scholarly journals Dystrophin and calcium current are decreased in cardiomyocytes expressing Cre enzyme driven by αMHC but not TNT promoter

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ludovic Gillet ◽  
Sabrina Guichard ◽  
Maria C. Essers ◽  
Jean-Sébastien Rougier ◽  
Hugues Abriel

AbstractThe Cre/lox system is a potent technology to control gene expression in mouse tissues. However, cardiac-specific Cre recombinase expression alone can lead to cardiac alterations when no loxP sites are present, which is not well understood. Many loxP-like sites have been identified in the mouse genome that might be Cre sensitive. One of them is located in the Dmd gene encoding dystrophin, a protein important for the function and stabilization of voltage-gated calcium (Cav1.2) and sodium (Nav1.5) channels, respectively. Here, we investigate whether Cre affects dystrophin expression and function in hearts without loxP sites in the genome. In mice expressing Cre under the alpha-myosin heavy chain (MHC-Cre) or Troponin T (TNT-Cre) promoter, we investigated dystrophin expression, Nav1.5 expression, and Cav1.2 function. Compared to age-matched MHC-Cre− mice, dystrophin protein level was significantly decreased in hearts from MHC-Cre+ mice of more than 12-weeks-old. Quantitative RT-PCR revealed decreased mRNA levels of Dmd gene. Unexpectedly, calcium current (ICaL), but not Nav1.5 protein expression was altered in those mice. Surprisingly, in hearts from 12-week-old and older TNT-Cre+ mice, neither ICaL nor dystrophin and Nav1.5 protein content were altered compared to TNT-Cre−. Cre recombinase unpredictably affects cardiac phenotype, and Cre-expressing mouse models should be carefully investigated before experimental use.

2019 ◽  
Author(s):  
Ludovic Gillet ◽  
Sabrina Guichard ◽  
Maria C. Essers ◽  
Jean-Sébastien Rougier ◽  
Hugues Abriel

AbstractBackgroundThe Cre/lox system is a potent technology to control gene expression in mouse tissues. However, cardiac alterations following cardiac-specific Cre enzyme expression in non-loxP-flanked genome heart have been reported. Recently, many loxP like sites have been identified in the wild-type mouse genome. Interestingly one of them is localized in the Dmd gene encoding the dystrophin protein known to be crucial for stabilization of cardiac voltage-gated ion channels Nav1.5 and Cav1.2.AimHere, we studied the potential alteration of dystrophin expression in adult alpha-myosin heavy chain (MHC)-Cre mice, which are extensively used for cardiac-specific recombination, and investigated Troponin T (TNT)-Cre mice as a potential alternative.MethodsCardiac-specific MHC-Cre and TNT-Cre mouse lines expressing Cre recombinase under the control of the cardiac-specific alpha-myosin-heavy chain, and rat cardiac troponin T2 promoter respectively were used. Western blots, quantitative RT-PCR, immunostainings, and patch-clamp experiments were performed to characterize MHC-Cre and TNT-Cre mouse hearts and cardiomyocytes.ResultsDystrophin protein level was decreased in hearts from 12-week-old MHC-Cre+ mice compared to MHC-Cre-. Reduction of dystrophin was more pronounced with age. No significant difference was observed between 8-week-old MHC-Cre+ mice and MHC-Cre-. Immunostainings performed on cardiac sections showed reduced dystrophin signal at the lateral membrane of MHC-Cre+ cardiomyocytes. Quantitative RT-PCR showed decreased mRNA levels of Dmd gene encoding dystrophin. Finally, patch-clamp experiments showed a significant decrease in calcium current (ICaL) in adult MHC-Cre+ cardiomyocytes compared to MHC-Cre-. Neither dystrophin nor ICaL was reduced in adult TNT-Cre+ mouse hearts compared to TNT-Cre-.ConclusionIn contrary to TNT-Cre+ mice, the sole expression of Cre recombinase can alter the cardiac phenotype of MHC-Cre+ mice. Thus, researchers should include the “Cre-only” condition as control condition when designing experiments with Cre mouse strains.


