A-deficient Mice Research Articles

Three-dimensional analysis of partial restoration of spermatogenesis in vitamin A-deficient mice.

An animal model of the partial restoration of spermatogenesis may be useful in the field of reproductive biology and medicine. Vitamin A deficiency (VAD) induces the restorable arrest of spermatogenesis at the level of spermatogonia and is used as a mouse model of spermatogenesis disorder. We aimed to establish an animal model in which spermatogenesis is partially restored by switching a vitamin A deficiency diet to a normal vitamin A-containing diet and conduct a comprehensive analysis to identify vulnerable sites in the seminiferous tubules that affect the efficient restoration of spermatogenesis in this model. Mice fed a vitamin A deficiency diet until 12weeks old and then reared with a normal diet for 15weeks served as the restoration model. We performed three-dimensional reconstructions of the seminiferous tubules and analyzed the three-dimensional distribution of restored spermatogenesis throughout the testis. Fifteen weeks after the switch to the normal diet, spermatogenesis was restored in 78% of the length of seminiferous tubules. The percentage of restored spermatogenesis was lower in longer seminiferous tubules. An analysis of the distribution of spermatogenesis throughout the testis in this model revealed that it was restored less in portions of seminiferous tubules near the rete testis and hairpin curves and also in those located in the caudal region of the testis. These sites tended to correspond to sites with fewer spermatogonia in the vitamin A deficiency testis. We established an animal model of the partial restoration of spermatogenesis and examined the three-dimensional distribution of restored spermatogenesis in seminiferous tubules. The results obtained provide insights into the mechanisms underlying spermatogenesis disorders and may contribute to better clinical practices, such as the screening of drugs or therapeutic interventions for human male infertility and improvements in fertility preservation techniques for individuals undergoing chemotherapy.

Therapeutic strategy for Fabry disease by intravenous administration of adeno-associated virus 2 or 9 in α-galactosidase A-deficient mice.

Fabry disease (FD) is an inherited lysosomal storage disease caused by deficiency of α-galactosidase A (α-Gal A) encoded by the GLA gene. The symptoms of FD occur as a result of the accumulation of globotriaosylceramide (Gb3), comprising a substrate of α-Gal A, in the organs. Adeno-associated virus (AAV)-mediated gene therapy is a promising treatment for FD. α-Gal A knockout (GLAko) mice were injected intravenously with AAV2 (1 × 1011 viral genomes [vg]) or AAV9 (1 × 1011 or 2 × 1012 vg) vectors carrying human GLA (AAV-hGLA), and plasma, brain, heart, liver and kidney were tested for α-Gal A activity. The vector genome copy numbers (VGCNs) and Gb3 content in each organ were also examined. The plasma α-Gal A enzymatic activity was three-fold higher in the AAV9 2 × 1012 vg group than wild-type (WT) controls, which was maintained for up to 8 weeks after injection. In the AAV9 2 × 1012 vg group, the level of α-Gal A expression was high in the heart and liver, intermediate in the kidney, and low in the brain. VGCNs in the all organs of the AAV9 2 × 1012 vg group significantly increased compared to the phosphate-buffered-saline (PBS) group. Although Gb3 in the heart, liver and kidney of the AAV9 2 × 1012 vg was reduced compared to PBS group and AAV2 group, and the amount of Gb3 in the brain was not reduced. Systemic injection of AAV9-hGLA resulted in α-Gal A expression and Gb3 reduction in the organs of GLAko mice. To expect a higher expression of α-Gal A in the brain, the injection dosage, administration route and the timing of injection should be reconsidered.

Vitamin A Promotes the Fusion of Autophagolysosomes and Prevents Excessive Inflammasome Activation in Dextran Sulfate Sodium-Induced Colitis.

