Genotype�Cphenotype correlations in nonlethal osteogenesis imperfecta caused by mutations in the helical domain of collagen type I

Osteogenesis imperfecta (OI) is a heritable disorder with bone fragility that is often associated with short stature, tooth abnormalities (dentinogenesis imperfecta), and blue sclera. The most common mutations associated with OI result from the substitution for glycine by another amino acid in the triple helical domain of either the α1 or the α2 chain of collagen type I. In this study, we compared the results of genotype analysis and clinical examination in 161 OI patients (median age: 13 years) who had glycine mutations in the triple helical domain of α1(I) (n=67) or α2(I) (n=94). Serine substitutions were the most frequently encountered type of mutation in both chains. Compared with patients with serine substitutions in α2(I) (n=40), patients with serine substitutions in α1(I) (n=42) on average were shorter (median height z-score −6.0 vs −3.4; P=0.005), indicating that α1(I) mutations cause a more severe phenotype. Height correlated with the location of the mutation in the α2(I) chain but not in the α1(I) chain. Patients with mutations affecting the first 120 amino acids at the amino-terminal end of the collagen type I triple helix had blue sclera but did not have dentinogenesis imperfecta. Among patients from different families sharing the same mutation, about 90 and 75% were concordant for dentinogenesis imperfecta and blue sclera, respectively. These data should be useful to predict disease phenotype in newly diagnosed OI patients.     

Overexpression of scavenger receptor LOX-1 in endothelial cells promotes atherogenesis in the ApoE−/− mouse model

AimsThe oxidized low-density lipoprotein receptor LOX-1 is up-regulated on activated endothelial cells, for example, the endothelium of atherosclerosis-prone sites, in both human and animal models. We examined whether endothelial LOX-1 overexpression may contribute to atherogenesis.MethodsAdenoviral vectors expressing LOX-1 or LOXIN (a splice variant of LOX-1 with inhibitory function) were created and used to transduce the normally lesion-free common carotid artery, in high fat-fed female ApoE^?/? mice. Mice were placed on high-fat diet for 4 weeks prior to gene transfer with either LOX-1 or a combination of LOX-1 and LOXIN, and assessment of plaque development analyzed 6 weeks following gene transfer.ResultsCompared to controls, LOX-1 transduction induced a significant increase in plaque coverage within the common carotid artery to 91% compared to 50% after RAd66 control virus infection (P≤.05). This was inhibited by co-expression of LOXIN (62%).ConclusionsThese results demonstrate that up-regulation of LOX-1 promotes atherogenesis, highlighting LOX-1 function as a target for intervention. In addition, this study further demonstrated the inhibitory function of LOXIN.     

Alteration in nerves and neurotransmitter stimulation of lacrimal gland secretion in the TSP-1−/− mouse model of aqueous deficiency dry eye

The purpose of this study is to determine neural, vascular, protein secretion, and cellular signaling changes with disease progression in lacrimal glands of the thrombospondin-1^−/− (TSP-1^−/−) mouse model of dry eye compared to C57BL/6 wild-type (WT) mice. Neural innervation was reduced in TSP-1^−/− lacrimal glands compared to WT controls, whereas the number of blood vessels was increased. Intracellular Ca²⁺ stores and the amount of lysosomes, mitochondria, and secretory granules, but not the endoplasmic reticulum, were reduced in TSP-1^−/− compared to WT acini at 12 weeks of age. Ex vivo high KCl-evoked secretion was decreased in TSP-1^−/− compared to WT lacrimal gland tissue pieces. The α_1D-adrenergic agonist-stimulated response was increased in TSP-1^−/− at 4 and 24 weeks but decreased at 12 weeks, and the ATP and MeSATP-stimulated peak [Ca²⁺]_i responses were decreased at 24 weeks. These changes were observed prior to the appearance of mononuclear infiltrates. We conclude that in the lacrimal gland the absence of TSP-1: injures peripheral nerves; blocks efferent nerve activation; decreases protein secretion; and alters intracellular Ca²⁺ stores. Through these effects the absence of TSP-1 leads to disruption of ocular surface homeostasis and development of dry eye.     