2021 ◽  
Vol 118 (22) ◽  
pp. e2004840117
Author(s):  
Eric N. Olson

Recent advances in gene editing technologies are enabling the potential correction of devastating monogenic disorders through elimination of underlying genetic mutations. Duchenne muscular dystrophy (DMD) is an especially severe genetic disorder caused by mutations in the gene encoding dystrophin, a membrane-associated protein required for maintenance of muscle structure and function. Patients with DMD succumb to loss of mobility early in life, culminating in premature death from cardiac and respiratory failure. The disease has thus far defied all curative strategies. CRISPR gene editing has provided new opportunities to ameliorate the disease by eliminating DMD mutations and thereby restore dystrophin expression throughout skeletal and cardiac muscle. Proof-of-concept studies in rodents, large mammals, and human cells have validated the potential of this approach, but numerous challenges remain to be addressed, including optimization of gene editing, delivery of gene editing components throughout the musculature, and mitigation of possible immune responses. This paper provides an overview of recent work from our laboratory and others toward the genetic correction of DMD and considers the opportunities and challenges in the path to clinical translation. Lessons learned from these studies will undoubtedly enable further applications of gene editing to numerous other diseases of muscle and other tissues.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xinglong Su ◽  
Yingying Liu ◽  
Lu Han ◽  
Zhaojian Wang ◽  
Mengyang Cao ◽  
...  

AbstractPlatycodin D and platycoside E are two triterpenoid saponins in Platycodon grandiflorus, differing only by two glycosyl groups structurally. Studies have shown β-Glucosidase from bacteria can convert platycoside E to platycodin D, indicating the potential existence of similar enzymes in P. grandiflorus. An L9(34) orthogonal experiment was performed to establish a protocol for calli induction as follows: the optimal explant is stems with nodes and the optimum medium formula is MS + NAA 1.0 mg/L + 6-BA 0.5 mg/L to obtain callus for experimental use. The platycodin D, platycoside E and total polysaccharides content between callus and plant organs varied wildly. Platycodin D and total polysaccharide content of calli was found higher than that of leaves. While, platycoside E and total polysaccharide content of calli was found lower than that of leaves. Associating platycodin D and platycoside E content with the expression level of genes involved in triterpenoid saponin biosynthesis between calli and leaves, three contigs were screened as putative sequences of β-Glucosidase gene converting platycoside E to platycodin D. Besides, we inferred that some transcription factors can regulate the expression of key enzymes involved in triterpernoid saponins and polysaccharides biosynthesis pathway of P. grandiflorus. Totally, a candidate gene encoding enzyme involved in converting platycoside E to platycodin D, and putative genes involved in polysaccharide synthesis in P. grandiflorus had been identified. This study will help uncover the molecular mechanism of triterpenoid saponins biosynthesis in P. grandiflorus.


2020 ◽  
Vol 10 (1) ◽  
pp. 122
Author(s):  
Lilly-Ann Mohlkert ◽  
Jenny Hallberg ◽  
Olof Broberg ◽  
Gunnar Sjöberg ◽  
Annika Rydberg ◽  
...  

Preterm birth has been associated with altered cardiac phenotype in adults. Our aim was to test the hypothesis that children surviving extremely preterm birth have important structural or functional changes of the right heart or pulmonary circulation. We also examined relations between birth size, gestational age, neonatal diagnoses of bronchopulmonary dysplasia (BPD) and patent ductus arteriosus (PDA) with cardiac outcomes. We assessed a population-based cohort of children born in Sweden before 27 weeks of gestation with echocardiography at 6.5 years of age (n = 176). Each preterm child was matched to a healthy control child born at term. Children born preterm had significantly smaller right atria, right ventricles with smaller widths, higher relative wall thickness and higher estimated pulmonary vascular resistance (PVR) than controls. In preterm children, PVR and right ventricular myocardial performance index (RVmpi’) were significantly higher in those with a PDA as neonates than in those without PDA, but no such associations were found with BPD. In conclusion, children born extremely preterm exhibit higher estimated PVR, altered right heart structure and function compared with children born at term.


