TRPC5 controls the adrenaline-mediated counter regulation of hypoglycemia.

Hypoglycemia triggers autonomic and endocrine counter-regulatory responses to restore glucose homeostasis, a response that is impaired in patients with diabetes and its long-term complication hypoglycemia-associated autonomic failure (HAAF). We show that insulin-evoked hypoglycemia is severely aggravated in mice lacking the cation channel proteins TRPC1, TRPC4, TRPC5, and TRPC6, which cannot be explained by alterations in glucagon or glucocorticoid action. By using various TRPC compound knockout mouse lines, we pinpointed the failure in sympathetic counter-regulation to the lack of the TRPC5 channel subtype in adrenal chromaffin cells, which prevents proper adrenaline rise in blood plasma. Using electrophysiological analyses, we delineate a previously unknown signaling pathway in which stimulation of PAC1 or muscarinic receptors activates TRPC5 channels in a phospholipase-C-dependent manner to induce sustained adrenaline secretion as a crucial step in the sympathetic counter response to insulin-induced hypoglycemia. By comparing metabolites in the plasma, we identified reduced taurine levels after hypoglycemia induction as a commonality in TRPC5-deficient mice and HAAF patients.

Influence of new treatment modalities on adherence in glaucoma.

PURPOSE OF REVIEW: It is well known that glaucoma patients are not adherent to their therapeutic regimens. The issue of nonadherence is multifactorial and includes inadequate communication between doctors and patients, resulting in significant costs associated with enhanced disease progression. Therapeutic regimens are risk factors which often influences adherence rates. Thus, alternative treatment modalities, especially those risk factors that do not rely on patients' cooperation, may enable improvements in long-term outcomes of glaucoma in patient. RECENT FINDINGS: The studies selected for this review were divided into new medications, especially advancements in pharmaceutical approaches to treat glaucoma and new ways of delivering the medication, new surgical methods, especially minimally invasive surgery methods for glaucoma, and new studies about adherence in glaucoma. SUMMARY: Surprisingly, a very few studies on glaucoma medication or surgery addressed the concept of adherence. However, adherence is discussed in studies which consider psychological aspects of patients or communication issues between doctors and patients. Although these studies were performed in clinical settings, the issue of adherence is not addressed; despite it has significant effect on long-term outpatient care. A combination of both aspects, adherence and miscommunication, should be considered in studies.

Twenty-four hour intraocular pressure measurements and home tonometry.

PURPOSE OF REVIEW: IOP is the only treatable risk factor contributing to glaucoma and most management and treatment of glaucoma is based on IOP. However, current IOP measurements are limited to office hours and control of glaucoma in many patients would benefit from the ability to monitor IOP diurnally so as not to miss abnormal pressures, which occur outside of office hours Consequently, to improve patient care, the ability to enable accurate and minimally disruptive diurnal IOP monitoring would improve caring for these patients. RECENT FINDINGS: The studies we selected for this review can be divided into three categories: self-/home-tonometry, continuous invasive intraocular pressure measurements, and continuous noninvasive ocular measurements. SUMMARY: The desire to obtain better insight in our patients' true diurnal IOP has led to the development of home-tonometers, in addition to extraocular and intraocular continuous pressure measurement devices. All of the devices have respective advantages and disadvantages, but none to date completely fulfills the goal of providing a true diurnal IOP profile.Video abstracthttp://links.lww.com/COOP/A27.

Increasing healthcare costs: can we influence the costs of glaucoma care?

