Perioperative THR-184 and AKI after Cardiac Surgery.

AKI after cardiac surgery is associated with mortality, prolonged hospital length of stay, use of dialysis, and subsequent CKD. We evaluated the effects of THR-184, a bone morphogenetic protein-7 agonist, in patients at high risk for AKI after cardiac surgery. We conducted a randomized, double-blind, placebo-controlled, multidose comparison of the safety and efficacy of perioperative THR-184 using a two-stage seamless adaptive design in 452 patients between 18 and 85 years of age who were scheduled for nonemergent cardiac surgery requiring cardiopulmonary bypass and had recognized risk factors for AKI. The primary efficacy end point was the proportion of patients who developed AKI according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. The proportion of patients who developed AKI within 7 days of surgery was similar in THR-184 treatment groups and placebo groups (range, 74%-79%; P=0.43). Prespecified secondary end point analysis did not show significant differences in the severity of AKI stage (P=0.53) or the total duration of AKI (P=0.44). A composite of death, dialysis, or sustained impaired renal function by day 30 after surgery did not differ between groups (range, 11%-20%; P=0.46). Safety-related outcomes were similar across all treatment groups. In conclusion, compared with placebo, administration of perioperative THR-184 through a range of dose exposures failed to reduce the incidence, severity, or duration of AKI after cardiac surgery in high-risk patients.

Harnessing the BMP signaling pathway to control the formation of cancer stem cells by effects on epithelial-to-mesenchymal transition.

Cancer stem cells (CSCs) persist in tumors as a distinct population and may be causative in metastasis and relapse. CSC-rich tumors are associated with higher rates of metastasis and poor patient prognosis. Targeting CSCs therapeutically is challenging, since they seem to be resistant to standard chemotherapy. We have shown that a novel peptide agonist of bone morphogenetic protein (BMP) signaling, P123, is capable of inhibiting the growth of primary tumor cells by interacting with type I receptors selectively [activin receptor-like kinase 2 (ALK2) and ALK3, but not ALK6] and type II BMP receptors, activating SMAD 1/5/8 signaling and controlling the cell cycle pathway. Furthermore, the compound is capable of blocking transforming growth factor-ß induced epithelial-to-mesenchymal transition (EMT) in primary tumor cells, a critical step for tumor progression and metastasis. In addition, we have investigated the effects of P123 on self-renewal, growth, differentiation (reversal of EMT) and apoptosis of isolated human breast CSCs. We have shown that P123 and BMP-7 reverse the EMT process in human breast CSCs, and inhibit self-renewal and growth. Moreover, compared with single treatment with paclitaxel, co-treatment with paclitaxel and P123 showed an increase in cell apoptosis. Together, these findings suggest that P123 has the therapeutic potential to suppress both bulk tumor cells and CSCs. We believe that P123 represents a new class of drugs that have the potential to eliminate the primary tumor, prevent reoccurrence and metastasis, and enhance the treatment of breast cancer.

Inhibitors/antagonists of TGF-ß system in kidney fibrosis.

Renal fibrosis is a major hallmark of chronic kidney disease, regardless of the initial causes, and prominent renal fibrosis predicts poor prognosis for renal insufficiency. Transforming growth factor (TGF)-ß plays a pivotal role in the progression of renal fibrosis, and therapeutic interventions targeting TGF-ß have been successful and well tolerated in animal models. However, these interventions might have adverse effects by inducing systemic inflammation due to the strong bifunctional role of TGF-ß (pro-fibrotic and anti-inflammatory). This review of the current literature focuses on the inhibitors/antagonists of TGF-ß, and discusses possible therapeutic approaches targeting them, describing the effectiveness of orally active bone morphogenetic protein 7 mimetics in reversing established fibrosis. It will conclude with a brief discussion of possible future directions for research.

Bone morphogenetic protein-7 and Gremlin: New emerging therapeutic targets for diabetic nephropathy.

Specific therapies of diabetic nephropathy (DN) are not available, and current treatment strategies are limited to management of blood glucose levels and control of hypertension. The re-activation of developmental programs in DN suggests new potential therapeutic targets. Bone morphogenetic protein-7 (BMP-7) and its antagonist, Gremlin is revealed to be involved in renal development and diabetic nephropathy. This article reviews the changes of BMP-7 and Gremlin in diabetic kidney, the protective effects on diabetic nephropathy when targeting BMP-7 and Gremlin, and the possible mechanism. The reorganization of the re-activation of Gremlin and BMP-7 in diabetic kidney had shed light on the identification of novel therapeutic targets for DN.

Potential approaches to reverse or repair renal fibrosis.

The concept of reversing chronic kidney disease (CKD) has been intensively researched over the past decade. Indeed, as the prevalence of end-stage renal disease is constantly on the rise, the lack of established antifibrotic therapies is a considerable unmet need in clinical practice. Now, the possibility of effective antifibrotic treatment has been established in experimental models of CKD and multiple antifibrotic compounds-in kidney disease, as well as in fibrotic diseases of the skin, liver and lung-are being assessed in clinical trials. These strategies target various components of the fibrotic pathway, from signalling molecules that include transforming growth factor-ß, phosphatidylinositide 3-kinase and chemokines to microRNAs. Here, we discuss therapeutic concepts to inhibit or even reverse chronic kidney injury and review the leading candidate antifibrotic drugs to be introduced to clinical use.