scholarly journals A new drug candidates for glycogen storage disorders enhances glycogen catabolism: Lessons from Adult Polyglucosan Body Disease models

2021 ◽  
Author(s):  
Hilla Vaknin ◽  
Kumudesh Mishra ◽  
Jeevitha D’Souza ◽  
Monzer Marisat ◽  
Uri Sprecher ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Glycogen Storage ◽  
Cellular Level ◽  
Mitochondrial Activity ◽  
Atp Production ◽  
Drug Candidates ◽  
Polyglucosan Body ◽  
Adult Polyglucosan Body Disease ◽  
Storage Disorders

AbstractThis work employs Adult Polyglucosan Body Disease (APBD) models to explore the efficacy and mechanism of action of 144DG11, a new polyglucosan-reducing lead compound discovered by a high-throughput screen (HTS). APBD is an adult onset glycogen storage disorder (GSD) manifesting as a debilitating progressive axonopathic leukodystrophy. APBD is caused by glycogen branching enzyme (GBE) deficiency leading to poorly branched and insoluble glycogen inclusions, which precipitate as neuropathogenic polyglucosans (PG). 144DG11 led to prolonged survival and improved motor parameters in a GBE knockin (Gbeys/ys) APBD mouse model. Histopathologically, 144DG11 reduced PG and glycogen levels in brain, liver, heart, and peripheral nerve. Indirect calorimetry experiments revealed that 144DG11 increases carbohydrate burn at the expense of fat burn, suggesting metabolic mobilization of pathogenic PG. These results were also reflected at the cellular level by increased glycolytic, mitochondrial and total ATP production. Mechanistically, we show that the molecular target of 144DG11 is the lysosomal membrane protein LAMP1, whose interaction with the compound, similar to LAMP1 knockdown, enhanced autolysosomal degradation of glycogen and lysosomal acidification. Enhanced mitochondrial activity and lysosomal modifications were also the most pronounced effects of 144DG11 in APBD patient fibroblasts as discovered by image-based multiparametric phenotyping analysis and corroborated by proteomics. In summary, this work presents a broad mechanistic and target-based characterization of 144DG11 in in vivo and cell models of the prototypical GSD APBD. This investigation warrants development of 144DG11 into a safe and efficacious GSD therapy.One Sentence SummaryA new compound, demonstrated to ameliorate APBD in vivo and ex vivo by autophagic catabolism of glycogen, may potentially become a universal drug for glycogen storage disorders.

Glycogen Storage Disorders

2016 ◽  
Author(s):  
David Cassiman ◽  
Pascal Laforêt ◽  
Fanny Mochel
Keyword(s):  
Axonal Neuropathy ◽  
Glycogen Storage ◽  
Exercise Intolerance ◽  
Polyglucosan Body ◽  
Major Energy Source ◽  
Cns Effects ◽  
The Brain ◽  
Adult Polyglucosan Body Disease ◽  
Storage Disorders ◽  
Gsd Ii

Glucose is the body’s major energy source, and carbohydrate serves as fuel—particularly during high-intensity exercise that requires rapid energy release. A deficiency of any of the enzymes involved in the catabolism of glycogen to glucose may cause symptoms, with hypoglycemia and exercise intolerance as the most common presentations. Glycogen storage disorders (GSD) affect muscle, liver, and brain. The most common GSDs affecting muscle are GSD II (Pompe disease) and GSD V (McArdle disease). GSDs affecting mainly the liver are GSD I, III, IV, VI, IX, XI. Most liver-GSDs present during infancy, with symptoms of hypoglycemia, impressive hepatomegaly, and retarded growth. Adult presentations have been reported for GSD Ia, III, IV, and IX.Adult polyglucosan body disease (APBD) is the main GSD affecting primarily the brain and mainly characterized by spastic paraplegia, axonal neuropathy and leukodystrophy. APBD is a subtype of GSD IV and is due to a deficiency of glycogen branching enzyme (GBE). Besides GSD IV, other GSDs have been reported to have CNS effects in some patients—notably GSD II and GSD III.

scholarly journals hPSC-Derived Enteric Ganglioids Model Human ENS Development and Function

2022 ◽  
Author(s):  
Homa Majd ◽  
Ryan M Samuel ◽  
Jonathan T Ramirez ◽  
Ali Kalantari ◽  
Kevin Barber ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Xenograft Model ◽  
Developmental Relationships ◽  
Drug Candidates ◽  
Effective Strategies ◽  
Wide Range ◽  
Functional Features ◽  
And Function