Vitamin A ensures intestinal homeostasis, impacting acquired immunity and epithelial barrier function; however, its role in innate immunity is mostly unknown. Here, we studied the impact of vitamin A in different dextran sulfate sodium (DSS)-induced colitis animal models. Interestingly, more severe DSS-induced colitis was observed in vitamin A-deficient (VAD) mice than in vitamin A-sufficient (VAS) mice; the same was observed in VAD severe combined immunodeficient mice lacking T/B cells. Remarkably, IL-1β production, LC3B-II expression, and inflammasome activity in the lamina propria were significantly elevated in VAD mice. Electron microscopy revealed numerous swollen mitochondria with severely disrupted cristae. In vitro, non-canonical inflammasome signaling-induced pyroptosis, LC3B-II and p62 expression, and mitochondrial superoxide levels were increased in murine macrophages (RAW 264.7) pretreated with retinoic acid receptor antagonist (Ro41-5253). These findings suggest that vitamin A plays a crucial role in the efficient fusion of autophagosomes with lysosomes in colitis.

Overgrowth of Squamocolumnar Junction and Dysregulation of Stem Cell Lineages in the Stomach of Vitamin A-Deficient Mice

Junctional epithelia are common sites for pathological transformations. In mice, the stratified epithelium of the forestomach joins the simple glandular epithelium of the cardia at the limiting ridge. We previously demonstrated the expression of vitamin A receptors in the gastric stem/progenitor cells and their progeny and found that excess retinoic acid enhances cellular dynamics of gastric epithelium. This study examines how deficiency of vitamin A would alter gastric epithelial stem cell lineages. Three-week-old mice of both genders were weaned and fed with a vitamin A deficient (VAD) diet for 4 or 8 months. Sex- and weight-matched littermate mice received a standard (control) diet. To label S-phase cells, all mice received a single intraperitoneal injection of 5-bromo-2-deoxyuridine before being euthanized. Stomach tissues were processed for microscopic examination and protein analysis to investigate stem cell lineages using different stains, lectins, or antibodies. The Student’s t-test was used to compare quantified data showing differences between control and VAD groups. Eight-month-vitamin-A deficiency caused enlarged forestomach and overgrowth of the squamocolumnar junction with metaplastic and dysplastic cardiac glands, formation of intramucosal cysts, loss of surface mucosal integrity, increased amount of luminal surface mucus, and upregulation of trefoil factor 1 and H+,K+-ATPase. These changes were associated with decreased cell proliferation and upregulation of p63. In conclusion, vitamin A is necessary for maintaining gastric epithelial integrity and its deficiency predisposes the mouse stomach to precancerous lesions.

Action and Interaction between Retinoic Acid Signaling and Blood-Testis Barrier Function in the Spermatogenesis Cycle.

Spermatogenesis is a complex process occurring in mammalian testes, and constant sperm production depends on the exact regulation of the microenvironment in the testes. Many studies have indicated the crucial role of blood–testis barrier (BTB) junctions and retinoic acid (RA) signaling in the spermatogenesis process. The BTB consists of junctions between adjacent Sertoli cells, comprised mainly of tight junctions and gap junctions. In vitamin A-deficient mice, halted spermatogenesis could be rebooted by RA or vitamin A administration, indicating that RA is absolutely required for spermatogenesis. Accordingly, this manuscript will review and discuss how RA and the BTB regulate spermatogenesis and the interaction between RA signaling and BTB function.

A transgenic reporter mouse model for in vivo assessment of retinoic acid receptor transcriptional activation.

