Analysis of Brain Lipids in the Early-Onset Tay-Sachs Disease Mouse Model With the Combined Deficiency of ß-Hexosaminidase A and Neuraminidase 3.

Introduction: Tay-Sachs disease is an autosomal recessively inherited lysosomal storage disease that results from loss-of-function mutations in the HEXA gene coding ß-hexosaminidase A. HEXA gene deficiency affects the central nervous system owing to GM2 ganglioside accumulation in lysosomes resulting in progressive neurodegeneration in patients. We recently generated a novel mice model with a combined deficiency of ß-hexosaminidase A and neuraminidase 3 (Hexa-/-Neu3-/-) that mimics both the neuropathological and clinical abnormalities of early-onset Tay-Sachs disease. Here, we aimed to explore the secondary accumulation of lipids in the brain of Hexa-/-Neu3-/- mice. Materials and Methods: In the cortex and hippocampus of five-month-old WT, Hexa-/-, Neu3-/-, and Hexa-/-Neu3-/- mice, lipid levels belonging to glycerolipids, glycerophospholipids, and sterol lipids were evaluated using a shotgun lipidomics approach. The levels of myelin were also assessed by luxol fast blue staining and immunohistochemistry using antibodies against myelin basic protein. We further examined glycoconjugate and cholesterol levels by periodic acid-Schiff and filipin staining, respectively. Toluidine blue staining was also performed to display axonal degeneration. Results: Among glycerophospholipids, we demonstrated elevated levels of phosphatidylcholine-ether and lysophosphatidylcholine while decreased levels of phosphatidylcholine and phosphatidylserine in both cortex and hippocampus of Hexa-/-Neu3-/- mice. In the glycerolipid class, we showed an alleviated level of sphingomyelin in both cortex and hippocampus, but the higher levels of diacylglycerol and triacylglycerol were detected in only the hippocampus of Hexa-/-Neu3-/- mice. The lower level of sterol was also detected in the cortex of Hexa-/-Neu3-/- mice but not in the hippocampus. Histochemical studies showed a decrease in the myelin level and axonal degeneration indicating neuronal pathology in the brain of Hexa-/-Neu3-/- mice. Although glycoconjugate accumulation was evident both in the cortex and hippocampus, we did not detect any changes in the level of cholesterol. Conclusion: Our results indicate that alterations in lipid metabolism and neuropathology, such as demyelination and axonal degeneration, might be related to the dysfunctionality of lipid-related cellular pathways like autophagy. Understanding of brain-specific lipid alterations contributes to evaluating the effectiveness of treatments in Hexa-/-Neu3-/- mice in future studies.

Modulation of Gut Barrier Functions in Ulcerative Colitis by Hyaluronic Acid System.

The active stages of intestinal inflammation and the pathogenesis of ulcerative colitis are associated with superficial mucosal damage and intermittent wounding that leads to epithelial barrier defects and increased permeability. The standard therapeutic interventions for colitis have focused mainly on maintaining the remission levels of the disease. Nonetheless, such treatment strategies (using anti-inflammatory, immunomodulatory agents) do not address colitis' root cause, especially the mucosal damage and dysregulated intestinal barrier functions. Restoration of barrier functionality by mucosal healing or physical barrier protecting strategies shall be considered as an initial event in the disease suppression and progression. Herein, a biphasic hyaluronan (HA) enema suspension, naïve-HA systems that protect the dysregulated gut epithelium by decreasing the inflammation, permeability, and helping in maintaining the epithelial barrier integrity in the dextran sodium sulfate-induced colitis mice model is reported. Furthermore, HA-based system modulates intestinal epithelial junctional proteins and regulatory signaling pathways, resulting in attenuation of inflammation and mucosal protection. The results suggest that HA-based system can be delivered as an enema to act as a barrier protecting system for managing distal colonic inflammatory diseases, including colitis.

Sialidase neu4 deficiency is associated with neuroinflammation in mice.