PURPOSE OF REVIEW: Despite a decrease in real average growth rates per capita since 2009, healthcare costs continue to rise worldwide. Numerous patient-related and doctor-related factors have contributed to this rise. Glaucoma is the leading cause of irreversible blindness and requires chronic, usually lifelong treatment. As with other chronic diseases, the adherence to prescribed treatment is often low and maybe influenced by the cost of the therapy. The purpose of this review is to seek potential solutions to best control the escalating costs of glaucoma care. RECENT FINDINGS: The studies we selected for this review can be divided into four different categories: costs of diagnostic tests; costs of direct comparisons between drugs or laser and conventional surgery; patient-related factors (such as adherence); and general aspects regarding costs: theoretical models and calculations. SUMMARY: It is challenging to find reliable studies concerning this subject matter. As patients are under the umbrellas of variously organized healthcare systems which span different cultures, the costs between countries are difficult to compare. However, one common aspect to lower costs in glaucoma care is to improve patient adherence. Theoretical models with actual patient studies could enable cost reductions by comparing multiple diagnostic and therapeutic scenarios. VIDEO ABSTRACT: http://links.lww.com/COOP/A22.

OCaR1 endows exocytic vesicles with autoregulatory competence by preventing uncontrolled Ca2+ release, exocytosis, and pancreatic tissue damage.

Regulated exocytosis is initiated by increased Ca2+ concentrations in close spatial proximity to secretory granules, which is effectively prevented when the cell is at rest. Here we showed that exocytosis of zymogen granules in acinar cells was driven by Ca2+ directly released from acidic Ca2+ stores including secretory granules through NAADP-activated two-pore channels (TPCs). We identified OCaR1 (encoded by Tmem63a) as an organellar Ca2+ regulator protein integral to the membrane of secretory granules that controlled Ca2+ release via inhibition of TPC1 and TPC2 currents. Deletion of OCaR1 led to extensive Ca2+ release from NAADP-responsive granules under basal conditions as well as upon stimulation of GPCR receptors. Moreover, OCaR1 deletion exacerbated the disease phenotype in murine models of severe and chronic pancreatitis. Our findings showed OCaR1 as a gatekeeper of Ca2+ release that endows NAADP-sensitive secretory granules with an autoregulatory mechanism preventing uncontrolled exocytosis and pancreatic tissue damage.

PROTACs Targeting BRM (SMARCA2) Afford Selective In Vivo Degradation over BRG1 (SMARCA4) and Are Active in BRG1 Mutant Xenograft Tumor Models.

The identification of VHL-binding proteolysis targeting chimeras (PROTACs) that potently degrade the BRM protein (also known as SMARCA2) in SW1573 cell-based experiments is described. These molecules exhibit between 10- and 100-fold degradation selectivity for BRM over the closely related paralog protein BRG1 (SMARCA4). They also selectively impair the proliferation of the H1944 "BRG1-mutant" NSCLC cell line, which lacks functional BRG1 protein and is thus highly dependent on BRM for growth, relative to the wild-type Calu6 line. In vivo experiments performed with a subset of compounds identified PROTACs that potently and selectively degraded BRM in the Calu6 and/or the HCC2302 BRG1 mutant NSCLC xenograft models and also afforded antitumor efficacy in the latter system. Subsequent PK/PD analysis established a need to achieve strong BRM degradation (>95%) in order to trigger meaningful antitumor activity in vivo. Intratumor quantitation of mRNA associated with two genes whose transcription was controlled by BRM (PLAU and KRT80) also supported this conclusion.

Bicyclic and tricyclic heterocycle derivatives as histamine H3 receptor antagonists for the treatment of obesity.

A novel series of non-imidazole bicyclic and tricyclic histamine H3 receptor antagonists has been discovered. Compound 17 was identified as a centrally penetrant molecule with high receptor occupancy which demonstrates robust oral activity in rodent models of obesity. In addition compound 17 possesses clean CYP and hERG profiles and shows no behavioral changes in the Irwin test.

Synthesis and SAR studies of benzimidazolone derivatives as histamine H3-receptor antagonists.

A novel series of benzimidazolone-containing histamine H3-receptor antagonists were prepared and their structure-activity relationship was explored. These benzimidazolone analogs demonstrate potent H3-receptor binding affinities, no P450 enzyme inhibition, and strong H3 functional activity. Compound 1o exhibits the best overall profile with H3Ki=0.95nM and rat AUC=12.9µMh.