Background: Vitamin A is essential for a wide range of life processes throughout embryogenesis to adult life. With the aim of developing an in vivo model to monitor retinoic acid receptor (RAR) transactivation real-time in intact animals, we generated transgenic mice carrying a luciferase (luc) reporter gene under the control of retinoic acid response elements (RAREs) consisting of three copies of a direct repeat with five spacing nucleotides (DR5). Methods: Transgenic mice carrying a RARE dependent luciferase reporter flanked with insulator sequence were generated by pronuclear injection. RARE dependent luciferase activity was detected by in vivo imaging or in tissue extracts following manipulations with RAR/retinoid X receptor (RXR) agonists, RAR antagonists or in vitamin A deficient mice. Results: We found a strong induction of luciferase activity in a time and dose dependent manner by retinoic acid as well as RAR agonists, but not by the RXR agonist (using n=4-6 per group; 94 mice). In addition, luciferase activity was strongly reduced in vitamin A-deficient mice (n=6-9; 30 mice). These observations confirm that luciferase activity was controlled by RAR activation in the RARE-luc mouse. Luciferase activity was detectable in various organs, with high activity especially in brain and testis, indicating strong retinoid signalling in these tissues. Conclusion: The RARE-luc transgenic mice, which enabled real-time in vivo assessment of RAR activation, will be useful in understanding the normal physiology of vitamin A, the role of retinoid signalling in pathologies as well as to evaluate pharmacological ligands for RARs.

Vitamin A supplementation boosts control of antibiotic-resistant Salmonella infection in malnourished mice

Disseminated disease from non-typhoidal Salmonella enterica strains results in >20% mortality globally. Barriers to effective treatment include emerging multidrug resistance, antibiotic treatment failure, and risk factors such as malnutrition and related micronutrient deficiencies. Individuals in sub-Saharan Africa are disproportionately affected by non-typhoidal S. enterica bloodstream infections. To inform a clinical trial in people, we investigated vitamin A as a treatment in the context of antibiotic treatment failure in a mouse model of vitamin A deficiency. Vitamin A-deficient (VAD) mice exhibited higher systemic bacterial levels with a multidrug-resistant clinical isolate in comparison to mice on a control diet. Sex-specific differences in vitamin A deficiency and disseminated infection with S. enterica serotype Typhimurium (S. Typhimurium) were observed. VAD male mice had decreased weight gain compared to control male mice. Further, infected VAD male mice had significant weight loss and decreased survival during the course of infection. These differences were not apparent in female mice. In a model of disseminated S. Typhimurium infection and antibiotic treatment failure, we assessed the potential of two consecutive doses of vitamin A in alleviating infection in male and female mice on a VAD or control diet. We found that subtherapeutic antibiotic treatment synergized with vitamin A treatment in infected VAD male mice, significantly decreasing systemic bacterial levels, mitigating weight loss and improving survival. These results suggest that assessing vitamin A as a therapy during bacteremia in malnourished patients may lead to improved health outcomes in a subset of patients, especially in the context of antibiotic treatment failure.

Activin A Determines Steroid Levels and Composition in the Fetal Testis.

Activin A promotes fetal mouse testis development, including driving Sertoli cell proliferation and cord morphogenesis, but its mechanisms of action are undefined. We performed ribonucleic acid sequencing (RNA-seq) on testicular somatic cells from fetal activin A-deficient mice (Inhba KO) and wildtype littermates at embryonic day (E) E13.5 and E15.5. Analysis of whole gonads provided validation, and cultures with a pathway inhibitor discerned acute from chronic effects of altered activin A bioactivity. Activin A deficiency predominantly affects the Sertoli cell transcriptome. New candidate targets include Minar1, Sel1l3, Vnn1, Sfrp4, Masp1, Nell1, Tthy1 and Prss12. Importantly, the testosterone (T) biosynthetic enzymes present in fetal Sertoli cells, Hsd17b1 and Hsd17b3, were identified as activin-responsive. Activin-deficient testes contained elevated androstenedione (A4), displayed an Inhba gene dose-dependent A4/T ratio, and contained 11-keto androgens. The remarkable accumulation of lipid droplets in both Sertoli and germ cells at E15.5 indicated impaired lipid metabolism in the absence of activin A. This demonstrated for the first time that activin A acts on Sertoli cells to determine local steroid production during fetal testis development. These outcomes reveal how compounds that perturb fetal steroidogenesis can function through cell-specific mechanisms and can indicate how altered activin levels in utero may impact testis development.

