysin molecule were investigated. In our study, 42 Wistar albino rats were used. The animals were randomly divided into seven groups as obese, control, obese+DPP4i, control+DPP4i, obese+exercise, control+exercise, control+NaCl. To create experimental obesity, the animals that are targeted to be obese were separated and fed on a high fat diet for 8 weeks. After the obese model was created, sitagliptin was applied to the DPP4i groups and swimming exercise was applied to the exercise groups for obesity treatment. The last week of the study was performed reference memory learning test to the whole group with Morris water maze. Then, the hippocampus tissues were removed from the animals under anesthesia. mRNA and protein isolations were performed from the extracted tissues. Synaptophysin gene expressions were determined from mRNA samples by Real-Time PCR method. Synaptophysin protein levels were determined from protein lysates by Western Blot method. In the learning test, in the obese groups, there was a statistically significant difference between the average escape time of the DPP4i and exercise groups and the groups that did not (p<0.05). As a result, in groups where obesity is treated with DPP4i and exercise; It was concluded that cognitive performance was better than obese groups. There was a evident decrease in synaptophysin gene expression levels in obese groups compared to the control group. In the treatment groups, an increase was observed in synaptophysin gene expression levels in the DPP4 inhibitor and especially in the exercise groups compared to the control groups (P> 0.05). Gene expression results were similar in analyzes performed at the protein level. According to these results, in terms of performance in cognitive function due to obesity and synaptophysin gene relationship; DPP4 inhibitor showed as effective a result as exercise. This provides a resource for advanced molecular and metabolic research. Acknowledgement: This study was supported by The Scientific And Technological Research Council Of Turkey (TÜBİTAK) Project No. 219S063.