Glyconutrients

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Associations of regular glucosamine use with all-cause and cause-specific mortality a large prospective cohort study Annals of the Rheumatic Diseases
Associations of regular glucosamine use with all-cause and cause-specific mortality a large prospective cohort study Annals of the Rheumatic Diseases
Objectives To evaluate the associations of regular glucosamine use with all-cause and cause-specific mortality in a large prospective cohort. Methods This population-based prospective cohort study included 495 077 women and men (mean (SD) age, 56.6 (8.1) years) from the UK Biobank study. Participants were recruited from 2006 to 2010 and were followed up through 2018. We evaluated all-cause mortality and mortality due to cardiovascular disease (CVD), cancer, respiratory and digestive disease. HRs and 95% CIs for all-cause and cause-specific mortality were calculated using Cox proportional hazards models with adjustment for potential confounding variables. Results At baseline, 19.1% of the participants reported regular use of glucosamine supplements. During a median follow-up of 8.9 years (IQR 8.3–9.7 years), 19 882 all-cause deaths were recorded, including 3802 CVD deaths, 8090 cancer deaths, 3380 respiratory disease deaths and 1061 digestive disease deaths. In multivariable adjusted analyses, the HRs associated with glucosamine use were 0.85 (95% CI 0.82 to 0.89) for all-cause mortality, 0.82 (95% CI 0.74 to 0.90) for CVD mortality, 0.94 (95% CI 0.88 to 0.99) for cancer mortality, 0.73 (95% CI 0.66 to 0.81) for respiratory mortality and 0.74 (95% CI 0.62 to 0.90) for digestive mortality. The inverse associations of glucosamine use with all-cause mortality seemed to be somewhat stronger among current than non-current smokers (p for interaction=0.00080). Conclusions Regular glucosamine supplementation was associated with lower mortality due to all causes, cancer, CVD, respiratory and digestive diseases.
·ard.bmj.com·
Associations of regular glucosamine use with all-cause and cause-specific mortality a large prospective cohort study Annals of the Rheumatic Diseases
Beneficial Effects of Some Nutraceuticals Containing Glucosamine and Antioxidant against CCL4 Induced Brain Injury in Rats
Beneficial Effects of Some Nutraceuticals Containing Glucosamine and Antioxidant against CCL4 Induced Brain Injury in Rats
The present study is performed to investigate the effect of two different glucosamine containing drugs: Drug 1 and Drug 2 (D1 and D2) against CCl4 induced brain damage in male albino rats. Liverin (AM) was employed in the current study as an antioxidant reference drug. CCl4 administration caused a significant elevation in the levels of MDA and NO of brain tissue, in association with a significant decrease in the antioxidant defense system (GSH, SOD and GPX) that indicated the induction of oxidative stress in brain tissue. CCl4 administration induced brain injury as manifested by the obtained changes in neurotransmitter parameter (norepinephrine (NE), Dopamine (DA), Serotonin (5-HT), and Acetylcholinesterase AChE). The tested nutraceuticals and the antioxidant drug displayed a significant improvement against the undue effect of CCl4 via decreasing the brain tissue content of MDA, NO with the elevation of GSH content. Also, the significant increase in SOD and GPX enzymatic activity was obtained when compared to CCL4 group. In addition AM, D1, and D2 have an ameliorative effect on neurotransmitter parameter NE, DA, 5HT, and AChE. Results of this study suggest that both antioxidant drugs and tested nutraceuticals palliate the brain injuries through anti-oxidative effect, with the elimination of the deleterious effect of toxic metabolites of CCl4 on brain tissue.
·scirp.org·
Beneficial Effects of Some Nutraceuticals Containing Glucosamine and Antioxidant against CCL4 Induced Brain Injury in Rats
Chondroitin sulfateglucosamine hydrochloride induce a reduction in adr (...)
Chondroitin sulfateglucosamine hydrochloride induce a reduction in adr (...)
Purpose: Inflammation in osteoarthritis (OA) has been characterized by infiltration of immune cells and secretion of cytokines into synovial tissues. Also, noradrenaline levels, sympathetic nerve fiber distribution and β2-AR expression in the bone of rats have been associated with subchondral bone loss and increased osteoclast activity. All these data suggest the participation of the adrenergic and immune systems in the development and evolution of OA. However, the relationship among the systemic adrenergic and immune systems activation with the OA progression and treatment response is much less well known.
·oarsijournal.com·
Chondroitin sulfateglucosamine hydrochloride induce a reduction in adr (...)
