Aldosterone-producing adenomas (APAs) are benign tumors of the adrenal gland that constitutively produce the salt-retaining steroid hormone aldosterone and cause millions of cases of severe hypertension worldwide. Either of 2 somatic mutations in the potassium channel KCNJ5 (G151R and L168R, hereafter referred to as KCNJ5MUT) in adrenocortical cells account for half of APAs worldwide. These mutations alter channel selectivity to allow abnormal Na+ conductance, resulting in membrane depolarization, calcium influx, aldosterone production, and cell proliferation. Because APA diagnosis requires a difficult invasive procedure, patients often remain undiagnosed and inadequately treated. Inhibitors of KCNJ5MUT could allow noninvasive diagnosis and therapy of APAs carrying KCNJ5 mutations. Here, we developed a high-throughput screen for rescue of KCNJ5MUT-induced lethality and identified a series of macrolide antibiotics, including roxithromycin, that potently inhibit KCNJ5MUT, but not KCNJ5WT. Electrophysiology demonstrated direct KCNJ5MUT inhibition. In human aldosterone-producing adrenocortical cancer cell lines, roxithromycin inhibited KCNJ5MUT-induced induction of CYP11B2 (encoding aldosterone synthase) expression and aldosterone production. Further exploration of macrolides showed that KCNJ5MUT was similarly selectively inhibited by idremcinal, a macrolide motilin receptor agonist, and by synthesized macrolide derivatives lacking antibiotic or motilide activity. Macrolide-derived selective KCNJ5MUT inhibitors thus have the potential to advance the diagnosis and treatment of APAs harboring KCNJ5MUT.
Ute I. Scholl, Laura Abriola, Chengbiao Zhang, Esther N. Reimer, Mark Plummer, Barbara I. Kazmierczak, Junhui Zhang, Denton Hoyer, Jane S. Merkel, Wenhui Wang, Richard P. Lifton
The quantity and activation state of adipose tissue macrophages (ATMs) impact the development of obesity-induced metabolic diseases. Appetite-controlling hormones play key roles in obesity; however, our understanding of their effects on ATMs is limited. Here, we have shown that human and mouse ATMs express NPFFR2, a receptor for the appetite-reducing neuropeptide FF (NPFF), and that NPFFR2 expression is upregulated by IL-4, an M2-polarizing cytokine. Plasma levels of NPFF decreased in obese patients and high-fat diet–fed mice and increased following caloric restriction. NPFF promoted M2 activation and increased the proliferation of murine and human ATMs. Both M2 activation and increased ATM proliferation were abolished in NPFFR2-deficient ATMs. Mechanistically, the effects of NPFF involved the suppression of E3 ubiquitin ligase RNF128 expression, resulting in enhanced stability of phosphorylated STAT6 and increased transcription of the M2 macrophage–associated genes IL-4 receptor α (Il4ra), arginase 1 (Arg1), IL-10 (Il10), and alkylglycerol monooxygenase (Agmo). NPFF induced ATM proliferation concomitantly with the increase in N-Myc downstream-regulated gene 2 (Ndrg2) expression and suppressed the transcription of Ifi200 cell-cycle inhibitor family members and MAF bZIP transcription factor B (Mafb), a negative regulator of macrophage proliferation. NPFF thus plays an important role in supporting healthy adipose tissue via the maintenance of metabolically beneficial ATMs.
Syed F. Hassnain Waqas, Anh Cuong Hoang, Ya-Tin Lin, Grace Ampem, Hind Azegrouz, Lajos Balogh, Julianna Thuróczy, Jin-Chung Chen, Ivan C. Gerling, Sorim Nam, Jong-Seok Lim, Juncal Martinez-Ibañez, José T. Real, Stephan Paschke, Raphaëlle Quillet, Safia Ayachi, Frédéric Simonin, E. Marion Schneider, Jacqueline A. Brinkman, Dudley W. Lamming, Christine M. Seroogy, Tamás Röszer
Loss of first-phase insulin secretion is an early sign of developing type 2 diabetes (T2D). Ca2+ entry through voltage-gated L-type Ca2+ channels triggers exocytosis of insulin-containing granules in pancreatic β cells and is required for the postprandial spike in insulin secretion. Using high-resolution microscopy, we have identified a subset of docked insulin granules in human β cells and rat-derived clonal insulin 1 (INS1) cells for which localized Ca2+ influx triggers exocytosis with high probability and minimal latency. This immediately releasable pool (IRP) of granules, identified both structurally and functionally, was absent in β cells from human T2D donors and in INS1 cells cultured in fatty acids that mimic the diabetic state. Upon arrival at the plasma membrane, IRP granules slowly associated with 15 to 20 L-type channels. We determined that recruitment depended on a direct interaction with the synaptic protein Munc13, because expression of the II–III loop of the channel, the C2 domain of Munc13-1, or of Munc13-1 with a mutated C2 domain all disrupted L-type channel clustering at granules and ablated fast exocytosis. Thus, rapid insulin secretion requires Munc13-mediated recruitment of L-type Ca2+ channels in close proximity to insulin granules. Loss of this organization underlies disturbed insulin secretion kinetics in T2D.
