Optimization Efforts for Identification of Novel Highly Potent Keap1-Nrf2 Protein-Protein Interaction Inhibitors.

In research focused on protein-protein interaction (PPI) inhibitors, the optimization process to achieve both high inhibitory activity and favorable physicochemical properties remains challenging. Our previous study reported the discovery of novel and bioavailable Keap1-Nrf2 PPI inhibitor 8 which exhibited moderate in vivo activity in rats. In this work, we present our subsequent efforts to optimize this compound. Two distinct approaches were employed, targeting high energy water molecules and Ser602 as "hot spots" from the anchor with good aqueous solubility, metabolic stability, and membrane permeability. Through ligand efficiency (LE)-guided exploration, we identified two novel inhibitors 22 and 33 with good pharmacokinetics (PK) profiles and more potent in vivo activities, which appear to be promising chemical probes among the existing inhibitors.

Renal transcriptome analysis of uninephrectomized db/db mice identified a mechanism for the transition to severe diabetic nephropathy.

Diabetic nephropathy (DN), included in diabetic kidney disease (DKD), is a primary driver of end-stage renal disease (ESRD) leading to dialysis treatment. To develop new therapeutic drugs to prevent ESRD and avoid dialysis treatment, insight into DKD pathophysiology and animal models suitable for drug efficacy testing are needed. In this study, transcriptome analysis of kidneys from 26-week-old and 35-week-old uninephrectomized (UNX) db/db mice was used to identify the pathways that affect the deterioration of renal function in db/db mice. Differentially expressed genes suggested that there was increased interferon (IFN)-γ signaling during the 26 to 35-week period. Modules that changed between 26 and 35 weeks of age extracted by weighted gene co-expression network analysis (WGCNA) suggested increased the tumor necrosis factor (TNF)-α and nuclear factor-kappa B (NF-κB) signaling pathway in component cells of glomeruli. The protein-protein interaction (PPI) network analysis identified Cxcl16 as a hub gene for those signaling pathways, and it was shown that the pathways in this module changed when the glomerular filtration rate decreased in patients with DN. These results suggested the possibility that signaling mediated by Cxcl16 induced by IFN-γ and TNF-α between 26 and 35 weeks of age leads to renal fibrosis, resulting in severe disease. Drugs that target such pathways can be options for developing drugs for DN. We also think that the uninephrectomized db/db mouse can be used as an animal model of severe DKD and to evaluate efficacy in patients with DN.

Methyl and Fluorine Effects in Novel Orally Bioavailable Keap1-Nrf2 PPI Inhibitor.

Oxidative stress is one of the causes of progression of chronic kidney disease (CKD). Activation of the antioxidant protein regulator Nrf2 by inhibition of the Keap1-Nrf2 protein-protein interaction (PPI) is of interest as a potential treatment for CKD. We report the identification of the novel and weak PPI inhibitor 7 with good physical properties by a high throughput screening (HTS) campaign, followed by structural and computational analysis. The installation of only methyl and fluorine groups successfully provided the lead compound 25, which showed more than 400-fold stronger activity. Furthermore, these dramatic substituent effects can be explained by the analysis of using isothermal titration calorimetry (ITC). Thus, the resulting 25, which exhibited high oral absorption and durability, would be a CKD therapeutic agent because of the dose-dependent manner for up-regulation of the antioxidant protein heme oxigenase-1 (HO-1) in rat kidneys.

A Comparison of the Oncological Outcomes After Breast-Conserving Surgery With or Without Latissimus Dorsi Myocutaneous Flap Reconstruction for Breast Cancer.

BACKGROUND: There is little information on the oncological outcomes of breast-conserving surgery (BCS) with immediate reconstruction using a latissimus dorsi myocutaneous flap (LDMF) for breast cancer compared with BCS alone. PATIENTS AND METHODS: We conducted a retrospective cohort study from a single institution comparing the margin positivity rates after initial surgery, re-excision rates, and local recurrence (LR) between BCS with immediate LDMF reconstruction (n = 145) and BCS alone (n = 1040) performed from 2012 to 2017 for newly diagnosed stage 0-3 breast cancer. RESULTS: The positive rates of surgical margin after initial surgery were significantly lower in the BCS with LDMF group than in the BCS alone group (4.1 vs. 10.8%; P = .006). There were no marked differences in the re-excision rates between the BCS with LDMF and BCS alone groups (P = .1). At a median follow-up of 61 months, the surgical method (BCS with LD vs. BCS alone) was not associated with the LR-free survival after adjusting for various clinicopathologic factors (P = .8). CONCLUSION: Our findings suggest that BCS with immediate LDMF reconstruction is oncologically safe for breast cancer compared with BCS alone. However, further studies are needed.

[Primary Rhabdomyosarcoma of the Breast in a 16-Year-Old Girl].