Development of Liposome Systems for Enhancing the PK Properties of Bivalent PROTACs.

Proteolysis-Targeting Chimeras (PROTACs) are a promising new technology in drug development. They have rapidly evolved in recent years, with several of them in clinical trials. While most of these advances have been associated with monovalent protein degraders, bivalent PROTACs have also entered clinical trials, although progression to market has been limited. One of the reasons is the complex physicochemical properties of the heterobifunctional PROTACs. A promising strategy to improve pharmacokinetics of highly lipophilic compounds, such as PROTACs, is encapsulation in liposome systems. Here we describe liposome systems for intravenous administration to enhance the PK properties of two bivalent PROTAC molecules, by reducing clearance and increasing systemic coverage. We developed and characterized a PROTAC-in-cyclodextrin liposome system where the drug was retained in the liposome core. In PK studies at 1 mg/kg for GNE-01 the PROTAC-in-cyclodextrin liposome, compared to the solution formulation, showed a 80- and a 380-fold enhancement in AUC for mouse and rat studies, respectively. We further investigated the same PROTAC-in-cyclodextrin liposome system with the second PROTAC (GNE-02), where we monitored both lipid and drug concentrations in vivo. Similarly, in a mouse PK study of GEN-02, the PROTAC-in-cyclodextrin liposome system exhibited enhancement in plasma concentration of a 23× increase over the conventional solution formulation. Importantly, the lipid CL correlated with the drug CL. Additionally, we investigated a conventional liposome approach for GNE-02, where the PROTAC resides in the lipid bilayer. Here, a 5× increase in AUC was observed, compared to the conventional solution formulation, and the drug CL was faster than the lipid CL. These results indicate that the different liposome systems can be tailored to translate across multiple PROTAC systems to modulate and improve plasma concentrations. Optimization of the liposomes could further improve tumor concentration and improve the overall therapeutic index (TI). This delivery technology may be well suited to bring novel protein targeted PROTACs into clinics.

Steroidal C-21 heteroaryl thioethers (Part 2): discovery of orally bioavailable selective glucocorticoid receptor modulators (dissociated steroids).

The prednisolone C-21 heteroaryl thioethers have been synthesized and evaluated in cell based transrepression and transactivation assays. Most of the compounds demonstrated weak transactivational activity in both human and rat tyrosineaminotransferase functional assay while keeping potent anti-inflammatory activity. The benzimidazole thioether 7 exhibited comparable anti-inflammatory activity and improved safety profile compared to the classical oral steroid prednisolone.

Steroidal C-21 heteroaryl thioethers. Part 3: pregn-4-eno-[3,2-c]pyrazole fused A ring modified steroids as selective glucocorticoid receptor modulators (dissociated steroids).

The introduction of A ring pyrazole modification to the hydrocortisone C-21 heteroaryl thioethers generated compounds with excellent transrepression potency (IL-8 inhibition) compared to their hydrocortisone analogs. However, the transcriptional transactivation activity of these compounds were considerably higher than the corresponding hydrocortisone analogs. Among all the compounds evaluated, a quinoxaline thioether modification demonstrated the best overall in vitro separation.

Advances in Excimer Laser Trabeculostomy within the Landscape of Minimally-Invasive Glaucoma Surgery.

Primary open-angle glaucoma (POAG) is currently treated with a variety of surgical and non-surgical approaches. Minimally invasive glaucoma surgery (MIGS) involves several devices and procedures that lower intraocular pressure (IOP) by increasing aqueous outflow. The first laser-based MIGS procedure, Excimer Laser Trabeculostomy (ELT), has emerged as a safe and effective treatment option. This article reviews ELT within the context of alternative MIGS procedures and focuses on the historical development of ELT, principles and techniques of the ELT procedure, safety and efficacy data, comparison to other outflow procedures, and future augmentations to expand the use of ELT. Performed alone or as an adjunct to cataract surgery, ELT has minimal complications and has shown long-term effectiveness in lowering intraocular pressure in thousands of patients. The non-thermal laser-tissue interactions of excimer lasers minimize peripheral tissue damage and ensure outflow channel patency without requiring foreign body implants or creating blebs. The development of 2D optical and 3D optical coherence tomography (OCT) guidance systems will eliminate the need for a goniolens to visualize angle structures and enable thousands more surgeons to perform ELT in the future.