The mdr1a−/− mouse model of spontaneous colitis

There are many types of colitis models in animals that researchers use to elucidate the mechanism of action of human inflammatory bowel disease (IBD). These models are also used to test novel therapeutics and therapeutic treatment regimens. Here, we will review the characteristics of the mdr1a^−/− model of spontaneous colitis that we believe make this model an important part of the IBD researcher's toolbox. We will also share new data that will reinforce the fact that this model is relevant in the study of IBD. Mdrla^−/− mice lack the murine multiple drug resistance gene for P-glyco-protein 170 that is normally expressed in multiple tissues including intestinal epithelial cells. These mice spontaneously develop a form of colitis at around 12 wk of age. The fact that the complexity of this model mirrors the complexity of disease in humans, as well as recent literature that links MDR1 polymorphisms in humans to Crohn's Disease and Ulcerative Colitis, makes this an appropriate animal model to study.     

Altered generation of induced regulatory T cells in the FVB.mdr1a−/− mouse model of colitis

The FVB.mdr1a^−/− mouse, lacking the small molecule pump P-glycoprotein (P-gp), is a commonly used model for the study of spontaneous T cell–mediated colitis. In addition, MDR1 polymorphisms and P-gp deficiency in humans have been linked to the development of ulcerative colitis. We now demonstrate that mice with P-gp deficiency have decreased levels of Foxp3⁺ regulatory T cells (Tregs) in the intestinal lamina propria. This decrease is not due to either increased Treg apoptosis, altered Treg trafficking, or enhanced Treg plasticity to become Foxp3⁺IL-17⁺ cells. Instead, P-gp deficiency appears to restrict the development of induced Treg cells (iTregs), as fewer Foxp3⁺ iTregs developed from naive FVB.mdr1a^−/− T cells both upon transforming growth factor-β (TGF-β) treatment in vitro and after adoptive transfer into FVB.rag2^−/− recipients. Rather, in vitro TGF-β treatment results in a IL-17⁺CD4⁺ T cell. This failure of iTregs to develop explains the decrease in Foxp3⁺ Tregs in the FVB.mdr1a^−/− intestine, representing a need to investigate this novel disease mechanism in human inflammatory bowel disease patients with MDR1 polymorphisms.     

Genetic epidemiology,prevalence, and genotype–phenotype correlations in the Swedish population with osteogenesis imperfecta

Osteogenesis imperfecta (OI) is a rare hereditary bone fragility disorder, caused by collagen I mutations in 90% of cases. There are no comprehensive genotype–phenotype studies on >100 families outside North America, and no population-based studies determining the genetic epidemiology of OI. Here, detailed clinical phenotypes were recorded, and the COL1A1 and COL1A2 genes were analyzed in 164 Swedish OI families (223 individuals). Averages for bone mineral density (BMD), height and yearly fracture rate were calculated and related to OI and mutation type. N-terminal helical mutations in both the α1- and α2-chains were associated with the absence of dentinogenesis imperfecta (P<0.0001 vs 0.0049), while only those in the α1-chain were associated with blue sclera (P=0.0110). Comparing glycine with serine substitutions, α1-alterations were associated with more severe phenotype (P=0.0031). Individuals with type I OI caused by qualitative vs quantitative mutations were shorter (P<0.0001), but did not differ considering fractures or BMD. The children in this cohort were estimated to represent >95% of the complete Swedish pediatric OI population. The prevalence of OI types I, III, and IV was 5.16, 0.89, and 1.35/100 000, respectively (7.40/100 000 overall), corresponding to what has been estimated but not unequivocally proven in any population. Collagen I mutation analysis was performed in the family of 97% of known cases, with causative mutations found in 87%. Qualitative mutations caused 32% of OI type I. The data reported here may be helpful to predict phenotype, and describes for the first time the genetic epidemiology in >95% of an entire OI population.     

Personality and stereotype in osteogenesis imperfecta: behavioral phenotype or response to life's hard challenges?