Sialidases catalyze the removal of sialic acid residues from glycoproteins, oligosaccharides, and sialylated glycolipids. Sialidase Neu4 is in the lysosome and has broad substrate specificity. Previously generated Neu4-/- mice were viable, fertile and lacked gross morphological abnormalities, but displayed a marked vacuolization and lysosomal storage in lung and spleen cells. In addition, we showed that there is an increased level of GD1a ganglioside and a markedly decreased level of GM1 ganglioside in the brain of Neu4-/- mice. In this study, we further explored whether sialidase Neu4 deficiency causes neuroinflammation. We demostrated that elevated level of GD1a and GT1b is associated with an increased level of LAMP1-positive lysosomal vesicles and Tunel-positive neurons correlated with alterations in the expression of cytokines and chemokines in adult Neu4-/- mice. Astrogliosis and microgliosis were also significantly enhanced in the hippocampus, and cerebellum. These changes in brain immunity were accompanied by motor impairment in these mice. Our results indicate that sialidase Neu4 is a novel mediator of an inflammatory response in the mouse brain due to the altered catabolism of gangliosides.

A Self-Powered Piezo-Bioelectric Device Regulates Tendon Repair-Associated Signaling Pathways through Modulation of Mechanosensitive Ion Channels.

Tendon disease constitutes an unmet clinical need and remains a critical challenge in the field of orthopaedic surgery. Innovative solutions are required to overcome the limitations of current tendon grafting approaches, and bioelectronic therapies show promise in treating musculoskeletal diseases, accelerating functional recovery through the activation of tissue regeneration-specific signaling pathways. Self-powered bioelectronic devices, particularly piezoelectric materials, represent a paradigm shift in biomedicine, negating the need for battery or external powering and complementing existing mechanotherapy to accelerate the repair processes. Here, the dynamic response of tendon cells to a piezoelectric collagen-analogue scaffold comprised of aligned nanoscale fibers made of the ferroelectric material poly(vinylidene fluoride-co-trifluoroethylene) is shown. It is demonstrated that motion-powered electromechanical stimulation of tendon tissue through piezo-bioelectric device results in ion channel modulation in vitro and regulates specific tissue regeneration signaling pathways. Finally, the potential of the piezo-bioelectronic device in modulating the progression of tendinopathy-associated processes in vivo, using a rat Achilles acute injury model is shown. This study indicates that electromechanical stimulation regulates mechanosensitive ion channel sensitivity and promotes tendon-specific over non-tenogenic tissue repair processes.

GM2 ganglioside accumulation causes neuroinflammation and behavioral alterations in a mouse model of early onset Tay-Sachs disease.

BACKGROUND: Tay-Sachs disease (TSD), a type of GM2-gangliosidosis, is a progressive neurodegenerative lysosomal storage disorder caused by mutations in the α subunit of the lysosomal ß-hexosaminidase enzyme. This disease is characterized by excessive accumulation of GM2 ganglioside, predominantly in the central nervous system. Although Tay-Sachs patients appear normal at birth, the progressive accumulation of undegraded GM2 gangliosides in neurons leads to death. Recently, an early onset Tay-Sachs disease mouse model, with genotype Hexa-/-Neu3-/-, was generated. Progressive accumulation of GM2 led to premature death of the double KO mice. Importantly, this double-deficient mouse model displays typical features of Tay-Sachs patients, such as cytoplasmic vacuolization of nerve cells, deterioration of Purkinje cells, neuronal death, deceleration in movement, ataxia, and tremors. GM2-gangliosidosis is characterized by acute neurodegeneration preceded by activated microglia expansion, macrophage, and astrocyte activation, along with the production of inflammatory mediators. However, the mechanism of disease progression in Hexa-/-Neu3-/- mice, relevant to neuroinflammation is poorly understood. METHOD: In this study, we investigated the onset and progression of neuroinflammatory changes in the cortex, cerebellum, and retina of Hexa-/-Neu3-/- mice and control littermates by using a combination of molecular genetics and immunochemical procedures. RESULTS: We found elevated levels of pro-inflammatory cytokine and chemokine transcripts, such as Ccl2, Ccl3, Ccl4, and Cxcl10 and also extensive microglial and astrocyte activation and proliferation, accompanied by peripheral blood mononuclear cell infiltration in the vicinity of neurons and oligodendrocytes. Behavioral tests demonstrated a high level of anxiety, and age-dependent loss in both spatial learning and fear memory in Hexa-/-Neu3-/- mice compared with that in the controls. CONCLUSION: Altogether, our data suggest that Hexa-/-Neu3-/- mice display a phenotype similar to Tay-Sachs patients suffering from chronic neuroinflammation triggered by GM2 accumulation. Furthermore, our work contributes to better understanding of the neuropathology in a mouse model of early onset Tay-Sachs disease.