The enteric nervous system (ENS) plays a central role in gut physiology and mediating the crosstalk between the gastrointestinal (GI) tract and other organs. The human ENS has remained elusive, highlighting the need for an in vitro modeling and mapping blueprint. Here we map out the developmental and functional features of the human ENS, by establishing robust and scalable 2D ENS cultures and 3D enteric ganglioids from human pluripotent stem cells (hPSCs). These models recapitulate the remarkable neuronal and glial diversity found in primary tissue and enable comprehensive molecular analyses that uncover functional and developmental relationships within these lineages. As a salient example of the power of this system, we performed in-depth characterization of enteric nitrergic neurons (NO neurons) which are implicated in a wide range of GI motility disorders. We conducted an unbiased screen and identified drug candidates that modulate the activity of NO neurons and demonstrated their potential in promoting motility in mouse colonic tissue ex vivo. We established a high-throughput strategy to define the developmental programs involved in NO neuron specification and discovered that PDGFR inhibition boosts the induction of NO neurons in enteric ganglioids. Transplantation of these ganglioids in the colon of NO neuron-deficient mice results in extensive tissue engraftment, providing a xenograft model for the study of human ENS in vivo and the development of cell-based therapies for neurodegenerative GI disorders. These studies provide a framework for deciphering fundamental features of the human ENS and designing effective strategies to treat enteric neuropathies.  

scholarly journals In vivo study and thermodynamic investigation of two lanthanum complexes, La(dpp)3 and La(XT), for the treatment of bone resorption disorders

2015 ◽  
Vol 6 (11) ◽  
pp. 6439-6447 ◽  
Author(s):  
J. F. Cawthray ◽  
D. M. Weekes ◽  
O. Sivak ◽  
A. L. Creagh ◽  
F. Ibrahim ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Ex Vivo ◽  
In Vivo Study ◽  
Oral Drug ◽  
Thermodynamic Investigation ◽  
Preventative Measure ◽  
Drug Candidates

Lanthanum could act as a preventative measure against bone resorption disorders; two compounds are thoroughly investigated both in vivo and ex vivo as potential oral drug candidates.

Biological Sex Modifies Aldosterone’s Secretion at a Cellular Level

2021 ◽  
Author(s):  
Shadi K Gholami ◽  
Chee Sin Tay ◽  
Jessica M Lee ◽  
Eleanor Zagoren ◽  
Stephen A Maris ◽  
...  
Keyword(s):  
Feedback Loop ◽  
Ex Vivo ◽  
Plasma Renin ◽  
Receptor Activation ◽  
Zona Glomerulosa ◽  
Cellular Level ◽  
Activity Levels ◽  
Biological Sex ◽  
The Status

Inconsistencies have been reported on the effect of sex on aldosterone levels leading to clinical confusion. The reasons for these inconsistencies, are uncertain but include: estrogen and/or its receptor modulating target gene responses to mineralocorticoid receptor activation and aldosterone secretagogues’ levels. This study’s goal was to determine whether aldosterone’s biosynthesis also differed by sex. Two approaches were used. First, plasma renin activity (PRA) and aldosterone were measured in rats. Both were significantly higher in males. Secondly, using rat zona glomerulosa (ZG) cells, we assessed three ex-vivo areas:1) activity/levels of early steps in aldosterone’s biosynthesis (StAR and CYP11A1); 2) activity/levels of a late step (CYP11B2); and 3) the status of the MR mediated, ultrashort-feedback-loop. Females had higher expression of CYP11A1 and StAR; and increased CYP11A1 activity (increased pregnenolone/ corticosterone levels) but did not differ in CYP11B2 expression or activity (aldosterone/ levels). Activating the ZG’s MR (thereby activating the ultrashort-feedback-loop) reduced CYP11B2’s activity similarly in both sexes. Ex-vivo, these molecular effects were accompanied, in females, by lower aldosterone basally but higher aldosterone with angiotensin II stimulation. In conclusion, we documented that not only was there a sex-mediated difference in the activity of aldosterone’s biosynthesis, but also these differences at the molecular level, help explain the variable reports on aldosterone’s circulating levels. Basally, both in-vivo and ex-vivo, males had higher aldosterone levels, likely secondary to higher aldosterone secretagogue levels. However, in response to acute stimulation, aldosterone levels are higher in females because of the greater levels and/or activity of their StAR/CYP11A1.

scholarly journals Chronic coexistence of two troponin T isoforms in adult transgenic mouse cardiomyocytes decreased contractile kinetics and caused dilatative remodeling

2012 ◽  
Vol 303 (1) ◽  
pp. C24-C32 ◽  
Author(s):  
Zhi-Bin Yu ◽  
Hongguang Wei ◽  
J.-P. Jin
Keyword(s):  
Transgenic Mouse ◽  
Troponin T ◽  
Ex Vivo ◽  
Cellular Level ◽  
Wild Type ◽  
Negative Effects ◽  
Adult Cardiomyocytes ◽  
Cross Bridges ◽  
Contractile Performance