Chronic tubulointerstitial nephropathy induced by glucosamine a case r (...)
Chronic tubulointerstitial nephropathy induced by glucosamine a case r (...)
Glucosamine is a glycosylated amine and a slow-acting symptomatic treatment for osteoarthritis. Some experimental animal studies have shown that glucosamine can cause apoptosis in kidney tubular and mesangial cells as well as overexpression of transforming growth factor β1 (TGF-β1) and connective-ti …
·ncbi.nlm.nih.gov·
Chronic tubulointerstitial nephropathy induced by glucosamine a case r (...)
Clinical efficacy of glucosamine hydrochloride tablets in the treatment of cervical spondylosis. - PubMed - NCBI
Clinical efficacy of glucosamine hydrochloride tablets in the treatment of cervical spondylosis. - PubMed - NCBI
The aim of the stuy was to observe and analyze the effect of glucosamine hydrochloride tablets on patients with cervical spondylosis. This study was conducted on 130 patients diagnosed with cervical spondylosis who were treated in our hospital. The time period was from June 2015 to December 2017. Th …
·ncbi.nlm.nih.gov·
Clinical efficacy of glucosamine hydrochloride tablets in the treatment of cervical spondylosis. - PubMed - NCBI
Comparison of Glucosamine-Chondroitin Sulfate with and without Methyls (...)
Comparison of Glucosamine-Chondroitin Sulfate with and without Methyls (...)
Background: Glucosamine, chondroitinsulfate are frequently used to prevent further joint degeneration in osteoarthritis (OA). Methylsulfonylmethane (MSM) is a supplement containing organic sulphur and also reported to slow anatomical joint progressivity in the knee OA. The MSM is often combined with glucosamine and chondroitin sulfate. However, there are controversies whether glucosamine-chondroitin sulfate or their combination with methylsulfonylmethane could effectively reduce pain in OA. This study is aimed to compare clinical outcome of glucosamine-chondroitin sulfate (GC), glucosamine-chondroitin sulfate-methylsulfonylmethane (GCM), and placeboin patients with knee osteoarthritis (OA) Kellgren-Lawrence grade I-II. Methods: a double blind, randomized controlled clinical trial was conducted on 147 patients with knee OA Kellgren-Lawrence grade I-II. Patients were allocated by permuted block randomization into three groups: GC (n=49), GCM (n=50), or placebo (n=48) groups. GC group received 1500 mg of glucosamine + 1200 mg of chondroitin sulfate + 500 mg of saccharumlactis; GCM group received 1500 mg of glucosamine + 1200 mg of chondroitin sulfate + 500 mg of MSM; while placebo group received three matching capsules of saccharumlactis. The drugs were administered once daily for 3 consecutive months VAS and WOMAC scores were measured before treatment, then at 4th, 8th and 12th week after treatment. Results: on statistical analysis it was found that at the 12th week, there are significant difference between three treatment groups on the WOMAC score (p=0.03) and on the VAS score (p=0.004). When analyzed between weeks, GCM treatment group was found statistically significant on WOMAC score (p=0.01) and VAS score (p
·actamedindones.org·
Comparison of Glucosamine-Chondroitin Sulfate with and without Methyls (...)