The Second Case of Saposin A Deficiency and Altered Autophagy.

Krabbe disease is a lysosomal storage disease caused by galactosylceramidase deficiency, resulting in neurodegeneration with a rapid clinical downhill course within the first months of life in the classic infantile form. This process may be triggered by the accumulation of galactosylceramide (GalCer) in nervous tissues. Both the enzyme galactosylceramidase and its in vivo activator molecule, saposin A, are essential during GalCer degradation. A clinical manifestation almost identical to Krabbe disease is observed when, instead of the galactosylceramidase protein, the saposin A molecule is defective. Saposin A results from posttranslational processing of the precursor molecule, prosaposin, encoded by the PSAP gene. Clinical and neuroimaging findings in a 7-month-old child strongly suggested Krabbe disease, but this condition was excluded by enzymatic and genetic testing. However, at whole exome sequencing, the previously undescribed homozygous, obviously pathogenic PSAP gene NM_002778.3:c.209T>G(p.Val70Gly) variant was determined in the saposin A domain of the PSAP gene. Fibroblast studies showed GalCer accumulation and the activation of autophagy for the first time in a case of human saposin A deficiency. Our patient represents the second known case in the literature and provides new information concerning the pathophysiology of saposin A deficiency and its intralysosomal effects.

The publication rates of abstracts presented at the Turkish Respiratory Society (TUSAD) annual congress: adequate or not?

OBJECTIVE: In this study, we aimed to determine the publication status of the abstracts presented at the Turkish Respiratory Society Congress between 2011 and 2014. METHODS: The abstracts were classified according to presentation type (oral presentations, poster discussion, etc.), study type, study design, topic, publication status, time interval between the presentation and the publication date, and the journal in which the article was published. The conversion rate of presentations into full-text articles in peer-reviewed journals were surveyed through Elsevier's Scopus. RESULTS: The total number of abstracts submitted in the congress was 2 009. In terms of study type, the majority of abstracts were case reports (56.4%) and the remainder was original research. Totally, 179 abstracts were published in an indexed journal with an overall publication rate of 8.9%. 18.3% of oral presentations were converted into full-text article. Publication rates according to study types were 14.8% for original researches and 4.4% for case reports. The first three subspecialties with the highest publication rates were "sleep related breathing disorders" (16.9%), "interventional pulmonology" (16.7%) and "pleural diseases" (15.2%). Median publication/acceptance time was 8.0 months (0-38). CONCLUSION: This is the first study evaluating the publication rates of abstracts presented in a respiratory congress. Although the number of presented abstracts in the congress increased year by year, prominently in the case reports, over all conversion rates were decreased. We put forward that encouraging the authors to conduct higher-quality investigations would raise the publication rate as well as improve the scientific quality of congress.

Murine Sialidase Neu3 facilitates GM2 degradation and bypass in mouse model of Tay-Sachs disease.