Our previous in vivo and ex vivo studies suggested that coexistence of two or more troponin T (TnT) isoforms in adult cardiac muscle decreased cardiac function and efficiency (Huang QQ, Feng HZ, Liu J, Du J, Stull LB, Moravec CS, Huang X, Jin JP, Am J Physiol Cell Physiol 294: C213–C22, 2008; Feng HZ, Jin JP, Am J Physiol Heart Circ Physiol 299: H97–H105, 2010). Here we characterized Ca2+-regulated contractility of isolated adult cardiomyocytes from transgenic mice coexpressing a fast skeletal muscle TnT together with the endogenous cardiac TnT. Without the influence of extracellular matrix, coexistence of the two TnT isoforms resulted in lower shortening amplitude, slower shortening and relengthening velocities, and longer relengthening time. The level of resting cytosolic Ca2+ was unchanged, but the peak Ca2+ transient was lowered and the durations of Ca2+ rising and decaying were longer in the transgenic mouse cardiomyocytes vs. the wild-type controls. Isoproterenol treatment diminished the differences in shortening amplitude and shortening and relengthening velocities, whereas the prolonged durations of relengthening and Ca2+ transient in the transgenic cardiomyocytes remained. At rigor state, a result from depletion of Ca2+, resting sarcomere length of the transgenic cardiomyocytes became shorter than that in wild-type cells. Inhibition of myosin motor diminished this effect of TnT function on cross bridges. The length but not width of transgenic cardiomyocytes was significantly increased compared with the wild-type controls, corresponding to longitudinal addition of sarcomeres and dilatative remodeling at the cellular level. These dominantly negative effects of normal fast TnT demonstrated that chronic coexistence of functionally distinct variants of TnT in adult cardiomyocytes reduces contractile performance with pathological consequences.

scholarly journals In Vivo Chemical Screen in Zebrafish Embryos Identifies Regulators of Hematopoiesis Using a Semiautomated Imaging Assay

2016 ◽  
Vol 21 (9) ◽  
pp. 956-964 ◽  
Author(s):  
Guruchandar Arulmozhivarman ◽  
Martin Stöter ◽  
Marc Bickle ◽  
Martin Kräter ◽  
Manja Wobus ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Ex Vivo ◽  
Human Peripheral Blood ◽  
Screening Method ◽  
Cell Activity ◽  
Cell Types ◽  
Hematopoietic Stem ◽  
Drug Candidates

Hematopoietic stem and progenitor cells (HSPCs) generate all cell types of the blood and are crucial for homeostasis of all blood lineages in vertebrates. Hematopoietic stem cell transplantation (HSCT) is a rapidly evolving technique that offers potential cure for hematologic cancers, such as leukemia or lymphoma. HSCT may be autologous or allogenic. Successful HSCT depends critically on the abundance of engraftment-competent HSPCs, which are currently difficult to obtain in large numbers. Therefore, finding compounds that enhance either the number or the activity of HSPCs could improve prognosis for patients undergoing HSCT and is of great clinical interest. We developed a semiautomated screening method for whole zebrafish larvae using conventional liquid handling equipment and confocal microscopy. Applying this pipeline, we screened 550 compounds in triplicate for proliferation of HSPCs in vivo and identified several modulators of hematopoietic stem cell activity. One identified hit was valproic acid (VPA), which was further validated as a compound that expands and maintains the population of HSPCs isolated from human peripheral blood ex vivo. In summary, our in vivo zebrafish imaging screen identified several potential drug candidates with clinical relevance and could easily be further expanded to screen more compounds.

scholarly journals Theobroma cacao improves bone growth by modulating defective ciliogenesis in a mouse model of achondroplasia

2021 ◽  
Author(s):  
L. Martin ◽  
N. Kaci ◽  
C. Benoist-Lasselin ◽  
M. Mondoloni ◽  
S. Decaudaveine ◽  
...  
Keyword(s):  
Mouse Model ◽  
Primary Cilium ◽  
Theobroma Cacao ◽  
Primary Cilia ◽  
Bone Growth ◽  
Ex Vivo ◽  
Growth Factor Receptor ◽  
Drug Candidates ◽  
Bone Elongation