Eight-year follow-up of excimer laser trabeculostomy alone and combined with phacoemulsification in patients with open-angle glaucoma.

PURPOSE: To describe the 8-year results of excimer laser trabeculostomy (ELT) alone and ELT in conjunction with phacoemulsification (phaco). SETTING: University hospital. DESIGN: Retrospective review. METHODS: 308 nm excimer laser energy delivered through an intraocular fiber-optic probe created channels through the inner wall of Schlemm canal. 2 groups were studied: ELT alone and ELT + phaco. Inclusion criteria were adult patients with open-angle glaucoma or ocular hypertension on 1 or more intraocular pressure (IOP)-lowering medications and, in the ELT + phaco group, presence of visually significant cataract. Primary outcome measures were change of IOP from baseline and number of IOP-lowering medications. RESULTS: 164 eyes in 2 groups, ELT alone (n = 90) and ELT + phaco (n = 74), were followed up for 8 years. Baseline IOP was 22.17 ± 7.0 mm Hg and 21.9 ± 6.44 mm Hg in the ELT alone and the ELT + phaco groups, respectively. IOP in the ELT alone group decreased to 16.84 ± 5.2 mm Hg at 1 year (n = 69) and remained at 15.9 ± 3.5 (n = 19) at 8 years. IOP in the ELT + phaco group was 14.04 ± 4.1 mm Hg at 1 year (n = 63) and 13.7 ± 2.8 mm Hg at 8 years (n = 13). The number of IOP-lowering medications at baseline in the ELT alone group was 1.85 ± 0.8 and decreased to 1.19 ± 1.10 at 1 year and 1.4 ± 1.4 at 8 years. In the ELT + phaco group, it was 1.58 ± 0.8 at baseline and decreased to 0.97 ± 0.95 at 1 year and 1.85 ± 0.7 at 8 years. CONCLUSIONS: ELT demonstrated long-term IOP lowering and decrease in the number of IOP-lowering medications. Benefits of this laser-based implant-free microinvasive glaucoma surgery procedure included a high safety profile and long-term efficacy.

Selective PROTAC-mediated degradation of SMARCA2 is efficacious in SMARCA4 mutant cancers.

The mammalian SWItch/Sucrose Non-Fermentable (SWI/SNF) helicase SMARCA4 is frequently mutated in cancer and inactivation results in a cellular dependence on its paralog, SMARCA2, thus making SMARCA2 an attractive synthetic lethal target. However, published data indicates that achieving a high degree of selective SMARCA2 inhibition is likely essential to afford an acceptable therapeutic index, and realizing this objective is challenging due to the homology with the SMARCA4 paralog. Herein we report the discovery of a potent and selective SMARCA2 proteolysis-targeting chimera molecule (PROTAC), A947. Selective SMARCA2 degradation is achieved in the absence of selective SMARCA2/4 PROTAC binding and translates to potent in vitro growth inhibition and in vivo efficacy in SMARCA4 mutant models, compared to wild type models. Global ubiquitin mapping and proteome profiling reveal no unexpected off-target degradation related to A947 treatment. Our study thus highlights the ability to transform a non-selective SMARCA2/4-binding ligand into a selective and efficacious in vivo SMARCA2-targeting PROTAC, and thereby provides a potential new therapeutic opportunity for patients whose tumors contain SMARCA4 mutations.

Steroidal C-21 mercapto derivatives as dissociated steroids: discovery of an inhaled dissociated steroid.

