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American Journal of Medical Genetics.... Sep 2005
Topics: Abnormalities, Multiple; Aged; Codon, Nonsense; DNA Mutational Analysis; Eye Abnormalities; Family Health; Female; Humans; Laminin; Male; Mutation; Nephrosis; Pedigree; Syndrome
PubMed: 16097004
DOI: 10.1002/ajmg.a.30894 -
Current Topics in Membranes 2015Cell-extracellular matrix (ECM) interactions are essential for tissue development, homeostasis, and response to injury. Basement membranes (BMs) are specialized ECMs... (Review)
Review
Cell-extracellular matrix (ECM) interactions are essential for tissue development, homeostasis, and response to injury. Basement membranes (BMs) are specialized ECMs that separate epithelial or endothelial cells from stromal components and interact with cells via cellular receptors, including integrins and discoidin domain receptors. Disruption of cell-BM interactions due to either injury or genetic defects in either the ECM components or cellular receptors often lead to irreversible tissue injury and loss of organ function. Animal models that lack specific BM components or receptors either globally or in selective tissues have been used to help with our understanding of the molecular mechanisms whereby cell-BM interactions regulate organ function in physiological and pathological conditions. We review recently published works on animal models that explore how cell-BM interactions regulate kidney homeostasis in both health and disease.
Topics: Animals; Basement Membrane; Epithelial Cells; Humans; Kidney; Kidney Diseases; Protein Binding; Receptors, Cell Surface
PubMed: 26610916
DOI: 10.1016/bs.ctm.2015.07.003 -
Annals of the New York Academy of... Dec 2012Presynaptic active zones are synaptic vesicle release sites that play essential roles in the function and pathology of mammalian neuromuscular junctions (NMJs). The... (Review)
Review
Presynaptic active zones are synaptic vesicle release sites that play essential roles in the function and pathology of mammalian neuromuscular junctions (NMJs). The molecular mechanisms of active zone organization use presynaptic voltage-dependent calcium channels (VDCCs) in NMJs as scaffolding proteins. VDCCs interact extracellularly with the muscle-derived synapse organizer, laminin β2 and interact intracellularly with active zone-specific proteins, such as Bassoon, CAST/Erc2/ELKS2alpha, ELKS, Piccolo, and RIMs. These molecular mechanisms are supported by studies in P/Q- and N-type VDCCs double-knockout mice, and they are consistent with the pathological conditions of Lambert-Eaton myasthenic syndrome and Pierson syndrome, which are caused by autoantibodies against VDCCs or by a laminin β2 mutation. During normal postnatal maturation, NMJs maintain the density of active zones, while NMJs triple their size. However, active zones become impaired during aging. Propitiously, muscle exercise ameliorates the active zone impairment in aged NMJs, which suggests the potential for therapeutic strategies.
Topics: Abnormalities, Multiple; Aging; Animals; Autoantibodies; Calcium Channels; Eye Abnormalities; Humans; Lambert-Eaton Myasthenic Syndrome; Myasthenic Syndromes, Congenital; Nephrotic Syndrome; Nerve Tissue Proteins; Neuromuscular Junction; Presynaptic Terminals; Pupil Disorders
PubMed: 23252894
DOI: 10.1111/j.1749-6632.2012.06836.x -
Current Topics in Membranes 2015Studies on extracellular matrix proteins, cells, and genetically modified animals have converged to reveal mechanisms of basement membrane self-assembly as mediated by... (Review)
Review
Studies on extracellular matrix proteins, cells, and genetically modified animals have converged to reveal mechanisms of basement membrane self-assembly as mediated by γ1 subunit-containing laminins, the focus of this chapter. The basic model is as follows: A member of the laminin family adheres to a competent cell surface and typically polymerizes followed by laminin binding to the extracellular adaptor proteins nidogen, perlecan, and agrin. Assembly is completed by the linking of nidogen and heparan sulfates to type IV collagen, allowing it to form a second stabilizing network polymer. The assembled matrix provides structural support, anchoring the extracellular matrix to the cytoskeleton, and acts as a signaling platform. Heterogeneity of function is created in part by the isoforms of laminin that vary in their ability to polymerize and to interact with integrins, dystroglycan, and other receptors. Mutations in laminin subunits, affecting expression or LN domain-specific functions, are a cause of human diseases that include those of muscle, nerve, brain, and kidney.