Tay-Sachs disease is a severe lysosomal storage disorder caused by mutations in Hexa, the gene that encodes for the α subunit of lysosomal ß-hexosaminidase A (HEXA), which converts GM2 to GM3 ganglioside. Unexpectedly, Hexa-/- mice have a normal lifespan and show no obvious neurological impairment until at least one year of age. These mice catabolize stored GM2 ganglioside using sialidase(s) to remove sialic acid and form the glycolipid GA2, which is further processed by ß-hexosaminidase B. Therefore, the presence of the sialidase (s) allows the consequences of the Hexa defect to be bypassed. To determine if the sialidase NEU3 contributes to GM2 ganglioside degradation, we generated a mouse model with combined deficiencies of HEXA and NEU3. The Hexa-/-Neu3-/- mice were healthy at birth, but died at 1.5 to 4.5months of age. Thin-layer chromatography and mass spectrometric analysis of the brains of Hexa-/-Neu3-/- mice revealed the abnormal accumulation of GM2 ganglioside. Histological and immunohistochemical analysis demonstrated cytoplasmic vacuolation in the neurons. Electron microscopic examination of the brain, kidneys and testes revealed pleomorphic inclusions of many small vesicles and complex lamellar structures. The Hexa-/-Neu3-/- mice exhibited progressive neurodegeneration with neuronal loss, Purkinje cell depletion, and astrogliosis. Slow movement, ataxia, and tremors were the prominent neurological abnormalities observed in these mice. Furthermore, radiographs revealed abnormalities in the skeletal bones of the Hexa-/-Neu3-/- mice. Thus, the Hexa-/-Neu3-/- mice mimic the neuropathological and clinical abnormalities of the classical early-onset Tay-Sachs patients, and provide a suitable model for the future pre-clinical testing of potential treatments for this condition.

Effects of cell-mediated osteoprotegerin gene transfer and mesenchymal stem cell applications on orthodontically induced root resorption of rat teeth.

Aim: The aim of this study is to evaluate and compare therapeutic effects of mesenchymal stem cell (MSCs) and osteoprotegerin (OPG) gene transfer applications on inhibition and/or repair of orthodontically induced inflammatory root resorption (OIIRR). Materials and methods: Thirty Wistar rats were divided into four groups as untreated group (negative control), treated with orthodontic appliance group (positive control), MSCs injection group, and OPG transfected MSCs [gene therapy (GT) group]. About 100g of orthodontic force was applied to upper first molar teeth of rats for 14 days. MSCs and transfected MSC injections were performed at 1st, 6th, and 11th days to the MSC and GT group rats. At the end of experiment, upper first molar teeth were prepared for genetical, scanning electron microscopy (SEM), fluorescent microscopy, and haematoxylin eosin-tartrate resistant acid phosphatase staining histological analyses. Number of total cells, number of osteoclastic cells, number of resorption lacunae, resorption area ratio, SEM resorption ratio, OPG, RANKL, Cox-2 gene expression levels at the periodontal ligament (PDL) were calculated. Paired t-test, Kruskal-Wallis, and chi-square tests were performed. Results: Transferred MSCs showed marked fluorescence in PDL. The results revealed that number of osteoclastic cells, resorption lacunae, resorption area ratio, RANKL, and Cox-2 were reduced after single MSC injections significantly (P < 0.05). GT group showed the lowest number of osteoclastic cells (P < 0.01), number of resorption lacunae, resorption area ratio, and highest OPG expression (P < 0.001). Conclusions: Taken together all these results, MSCs and GT showed marked inhibition and/or repair effects on OIIRR during orthodontic treatment on rats.

Lysosomal Cathepsin A Plays a Significant Role in the Processing of Endogenous Bioactive Peptides.

Lysosomal serine carboxypeptidase Cathepsin A (CTSA) is a multifunctional enzyme with distinct protective and catalytic function. CTSA present in the lysosomal multienzyme complex to facilitate the correct lysosomal routing, stability and activation of with beta-galactosidase and alpha-neuraminidase. Beside CTSA has role in inactivation of bioactive peptides including bradykinin, substances P, oxytocin, angiotensin I and endothelin-I by cleavage of 1 or 2 amino acid(s) from C-terminal ends. In this study, we aimed to elucidate the regulatory role of CTSA on bioactive peptides in knock-in mice model of CTSAS190A . We investigated the level of bradykinin, substances P, oxytocin, angiotensin I and endothelin-I in the kidney, liver, lung, brain and serum from CTSAS190A mouse model at 3- and 6-months of age. Our results suggest CTSA selectively contributes to processing of bioactive peptides in different tissues from CTSAS190A mice compared to age matched WT mice.