A series of C-21 mercapto derivatives of hydrocortisone have been synthesized and evaluated in cell based transrepression and transactivation assays. The benzothiazole derivative, compound 6 not only showed a dissociated profile in vitro functional assays but also a pharmacological profile in a Brown-Norway rat therapeutic index model of asthma that dissociated side effects (thymolysis) while maintaining efficacy against pulmonary inflammation and lung function.

Reduction of hERG inhibitory activity in the 4-piperidinyl urea series of H3 antagonists.

Structural features of the substituted 4-piperidinyl urea analogs 1, responsible for the H3 antagonist activity, have been identified. Structure-activity relationship of the H3 receptor affinity, hERG ion channel inhibitory activity and their separation is described. Preliminary pharmacokinetic evaluation of the compounds of the series is addressed.

Cardiomyocyte-Specific Deletion of Orai1 Reveals Its Protective Role in Angiotensin-II-Induced Pathological Cardiac Remodeling.

Pathological cardiac remodeling correlates with chronic neurohumoral stimulation and abnormal Ca2+ signaling in cardiomyocytes. Store-operated calcium entry (SOCE) has been described in adult and neonatal murine cardiomyocytes, and Orai1 proteins act as crucial ion-conducting constituents of this calcium entry pathway that can be engaged not only by passive Ca2+ store depletion but also by neurohumoral stimuli such as angiotensin-II. In this study, we, therefore, analyzed the consequences of Orai1 deletion for cardiomyocyte hypertrophy in neonatal and adult cardiomyocytes as well as for other features of pathological cardiac remodeling including cardiac contractile function in vivo. Cellular hypertrophy induced by angiotensin-II in embryonic cardiomyocytes from Orai1-deficient mice was blunted in comparison to cells from litter-matched control mice. Due to lethality of mice with ubiquitous Orai1 deficiency and to selectively analyze the role of Orai1 in adult cardiomyocytes, we generated a cardiomyocyte-specific and temporally inducible Orai1 knockout mouse line (Orai1CM-KO). Analysis of cardiac contractility by pressure-volume loops under basal conditions and of cardiac histology did not reveal differences between Orai1CM-KO mice and controls. Moreover, deletion of Orai1 in cardiomyocytes in adult mice did not protect them from angiotensin-II-induced cardiac remodeling, but cardiomyocyte cross-sectional area and cardiac fibrosis were enhanced. These alterations in the absence of Orai1 go along with blunted angiotensin-II-induced upregulation of the expression of Myoz2 and a lack of rise in angiotensin-II-induced STIM1 and Orai3 expression. In contrast to embryonic cardiomyocytes, where Orai1 contributes to the development of cellular hypertrophy, the results obtained from deletion of Orai1 in the adult myocardium reveal a protective function of Orai1 against the development of angiotensin-II-induced cardiac remodeling, possibly involving signaling via Orai3/STIM1-calcineurin-NFAT related pathways.

Ocular hypotensive effect of the novel EP3/FP agonist ONO-9054 versus Xalatan: results of a 28-day, double-masked, randomised study.