Topics: Animals; Basement Membrane; Cell Adhesion; Collagen Type IV; Cytoskeleton; Humans; Laminin; Protein Multimerization
PubMed: 26610910
DOI: 10.1016/bs.ctm.2015.05.001 -
Nature Clinical Practice. Nephrology Jan 2008The glomerular basement membrane (GBM) is a specialized form of basement membrane that has a major role in the maintenance of the glomerular filtration barrier. Like all... (Review)
Review
The glomerular basement membrane (GBM) is a specialized form of basement membrane that has a major role in the maintenance of the glomerular filtration barrier. Like all basement membranes, it contains four main components: type IV collagen, laminin, nidogen, and heparan sulfate proteoglycans. Different isoforms of these large molecules are produced. These isoforms have a tissue-specific distribution; in the mature GBM, the major type IV collagen molecule is the alpha 3 alpha 4 alpha 5(IV) isoform, associated with laminin-521 (alpha 5 beta2 gamma 1), nidogen and agrin heparan sulfate proteoglycans. The importance of the GBM has been demonstrated by identification of hereditary glomerular diseases linked to structural anomalies of its components; for example, type IV collagen in Alport syndrome and familial benign hematuria, and laminin in Pierson syndrome. Type III collagen, an interstitial collagen, accumulates within the GBM of patients with the nail-patella syndrome, and abnormal deposition of fibronectin, another extracellular matrix protein, is characteristic of so-called fibronectin nephropathy. Development of animal models of these diseases has facilitated precise analysis of pathogenic mechanisms, but no specific treatments are available. Therapeutic trials in Alport syndrome nephropathy are underway, following promising preliminary results obtained in rodent and canine models of the disorder.
Topics: Animals; Collagen Type III; Collagen Type IV; Fibronectins; Glomerular Basement Membrane; Hematuria; Heterozygote; Humans; Kidney Diseases; Laminin; Mutation; Nail-Patella Syndrome; Nephritis, Hereditary; Phenotype
PubMed: 18094725
DOI: 10.1038/ncpneph0671 -
Seminars in Nephrology Jul 2012This article summarizes the basic cellular and extracellular events in the development of the glomerulus and assembly of the glomerular basement membrane (GBM), paying... (Review)
Review
This article summarizes the basic cellular and extracellular events in the development of the glomerulus and assembly of the glomerular basement membrane (GBM), paying special attention to laminin (LM) and type IV collagen. Cellular receptors for GBM proteins, including the integrins, dystroglycan, and discoidin domain receptor 1 also are discussed. Evidence is reviewed showing that the laminin isoform present in the earliest GBM, LM-111, and final isoform found in the mature GBM, LM-521, are each derived from both endothelial cells and podocytes. Although the early collagen α1α2α1(IV) similarly derives from endothelial cells and podocytes, collagen α3α4α5(IV) found in fully mature GBM is a product solely of podocytes. Genetic diseases affecting laminin and type IV collagen synthesis also are presented, with an emphasis on mutations to LAMB2 (Pierson syndrome) and COL4A3, COL4A4, and COL4A5 (Alport syndrome), and their experimental mouse models. Stress is placed on the assembly of a compositionally correct GBM for the acquisition and maintenance of glomerular barrier properties.
Topics: Animals; Collagen Type IV; Endothelium; Glomerular Basement Membrane; Heparan Sulfate Proteoglycans; Humans; Kidney Diseases; Laminin; Podocytes
PubMed: 22958488
DOI: 10.1016/j.semnephrol.2012.06.005 -
Anales de Pediatria (Barcelona, Spain :... Dec 2016
Topics: Abnormalities, Multiple; Eye Abnormalities; Female; Humans; Infant, Newborn; Mutation; Myasthenic Syndromes, Congenital; Nephrotic Syndrome; Pupil Disorders
PubMed: 26975222
DOI: 10.1016/j.anpedi.2016.01.025 -
Journal of the American Society of... Mar 2018Pierson syndrome is a congenital nephrotic syndrome with eye and neurologic defects caused by mutations in laminin 2 (), a major component of the glomerular basement...
Pierson syndrome is a congenital nephrotic syndrome with eye and neurologic defects caused by mutations in laminin 2 (), a major component of the glomerular basement membrane (GBM). Pathogenic missense mutations in human LAMB2 cluster in or near the laminin amino-terminal (LN) domain, a domain required for extracellular polymerization of laminin trimers and basement membrane scaffolding. Here, we investigated an LN domain missense mutation, LAMB2-S80R, which was discovered in a patient with Pierson syndrome and unusually late onset of proteinuria. Biochemical data indicated that this mutation impairs laminin polymerization, which we hypothesized to be the cause of the patient's nephrotic syndrome. Testing this hypothesis in genetically altered mice showed that the corresponding amino acid change (LAMB2-S83R) alone is not pathogenic. However, expression of LAMB2-S83R significantly increased the rate of progression to kidney failure in a mouse model of autosomal recessive Alport syndrome and increased proteinuria in females that exhibit a mild form of X-linked Alport syndrome due to mosaic deposition of collagen 345(IV) in the GBM. Collectively, these data show the pathogenicity of LAMB2-S80R and provide the first evidence of genetic modification of Alport phenotypes by variation in another GBM component. This finding could help explain the wide range of Alport syndrome onset and severity observed in patients with Alport syndrome, even for family members who share the same mutation. Our results also show the complexities of using model organisms to investigate genetic variants suspected of being pathogenic in humans.