Fifty-five adults with osteogenesis imperfecta [OI] types III and IV were interviewed to chronicle their medical, personal, and social experiences in living with OI. Subjects were recruited through the Osteogenesis Imperfecta Foundation, through physician referrals, and through other persons with OI. One purpose of the research was to examine the stereotypes of high intelligence and euphoric personality often attributed to persons with OI, and to explore whether these characteristics might constitute a behavioral phenotype. Participants were observed by the researcher to be characteristically bright, talkative, articulate, "up" emotionally, and accomplished. In fact, most of the persons illustrated well the characteristics of the stereotype. Participants suggested and described life experiences and difficult medical and social challenges which they felt could contribute to the development of the attributed characteristics. The history of the "euphoric" attribution is traced. Many participants expressed derision concerning this attribution. The commonly understood meaning of this term trivializes the years of painful medical procedures, suffering, and related hardships experienced by subjects in their lives. I suggest that the concept of "resilience" offers a more appropriate context for related future research with this population. The consideration of the exceptional challenges faced by persons with OI and others with such demanding medical conditions throughout their life cycles would add a significant environmental dimension to the study of behavioral phenotypes.     

Two sibs with an unusual pattern of skeletal malformations resembling osteogenesis imperfecta: a new type of skeletal dysplasia?

We report a 6 year old boy with multiple fractures owing to bilateral, peculiar, wave-like defects of the tibial corticalis with alternative hyperostosis and thinning. Furthermore, he had Wormian bones of the skull, dentinogenesis imperfecta, and a distinct facial phenotype with hypertelorism and periorbital fullness. Collagen studies showed normal results. His sister, aged 2 years, showed the same facial phenotype and dental abnormalities as well as Wormian bones, but no radiographical abnormalities of the tubular bones so far. The mother also had dentine abnormalities but no skeletal abnormalities on x ray. This entity is probably the same as that described in a sporadic case by Suarez and Stickler in 1974. In spite of the considerable overlap with osteogenesis imperfecta (bone fragility, Wormian bones, and dentinogenesis imperfecta), we believe this disorder to be a different entity, in particular because of the unique cortical defects, missing osteopenia, and normal results of collagen studies.     

Adipose-derived stem cells were impaired in restricting CD4+T cell proliferation and polarization in type 2 diabetic ApoE−/− mouse

BackgroundAtherosclerosis (AS) is the most common and serious complication of type 2 diabetes mellitus (T2DM) and is accelerated via chronic systemic inflammation rather than hyperglycemia. Adipose tissue is the major source of systemic inflammation in abnormal metabolic state. Pro-inflammatory CD4⁺T cells play pivotal role in promoting adipose inflammation. Adipose-derived stem cells (ADSCs) for fat regeneration have potent ability of immunosuppression and restricting CD4⁺T cells as well. Whether T2DM ADSCs are impaired in antagonizing CD4⁺T cell proliferation and polarization remains unclear.MethodsWe constructed type 2 diabetic ApoE^−/− mouse models and tested infiltration and subgroups of CD4⁺T cell in stromal-vascular fraction (SVF) in vivo. Normal/T2DM ADSCs and normal splenocytes with or without CD4 sorting were separated and co-cultured at different scales ex vivo. Immune phenotypes of pro- and anti-inflammation of ADSCs were also investigated. Flow cytometry (FCM) and ELISA were applied in the experiments above.ResultsCD4⁺T cells performed a more pro-inflammatory phenotype in adipose tissue in T2DM ApoE^−/− mice in vivo. Restriction to CD4⁺T cell proliferation and polarization was manifested obviously weakened after co-cultured with T2DM ADSCs ex vivo. No obvious distinctions were found in morphology and growth type of both ADSCs. However, T2DM ADSCs acquired a pro-inflammatory immune phenotype, with secreting less PGE2 and expressing higher MHC-II and co-stimulatory molecules (CD40, CD80). Normal ADSCs could also obtain the phenotypic change after cultured with T2DM SVF supernatant.ConclusionCD4⁺T cell infiltration and pro-inflammatory polarization exist in adipose tissue in type 2 diabetic ApoE^−/− mice. T2DM ADSCs had impaired function in restricting CD4⁺T lymphocyte proliferation and pro-inflammatory polarization due to immune phenotypic changes.     

