Biomedical subjects

Eulàlia Montell

Publications and source records attributed to Eulàlia Montell.

9 recordsLinked to original sources

PubMed2006

Long-term cultured human myotubes decrease contractile gene expression and regulate apoptosis-related genes.

The present study examined time-dependent changes in the gene expression profile of long-term cultured human myotubes. Microarray transcriptional analysis was performed in a primary culture of differentiated myotubes from one subject over seven weeks. This analysis showed a main gradual fall in genes of the contractile apparatus, and a broad upregulation of genes involved in cell development and growth, followed by stress response and signal transduction. Glucose metabolism was also monitored, but no significant alterations in glucose uptake, oxidation or glycogen storage were observed. Mitochondrial membrane potential, or the amount of membrane lipid peroxides, remained similarly unchanged, nor was lactate dehydrogenase leakage observed. Time-dependent changes in eight genes were validated by real-time RT-PCR in primary cultured myotubes from four subjects, of similar age and isolated after equivalent replication cycles in vitro and differentiated over seven weeks. Insulin-like growth factor-binding protein 2 (IGFBP2), a modulator of the IGF signal, was upregulated. The antiapoptotic gene heat-shock 70-kd protein 2 (HSPA2) was induced, whereas the proapoptotic tumor necrosis factor receptor superfamily, member 25 (WSL-1) was suppressed. A decline in the muscle-specific gene M-cadherin and contraction genes, such as slow-twitch troponin I (TNNI1) and myosin heavy chain 2 (MYH2), myosin light chain 1 (MYL1) and myosin-binding protein H (MYBPH), which are expressed in adult fast-twitch muscle, was shown. In summary, these data demonstrate extensive downregulation of contractile genes and modulation of apoptosis-related genes, in favour of cell survival, during maintenance of cultured human myotubes.

Adolescent↗

PubMed2005

Clinical and histopathological improvement of psoriasis with oral chondroitin sulfate: a serendipitous finding.

We describe the clinical and histopathological results of plaque psoriasis in eleven adult patients with knee osteoarthritis and long-standing, moderate to severe psoriasis resistant to conventional therapy treated with chondroitin sulfate. Patients received 800 mg per day of chondroitin sulfate for 2 months. Skin biopsies were obtained before and after treatment. All patients but one presented a dramatic improvement of the condition of the skin, with a reduction of swelling, redness, flaking, and itching (clearance of psoriasis in one patient), increase in the hydration and softening of the skin, and amelioration of scaling. Histopathologically, there was a statistically significant decrease in epidermal thickness, a decrease in the thickness between the stratum basale and the stratum granulosum, a significant improvement of the degree of psoriasis activity, and a decrease in the number of keratinocytes stained with Ki-67. The confirmation of these serendipitous findings in controlled prospective studies could represent an important advance in the therapeutic armamentarium for patients with psoriasis given the excellent safety profile of chondroitin sulfate.

Administration, Oral↗

PubMed2005

Impact on fatty acid metabolism and differential localization of FATP1 and FAT/CD36 proteins delivered in cultured human muscle cells.

We compared the intracellular distribution and regulatory role of fatty acid transporter protein (FATP1) and fatty acid translocase (FAT/CD36) on muscle cell fatty acid metabolism. With the use of adenoviruses, FATP1 and FAT genes were delivered to primary cultured human muscle cells. FATP1 and FAT moderately enhanced palmitate and oleate transport evenly at concentrations of 0.05, 0.5, and 1 mM. Long-term (16 h) consumption of palmitate and oleate from the media, and particularly incorporation into triacylglyceride (TAG), was stimulated equivalently by FATP1 and FAT at all fatty acid concentrations tested. In contrast, long-term CO(2) production was reduced by FATP1 and FAT at all doses of palmitate and at the lower concentrations of oleate. Neither FATP1 nor FAT markedly altered the production of acid-soluble metabolic intermediates from palmitate or oleate. The intracellular localization of fusion constructs of FATP1 and FAT with enhanced green fluorescent protein (EGFP) was examined. Independently of fatty acid treatment, FATPGFP was observed throughout the cytosol in a reticular pattern and concentrated in the perinuclear region, partly overlapping with the Golgi marker GM-130. FATGFP was found in the extracellular membrane and in cytosolic vesicles not coincident with GM-130. Neither FATP1 nor FAT proteins colocalized with lipid droplets in oleate-treated cells. We conclude that whereas FAT is localized on the extracellular membrane, FATP1 is active in the cytosol and imports fatty acids into myotubes. Overall, both FATP1 and FAT stimulated transport and consumption of palmitate and oleate, which they channeled away from complete oxidation and toward TAG synthesis.

Biological Transport, Active↗

PubMed2004

[Clinical and histopathological improvement of psoriasis in patients with osteoarthritis treated with chondroitin sulfate: report of 3 cases].

