Insights into LRRK2 function and dysfunction from transgenic and knockout rodent models

2012 ◽  
Vol 40 (5) ◽  
pp. 1080-1085 ◽  
Author(s):  
Maximilian Sloan ◽  
Javier Alegre-Abarrategui ◽  
Richard Wade-Martins
Keyword(s):  
Autosomal Dominant ◽  
Therapeutic Interventions ◽  
Present Review ◽  
Chromosome 12 ◽  
Rodent Models ◽  
Leucine Rich Repeat ◽  
Transgenic Expression ◽  
Cellular Processes ◽  
Cytoskeletal Dynamics ◽  
Underlying Mechanisms

Mutations in the LRRK2 (leucine-rich repeat kinase 2) gene on chromosome 12 cause autosomal dominant PD (Parkinson's disease), which is indistinguishable from sporadic forms of the disease. Numerous attempts have therefore been made to model PD in rodents via the transgenic expression of LRRK2 and its mutant variants and to elucidate the function of LRRK2 by knocking out rodent Lrrk2. Although these models often only partially recapitulate PD pathology, they have helped to elucidate both the normal and pathological function of LRRK2. In particular, LRRK2 has been suggested to play roles in cytoskeletal dynamics, synaptic machinery, dopamine homoeostasis and autophagic processes. Our understanding of how these pathways are affected, their contribution towards PD development and their interaction with one another is still incomplete, however. The present review summarizes the findings from LRRK2 rodent models and draws potential connections between the apparently disparate cellular processes altered, in order to better understand the underlying mechanisms of LRRK2 dysfunction and illuminate future therapeutic interventions.

scholarly journals Cellular and Molecular Mechanisms of Kidney Injury in 2,8-Dihydroxyadenine Nephropathy

2020 ◽  
Vol 31 (4) ◽  
pp. 799-816 ◽  
Author(s):  
Barbara Mara Klinkhammer ◽  
Sonja Djudjaj ◽  
Uta Kunter ◽  
Runolfur Palsson ◽  
Vidar Orn Edvardsson ◽  
...  
Keyword(s):  
Clinical Relevance ◽  
Molecular Mechanisms ◽  
Granulomatous Inflammation ◽  
Kidney Injury ◽  
Rare Condition ◽  
Therapeutic Interventions ◽  
Renal Tubules ◽  
Rodent Models ◽  
Adenine Phosphoribosyltransferase ◽  
Reparative Process

BackgroundHereditary deficiency of adenine phosphoribosyltransferase causes 2,8-dihydroxyadenine (2,8-DHA) nephropathy, a rare condition characterized by formation of 2,8-DHA crystals within renal tubules. Clinical relevance of rodent models of 2,8-DHA crystal nephropathy induced by excessive adenine intake is unknown.MethodsUsing animal models and patient kidney biopsies, we assessed the pathogenic sequelae of 2,8-DHA crystal-induced kidney damage. We also used knockout mice to investigate the role of TNF receptors 1 and 2 (TNFR1 and TNFR2), CD44, or alpha2-HS glycoprotein (AHSG), all of which are involved in the pathogenesis of other types of crystal-induced nephropathies.ResultsAdenine-enriched diet in mice induced 2,8-DHA nephropathy, leading to progressive kidney disease, characterized by crystal deposits, tubular injury, inflammation, and fibrosis. Kidney injury depended on crystal size. The smallest crystals were endocytosed by tubular epithelial cells. Crystals of variable size were excreted in urine. Large crystals obstructed whole tubules. Medium-sized crystals induced a particular reparative process that we term extratubulation. In this process, tubular cells, in coordination with macrophages, overgrew and translocated crystals into the interstitium, restoring the tubular luminal patency; this was followed by degradation of interstitial crystals by granulomatous inflammation. Patients with adenine phosphoribosyltransferase deficiency showed similar histopathological findings regarding crystal morphology, crystal clearance, and renal injury. In mice, deletion of Tnfr1 significantly reduced tubular CD44 and annexin two expression, as well as inflammation, thereby ameliorating the disease course. In contrast, genetic deletion of Tnfr2, Cd44, or Ahsg had no effect on the manifestations of 2,8-DHA nephropathy.ConclusionsRodent models of the cellular and molecular mechanisms of 2,8-DHA nephropathy and crystal clearance have clinical relevance and offer insight into potential future targets for therapeutic interventions.