Effects of platelet factors on biodegradation and osteogenesis in metaphyseal defects filled with nanoparticular hydroxyapatite—an experimental study in minipigs

There are no studies on the cellular activity in the early phase of biodegradation and bone healing of bone substitutes loaded with platelet factors (PLF). The purpose of this study was to evaluate the cellular effects of PLF in combination with nanoparticulate hydroxyapatite (HA) on the biodegradation and bone formation after 20 days. Autogenous PLFs were obtained by centrifugation of miniature pig blood samples and subsequent degranulation of platelets by calcium and thrombin. A cylindrical bone defect with a diameter of 8.9 mm was created in the distal femoral condyle of 20 miniature pigs. Four of the defects were left empty, 8 were filled with HA with loading and 8 with HA loaded with PLF. The distal femur was harvested after 20 days and TRAP-staining, cathepsin-K and CD44 staining and scanning electron microscopy were performed for cellular assessment of biodegradation was done. Histomorphometry of new bone formation and of biodegradation of HA material was performed. PLF loading of HA led to statistically significant more TRAP-positive cells with enhanced biodegradation of the nanoparticulate HA but no statistically enhanced new bone formation compared to unloaded HA. Furthermore, there was a higher number of CD44 and cathepsin-K positive cells by PLF-loading. In summary, PLF led to stimulation of the cellular process of the biodegradation of HA.     

Understanding the complexity of γδ T-cell subsets in mouse and human

γδ T cells are increasingly recognized as having important functional roles in a range of disease scenarios such as infection, allergy, autoimmunity and cancer. With this has come realization that γδ cells are not a homogeneous population of cells with a single physiological role. Instead, ever increasing complexity in both phenotype and function is being ascribed to γδ cell subsets from various tissues and locations, and in both mouse and human. Here, we review this complexity by describing how diverse γδ cell subsets are generated in the murine thymus, and how these events relate to subsequent γδ subset function in the periphery. We then review the two major γδ cell populations in human, highlighting the several similarities of Vδ1(+) cells to certain murine γδ subsets, and describing the remarkable functional plasticity of human Vδ2(+) cells. A better understanding of this spectrum of γδ cell phenotypes should facilitate more targeted approaches to utilise their tremendous functional potential in the clinic.     

Different antiviral effects of IFNα and IFNβ in an HBV mouse model

Interferons α and β (IFNα and IFNβ) are type I interferons produced by the host to control pathogen propagation. However, only a minority of chronic hepatitis B (CHB) patients generate a sustained response after treatment with recombinant IFNα. The anti-HBV effect of IFNβ and the underlying mechanism are not well-understood. Here, we compared the antiviral activities of IFNα and IFNβ by application of IFNα or IFNβ expression plasmids using the well-established HBV hydrodynamic injection (HI) mouse model. Injection of IFNα expression plasmid could significantly reduce HBV serum markers including HBsAg, HBeAg and HBV DNA as well as the number of HBcAg positive cells in the liver, while IFNβ showed only a weak inhibition of HBV replication. In contrast to IFNβ, IFNα resulted in elevated expression levels of IFN stimulated genes (ISGs) as well as the proinflammatory cytokine interleukin 6 (IL6) in the liver. Moreover, IFNβ treated mice showed higher expression levels of the anti-inflammatory cytokines IL10 and TGFβ in the liver compared to IFNα. Our results demonstrated that both IFNα and IFNβ exert antiviral activities against HBV in HI mouse model, but IFNα is more effective than IFNβ.     

Inhibition of the NF-κB and p38 MAPK pathways by scopoletin reduce the inflammation caused by carrageenan in the mouse model of pleurisy

Natural products have long been used worldwide as therapeutic agents, but it is only recently, in response to the new challenges posed by global population aging, that interest in research into potentially therapeutic natural products has reemerged. In this context, coumarins, chemical compounds found in plants that have known anti-inflammatory activity, are promising candidates for the development of new drugs. In this study we test the effect of scopoletin, a coumarin found in several plant species, on carrageenan-induced inflammation in the mouse model of pleurisy. Initially, the effects of scopoletin on leukocyte migration and exudate concentrations were evaluated at three different doses (0.1, 1 and 5?mg/kg) and time (0.5–4?h before pleurisy). In the next step, we chose the lowest dose capable of inhibiting the inflammatory parameters (1?mg/kg), in order to analyze the myeloperoxidase and adenosine deaminase activities, the nitric oxide, tumor necrosis factor-α, and interleukin 1β levels in the fluid leakage, and the p65 subunit of NF-κB and p38 MAPK phosphorylation. Scopoletin at a dose of 1?mg/kg was able to significantly reduce cell migration and exudation to the pleural fluid (p?p?p?相似文献   

Correlation of Aβ deposition in the nasal cavity with the formation of senile plaques in the brain of a transgenic mouse model of Alzheimer's disease

The deposition of β-amyloid peptides (Aβ) is commonly reported in the nasal cavity of Alzheimer's disease (AD) patients, although the pathological significance of this finding is unknown. This study compared Aβ concentrations in the nasal area with those in the brain, blood, and cerebrospinal fluid, respectively. Immunohistochemical analysis identified Aβ deposits in the nasal epithelium of Tg2576 mice. Enzyme-linked immunosorbent assay measurements revealed a correlation between the content of Aβ42 in the nasal area and that in the brain, but not with that in the blood. These results suggest that the highly accessible nasal cavity could be a useful site for diagnostic analysis of AD based on Aβ content.     