Systemic mRNA Therapy for the Treatment of Fabry Disease: Preclinical Studies in Wild-Type Mice, Fabry Mouse Model, and Wild-Type Non-human Primates

Fabry disease is an X-linked lysosomal storage disease caused by loss of alpha galactosidase A (α-Gal A) activity and is characterized by progressive accumulation of globotriaosylceramide and its analogs in all cells and tissues. Although enzyme replacement therapy (ERT) is considered standard of care, the long-term effects of ERT on renal and cardiac manifestations remain uncertain and thus novel therapies are desirable. We herein report preclinical studies evaluating systemic messenger RNA (mRNA) encoding human α-Gal A in wild-type (WT) mice, α-Gal A-deficient mice, and WT non-human primates (NHPs). The pharmacokinetics and distribution of h-α-Gal A mRNA encoded protein in WT mice demonstrated prolonged half-lives of α-Gal A in tissues and plasma. Single intravenous administration of h-α-Gal A mRNA to Gla-deficient mice showed dose-dependent protein activity and substrate reduction. Moreover, long duration (up to 6weeks) of substrate reductions in tissues and plasma were observed after a single injection. Furthermore, repeat i.v. administration of h-α-Gal A mRNA showed a sustained pharmacodynamic response and efficacy in Fabry mice model. Lastly, multiple administrations to non-human primates confirmed safety and translatability. Taken together, these studies across species demonstrate preclinical proof-of-concept of systemic mRNA therapy for the treatment of Fabry disease and this approach may be useful for other lysosomal storage disorders.

Progressive hearing loss in vitamin A-deficient mice which may be protected by the activation of cochlear melanocyte

Vitamin A deficiency (VAD) produces various pathologic phenotypes in humans and animals. However, evidence regarding the effect of VAD on hearing function has been inconsistent. In this study, we evaluated the effect of VAD on hearing function in two mouse models of VAD. Hearing ability was evaluated on the basis of auditory brainstem response from 3 to 20 weeks after birth in C57BL/6 (pigmented) and imprinting control region (albino) mice. The two mice strains were divided into the VAD (purified vitamin A-free diet from 7 days after pregnancy) and control (normal diet) groups. Albino VAD mice exhibited hearing loss after 6 weeks and became deaf at 18 weeks. Histological findings revealed degenerative changes in outer hair cells and neuronal loss in the spiral ganglion in albino VAD mice. In contrast, pigmented VAD mice, except those with middle-ear infection, showed no significant hearing loss. Interestingly, pigmented VAD mice exhibited melanocyte activation in the stria vascularis and upregulation of tyrosinase. Recovery of hearing after noise exposure was poorer in pigmented VAD mice than in control mice. In conclusion, complete VAD might be related to age-related or noise-induced hearing loss in mice, protection against which might involve melanocyte activation.

IL-17 Receptor Signaling Negatively Regulates the Development of Tubulointerstitial Fibrosis in the Kidney.

Chronic inflammation has an important role in the development and progression of most fibrotic diseases, for which no effective treatments exist. Tubulointerstitial fibrosis (TF) is characterized by irreversible deposition of fibrous tissue in chronic kidney diseases. Prolonged injurious stimuli and chronic inflammation regulate downstream events that lead to TF. In recent years, interleukin-17 (IL-17) has been strongly linked to organ fibrosis. However, the role of IL-17 receptor signaling in TF is an active area of debate. Using the unilateral ureteral obstruction (UUO) mouse model of TF, we show that IL-17 receptor A-deficient mice (Il17ra−/−) exhibit increased TF in the obstructed kidney. Consequently, overexpression of IL-17 restored protection in mice with UUO. Reduced renal expression of matrix-degrading enzymes results in failure to degrade ECM proteins, thus contributing to the exaggerated TF phenotype in Il17ra−/− mice. We demonstrate that the antifibrotic kallikrein-kinin system (KKS) is activated in the obstructed kidney in an IL-17-dependent manner. Accordingly, Il17ra−/− mice receiving bradykinin, the major end-product of KKS activation, prevents TF development by upregulating the expression of matrix-degrading enzymes. Finally, we show that treatment with specific agonists for bradykinin receptor 1 or 2 confers renal protection against TF. Overall, our results highlight an intriguing link between IL-17 and activation of KKS in protection against TF, the common final outcome of chronic kidney conditions leading to devastating end-stage renal diseases.

