ML 204

ML204 is a novel potent antagonist that selectively modulates native TRPC4/C5 ion channels. IC50 value: Target: TRPC4/C5 inhibitor ML204 inhibited TRPC4β-mediated intracellular Ca(2+) rise with an IC(50) value of 0.96 μm and exhibited 19-fold selectivity against muscarinic receptor-coupled TRPC6 channel activation. In whole-cell patch clamp recordings, ML204 blocked TRPC4β currents activated through either μ-opioid receptor stimulation or intracellular dialysis of guanosine 5'-3-O-(thio)triphosphate (GTPγS), suggesting a direct interaction of ML204 with TRPC4 channels rather than any interference with the signal transduction pathways. Selectivity studies showed no appreciable block by 10-20 μm ML204 of TRPV1, TRPV3, TRPA1, and TRPM8, as well as KCNQ2 and native voltage-gated sodium, potassium, and calcium channels in mouse dorsal root ganglion neurons. In isolated guinea pig ileal myocytes, ML204 blocked muscarinic cation currents activated by bath application of carbachol or intracellular infusion of GTPγS, demonstrating its effectiveness on native TRPC4 currents [1]. ML204 blocked TRPC4 channels in an electrophysiological assay with an IC value of 2.6 μM and was also active in fluorescent and electrophysiological assays in which TRPC4 channels were activated by different mechanisms, indicating direct block of TRPC4 channels. Selectivity for block of TRPC4 channels was examined in fluorescent and electrophysiological experiments against closely related TRPC channels and more distantly related TRPV, TRPA and TRPM channels, and against non-TRP ion channels. ML204 afforded good selectivity (19-fold) against TRPC6 channels and more modest selectivity against TRPC3 and TRPC5 (9-fold) channels [2].

References:
[1]. Miller M, et al. Identification of ML204, a novel potent antagonist that selectively modulates native TRPC4/C5 ion channels. J Biol Chem. 2011 Sep 23;286(38):33436-46. [2]. Miller MR, et al. Novel Chemical Inhibitor of TRPC4 Channels. Probe Reports from the NIH Molecular Libraries Program [Internet].

miR-204-5p acts as a tumor suppressor by targeting matrix metalloproteinases-9 and B-cell lymphoma-2 in malignant melanoma.[Pubmed:28280358]

Onco Targets Ther. 2017 Feb 27;10:1237-1246.

An increasing number of microRNAs have been found to be involved in tumorigenesis, including melanoma tumorigenesis. miR-204-5p is down-regulated and functions as a tumor suppressor in many human malignant tumors. miR-204-5p expression is also decreased in melanoma tissues, but its biological roles and molecular mechanisms in malignant melanoma remain unclear. In this study, the aberrant down-regulation of miR-204-5p was detected in melanoma, especially in metastatic melanoma. miR-204-5p also served as a protective factor for the prognosis of melanoma patients. We determined that miR-204-5p suppresses cell proliferation, migration and invasion, and promotes cell apoptosis in melanoma. Matrix metalloproteinases-9 and B-cell lymphoma-2 are the functional targets of miR-204-5p, through which it plays an important biological role in malignant melanoma. The effect of miR-204-5p on malignant melanoma is verified using a xenograft model. We also determined that miR-204-5p increases 5-fluorouracil and cisplatin (DDP) chemosensitivity in malignant melanoma cells. This finding elucidates new functions and mechanisms for miR-204-5p in melanoma development, and provides potential therapeutic targets for the treatment of melanoma.

Sus scrofa miR-204 and miR-4331 Negatively Regulate Swine H1N1/2009 Influenza A Virus Replication by Targeting Viral HA and NS, Respectively.[Pubmed:28368362]

Int J Mol Sci. 2017 Apr 3;18(4). pii: ijms18040749.

The prevalence of swine pandemic H1N1/2009 influenza A virus (SIV-H1N1/2009) in pigs has the potential to generate novel reassortant viruses, posing a great threat to human health. Cellular microRNAs (miRNAs) have been proven as promising small molecules for regulating influenza A virus replication by directly targeting viral genomic RNA. In this study, we predicted potential Sus scrofa (ssc-, swine) miRNAs targeting the genomic RNA of SIV-H1N1/2009 by RegRNA 2.0, and identified ssc-miR-204 and ssc-miR-4331 to target viral HA and NS respectively through dual-luciferase reporter assays. The messenger RNA (mRNA) levels of viral HA and NS were significantly suppressed when newborn pig trachea (NPTr) cells respectively overexpressed ssc-miR-204 and ssc-miR-4331 and were infected with SIV-H1N1/2009, whereas the suppression effect could be restored when respectively decreasing endogenous ssc-miR-204 and ssc-miR-4331 with inhibitors. Because of the importance of viral HA and NS in the life cycle of influenza A virus, ssc-miR-204 and ssc-miR-4331 exhibited an inhibition effect on SIV-H1N1/2009 replication. The antiviral effect was sequence-specific of SIV-H1N1/2009, for the target sites in HA and NS of H5N1 or H9N2 influenza A virus were not conserved. Furthermore, SIV-H1N1/2009 infection reversely downregulated the expression of ssc-miR-204 and ssc-miR-4331, which might facilitate the virus replication in the host. In summary, this work will provide us some important clues for controlling the prevalence of SIV-H1N1/2009 in pig populations.