scholarly journals Phos-tag analysis of Rab10 phosphorylation by LRRK2: a powerful assay for assessing kinase function and inhibitors

2016 ◽  
Vol 473 (17) ◽  
pp. 2671-2685 ◽  
Author(s):  
Genta Ito ◽  
Kristina Katsemonova ◽  
Francesca Tonelli ◽  
Pawel Lis ◽  
Marco A.S. Baptista ◽  
...  
Keyword(s):  
Autosomal Dominant ◽  
Mouse Lung ◽  
Rab Gtpase ◽  
Leucine Rich Repeat ◽  
Serine Residue ◽  
Mouse Embryonic Fibroblasts ◽  
Embryonic Fibroblasts ◽  
The Impact ◽  
Effector Binding

Autosomal dominant mutations that activate the leucine-rich repeat kinase 2 (LRRK2) cause inherited Parkinson's disease. Recent work has revealed that LRRK2 directly phosphorylates a conserved threonine/serine residue in the effector-binding switch-II motif of a number of Rab GTPase proteins, including Rab10. Here we describe a facile and robust method to assess phosphorylation of endogenous Rab10 in mouse embryonic fibroblasts (MEFs), lung and spleen-derived B-cells, based on the ability of the Phos-tag reagent to retard the electrophoretic mobility of LRRK2-phosphorylated Rab10. We exploit this assay to show that phosphorylation of Rab10 is ablated in kinase-inactive LRRK2[D2017A] knockin MEFs and mouse lung, demonstrating that LRRK2 is the major Rab10 kinase in these cells/tissue. We also establish that the Phos-tag assay can be deployed to monitor the impact that activating LRRK2 pathogenic (G2019S and R1441G) knockin mutations have on stimulating Rab10 phosphorylation. We show that upon addition of LRRK2 inhibitors, Rab10 is dephosphorylated within 1–2 min, markedly more rapidly than the Ser935 and Ser1292 biomarker sites that require 40–80 min. Furthermore, we find that phosphorylation of Rab10 is suppressed in LRRK2[S910A+S935A] knockin MEFs indicating that phosphorylation of Ser910 and Ser935 and potentially 14-3-3 binding play a role in facilitating the phosphorylation of Rab10 by LRRK2 in vivo. The Rab Phos-tag assay has the potential to significantly aid with evaluating the effect that inhibitors, mutations and other factors have on the LRRK2 signalling pathway.

scholarly journals Transgenic expression of cyclooxygenase-2 in pancreatic acinar cells induces chronic pancreatitis

2019 ◽  
Vol 316 (1) ◽  
pp. G179-G186
Author(s):  
Haojie Huang ◽  
Jiaxiang Chen ◽  
Lisi Peng ◽  
Yao Yao ◽  
Defeng Deng ◽  
...  
Keyword(s):  
Chronic Pancreatitis ◽  
Transgenic Mice ◽  
Fibrous Tissue ◽  
Acinar Cells ◽  
Cyclooxygenase 2 ◽  
Therapeutic Interventions ◽  
Pancreatic Stellate Cells ◽  
Pancreatic Acinar Cells ◽  
Transgenic Expression ◽  
Cox 2

Replacement of the exocrine parenchyma by fibrous tissue is a main characteristic of chronic pancreatitis. Understanding the mechanisms of pancreatic fibrogenesis is critical for the development of preventive and therapeutic interventions. Cyclooxygenase-2 (COX-2), a rate-limiting enzyme for prostaglandin synthesis, is expressed in patients with chronic pancreatitis. However, it is unknown whether COX-2 can cause chronic pancreatitis. To investigate the roles of pancreatic acinar COX-2 in fibrogenesis and the development of chronic pancreatitis, COX-2 was ectopically expressed specifically in pancreatic acinar cells in transgenic mice. Histopathological changes and expression levels of several profibrogenic factors related to chronic pancreatitis were evaluated. COX-2 was expressed in the pancreas of the transgenic mice, as detected by Western blot analysis. Immunohistochemical staining showed COX-2 was specifically expressed in pancreatic acinar cells. COX-2 expression led to progressive changes in the pancreas, including pancreas megaly, persistent inflammation, collagen deposition, and acinar-to-ductal metaplasia. Quantitative RT-PCR and immunostaining showed that profibrogenic factors were upregulated and pancreatic stellate cells were activated in the COX-2 transgenic mice. Expression of COX-2 in pancreatic acinar cells is sufficient to induce chronic pancreatitis. Targeting this pathway may be valuable in the prevention of chronic pancreatitis. NEW & NOTEWORTHY COX-2 expression is observed in pancreatic tissues of human chronic pancreatitis. In this study, we showed that COX-2 expression caused the development of chronic pancreatitis in transgenic mice, supporting the idea that COX-2 inhibition may be an effective preventive and therapeutic strategy.