Inflammation ◽  
2021 ◽  
Author(s):  
Shangrila Parvin ◽  
Clintoria R. Williams ◽  
Simone A. Jarrett ◽  
Sandra M. Garraway

Abstract— Accumulating evidence supports that spinal cord injury (SCI) produces robust inflammatory plasticity. We previously showed that the pro-inflammatory cytokine tumor necrosis factor (TNF)α is increased in the spinal cord after SCI. SCI also induces a systemic inflammatory response that can impact peripheral organ functions. The kidney plays an important role in maintaining cardiovascular health. However, SCI-induced inflammatory response in the kidney and the subsequent effect on renal function have not been well characterized. This study investigated the impact of high and low thoracic (T) SCI on C-fos, TNFα, interleukin (IL)-1β, and IL-6 expression in the kidney at acute and sub-chronic timepoints. Adult C57BL/6 mice received a moderate contusion SCI or sham procedures at T4 or T10. Uninjured mice served as naïve controls. mRNA levels of the proinflammatory cytokines IL-1β, IL-6, TNFα, and C-fos, and TNFα and C-fos protein expression were assessed in the kidney and spinal cord 1 day and 14 days post-injury. The mRNA levels of all targets were robustly increased in the kidney and spinal cord, 1 day after both injuries. Whereas IL-6 and TNFα remained elevated in the spinal cord at 14 days after SCI, C-fos, IL-6, and TNFα levels were sustained in the kidney only after T10 SCI. TNFα protein was significantly upregulated in the kidney 1 day after both T4 and T10 SCI. Overall, these results clearly demonstrate that SCI induces robust systemic inflammation that extends to the kidney. Hence, the presence of renal inflammation can substantially impact renal pathophysiology and function after SCI.


Genetics ◽  
1998 ◽  
Vol 150 (2) ◽  
pp. 553-562
Author(s):  
Margaret I Kanipes ◽  
John E Hill ◽  
Susan A Henry

Abstract The isolation of mutants of Schizosaccharomyces pombe defective in the synthesis of phosphatidylcholine via the methylation of phosphatidylethanolamine is reported. These mutants are choline auxotrophs and fall into two unlinked complementation groups, cho1 and cho2. We also report the analysis of the cho1+ gene, the first structural gene encoding a phospholipid biosynthetic enzyme from S. pombe to be cloned and characterized. The cho1+ gene disruption mutant (cho1Δ) is viable if choline is supplied and resembles the cho1 mutants isolated after mutagenesis. Sequence analysis of the cho1+ gene indicates that it encodes a protein closely related to phospholipid methyltransferases from Saccharomyces cerevisiae and rat. Phospholipid methyltransferases encoded by a rat liver cDNA and the S. cerevisiae OPI3 gene are both able to complement the choline auxotrophy of the S. pombe cho1 mutants. These results suggest that both the structure and function of the phospholipid N-methyltransferases are broadly conserved among eukaryotic organisms.


ASN NEURO ◽  
2021 ◽  
Vol 13 ◽  
pp. 175909142110097
Author(s):  
Kui Cui ◽  
Fan Yang ◽  
Turan Tufan ◽  
Muhammad U. Raza ◽  
Yanqiang Zhan ◽  
...  

Dysfunction of the central noradrenergic and dopaminergic systems is the primary neurobiological characteristic of Parkinson’s disease (PD). Importantly, neuronal loss in the locus coeruleus (LC) that occurs in early stages of PD may accelerate progressive loss of dopaminergic neurons. Therefore, restoring the activity and function of the deficient noradrenergic system may be an important therapeutic strategy for early PD. In the present study, the lentiviral constructions of transcription factors Phox2a/2b, Hand2 and Gata3, either alone or in combination, were microinjected into the LC region of the PD model VMAT2 Lo mice at 12 and 18 month age. Biochemical analysis showed that microinjection of lentiviral expression cassettes into the LC significantly increased mRNA levels of Phox2a, and Phox2b, which were accompanied by parallel increases of mRNA and proteins of dopamine β-hydroxylase (DBH) and tyrosine hydroxylase (TH) in the LC. Furthermore, there was considerable enhancement of DBH protein levels in the frontal cortex and hippocampus, as well as enhanced TH protein levels in the striatum and substantia nigra. Moreover, these manipulations profoundly increased norepinephrine and dopamine concentrations in the striatum, which was followed by a remarkable improvement of the spatial memory and locomotor behavior. These results reveal that over-expression of these transcription factors in the LC improves noradrenergic and dopaminergic activities and functions in this rodent model of PD. It provides the necessary groundwork for the development of gene therapies of PD, and expands our understanding of the link between the LC-norepinephrine and dopamine systems during the progression of PD.


2021 ◽  
Vol 22 (2) ◽  
pp. 914
Author(s):  
Katarzyna Binięda ◽  
Weronika Rzepnikowska ◽  
Damian Kolakowski ◽  
Joanna Kaminska ◽  
Andrzej Antoni Szczepankiewicz ◽  
...  