Mechanism underlying the suppressor activity of retinoic acid on IL4-induced IgE synthesis and its physiological implication

The present study extends an earlier report that retinoic acid (RA) down-regulates IgE Ab synthesis in vitro. Here, we show the suppressive activity of RA on IgE production in vivo and its underlying mechanisms. We found that RA down-regulated IgE class switching recombination (CSR) mainly through RA receptor α (RARα). Additionally, RA inhibited histone acetylation of germ-line ε (GL ε) promoter, leading to suppression of IgE CSR. Consistently, serum IgE levels were substantially elevated in vitamin A-deficient (VAD) mice and this was more dramatic in VAD-lecithin:retinol acyltransferase deficient (LRAT−/−) mice. Further, serum mouse mast cell protease-1 (mMCP-1) level was elevated while frequency of intestinal regulatory T cells (Tregs) were diminished in VAD LRAT−/− mice, reflecting that deprivation of RA leads to allergic immune response. Taken together, our results reveal that RA has an IgE-repressive activity in vivo, which may ameliorate IgE-mediated allergic disease.

Retraction: Nitric Oxide Mediates Relative Airway Hyporesponsiveness to Lipopolysaccharide in Surfactant Protein A-Deficient Mice.

Retraction: Nitric Oxide Mediates Relative Airway Hyporesponsiveness to Lipopolysaccharide in Surfactant Protein A-Deficient Mice.

Maternal vitamin A deficiency during pregnancy affects vascularized islet development

Vitamin A deficiency is known to affect 20 million pregnant women worldwide. However, the prenatal effects of maternal vitamin A deficiency on pancreas development have not been clearly determined. The present study examined how maternal vitamin A deficiency affects fetal islet development. Vitamin A-deficient mice were generated by feeding female mice with a chemically defined diet lacking vitamin A prior to mating as well as during pregnancy. We found that maternal vitamin A deficiency during pregnancy affected fetal pancreas development. Although the exocrine differentiation appeared normal, development of islet tissue was impaired. In the pancreas of neonatal mice, only a few endocrine cell clusters were formed, and these cell clusters lacked capillary endothelial cells. To further determine how vitamin A metabolites, such as retinoic acid, regulate vascularized islet development, ex vivo culture of embryonic pancreas either in the presence of 4-diethylaminobenzaldehyde (DEAB; an inhibitor of retinaldehyde dehydrogenase), all-trans retinoic acid (atRA) or retinoic acid receptor agonist (E)-4-[2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthylenyl)-1-propenyl] benzoic acid (TTNPB) was carried out. We found that the addition of DEAB blocked vascularization and suppressed β-cell differentiation. Conversely, atRA or TTNPB promoted β-cell differentiation accompanied by enhanced expression of vascular basement component, laminin. We further demonstrated that atRA regulated vascularization via upregulating vascular endothelial growth factor-A (VEGF-A) secretion in embryonic pancreas and treatment with VEGF-A was able to partially rescue vascularization and β-cell differentiation in DEAB-treated embryonic pancreas cultures. The findings explain why maternal vitamin A deficiency affects fetal islet development and support an essential role of retinoid signaling in regulating vascularized islet development.

De Novo-Synthesized Retinoic Acid in Ovarian Antral Follicles Enhances FSH-Mediated Ovarian Follicular Cell Differentiation and Female Fertility.