AbstractA gain-of-function mutation in the fibroblast growth factor receptor 3 gene (FGFR3) results in achondroplasia (ACH), the most frequent form of dwarfism. The constitutive activation of FGFR3 impaired bone formation and elongation and many signaling transduction pathways. Identification of new and relevant compounds targeting the FGFR3 signaling pathway is of broad importance for the treatment of ACH. Natural plant compounds are the prime sources of drug candidates. Here, we found that the phenol compound (-)-epicatechin isolated from Theobroma cacao effectively inhibits FGFR3’s downstream signaling pathways. Transcriptomic analysis in Fgfr3 mouse model showed that ciliary mRNA expression was modified and influenced significantly by the Indian hedgehog and PKA pathways. (-)-Epicatechin is able to rescue impairments in the expression of these mRNA that control both the structural organization of the primary cilium and ciliogenesis-related genes. In femurs isolated from a mouse model (Fgfr3Y367C/+) of ACH, we showed that (-)-epicatechin countered the bone growth impairment during 6 days of ex vivo cultures. We confirmed in vivo that daily subcutaneous injections of (-)-epicatechin in Fgfr3Y367C/+ mice increased bone elongation and rescued the primary cilium defect observed in chondrocytes. This modification of the primary cilia promoted the typical columnar arrangement of flat proliferative chondrocytes and thus enhanced bone elongation. The results of the present proof-of-principle study illustrated (-)-epicatechin’s ability may facilitate the development of (-)-epicatechin as a treatment for patients with ACH.

P712Non-neuronal cholinergic system prevents coronary vascular dysfunction in diabetic heart

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
E Saw ◽  
H Tsuchimochi ◽  
J T Pearson ◽  
K Yoshihiko ◽  
D O Schwenke ◽  
...  
Keyword(s):  
Cholinergic System ◽  
Coronary Circulation ◽  
Ex Vivo ◽  
Vascular Dysfunction ◽  
Myocardial Damage ◽  
Hypoxic Condition ◽  
Diabetic Heart ◽  
Third Order ◽  
Atp Production

Abstract Background Diabetic individuals suffer extensive myocardial damage during ischemia due to impaired ATP production and coronary vascular dysfunction. The cardiomyocytes possess a non-neuronal cholinergic system (NNCS) as it has choline acetyltransferase (ChAT) to synthesize acetylcholine (ACh). ACh released from cardiomyocytes activates hypoxia-inducible factor-1 pathway in an auto/paracrine manner under non-hypoxic condition. Activation of this pathway via NNCS promotes angiogenesis and is a promising mechanism to target ischemia in diabetes. Aim To investigate if activation of NNCS could improve the coronary vasculature in diabetic heart. Methods Type-2 diabetic db/db mice with ventricle-specific ChAT transgene (db/db-ChAT-tg) and control db/db mice of 12- and 24-weeks old were used. Catheterization of the jugular vein and carotid artery was performed in combination with synchrotron radiation microangiography to visualize the in-vivo coronary circulation. Changes of the coronary circulation to ACh (10μg/kg/min) and sodium nitroprusside (SNP, 10μg/kg/min) were assessed. Immunofluorescence analysis was performed to measure the density of arterioles and capillaries ex-vivo. Results In comparison to db/db mice, the number of second and third order vessels was higher in the db/db-ChAT-tg mice of 12- and 24-weeks old under baseline condition. In response to ACh and SNP, number of third order vessels were further increased in the db/db-ChAT-tg mice of both ages. However, the magnitude of the diameter changes in db/db-ChAT-tg mice was comparable to that in db/db mice of both ages. Besides, the db/db-ChAT-tg mice had increased density of arterioles and capillaries compared to the db/db mice of both ages. Conclusion NNCS-induced angiogenesis prevents coronary vascular dysfunction in diabetic heart.

scholarly journals Oxoglutarate Carrier Inhibition Reduced Melanoma Growth and Invasion by Reducing ATP Production

Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1128
Author(s):  
Jae-Seon Lee ◽  
Jiwon Choi ◽  
Seon-Hyeong Lee ◽  
Joon Hee Kang ◽  
Ji Sun Ha ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Tumor Growth ◽  
Cancer Cells ◽  
Xenograft Model ◽  
Melanoma Cells ◽  
Mitochondrial Activity ◽  
Dependent Manner ◽  
Atp Production ◽  
Oxoglutarate Carrier

Recent findings indicate that (a) mitochondria in proliferating cancer cells are functional, (b) cancer cells use more oxygen than normal cells for oxidative phosphorylation, and (c) cancer cells critically rely on cytosolic NADH transported into mitochondria via the malate-aspartate shuttle (MAS) for ATP production. In a spontaneous lung cancer model, tumor growth was reduced by 50% in heterozygous oxoglutarate carrier (OGC) knock-out mice compared with wild-type counterparts. To determine the mechanism through which OGC promotes tumor growth, the effects of the OGC inhibitor N-phenylmaleimide (NPM) on mitochondrial activity, oxygen consumption, and ATP production were evaluated in melanoma cell lines. NPM suppressed oxygen consumption and decreased ATP production in melanoma cells in a dose-dependent manner. NPM also reduced the proliferation of melanoma cells. To test the effects of NPM on tumor growth and metastasis in vivo, NPM was administered in a human melanoma xenograft model. NPM reduced tumor growth by approximately 50% and reduced melanoma invasion by 70% at a dose of 20 mg/kg. Therefore, blocking OGC activity may be a useful approach for cancer therapy.

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