Changes in the inflammatory markers with advancing stages of diabetic nephropathy and the role of pentraxin-3.

BACKGROUND: Immunological and inflammatory mechanisms have been shown to have role in both the development and progression of diabetic nephropathy (DNP). There is need for more specific markers for inflammation as the ones commonly used are influenced by many factors. Pentraxin-3 (PTX-3) seems to be a potential candidate. We aimed in our study to evaluate the changes of PTX-3 levels in different stages of DNP and its relationship with other inflammatory markers. METHODS: This is a cross sectional study in which patients with DNP at different stages were involved. Patient were divided into three groups according to estimated glomerular filtration rate (eGFR), microalbuminuria and proteinuria levels: Group-1: eGFR >60 mL/min and microalbuminuria, Group-2: eGFR >60 mL/min and macroalbuminuria, Group-3: eGFR <60 mL/min and macroalbuminuria. Besides the routine biochemical parameters, levels of PTX-3, high sensitivity C-reactive protein (hsCRP), interleukin (IL)-1 and tumor necrosis factor (TNF)-α was measured. Groups were compared with each other regarding the study parameters and correlation of PTX-3 with other markers was evaluated. RESULTS: The mean PTX-3 level in Group-2 (0.94 ± 0.26 ng/mL) and -3 (1.35 ± 1.55 ng/mL) were higher than in Group-1 (0.81 ± 0.25 ng/mL) (p = 0.009 and p = 0.012). There was a significant correlation of PTX-3 with proteinuria (r = 0.266, p = 0.016), microalbuminuria (r = 0.304, p = 0.014) and hypoalbuminemia (r = 0.197, p = 0.043). PTX-3 was not correlated with other markers of inflammation (IL-1, TNF-α and hsCRP) and diabetic metabolic parameters (hbA1c, C-peptide, insulin and HOMA-IR). PTX-3, IL-1 and TNF-α levels increased with the advancing stage of DNP while hsCRP level did not change. CONCLUSION: PTX-3 that increases similar to other markers of inflammation (IL-1, TNF-α) is a better inflammatory marker than hsCRP. Furthermore, there is a relationship between PTX-3 and proteinuria independent from eGFR.

A case of newly diagnosed klippel trenaunay weber syndrome presenting with nephrotic syndrome.

Klippel Trenaunay Weber syndrome (KTWS) is a rare disease characterized by hemihypertrophy, variceal enlargement of the veins, and arteriovenous (AV) malformations. Renal involvement in KTWS is not known except in rare case reports. Herein, we present a case of KTWS with nephrotic syndrome. A 52-year-old male was admitted due to dyspnea and swelling of the body for the last three months. The pathological physical findings were diffuse edema, decreased lung sounds at the right basal site, increased diameter and decreased length of the left leg compared with the right one, diffuse variceal enlargements, and a few hemangiomatous lesions on the left leg. The pathological laboratory findings were hypoalbuminemia, hyperlipidemia, increased creatinine level (1.23 mg/dL), and proteinuria (7.6 g/day). Radiographic pathological findings were cystic lesions in the liver, spleen, and kidneys, splenomegaly, AV malformation on the left posterolateral thigh, and hypertrophy of the soft tissues of the proximal left leg. He was diagnosed to have KTWS with these findings. Renal biopsy was performed to determine the cause of nephrotic syndrome. The pathologic examination was consistent with focal segmental sclerosis (FSGS). He was started on oral methylprednisolone at the dosage of 1 mg/kg and began to be followedup in the nephrology outpatient clinic.