Nikhil R. Gandasi, Peng Yin, Michela Riz, Margarita V. Chibalina, Giuliana Cortese, Per-Eric Lund, Victor Matveev, Patrik Rorsman, Arthur Sherman, Morten G. Pedersen, Sebastian Barg
The clinical utility of inhibiting cytochrome P450 17A1 (CYP17), a cytochrome p450 enzyme that is required for the production of androgens, has been exemplified by the approval of abiraterone for the treatment of castration-resistant prostate cancer (CRPC). Recently, however, it has been reported that CYP17 inhibitors can interact directly with the androgen receptor (AR). A phase I study recently reported that seviteronel, a CYP17 lyase–selective inhibitor, demonstrated a sustained reduction in prostate-specific antigen in a patient with CRPC, and another study showed seviteronel’s direct effects on AR function. This suggested that seviteronel may have therapeutically relevant activities in addition to its ability to inhibit androgen production. Here, we have demonstrated that CYP17 inhibitors, with the exception of orteronel, can function as competitive AR antagonists. Conformational profiling revealed that the CYP17 inhibitor–bound AR adopted a conformation that resembled the unliganded AR (apo-AR), precluding nuclear localization and DNA binding. Further, we observed that seviteronel and abiraterone inhibited the growth of tumor xenografts expressing the clinically relevant mutation AR-F876L and that this activity could be attributed entirely to competitive AR antagonism. The results of this study suggest that the ability of CYP17 inhibitors to directly antagonize the AR may contribute to their clinical efficacy in CRPC.
John D. Norris, Stephanie J. Ellison, Jennifer G. Baker, David B. Stagg, Suzanne E. Wardell, Sunghee Park, Holly M. Alley, Robert M. Baldi, Alexander Yllanes, Kaitlyn J. Andreano, James P. Stice, Scott A. Lawrence, Joel R. Eisner, Douglas K. Price, William R. Moore, William D. Figg, Donald P. McDonnell
Despite the benefit of insulin, blockade of autoimmune attack and regeneration of pancreatic islets are ultimate goals for the complete cure of type 1 diabetes (T1D). Long-term consumption of ω-3 polyunsaturated fatty acids (PUFAs) is known to suppress inflammatory processes, making these fatty acids candidates for the prevention and amelioration of autoimmune diseases. Here, we explored the preventative and therapeutic effects of ω-3 PUFAs on T1D. In NOD mice, dietary intervention with ω-3 PUFAs sharply reduced the incidence of T1D, modulated the differentiation of Th cells and Tregs, and decreased the levels of IFN-γ, IL-17, IL-6, and TNF-α. ω-3 PUFAs exerted similar effects on the differentiation of CD4+ T cells isolated from human peripheral blood mononuclear cells. The regulation of CD4+ T cell differentiation was mediated at least in part through ω-3 PUFA eicosanoid derivatives and by mTOR complex 1 (mTORC1) inhibition. Importantly, therapeutic intervention in NOD mice through nutritional supplementation or lentivirus-mediated expression of an ω-3 fatty acid desaturase, m
Xinyun Bi, Fanghong Li, Shanshan Liu, Yan Jin, Xin Zhang, Tao Yang, Yifan Dai, Xiaoxi Li, Allan Zijian Zhao
It is well established that somatic genomic changes can influence phenotypes in cancer, but the role of adaptive changes in developmental disorders is less well understood. Here we have used next-generation sequencing approaches to identify de novo heterozygous mutations in sterile α motif domain–containing protein 9 (
Federica Buonocore, Peter Kühnen, Jenifer P. Suntharalingham, Ignacio Del Valle, Martin Digweed, Harald Stachelscheid, Noushafarin Khajavi, Mohammed Didi, Angela F. Brady, Oliver Blankenstein, Annie M. Procter, Paul Dimitri, Jerry K.H. Wales, Paolo Ghirri, Dieter Knöbl, Brigitte Strahm, Miriam Erlacher, Marcin W. Wlodarski, Wei Chen, George K. Kokai, Glenn Anderson, Deborah Morrogh, Dale A. Moulding, Shane A. McKee, Charlotte M. Niemeyer, Annette Grüters, John C. Achermann
Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant neuromuscular disorder that is characterized by extreme variability in symptoms, with females being less severely affected than males and presenting a higher proportion of asymptomatic carriers. The sex-related factors involved in the disease are not known. Here, we have utilized myoblasts isolated from FSHD patients (FSHD myoblasts) to investigate the effect of estrogens on muscle properties. Our results demonstrated that estrogens counteract the differentiation impairment of FSHD myoblasts without affecting cell proliferation or survival. Estrogen effects are mediated by estrogen receptor β (ERβ), which reduces chromatin occupancy and transcriptional activity of double homeobox 4 (DUX4), a protein whose aberrant expression has been implicated in FSHD pathogenesis. During myoblast differentiation, we observed that the levels and activity of DUX4 increased progressively and were associated with its enhanced recruitment in the nucleus. ERβ interfered with this recruitment by relocalizing DUX4 in the cytoplasm. This work identifies estrogens as a potential disease modifier that underlie sex-related differences in FSHD by protecting against myoblast differentiation impairments in this disease.