BACKGROUND AND OBJECTIVE: After prescribing chrondroitin sulfate for the symptomatic treatment of osteoarthritis, it has been observed that some patients with concomitant psoriasis experience a marked improvement of skin lesions. We describe the clinical and histopathological results of the erythematous and desquamative plaques of three patients with osteoarthritis and psoriasis treated with chondroitin sulfate. PATIENTS AND METHOD: Three adult patients with bilateral knee osteoarthritis and long-standing psoriasis characterized by extensive erythematous, desquamative, and hyperkeratotic plaques, which were resistant to different treatment modalities, received 800 mg/day of chondroitin sulfate during two months. Skin biopsies were obtained before and after treatment. RESULTS: All three patients presented a marked clinical improvement in both pathologies. In addition to a decrease in the thickness of the epidermis (total epidermal thickness, maximal thickness from the basal layer to the beginning of the corneal layer, and maximal thickness of the corneal layer), a decrease in the number of keratinocytes in the proliferative phase, a decrease in the degree of psoriatic activity, and a substitution of parakeratotic keratinization by orthokeratotic keratinization were observed. CONCLUSIONS: The administration of chrondroitin sulfate resulted in a significant clinical and histological improvement of the psoriatic lesions. The confirmation of these preliminary results in future clinical trials could represent an important advance in the therapeutic armamentarium of patients with psoriasis given the excellent safety profile of this drug.

Aged↗

PubMed2004

beta3-adrenoceptor agonist prevents alterations of muscle diacylglycerol and adipose tissue phospholipids induced by a cafeteria diet.

BACKGROUND: Insulin resistance induced by a high fat diet has been associated with alterations in lipid content and composition in skeletal muscle and adipose tissue. Administration of beta3-adrenoceptor (beta3-AR) agonists was recently reported to prevent insulin resistance induced by a high fat diet, such as the cafeteria diet. The objective of the present study was to determine whether a selective beta3-AR agonist (ZD7114) could prevent alterations of the lipid profile of skeletal muscle and adipose tissue lipids induced by a cafeteria diet. METHODS: Male Sprague-Dawley rats fed a cafeteria diet were treated orally with either the beta3-AR agonist ZD7114 (1 mg/kg per day) or the vehicle for 60 days. Rats fed a chow diet were used as a reference group. In addition to the determination of body weight and insulin plasma level, lipid content and fatty acid composition in gastronemius and in epididymal adipose tissue were measured by gas-liquid chromatography, at the end of the study. RESULTS: In addition to higher body weights and plasma insulin concentrations, rats fed a cafeteria diet had greater triacylglycerol (TAG) and diacylglycerol (DAG) accumulation in skeletal muscle, contrary to animals fed a chow diet. As expected, ZD7114 treatment prevented the excessive weight gain and hyperinsulinemia induced by the cafeteria diet. Furthermore, in ZD7114 treated rats, intramyocellular DAG levels were lower and the proportion of polyunsaturated fatty acids, particularly arachidonic acid, in adipose tissue phospholipids was higher than in animals fed a cafeteria diet. CONCLUSIONS: These results show that activation of the beta3-AR was able to prevent lipid alterations in muscle and adipose tissue associated with insulin resistance induced by the cafeteria diet. These changes in intramyocellular DAG levels and adipose tissue PL composition may contribute to the improved insulin sensitivity associated with beta3-AR activation.

Journal Article↗

PubMed2004

Regulation of glycogen metabolism in cultured human muscles by the glycogen phosphorylase inhibitor CP-91149.

Pharmacological inhibition of liver GP (glycogen phosphorylase), which is currently being studied as a treatment for Type II (non-insulin-dependent) diabetes, may affect muscle glycogen metabolism. In the present study, we analysed the effects of the GP inhibitor CP-91149 on non-engineered or GP-overexpressing cultured human muscle cells. We found that CP-91149 treatment decreased muscle GP activity by (1) converting the phosphorylated AMP-independent a form into the dephosphorylated AMP-dependent b form and (2) inhibiting GP a activity and AMP-mediated GP b activation. Dephosphorylation of GP was exerted, irrespective of incubation of the cells with glucose, whereas inhibition of its activity was synergic with glucose. As expected, CP-91149 impaired the glycogenolysis induced by glucose deprivation. CP-91149 also promoted the dephosphorylation and activation of GS (glycogen synthase) in non-engineered or GP-overexpressing cultured human muscle cells, but exclusively in glucose-deprived cells. However, this inhibitor did not activate GS in glucose-deprived but glycogen-replete cells overexpressing PTG (protein targeting to glycogen), thus suggesting that glycogen inhibits the CP-91149-mediated activation of GS. Consistently, CP-91149 promoted glycogen resynthesis, but not its overaccumulation. Hence, treatment with CP-91149 impairs muscle glycogen breakdown, but enhances its recovery, which may be useful for the treatment of Type II (insulin-dependent) diabetes.