scholarly journals MiRNA-143 mediates the proliferative signaling pathway of FSH and regulates estradiol production

2017 ◽  
Vol 234 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Li Zhang ◽  
XiaoXin Zhang ◽  
Xuejing Zhang ◽  
Yu Lu ◽  
Lei Li ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Granulosa Cell ◽  
Granulosa Cells ◽  
Loss Of Function ◽  
Cellular Processes ◽  
Cell Functions ◽  
Genes Expression ◽  
Underlying Mechanisms

MicroRNAs (MiRNAs) play important regulatory roles in many cellular processes. MiR-143 is highly enriched in the mouse ovary, but its roles and underlying mechanisms are not well understood. In the current study, we show that miR-143 is located in granulosa cells of primary, secondary and antral follicles. To explore the specific functions of miR-143, we transfected miR-143 inhibitor into primary cultured granulosa cells to study the loss of function of miR-143 and the results showed that miR-143 silencing significantly increased estradiol production and steroidogenesis-related gene expression. Moreover, our in vivo and in vitro studies showed that follicular stimulating hormone (FSH) significantly decreased miR-143 expression. This function of miR-143 is accomplished by its binding to the 3’-UTR of KRAS mRNA. Furthermore, our results demonstrated that miR-143 acts as a negative regulating molecule mediating the signaling pathway of FSH and affecting estradiol production by targeting KRAS. MiR-143 also negatively acts in regulating granulosa cells proliferation and cell cycle-related genes expression. These findings indicate that miR-143 plays vital roles in FSH-induced estradiol production and granulosa cell proliferation, providing a novel mechanism that involves miRNA in regulating granulosa cell functions.

Chromosome 12-linked autosomal dominant scapuloperoneal muscular dystrophy

1996 ◽  
Vol 39 (4) ◽  
pp. 507-520 ◽  
Author(s):  
K. C. Wilhelmsen ◽  
D. M. Blake ◽  
T. Lynch ◽  
J. Mabutas ◽  
M. De Vera ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Autosomal Dominant ◽  
Chromosome 12

scholarly journals Lipocalin 2 as Putative Modulator of Local Inflammatory Processes in the Spinal Cord and Component of Organ Cross-talk After Spinal Cord Injury

2021 ◽  
Author(s):  
Victoria Behrens ◽  
Clara Voelz ◽  
Nina Müller ◽  
Weiyi Zhao ◽  
Tim Clarner ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Serum ◽  
Negative Influence ◽  
Lipocalin 2 ◽  
Cellular Processes ◽  
Cord Injury ◽  
Inflammatory Processes ◽  
Underlying Mechanisms ◽  
Sites Of Action

Abstract Lipocalin 2 (Lcn2), an immunomodulator, regulates various cellular processes such as iron transport and defense against bacterial infection. Under pathological conditions, Lcn2 promotes neuroinflammation via the recruitment and activation of immune cells and glia, particularly microglia and astrocytes. Although it seems to have a negative influence on the functional outcome in spinal cord injury (SCI), the extent of its involvement in SCI and the underlying mechanisms are not yet fully known. In this study, using a SCI contusion mouse model, we first investigated the expression pattern of Lcn2 in different parts of the CNS (spinal cord and brain), blood serum and in the liver. Interestingly, we could note a significant increase in Lcn2 throughout the whole spinal cord, in the brain, liver and in blood serum. This demonstrates the diversity of its possible sites of action in SCI. Further, genetic deficiency of Lcn2 (Lcn2-/-) significantly reduced certain aspects of gliosis in the SCI-mice. Taken together, our studies provide first valuable hints, suggesting that Lcn2 is involved in the local and systemic effects post SCI, and might modulate the impairment of different peripheral organs after injury.