BACKGROUND/AIMS: ONO-9054 is being developed for the reduction of intraocular pressure (IOP) in patients with ocular hypertension (OHT) and open-angle glaucoma (OAG). This study compared the novel dual EP3/FP agonist ONO-9054 with the FP agonist Xalatan. METHODS: Adults (n=123) with bilateral mild/moderate OAG or OHT, with unmedicated IOP of ≥24 mm Hg at 8:00 hours, ≥21 mm Hg at 10:00 hours and ≤36 mm Hg, were randomised 1:1 to receive ONO-9054 (0.003%, 30 µg/mL) or Xalatan (0.005%, 50 µg/mL) once daily for 28 days. RESULTS: Day 29 mean diurnal IOP was -7.2 mm Hg for ONO-9054 vs -6.6 mm Hg for Xalatan. At 08:00 hours, the IOPs were comparable, and at all later time points the decrease in IOP was greater for ONO-9054. On day 29, the odds of a mean IOP reduction of ≤-25%, ≤-30% and ≤-35% for ONO-9054 were 2.39, 2.37 and 4.85 times more, respectively, than the odds for Xalatan (p<0.05, post hoc analyses). The percentage of subjects achieving target IOPs on day 29 (≤17, ≤16 and ≤15 mm Hg) was greater for ONO-9054 than for Xalatan; the odds of achieving an IOP ≤15 mm Hg for ONO-9054 were 2.4 times more than the odds for Xalatan (p<0.01, post hoc analysis). CONCLUSIONS: Subjects randomised to receive ONO-9054 were more likely to achieve a greater per cent reduction in IOP and were more likely to achieve target IOPs than those receiving Xalatan. The effects of ONO-9054 in reducing IOP appear to persist longer than those of Xalatan. TRIAL REGISTRATION NUMBER: NCT02083289, Results.

EP3/FP dual receptor agonist ONO-9054 administered morning or evening to patients with open-angle glaucoma or ocular hypertension: results of a randomised crossover study.

BACKGROUND/AIMS: The novel prostaglandin E (EP) 3 and prostaglandin F (FP) receptor agonist ONO-9054 is effective in lowering intraocular pressure (IOP) in patients with ocular hypertension and open-angle glaucoma when administered once daily. This study compares the effects of morning (AM) versus evening (PM) dosing of ONO-9054 on tolerability and IOP lowering. METHODS: This was a single-centre, randomised, double-masked, two-sequence, placebo-controlled crossover study in 12 subjects with bilateral primary open-angle glaucoma or ocular hypertension. Two 14-day crossover regimens were separated by a 2-week washout: ONO-9054 (1 drop to each eye) in the morning (07:00) and vehicle in the evening (19:00) and vice versa. IOP was measured multiple times during select days. Ocular examinations also evaluated safety and tolerability. RESULTS: Mild ocular hyperaemia, reported by six subjects with PM dosing, was the most frequent adverse event. Mild to moderate dryness was also slightly more frequent after PM dosing. Maximum IOP reduction from baseline occurred on day 2 with decreases from baseline of -7.4 mm Hg (-30.8%) for AM dosing and -9.1 mm Hg, (-38.0%) for PM dosing; after 14 days, mean reduction in IOP was -6.8 mm Hg (-28.6%) for AM dosing and -7.5 mm Hg (-31.0%) for PM dosing. CONCLUSIONS: PM dosing of ONO-0954 was associated with a slightly increased frequency of mild hyperaemia and mild to moderate dryness. Both dosing schedules provided sustained reduction in IOP. TRIAL REGISTRATION NUMBER: NCT01670266.

Recent advances in the development of novel glucocorticoid receptor modulators.

IMPORTANCE OF THE FIELD: The glucocorticoid receptor plays a number of fundamental roles in human physiology. Glucocorticosteroids are the ultimate anti-inflammatory and immunosuppressive agents highly efficacious in the treatment of serious diseases, but also associated with serious side effects. Improvement in the therapeutic profiles of drugs, acting at the glucocorticoid receptor, is highly desired and may potentially arise from the separation of their gene transactivating and gene transrepressing properties. AREAS COVERED IN THIS REVIEW: The review summarizes progress towards novel glucocorticoid drug candidates as indicated by the patent applications over the last 2 years (2008 - 2009). A brief discussion of glucocorticoid receptor biology and previous drug candidates is included. WHAT THE READER WILL GAIN: The understanding of the structural scope and biological profiles of the glucocorticoid receptor modulators, currently in preclinical and clinical development, based on the review of approximately 180 composition-of-matter and method-of-use patent applications. TAKE HOME MESSAGE: The information on the good chemotypical diversity of glucocorticoid receptor modulators needs to be supplemented by the clinical data - presumably, soon to become available - to allow a look into a possible improvement in therapeutic index over the classic glucocorticosteroids.