Emanuela Teveroni, Marsha Pellegrino, Sabrina Sacconi, Patrizia Calandra, Isabella Cascino, Stefano Farioli-Vecchioli, Angela Puma, Matteo Garibaldi, Roberta Morosetti, Giorgio Tasca, Enzo Ricci, Carlo Pietro Trevisan, Giuliana Galluzzi, Alfredo Pontecorvi, Marco Crescenzi, Giancarlo Deidda, Fabiola Moretti
Obesity causes insulin resistance, and PPARγ ligands such as rosiglitazone are insulin sensitizing, yet the mechanisms remain unclear. In C57BL/6 (B6) mice, obesity induced by a high-fat diet (HFD) has major effects on visceral epididymal adipose tissue (eWAT). Here, we report that HFD-induced obesity in B6 mice also altered the activity of gene regulatory elements and genome-wide occupancy of PPARγ. Rosiglitazone treatment restored insulin sensitivity in obese B6 mice, yet, surprisingly, had little effect on gene expression in eWAT. However, in subcutaneous inguinal fat (iWAT), rosiglitazone markedly induced molecular signatures of brown fat, including the key thermogenic gene
Raymond E. Soccio, Zhenghui Li, Eric R. Chen, Yee Hoon Foong, Kiara K. Benson, Joanna R. Dispirito, Shannon E. Mullican, Matthew J. Emmett, Erika R. Briggs, Lindsey C. Peed, Richard K. Dzeng, Carlos J. Medina, Jennifer F. Jolivert, Megan Kissig, Satyajit R. Rajapurkar, Manashree Damle, Hee-Woong Lim, Kyoung-Jae Won, Patrick Seale, David J. Steger, Mitchell A. Lazar
MicroRNAs (miRNAs) are negative modulators of gene expression that fine-tune numerous biological processes. miRNA loss-of-function rarely results in highly penetrant phenotypes, but rather, influences cellular responses to physiologic and pathophysiologic stresses. Here, we have reported that a single member of the evolutionarily conserved miR-7 family, miR-7a2, is essential for normal pituitary development and hypothalamic-pituitary-gonadal (HPG) function in adulthood. Genetic deletion of
Kashan Ahmed, Mary P. LaPierre, Emanuel Gasser, Rémy Denzler, Yinjie Yang, Thomas Rülicke, Jukka Kero, Mathieu Latreille, Markus Stoffel
Primary adrenal insufficiency is life threatening and can present alone or in combination with other comorbidities. Here, we have described a primary adrenal insufficiency syndrome and steroid-resistant nephrotic syndrome caused by loss-of-function mutations in sphingosine-1-phosphate lyase (SGPL1). SGPL1 executes the final decisive step of the sphingolipid breakdown pathway, mediating the irreversible cleavage of the lipid-signaling molecule sphingosine-1-phosphate (S1P). Mutations in other upstream components of the pathway lead to harmful accumulation of lysosomal sphingolipid species, which are associated with a series of conditions known as the sphingolipidoses. In this work, we have identified 4 different homozygous mutations, c.665G>A (p.R222Q), c.1633_1635delTTC (p.F545del), c.261+1G>A (p.S65Rfs*6), and c.7dupA (p.S3Kfs*11), in 5 families with the condition. In total, 8 patients were investigated, some of whom also manifested other features, including ichthyosis, primary hypothyroidism, neurological symptoms, and cryptorchidism.
Rathi Prasad, Irene Hadjidemetriou, Avinaash Maharaj, Eirini Meimaridou, Federica Buonocore, Moin Saleem, Jenny Hurcombe, Agnieszka Bierzynska, Eliana Barbagelata, Ignacio Bergadá, Hamilton Cassinelli, Urmi Das, GOSgene, Ruth Krone, Bulent Hacihamdioglu, Erkan Sari, Ediz Yesilkaya, Helen L. Storr, Maria Clemente, Monica Fernandez-Cancio, Nuria Camats, Nanik Ram, John C. Achermann, Paul P. Van Veldhoven, Leonardo Guasti, Debora Braslavsky, Tulay Guran, Louise A. Metherell