scholarly journals Regulation of Rho GTPases in the Vasculature by Cullin3-Based E3 Ligase Complexes

2021 ◽  
Vol 9 ◽  
Author(s):  
Fabienne Podieh ◽  
Peter L. Hordijk
Keyword(s):  
Rho Gtpases ◽  
Vascular Function ◽  
Rho Gtpase ◽  
Current Knowledge ◽  
E3 Ligase ◽  
Small Gtpases ◽  
E3 Ligases ◽  
Cellular Processes ◽  
Ubiquitin E3 Ligase ◽  
Cytoskeletal Dynamics

Cullin3-based ubiquitin E3 ligases induce ubiquitination of substrates leading to their proteasomal or lysosomal degradation. BTB proteins serve as adaptors by binding to Cullin3 and recruiting substrate proteins, which enables specific recognition of a broad spectrum of targets. Hence, Cullin3 and its adaptors are involved in myriad cellular processes and organ functions. Cullin3-based ubiquitin E3 ligase complexes target small GTPases of the Rho subfamily, which are key regulators of cytoskeletal dynamics and cell adhesion. In this mini review, we discuss recent insights in Cullin3-mediated regulation of Rho GTPases and their impact on cellular function and disease. Intriguingly, upstream regulators of Rho GTPases are targeted by Cullin3 complexes as well. Thus, Rho GTPase signaling is regulated by Cullin3 on multiple levels. In addition, we address current knowledge of Cullin3 in regulating vascular function, focusing on its prominent role in endothelial barrier function, angiogenesis and the regulation of blood pressure.

scholarly journals Systems-based proteomics to resolve the biology of Alzheimer’s disease beyond amyloid and tau

2020 ◽  
Vol 46 (1) ◽  
pp. 98-115 ◽  
Author(s):  
Sruti Rayaprolu ◽  
Lenora Higginbotham ◽  
Pritha Bagchi ◽  
Caroline M. Watson ◽  
Tian Zhang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Brain Network ◽  
Protein Biomarkers ◽  
Cellular Processes ◽  
Complex Protein ◽  
Underlying Mechanisms ◽  
Novel Protein

AbstractThe repeated failures of amyloid-targeting therapies have challenged our narrow understanding of Alzheimer’s disease (AD) pathogenesis and inspired wide-ranging investigations into the underlying mechanisms of disease. Increasing evidence indicates that AD develops from an intricate web of biochemical and cellular processes that extend far beyond amyloid and tau accumulation. This growing recognition surrounding the diversity of AD pathophysiology underscores the need for holistic systems-based approaches to explore AD pathogenesis. Here we describe how network-based proteomics has emerged as a powerful tool and how its application to the AD brain has provided an informative framework for the complex protein pathophysiology underlying the disease. Furthermore, we outline how the AD brain network proteome can be leveraged to advance additional scientific and translational efforts, including the discovery of novel protein biomarkers of disease.

scholarly journals Analysis of the LRRK2 p.G2019S mutation in Colombian Parkinson’s Disease Patients

2015 ◽  
pp. 117-121 ◽  
Author(s):  
Andres Felipe Duque ◽  
Juan Carlos Lopez ◽  
Helena Hernandez ◽  
Bruno Benitez ◽  
Juan Jose Yunis ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson Disease ◽  
Latin American ◽  
Autosomal Dominant ◽  
Late Onset ◽  
Causal Factor ◽  
Leucine Rich Repeat ◽  
Common Cause ◽  
Asymptomatic Control ◽  
Normal Controls

Introduction: Mutations in the leucine-rich repeat kinase 2 gene (LRRK2 or Dardarin) are considered to be a common cause of autosomal dominant and sporadic Parkinson´s disease, but the prevalence of these mutations varies among populations. Objective: to analysed the frequency of the LRRK2 p.G2019S mutation (c.6055G>A transition) in a sample of Colombian patients. Materials and Methods: In the present study we have analysed the frequency of the LRRK2 p.G2019S mutation in 154 patients with familial or sporadic Parkinson Disease, including early and late onset patients, and 162 normal controls. Results: Our results show occurrence of this mutation in two cases (2/154, 1.3%) with classical Parkinson´s signs, and one completely asymptomatic control (1/162, 0.6%). Conclusion: The p.G2019S mutation is not an important causal factor of Parkinson Disease in Colombia having similar frequencies to those reported in other Latin American populations.

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