Amides↗

PubMed2004

Weather conditions can influence rheumatic diseases.

In daily clinical practice, many patients attribute joint pain to weather conditions. There is little information published on this subject and most of it is contradictory. The objective of this study was to evaluate the effect of climatic conditions in rheumatic patients. The present work was carried out with patients attending the Instituto Poal de Reumatologia of Barcelona and the data were analyzed by Bioibérica Farma (Spain). It was a prospective, double-blind study including 92 patients with rheumatic disorders (80 with osteoarthritis, 12 with rheumatoid arthritis) compared to a control group of 42 subjects. The evaluation of pain (Huskisson VAS) and functional capacity (Health Assessment Questionnaire, HAQ) were determined daily during one month. The climatic variables studied were temperature, humidity and barometric pressure. The results obtained have been subject to binary regression analysis. Our data demonstrate that osteoarthritic patients experience increased joint pain in response to a decrease in pressure, indicating that low atmospheric pressure conditions exacerbate joint pain in these patients. Our work also suggests that some meteorological variables affect the occurrence of pain in rheumatoid arthritis, since we have found that low temperature increases the risk of joint pain. Therefore, these data suggest that in the future it may be possible to modulate pharmacological and non-pharmacological treatments for some osteoarthritic patients depending on the predictable weather conditions in order to avoid, as much as possible, the disease-associated joint pain and functional incapacity, thus improving patients' quality of life.

Arthritis, Rheumatoid↗

PubMed2003

Regulation and function of the muscle glycogen-targeting subunit of protein phosphatase 1 (GM) in human muscle cells depends on the COOH-terminal region and glycogen content.

G(M), the muscle-specific glycogen-targeting subunit of protein phosphatase 1 (PP1) targeted to the sarcoplasmic reticulum, was proposed to regulate recovery of glycogen in exercised muscle, whereas mutation truncation of its COOH-terminal domain is known to be associated with type 2 diabetes. Here, we demonstrate differential effects of G(M) overexpression in human muscle cells according to glycogen concentration. Adenovirus-mediated delivery of G(M) slightly activated glycogen synthase (GS) and inactivated glycogen phosphorylase (GP) in glycogen-replete cells, causing an overaccumulation of glycogen and impairment of glycogenolysis after glucose deprivation. Differently, in glycogen-depleted cells, G(M) strongly increased GS activation with no further enhancement of early glycogen resynthesis and without affecting GP. Effects of G(M) on GS and GP were abrogated by treatment with dibutyryl cyclic AMP. Expression of a COOH-terminal deleted-mutant (G(M) Delta C), lacking the membrane binding sequence to sarcoplasmic reticulum, failed to activate GS in glycogen-depleted cells, while behaving similar to native G(M) in glycogen-replete cells. This is explained by loss of stability of the G(M) Delta C protein following glycogen-depletion. In summary, G(M) promotes glycogen storage and inversely regulates GS and GP activities, while, specifically, synthase phosphatase activity of G(M)-PP1 is inhibited by glycogen. The conditional loss of function of the COOH-terminal deleted G(M) construct may help to explain the reported association of truncation mutation of G(M) with insulin resistance in human subjects.

Cells, Cultured↗

PubMed2001

Effects of modulation of glycerol kinase expression on lipid and carbohydrate metabolism in human muscle cells.

Glycerol is taken up by human muscle in vivo and incorporated into lipids, but little is known about regulation of glycerol metabolism in this tissue. In this study, we have analyzed the role of glycerol kinase (GlK) in the regulation of glycerol metabolism in primary cultured human muscle cells. Isolated human muscle cells exhibited lower GlK activity than fresh muscle explants, but the activity in cultured cells was increased by exposure to insulin. [U-(14)C]Glycerol was incorporated into cellular phospholipids and triacylglycerides (TAGs), but little or no increase in TAG content or lactate release was observed in response to changes in the medium glycerol concentration. Adenovirus-mediated delivery of the Escherichia coli GlK gene (AdCMV-GlK) into muscle cells caused a 30-fold increase in GlK activity, which was associated with a marked rise in the labeling of phospholipid or TAG from [U-(14)C]glycerol compared with controls. Moreover, GlK overexpression caused [U-(14)C]glycerol to be incorporated into glycogen, which was dependent on the activation of glycogen synthase. Co-incubation of AdCMV-GlK-treated muscle cells with glycerol and oleate resulted in a large accumulation of TAG and an increase in lactate production. We conclude that GlK is the limiting step in muscle cell glycerol metabolism. Glycerol 3-phosphate is readily used for TAG synthesis but can also be diverted to form glycolytic intermediates that are in turn converted to glycogen or lactate. Given the high levels of glycerol in muscle interstitial fluid, these finding suggest that changes in GlK activity in muscle can exert important influences on fuel deposition in this tissue.

Adenoviridae↗