Retinoic acid (RA) is the active form of vitamin A and is synthesized from retinol by two key enzymes, alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH). As the physiological precursor of RA, retinol impacts female reproductive functions and fertility. The expression of Adh1 and Adh5 as well as Aldh1a1 and Aldh1a7 are significantly increased in the ovaries of mice treated with equine chorionic gonadotropin/FSH. The RA receptor is expressed and localized in granulosa cells and is activated by endogenous RA as indicated by LacZ expression in granulosa cells of RA-responsive transgene-LacZ transgenic mice (RA reporter mice). Coinjection of the ADH inhibitor, 4-methylpyrazole, with equine chorionic gonadotropin significantly decreases the number and developmental competence of oocytes ovulated in response to human chorionic gonadotropin/LH as compared with controls. Injections of RA completely reverse the effects of the inhibitor of ovulation and oocyte development. When mice were fed a retinol-free, vitamin A-deficient diet that significantly reduced the serum levels of retinol, the expression of the LH receptor (Lhcgr) was significantly lower in the ovaries of the vitamin A-deficient mice, and injections of human chorionic gonadotropin failed to induce genes controlling ovulation. These results indicate that ovarian de novo biosynthesis of RA is required for the follicular expression of Lhcgr in granulosa cells and their ability to respond to the ovulatory LH surge.

Vitamin A Inhibits Development of Dextran Sulfate Sodium-Induced Colitis and Colon Cancer in a Mouse Model.

Vitamin A is essential to mucosal immunity and cell differentiation. The fact that lack of it might involve chronic inflammation and increased risk of cancer has been reported. Little is known about the mechanism of vitamin A deficiency in the development of colitis and its influence on development of colorectal cancer. To determine the influence of vitamin A deficiency on colitis and colorectal cancer development, an experimental study using a colitis mouse model was performed. Dextran sulfate sodium (DSS) colitis was induced in vitamin A-deficient and vitamin A-supplemented mice. Further, colorectal carcinoma was induced by a combination of azoxymethane preinjection and DSS colitis. Results were compared between the two groups mainly by immunohistochemical analysis. Colitis was more severe and recovery from colitis was slower in vitamin A-deficient mice than in vitamin A-supplemented mice. Compared with vitamin A-supplemented mice, vitamin A-deficient mice had decreases in colonic subepithelial myofibroblasts and the ratio of mucosal IgA+/IgG+ cells, increases in CD11c+ dendritic cells, and a higher rate of development of colorectal carcinoma with colitis following azoxymethane. Vitamin A lipid droplets in subepithelial myofibroblasts were decreased in vitamin A-deficient mice, suggesting alterations in colonic crypt niche function. Thus, vitamin A inhibited colitis and the development of colorectal cancer.

Retinoid signaling controls spermatogonial differentiation by regulating expression of replication-dependent core histone genes.

Retinoic acid (RA) signaling is crucial for spermatogonial differentiation, which is a key step for spermatogenesis. We explored the mechanisms underlying spermatogonial differentiation by targeting expression of a dominant-negative mutant of retinoic acid receptor α (RARα) specifically to the germ cells of transgenic mice to subvert the activity of endogenous receptors. Here we show that: (1) inhibition of retinoid signaling in germ cells completely blocked spermatogonial differentiation identical to vitamin A-deficient (VAD) mice; (2) the blockage of spermatogonial differentiation by impaired retinoid signaling resulted from an arrest of entry of the undifferentiated spermatogonia into S phase; and (3) retinoid signaling regulated spermatogonial differentiation through controlling expression of its direct target genes, including replication-dependent core histone genes. Taken together, our results demonstrate that the action of retinoid signaling on spermatogonial differentiation in vivo is direct through the spermatogonia itself, and provide the first evidence that this is mediated by regulation of expression of replication-dependent core histone genes.

Retinoic-acid-mediated HRas stabilization induces neuronal differentiation of neural stem cells during brain development.

