Inflammasome in ALS Skeletal Muscle: NLRP3 as a Potential Biomarker.

Since NLRP3 inflammasome plays a pivotal role in several neurodegenerative disorders, we hypothesized that levels of inflammasome components could help in diagnosis or prognosis of amyotrophic lateral sclerosis (ALS). Gene and protein expression was assayed by RT-PCR and Western blot. Spearman's correlation coefficient was used to determine the linear correlation of transcriptional expression levels with longevity throughout disease progression in mice models. Kaplan-Meier analysis was performed to evaluate MCC950 effects (NLRP3 inhibitor) on lifespan of SOD1G93A mice. The results showed significant alterations in NLRP3 inflammasome gene and protein levels in the skeletal muscle of SOD1G93A mice. Spearman's correlation coefficient revealed a positive association between Nlrp3 transcriptional levels in skeletal muscle and longevity of SOD1G93A mice (r = 0.506; p = 0.027). Accordingly, NLRP3 inactivation with MCC950 decreased the lifespan of mice. Furthermore, NLRP3 mRNA levels were significantly elevated in the blood of ALS patients compared to healthy controls (p = 0.03). In conclusion, NLRP3 could be involved in skeletal muscle pathogenesis of ALS, either through inflammasome or independently, and may play a dual role during disease progression. NLRP3 gene expression levels could be used as a biomarker to improve diagnosis and prognosis in skeletal muscle from animal models and also to support diagnosis in clinical practice with the blood of ALS patients.

Impact of gilt immunocastration on weight losses and instrumental and chemical characteristics of Teruel dry-cured ham.

A total of 32 fresh hams intended for the Spanish Protected Designation of Origin "Teruel ham" were used to evaluate the impact of gilt immunocastration (vs. entire gilts) on weight losses during the dry-curing process. After processing, 20 dry-cured hams (10 of each group) were chosen at random to assess instrumental and chemical characteristics. Hams from immunocastrated gilts tended (P = 0.057) to present lower weight losses, they were fattier (P < 0.05) at both subcutaneous and intramuscular levels and had lower (P < 0.05) water activity and volatile compounds that provide unpleasant odors than those from entire gilts. However, immunocastration increased (P < 0.05) slightly sodium chloride and sodium nitrite contents, being normal levels. Fatty acid profile was not significantly affected (P > 0.05). It can be concluded that, in general, immunocastration could be a good strategy in gilts to improve the quality of Teruel dry-cured ham.

Sex, fiber-type, and age dependent in vitro proliferation of mouse muscle satellite cells.

During postnatal growth and after muscle injury, satellite cells proliferate and differentiate into myotubes to form and repair musculature. Comparison of studies on satellite cell proliferation and differentiation characteristics is confounded by the heterogeneity of the experimental conditions used. To examine the influence of sex, age, and fiber-type origin on in vitro properties of satellite cells derived from postnatal muscles, fast extensor digitorum longus (EDL) and slow soleus (SOL) muscles were extracted from male and female mice of 1 week to 3 months of age. Myoblast proliferation and myogenic regulatory factor (MRF) expression was measured from cultures of freshly isolated satellite cells. Higher proliferation rate and elevated Myod1 expression was found in male EDL and SOL derived cells compared with females at age of 40, 60, and 120 days, whereas inverse tendency for cell proliferation was apparent in EDL of juvenile (7-day-old) pups. Myogenin and Mrf4 transcripts were generally elevated in males of 40 and 60 days of age and in female EDL of juveniles. However, these differentiation markers did not significantly correlate with proliferation rate at all ages. Pax7, whose overexpression can block myogenesis, was up-regulated especially in 40-day-old females where MRF expression was low. These results indicate that gender, postnatal age, and muscle fiber origin affect proliferation and muscle transcription factor expression in vitro. The results also support the view that satellite cells originating from slow and fast muscles are intrinsically different and warrant further studies on the effect of cell origin for therapeutic approaches.

Melatonin protects against taurolithocholic-induced oxidative stress in rat liver.

Cholestasis, encountered in a variety of clinical disorders, is characterized by intracellular accumulation of toxic bile acids in the liver. Furthermore, oxidative stress plays an important role in the pathogenesis of bile acids. Taurolithocholic acid (TLC) was revealed in previous studies as the most pro-oxidative bile acid. Melatonin, a well-known antioxidant, is a safe and widely used therapeutic agent. Herein, we investigated the hepatoprotective role of melatonin on lipid and protein oxidation induced by TLC alone and in combination with FeCl(3) and ascorbic acid in rat liver homogenates and hepatic membranes. The lipid peroxidation products, malondialdehyde and 4-hydroxyalkenals (MDA + 4-HDA), and carbonyl levels were quantified as indices of oxidative damage to hepatic lipids and proteins, respectively. In the current study, the rise in MDA + 4-HDA levels induced by TLC was inhibited by melatonin in a concentration-dependent manner in both liver homogenates and in hepatic membranes. Melatonin also had protective effects against structural damage to proteins induced by TLC in membranes. These results suggest that the indoleamine melatonin may potentially act as a protective agent in the therapy of those diseases that involve bile acid toxicity.

Melatonin and structurally-related compounds protect synaptosomal membranes from free radical damage.

Since biological membranes are composed of lipids and proteins we tested the in vitro antioxidant properties of several indoleamines from the tryptophan metabolic pathway in the pineal gland against oxidative damage to lipids and proteins of synaptosomes isolated from the rat brain. Free radicals were generated by incubation with 0.1 mM FeCl(3), and 0.1 mM ascorbic acid. Levels of malondialdehyde (MDA) plus 4-hydroxyalkenal (4-HDA), and carbonyl content in the proteins were measured as indices of oxidative damage to lipids and proteins, respectively. Pinoline was the most powerful antioxidant evaluated, with melatonin, N-acetylserotonin, 5-hydroxytryptophan, 5-methoxytryptamine, 5-methoxytryptophol, and tryptoline also acting as antioxidants.