We report a case of primary breast rhabdomyosarcoma. A 16-year-old girl noticed tumor of her right breast and consulted a local clinic. From the result of core needle biopsy, breast sarcoma was suspected, so she attended our hospital. Breast ultrasonography showed a mosaic pattern tumor occupying the whole right breast. CT images revealed an axillary node metastasis and no distant organ metastasis. Immunohistochemical staining of the tumor yielded positive results for desmin, MyoD1, and myogenin. Based on reverse transcription polymerase chain reaction(RT-PCR), she was diagnosed as an alveolar rhabdomyosarcoma with PAX3-FKHR(FOXO1)fusion transcripts[t(2;13)(q35;q14)]. She underwent total mastectomy and dissection of axillary lymph nodes. After surgery, the whole-body magnetic resonance imaging(MRI) demonstrated metastases of sacrum and left foot, so she was under systemic chemotherapy.

A Novel TNF-α Converting Enzyme (TACE) Selective Inhibitor JTP-96193 Prevents Insulin Resistance in KK-Ay Type 2 Diabetic Mice and Diabetic Peripheral Neuropathy in Type 1 Diabetic Mice.

Tumor necrosis factor-α (TNF-α) converting enzyme/a disintegrin and metalloproteinase domain-containing protein 17 (TACE/ADAM17) is a key sheddase that releases TNF-α from its inactive precursor and is thought as a new drug target to inhibit TNF-α production. In the present study, pharmacological effects of a novel TACE selective inhibitor, JTP-96193, on type 2 diabetes and diabetic peripheral neuropathy (DPN) as its major complication was examined. Enzyme inhibitory activity of JTP-96193 on TACE and other ADAMs was measured in in vitro. High fat-induced obese mice and type 2 diabetic KK-Ay mice were used to evaluate the effect of JTP-96193 on insulin resistance. Finally, streptozotocin (STZ)-induced diabetic mice were treated with JTP-96193 to evaluate the sciatic motor nerve conduction velocities (MNCV). JTP-96193 selectively inhibited human TACE activity with IC50 value of 5.4 nM and showed more than 1800-fold selectivity against other matrix metalloproteinases. In mouse models of obesity and diabetes, JTP-96193 reduced the TNF-α release from the fat tissue and prevented development of diabetes and improved insulin resistance, respectively. Furthermore, JTP-96193 prevented delay of sciatic MNCV without any effects on blood glucose or insulin levels in STZ-induced diabetic mice. TACE inhibitor is effective on insulin resistance and DPN independent from glucose-lowering effect. These pharmacological properties of JTP-96193 may be helpful to treat type 2 diabetes accompanied by its microvascular complications.

JTS-653 blocks afferent nerve firing and attenuates bladder overactivity without affecting normal voiding function.

PURPOSE: We evaluated the role of TRPV1 in bladder overactivity based on afferent nerve firing and urodynamic parameters using the selective TRPV1 antagonist JTS-653. MATERIALS AND METHODS: We evaluated the effects of JTS-653 on the increased pelvic nerve discharge and intravesical pressure induced by intravesical infusion of 100 µM capsaicin in anesthetized rats. The effects of JTS-653 on the urodynamic parameters of bladder overactivity induced by intravesical infusion of 30 nM resiniferatoxin or 0.2% acetic acid, or on normal bladder activity were evaluated by cystometry in conscious rats. The effects of JTS-653 on carbachol induced contraction were investigated using bladder muscle strips. RESULTS: JTS-653 significantly suppressed the capsaicin induced increase in nerve discharge and intravesical pressure. Intravesical infusion of resiniferatoxin or acetic acid decreased the intercontraction interval and voided volume. JTS-653 significantly increased the intercontraction interval and voided volume in rats with resiniferatoxin or acetic acid induced bladder overactivity without affecting maximal voiding pressure. The antimuscarinic agent propiverine significantly decreased maximal voiding pressure but did not affect the intercontraction interval or voided volume in rats with acetic acid induced bladder overactivity. In normal rats JTS-653 showed no significant effects on the intercontraction interval, voided volume or maximal voiding pressure. JTS-653 did not affect carbachol induced contraction of the bladder muscle. CONCLUSIONS: Our findings suggest that TRPV1 is involved in bladder overactivity via afferent nerve activation but it is not associated with normal voiding function. A TRPV1 antagonist would be a useful drug for bladder overactivity with a different pharmacological profile than antimuscarinic agents.

Discovery of a potent and short-acting oral calcilytic with a pulsatile secretion of parathyroid hormone.

Short-acting oral calcilytics, calcium-sensing receptor (CaSR) antagonists, have been considered as alternatives for parathyroid hormone (PTH), an injectable bone anabolic drug used in the treatment of osteoporosis. Previously, we identified aminopropandiol 1, which transiently stimulated endogenous PTH secretion in rats. However, the inhibition of cytochrome P450 (CYP) 2D6 and the low bioavailability of 1 remain to be solved. Attempts to change the physicochemical properties of the highly lipophilic amine 1 by introduction of a carboxylic acid group as well as further structural modifications led to the discovery of the highly potent biphenylcarboxylic acid 15, with a markedly reduced CYP2D6 inhibition and a significantly improved bioavailability. Compound 15 evoked a rapid and transient elevation of endogenous PTH levels in rats after oral administration in a dose-dependent manner at a dose as low as 1 mg/kg. The PTH secretion pattern correlated with the pharmacokinetic profile and agreed well with that of the exogenous PTH injection which exerts a bone anabolic effect.