Ras signaling is tightly regulated during neural stem cell (NSC) differentiation, and defects in this pathway result in aberrant brain development. However, the mechanism regulating Ras signaling during NSC differentiation was unknown. Here, we show that stabilized HRas specifically induces neuronal differentiation of NSCs. Lentivirus-mediated HRas overexpression and knockdown resulted in stimulation and inhibition, respectively, of NSC differentiation into neuron in the ex vivo embryo. Retinoic acid, an active metabolite of vitamin A, promoted neuronal differentiation of NSCs by stabilizing HRas, and HRas knockdown blocked the retinoic acid effect. Vitamin-A-deficient mice displayed abnormal brain development with reduced HRas levels and a reduced thickness of the postmitotic region containing differentiated neurons. All of these abnormal phenotypes were rescued with the restoration of HRas protein levels achieved upon feeding with a retinoic-acid-supplemented diet. In summary, this study shows that retinoic acid stabilizes HRas protein during neurogenesis, and that this is required for NSC differentiation into neurons and murine brain development.

Comprehensive and differential long-term characterization of the alpha-galactosidase A deficient mouse model of Fabry disease focusing on the sensory system and pain development.

BackgroundFabry disease is an X-linked lysosomal storage disorder due to impaired activity of alpha-galactosidase A with intracellular accumulation of globotriaosylceramide. Associated small fiber pathology leads to characteristic pain in Fabry disease. We systematically assessed sensory system, physical activity, metabolic parameters, and morphology of male and female mice with alpha-galactosidase A deficiency (Fabry ko) from 2 to 27 months of age and compared results with those of age- and gender-matched wild-type littermates of C57Bl/6J background.ResultsFrom the age of two months, male and female Fabry mice showed mechanical hypersensitivity (p < 0.001 each) compared to wild-type littermates. Young Fabry ko mice of both genders were hypersensitive to heat stimulation (p < 0.01) and developed heat hyposensitivity with aging (p < 0.05), while cold hyposensitivity was present constantly in young (p < 0.01) and old (p < 0.05) Fabry ko mice compared to wild-type littermates. Stride angle increased only in male Fabry ko mice with aging (p < 0.01) in comparison to wild-type littermates. Except for young female mice, male (p < 0.05) and female (p < 0.01) Fabry ko mice had a higher body weight than wild-type littermates. Old male Fabry ko mice were physically less active than their wild-type littermates (p < 0.05), had lower chow intake (p < 0.001), and lost more weight (p < 0.001) in a one-week treadmill experiment than wild-type littermates. Also, Fabry ko mice showed spontaneous pain protective behavior and developed orofacial dysmorphism resembling patients with Fabry disease.ConclusionsMice with alpha-galactosidase A deficiency show age-dependent and distinct deficits of the sensory system. alpha-galactosidase A-deficient mice seem to model human Fabry disease and may be helpful when studying the pathophysiology of Fabry-associated pain.

Lyso-glycosphingolipid abnormalities in different murine models of lysosomal storage disorders

In lysosomal glycosphingolipid storage disorders, marked elevations in corresponding glycosphingoid bases (lyso-glycosphingolipids) have been reported, such as galactosylsphingosine in Krabbe disease, glucosylsphingosine in Gaucher disease and globotriaosylsphingosine in Fabry disease. Using LC–MS/MS, we comparatively investigated the occurrence of abnormal lyso-glycosphingolipids in tissues and plasma of mice with deficiencies in lysosomal α-galactosidase A, glucocerebrosidase and galactocerebrosidase. The nature and specificity of lyso-glycosphingolipid abnormalities are reported and compared to that in correspondingly more abundant N-acylated glycosphingolipids. Specific elevations in tissue and plasma globotriaosylsphingosine were detected in α-galactosidase A-deficient mice; glucosylsphingosine in glucocerebrosidase-deficient mice and galactosylsphingosine in galactocerebrosidase-deficient animals. A similar investigation was conducted for two mouse models of Niemann Pick type C (Npc1nih and Npc1nmf164), revealing significant tissue elevation of several neutral glycosphingolipids and concomitant increased plasma glucosylsphingosine. This latter finding was recapitulated by analysis of plasma of NPC patients. The value of plasma glucosylsphingosine in biochemical confirmation of the diagnosis of NPC is discussed.