Topics: Abnormalities, Multiple; Animals; Autoantigens; Collagen Type IV; Disease Models, Animal; Disease Progression; Eye Abnormalities; Female; Glomerular Basement Membrane; Humans; Kidney Failure, Chronic; Laminin; Mice; Mice, Transgenic; Mutation, Missense; Myasthenic Syndromes, Congenital; Nephritis, Hereditary; Nephrotic Syndrome; Phenotype; Polymerization; Proteinuria; Pupil Disorders
PubMed: 29263159
DOI: 10.1681/ASN.2017090997 -
Nature Communications Jan 2023Laminin polymerization is the major step in basement membranes assembly. Its failures cause laminin N-terminal domain lamininopathies including Pierson syndrome. We have...
Laminin polymerization is the major step in basement membranes assembly. Its failures cause laminin N-terminal domain lamininopathies including Pierson syndrome. We have employed cryo-electron microscopy to determine a 3.7 Å structure of the trimeric laminin polymer node containing α1, β1 and γ1 subunits. The structure reveals the molecular basis of calcium-dependent formation of laminin lattice, and provides insights into polymerization defects manifesting in human disease.
Topics: Humans; Laminin; Cryoelectron Microscopy; Polymerization; Nephrotic Syndrome; Pupil Disorders; Basement Membrane
PubMed: 36658135
DOI: 10.1038/s41467-023-36077-z -
BMC Nephrology Aug 2020Congenital nephrotic syndrome (CNS) and infantile nephrotic syndrome (INS) cause substantial morbidity and mortality. In Japan, there is a lack of knowledge regarding... (Observational Study)
Observational Study
BACKGROUND
Congenital nephrotic syndrome (CNS) and infantile nephrotic syndrome (INS) cause substantial morbidity and mortality. In Japan, there is a lack of knowledge regarding the characteristics of CNS and INS. This study aimed to clarify the characteristics of CNS and INS in Japan.
METHODS
This cross-sectional nationwide survey obtained data from 44 institutions in Japan managing 92 patients with CNS or INS, by means of two survey questionnaires sent by postal mail. Patients aged < 16 years by 1 April 2015, with a diagnosis of CNS or INS, were included in this study. The primary outcome was end-stage kidney disease.
RESULTS
A total of 83 patients with CNS or INS were analyzed. The most frequent disease type was non-Finnish (60.2%); 33 patients (39.8%) had Finnish type. Among those with non-Finnish-type disease, 26 had no syndrome and 24 had a syndrome, of which the most frequent was Denys-Drash syndrome (70.8%). Patients with non-Finnish-type disease with syndrome showed the earliest progression to end-stage kidney disease compared with the other two groups, whereas patients with non-Finnish-type disease without syndrome progressed more slowly compared with the other two groups. In the Finnish-type group, the disease was diagnosed the earliest; a large placenta was reported more frequently; genetic testing was more frequently performed (93.8%); mental retardation was the most frequent extra-renal symptom (21.2%); and thrombosis and infection were more frequent compared with the other groups. Patients with non-Finnish-type disease with syndrome had a higher frequency of positive extra-renal symptoms (79.2%), the most common being urogenital symptoms (54.2%). Treatment with steroids and immunosuppressants was more frequent among patients with non-Finnish-type disease without syndrome. Two patients with non-Finnish-type disease without syndrome achieved complete remission. In all groups, unilateral nephrectomy was performed more often than bilateral nephrectomy and peritoneal dialysis was the most common renal replacement therapy.
CONCLUSIONS
The present epidemiological survey sheds light on the characteristics of children with CNS and INS in Japan. A high proportion of patients underwent genetic examination, and patient management was in accord with current treatment recommendations and practices.
TRIAL REGISTRATION
Not applicable.
Topics: Adolescent; Child; Child, Preschool; Denys-Drash Syndrome; Disease Progression; Female; Genetic Testing; Glucocorticoids; Humans; Immunosuppressive Agents; Infant; Infant, Newborn; Intellectual Disability; Japan; Kaplan-Meier Estimate; Kidney Failure, Chronic; Male; Myasthenic Syndromes, Congenital; Nephrectomy; Nephrotic Syndrome; Organ Size; Placenta; Pregnancy; Pupil Disorders; Renal Replacement Therapy; Surveys and Questionnaires; Syndrome
PubMed: 32838745
DOI: 10.1186/s12882-020-02010-5