Charcot-Marie-Tooth disease (CMT) is a heritable neurodegenerative disease that displays great genetic heterogeneity. The genes and mutations that underlie this heterogeneity have been extensively characterized by molecular genetics. However, the molecular pathogenesis of the vast majority of CMT subtypes remains terra incognita. Any attempts to perform experimental therapy for CMT disease are limited by a lack of understanding of the pathogenesis at a molecular level. In this study, we aim to identify the molecular pathways that are disturbed by mutations in the gene encoding GDAP1 using both yeast and human cell, based models of CMT-GDAP1 disease. We found that some mutations in GDAP1 led to a reduced expression of the GDAP1 protein and resulted in a selective disruption of the Golgi apparatus. These structural alterations are accompanied by functional disturbances within the Golgi. We screened over 1500 drugs that are available on the market using our yeast-based CMT-GDAP1 model. Drugs were identified that had both positive and negative effects on cell phenotypes. To the best of our knowledge, this study is the first report of the Golgi apparatus playing a role in the pathology of CMT disorders. The drugs we identified, using our yeast-based CMT-GDAP1 model, may be further used in translational research.


2000 ◽  
Vol 279 (6) ◽  
pp. R2329-R2335 ◽  
Author(s):  
Paul Trayhurn ◽  
Jacqueline S. Duncan ◽  
Anne M. Wood ◽  
John H. Beattie

White adipose tissue (WAT) has been examined to determine whether the gene encoding metallothionein (MT), a low-molecular-weight stress response protein, is expressed in the tissue and whether MT may be a secretory product of adipocytes. The MT-1 gene was expressed in epididymal WAT, with MT-1 mRNA levels being similar in lean and obese ( ob/ ob) mice. MT-1 mRNA was found in each of the main adipose tissue sites (epididymal, perirenal, omental, subcutaneous), and there was no major difference between depots. Separation of adipocytes from the stromal-vascular fraction of WAT indicated that the MT gene (MT-1 and MT-2) was expressed in adipocytes themselves. Treatment of mice with zinc had no effect on MT-1 mRNA levels in WAT, despite strong induction of MT-1 expression in the liver. MT-1 gene expression in WAT was also unaltered by fasting or norepinephrine. However, administration of a β3-adrenoceptor agonist, BRL-35153A, led to a significant increase in MT-1 mRNA. On differentiation of fibroblastic preadipocytes to adipocytes in primary culture, MT was detected in the medium, suggesting that the protein may be secreted from WAT. It is concluded that WAT may be a significant site of MT production; within adipocytes, MT could play an antioxidant role in protecting fatty acids from damage.


2013 ◽  
Vol 451 (3) ◽  
pp. 453-461 ◽  
Author(s):  
Claudia C. S. Chini ◽  
Carlos Escande ◽  
Veronica Nin ◽  
Eduardo N. Chini

The nuclear receptor Rev-erbα has been implicated as a major regulator of the circadian clock and integrates circadian rhythm and metabolism. Rev-erbα controls circadian oscillations of several clock genes and Rev-erbα protein degradation is important for maintenance of the circadian oscillations and also for adipocyte differentiation. Elucidating the mechanisms that regulate Rev-erbα stability is essential for our understanding of these processes. In the present paper, we report that the protein DBC1 (Deleted in Breast Cancer 1) is a novel regulator of Rev-erbα. Rev-erbα and DBC1 interact in cells and in vivo, and DBC1 modulates the Rev-erbα repressor function. Depletion of DBC1 by siRNA (small interfering RNA) in cells or in DBC1-KO (knockout) mice produced a marked decrease in Rev-erbα protein levels, but not in mRNA levels. In contrast, DBC1 overexpression significantly enhanced Rev-erbα protein stability by preventing its ubiquitination and degradation. The regulation of Rev-erbα protein levels and function by DBC1 depends on both the N-terminal and C-terminal domains of DBC1. More importantly, in cells depleted of DBC1, there was a dramatic decrease in circadian oscillations of both Rev-erbα and BMAL1. In summary, our data identify DBC1 as an important regulator of the circadian receptor Rev-erbα and proposes that Rev-erbα could be involved in mediating some of the physiological effects of DBC1.


Sign in / Sign up

Export Citation Format

Share Document