Type XIX collagen: a promising biomarker from the basement membranes.

Among collagen members in the collagen superfamily, type XIX collagen has raised increasing interest in relation to its structural and biological roles. Type XIX collagen is a Fibril-Associated Collagen with Interrupted Triple helices member, one main subclass of collagens in this superfamily. This collagen contains a triple helix composed of three polypeptide segments aligned in parallel and it is associated with the basement membrane zone in different tissues. The molecular structure of type XIX collagen consists of five collagenous domains, COL1 to COL5, interrupted by six non-collagenous domains, NC1 to NC6. The most relevant domain by which this collagen exerts its biological roles is NC1 domain that can be cleavage enzymatically to release matricryptins, exerting anti-tumor and anti-angiogenic effect in murine and human models of cancer. Under physiological conditions, type XIX collagen expression decreases after birth in different tissues although it is necessary to keep its basal levels, mainly in skeletal muscle and hippocampal and telencephalic interneurons in brain. Notwithstanding, in amyotrophic lateral sclerosis, altered transcript expression levels show a novel biological effect of this collagen beyond its structural role in basement membranes and its anti-tumor and anti-angiogenic properties. Type XIX collagen can exert a compensatory effect to ameliorate the disease progression under neurodegenerative conditions specific to amyotrophic lateral sclerosis in transgenic SOD1G93A mice and amyotrophic lateral sclerosis patients. This novel biological role highlights its nature as prognostic biomarker of disease progression in and as promising therapeutic target, paving the way to a more precise prognosis of amyotrophic lateral sclerosis.

Effect of Cryopreserved Amniotic Membrane on the Mechanical Properties of Skeletal Muscle after Strabismus Surgery in Rabbits.

PURPOSE: To study the functional recovery of the superior rectus muscle (SRM) after its partial resection in a rabbit model with and without cryopreserved amniotic membrane (AM). MATERIAL AND METHODS: Resection of the right and left SRMs of 30 rabbits was performed. On the left eyes, a single sheet of equine cryopreserved AM was placed covering the muscle edge sutured. Active and passive mechanical properties of muscles operated with and without AM were monitored over time at 30 (n = 10), 60 (n = 10), and 90 (n = 10) days after surgery. Muscle samples were extracted and electrically stimulated to register the force exerted by the samples, characterizing its active behavior. They were, then, subjected to stretching test to obtain its resistance to deformation, known as passive behavior. Moreover, right and left eyes of a control group (n = 5) were equally subjected to active and passive tests to characterize the physiological behavior of SRM muscles. RESULTS: On active function examination, statistically significant differences were documented between the following: control vs AM and no AM at 30 days (p = 0.002 and p = 0.04, respectively). All other comparisons were insignificant (p > 0.05). On passive function analysis, significant differences were only found between control vs. no AM at 30 days (p = 0.004) and between AM vs. no AM at 30 days (p = 0.002). Indeed, muscle operated without AM did not recover a normal passive function until 60 days after surgery. CONCLUSION: Cryopreserved AM is effective in accelerating recovery of SRM passive function in rabbits. Nevertheless, AM produced no significant effect on recovery of SRM active function..

Fragment C tetanus toxin: a putative activity-dependent neuroanatomical tracer.

The non-toxic C fragment of tetanus toxin fused to the beta-galactosidase enzyme was analysed as a neuroanatomical tracer. After intramuscular injection in rat tongue, its location in the hypoglossal network was compared with other classic tracers such as neurotropic viruses. The hybrid protein reached second and higher-order neurons after crossing several synapses. It appears to be a powerful tool to map neuronal circuits since the protein is easy to handle and detect and its transsynaptic transport is potential activity-dependent.

Optimal methods to characterize the G93A mouse model of ALS.

In the present study, we used the SOD1 (G93A) mutant transgenic mice as a model of amyotrophic lateral sclerosis (ALS). This model is widely used as a laboratory tool to study experimental treatments in vivo for ALS to investigate new therapeutic strategies for this neurodegenerative disease. Such studies require the objective quantification of different parameters while mice develop the disease. We have applied a battery of different and specific tests: scoring of motor deficits by a trained observer, weighing, survival measure, hanging wire test, rotarod task and electromyography, most of them commonly used to evaluate G93A animals. We have critically compared these methods, showing the significant influence of gender on the onset of symptoms, and the optimal moment to apply each test. These results should be taken into account in future therapeutic assays on this ALS model.

A non-viral vector for targeting gene therapy to motoneurons in the CNS.

Gene therapy vectors that can be targeted to motoneuronal cells are required in the field of neurodegenerative diseases. We propose the use of the atoxic fragment C of tetanus toxin (TTC) as biological activity carrier to the motoneurons. Naked DNA encoding beta-galactosidase-TTC hybrid protein was used to transfect muscle cells in vivo, resulting in a selective gene transfer of the enzymatic activity to the CNS. In the muscle, level expression of beta-galactosidase was readily detectable 24 h after injection, reaching a maximum after 4 days and gradually decreasing thereafter. Labelling in the hypoglossal motoneurons and motor cortex was observed from 4 days after injection. In this paper, we show that TTC works as an enzymatic activity carrier to the CNS when muscle cells are transfected in vivo. We have also shown that the presence of TTC does not have any influence on the expression of the transfected gene. Both these results warrant further studies of TTC as a means of treating motoneuron diseases in the field of gene therapy.