Complications and Outcomes After Gynecomastia Surgery: Analysis of 204 Pediatric and 1583 Adult Cases from a National Multi-center Database.[Pubmed:28341949]

Aesthetic Plast Surg. 2017 Aug;41(4):761-767.

BACKGROUND: Gynecomastia is a common disease that is prevalent across all age groups of boys and men. Although benign in nature, it can lead to psychological and social distress, prompting affected patients to seek medical attention. Management strategies include observation and drug therapy, yet surgical procedures remain the hallmark of treatment. The goal of this study was to analyze patient demographics, outcomes, and complication rates of gynecomastia surgery in a large multi-institutional cohort. METHODS: We performed a retrospective analysis of the American College of Surgeons National Surgical Quality Improvement Program adult and pediatric databases to produce two cohorts that underwent gynecomastia surgical repair. The two populations were compared for comorbidities, perioperative details, and complication rates. Multivariate analyses helped detect risk factors associated with adverse events. RESULTS: A total of 204 pediatric and 1583 adult male patients were identified in our analysis. Mean ages were 15.8 and 39.6 years, respectively. A BMI of 28.2 in the latter cohort revealed an overweight adult population. Preoperative comorbidities (0.0-4.9% in children, 0.0-6.4% in adults) and American Society of Anesthesiologists scores (ASA 1 + 2: 98.5 and 82.7%) symbolized a healthy population. Procedures were subsequently performed mostly as outpatient (84.3 and 93.9%) and with short hospitalization durations (0.27 and 0.06 days). Our results demonstrated low surgical (3.9 and 1.9%) and medical (0.0 and 0.3%) complications within the standardized 30-day postoperative period. Children and adolescents, however, required double mean operative times compared to adults (111.3 vs 56.7 min). CONCLUSION: Operative gynecomastia treatment remains a safe treatment modality across all age groups. Patients with known preoperative medical or surgical comorbidities necessitate more extensive perioperative assessment and monitoring. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Identification of ML204, a novel potent antagonist that selectively modulates native TRPC4/C5 ion channels.[Pubmed:21795696]

J Biol Chem. 2011 Sep 23;286(38):33436-46.

Transient receptor potential canonical (TRPC) channels are Ca(2+)-permeable nonselective cation channels implicated in diverse physiological functions, including smooth muscle contractility and synaptic transmission. However, lack of potent selective pharmacological inhibitors for TRPC channels has limited delineation of the roles of these channels in physiological systems. Here we report the identification and characterization of ML204 as a novel, potent, and selective TRPC4 channel inhibitor. A high throughput fluorescent screen of 305,000 compounds of the Molecular Libraries Small Molecule Repository was performed for inhibitors that blocked intracellular Ca(2+) rise in response to stimulation of mouse TRPC4beta by mu-opioid receptors. ML204 inhibited TRPC4beta-mediated intracellular Ca(2+) rise with an IC(50) value of 0.96 mum and exhibited 19-fold selectivity against muscarinic receptor-coupled TRPC6 channel activation. In whole-cell patch clamp recordings, ML204 blocked TRPC4beta currents activated through either mu-opioid receptor stimulation or intracellular dialysis of guanosine 5'-3-O-(thio)triphosphate (GTPgammaS), suggesting a direct interaction of ML204 with TRPC4 channels rather than any interference with the signal transduction pathways. Selectivity studies showed no appreciable block by 10-20 mum ML204 of TRPV1, TRPV3, TRPA1, and TRPM8, as well as KCNQ2 and native voltage-gated sodium, potassium, and calcium channels in mouse dorsal root ganglion neurons. In isolated guinea pig ileal myocytes, ML204 blocked muscarinic cation currents activated by bath application of carbachol or intracellular infusion of GTPgammaS, demonstrating its effectiveness on native TRPC4 currents. Therefore, ML204 represents an excellent novel tool for investigation of TRPC4 channel function and may facilitate the development of therapeutics targeted to TRPC4.