An autoimmunized mouse model recapitulates key features in the pathogenesis of Sjögren's syndrome

The pathogenesis of Sj?gren's syndrome (SS) is poorly understood. To evaluate an autoimmunization-induced experimental SS model, we firstly observed the phenotype of lymphocyte infiltration in the enlarged submandibular gland (SG). Furthermore, significant activation of caspase-3 and a high ratio of Bax-to-Bcl-2 were detected, indicating the inflammatory apoptosis associated with developmental foci. Meanwhile, the dysregulated cytokines, such as tumor necrosis factor α, IL-1β and IL-6 mRNA expression, were found to be over-expressed. A progressive decrease of aquaporin 5 and its subcellular translocation from apical to basal membrane in SG was found to be associated with the abnormally expressed M3 muscarinic acetylcholine receptor. This pattern was found to be similar to that seen in human SS and possibly contributed to the saliva secretion deficiency. Thus, this autoimmunization-induced model recapitulates the key features of human SS and may have potential for studying the pathogenesis of human SS.     

A novel lacrimal gland autoantigen in the NOD mouse model of Sjögren's syndrome

Recent research has demonstrated a crucial role for autoantibodies in the pathogenesis of Sjögren's syndrome (SS)‐like disease in the non‐obese diabetic (NOD) mouse, but it remains to be determined which antibody species among all those present are directly related to the various aspects of pathology. To identify autoantigens in the NOD mouse system, we have taken the approach of using immunoglobulin (Ig)G purified from sera of NOD mice exhibiting SS‐like symptoms to screen cDNA expression libraries derived from exocrine gland mRNA. Here we report the identification of a novel autoantigen, designated LGP10, expressed in lacrimal and submandibular glands. Autoantibodies to this protein are prominent in the sera of NOD mice starting at 11–12 weeks of age, but not in control nonautoimmune mice. LGP10 has no known function, but bears similarities to various other proteins produced by epithelia. Interestingly, all of these similar proteins have been linked to immunosuppression and/or steroid binding, both processes that could have a significant impact on pathological features of SS.     

Accumulation and distribution of α-synuclein and ubiquitin in the CNS of Gaucher disease mouse models

Gaucher disease, a prevalent lysosomal storage disease, is caused by insufficient activity of acid β-glucosidase (GCase) and resultant glucosylceramide accumulation. Recently in Parkinson disease (PD) patients, heterozygous mutations in GCase have been associated with earlier onset and more progressive PD. To understand the pathogenic relationships between GCase variants and Parkinsonism, α-synuclein and ubiquitin distributions and levels in the brains of several mouse models containing GCase variants were evaluated by immunohistochemistry. Progressive α-synuclein and ubiquitin aggregate accumulations were observed in the cortex, hippocampus, basal ganglia, brainstem, and some cerebellar regions between 4 and 24 weeks in mice that were homozygous for GCase [D409H (9H) or V394L (4L)] variants and also had a prosaposin hypomorphic (PS-NA) transgene. In 4L/PS-NA and 9H/PS-NA mice, this was coincident with progressive neurological manifestations and brain glucosylceramide accumulation. Ultrastructural studies showed electron dense inclusion bodies in neurons and axons of 9H/PS-NA brains. α-synuclein aggregates were also observed in ventricular, brainstem, and cerebellar regions of older mice (>42-weeks) with the GCase variant (D409H/D409H) without overt neurological disease. In a chemically induced GCase deficiency, α-synuclein aggregates and glucosylceramide accumulation also occurred. These studies demonstrate a relationship between glucosylceramide accumulation and α-synuclein aggregates, and implicate glucosylceramide accumulation as risk factor for the α-synucleinopathies.