Effect of Glucosamine Conjugate-Functionalized Liposomes on Glioma Cell and Healthy Brain An Insight for Future Application in Brain Infusion SpringerLink
Effect of Glucosamine Conjugate-Functionalized Liposomes on Glioma Cell and Healthy Brain An Insight for Future Application in Brain Infusion SpringerLink
Conjugation of D-glucosamine with lipophilic moiety can ease its application in surface modification of liposomes. Interestingly, although D-glucosamine is safe, studies have shed light on “toxic effect” of its conjugates on cancer cells and highlighted its application in targeting glioma. However, understanding the safety of such conjugates for local delivery to the brain is unavailable. Herein, after successful synthesis of D-glucosamine conjugate (GC), the toxicity of functionalized liposome was evaluated both in vitro and in vivo. The study revealed a significant effect on cytotoxicity and apoptosis in vitro as assessed on grade IV-resistant glioma cell lines, SF268, U87MG, using MTT assay and PI staining. Additionally, this effect was not observed on normal human erythrocytes in the hemolysis assay. Furthermore, we demonstrated that GC liposomes were non-toxic to the normal brain tissues of healthy Sprague-Dawley rats. Successful functionalization yielded liposome with uniform particle size, stability, and cellular uptake. With
·link.springer.com·
Effect of Glucosamine Conjugate-Functionalized Liposomes on Glioma Cell and Healthy Brain An Insight for Future Application in Brain Infusion SpringerLink
Effects of glucosamine against morphine-induced antinociceptive tolerance and dependence in mice Journal of Biomedical Science Full Text
Effects of glucosamine against morphine-induced antinociceptive tolerance and dependence in mice Journal of Biomedical Science Full Text
Background The most important limitations of morphine in pain therapy are its tolerance and dependence. In this study, we evaluated the protective effect of glucosamine against morphine-induced tolerance and dependence in mice. Methods Mice received twice daily morphine (20 mg/kg, s.c.) alone, or along with orally administered glucosamine (500, 1000 and 2000 mg/kg), for 9 continuous days. To assess antinociceptive effect of morphine, percentage of maximal possible effect (%MPE) of animals exposed to thermal stimulus was measured in the hot plate test, 30 min after morphine administration. Test was performed on days 1, 3, 5, 7 and 9. The effect of glucosamine on the naloxone (5 mg/kg, i.p.)-precipitated morphine withdrawal, was also evaluated. Changes in brain gene expression levels of induced nitric oxide synthase (iNOS), enzyme responsible for nitric oxide generation, as well as pro-inflammatory mediator, tumor necrosis alpha (TNF-α) were measured in morphine tolerated animals, as well as after withdrawal by real-time polymerase chain reaction (RT-PCR). Protein content of TNF-α was evaluated via ELISA assay. Results Tolerance to antinociceptive effect of morphine was developed after 7 days of morphine treatment. The concurrent administration of glucosamine (500, 1000 and 2000 mg/kg) with morphine, significantly inhibited tolerance development, on days 7 and 9. In addition, glucosamine ameliorated the naloxone-precipitated opioid withdrawal symptoms (tremor, jumping, teeth chattering, grooming). However, diarrhea was significantly improved only with the dose of 500 mg/kg. Increased mRNA expression of iNOS as well as TNF-α mRNA expression and protein, after both morphine tolerance and withdrawal, were considerably reduced by glucosamine (1000 mg/kg) in the morphine withdrawal animals. Conclusion These data support the utility of glucosamine in attenuating both tolerance to nociceptive effects of morphine as well as withdrawal-induced behavioral profile. Anti-oxidant and anti-inflammatory effects are responsible, at least in part, for the protective effects of this drug.
·jbiomedsci.biomedcentral.com·
Effects of glucosamine against morphine-induced antinociceptive tolerance and dependence in mice Journal of Biomedical Science Full Text
Efficacy of Glucosamine Sulphate in Skin Ageing Results from an ex viv (...)
Efficacy of Glucosamine Sulphate in Skin Ageing Results from an ex viv (...)
Background: Glucosamine sulphate (GS) is essential in the biosynthesis of glycolipids, glycoproteins, glycosaminoglycans (GAGs), hyaluronate, and proteoglycans. Connective tissues primarily contain collagen and proteoglycans and play an important role in skin ageing. Objective: The objectives were to assess ex vivo the impact of GS on skin ageing p
·karger.com·
Efficacy of Glucosamine Sulphate in Skin Ageing Results from an ex viv (...)
Evaluation of the effect of N-acetyl-glucosamine administration on bio (...)
Evaluation of the effect of N-acetyl-glucosamine administration on bio (...)
The present study aimed to evaluate the effect of N‑acetyl‑glucosamine (GlcNAc) on the joint health of healthy individuals without arthritic symptoms. A randomized double‑blind placebo‑controlled clinical trial was performed to investigate the effect of oral administration of a GlcNAc‑containing test supplement (low dose, 500 mg/day and high dose, 1,000 mg/day) on cartilage metabolism in healthy individuals with a mean age of 48.6±1.3 years (range, 23‑64 years) by analyzing the ratio of type II collagen degradation to type II collagen synthesis using type II collagen degradation (C2C) and synthesis (PIICP) markers. The results indicated that the changes in C2C/PIICP ratios from the baseline were suppressed in the treated with low and high doses of GlcNAc, compared with the placebo group at week 16 during intervention. To further elucidate the effect of GlcNAc, subjects with impaired cartilage metabolism were evaluated. Notably, the changes in the C2C/PIICP ratios were markedly suppressed in the groups treated with low and high doses of GlcNAc at week 16. Finally, to exclude the effect of heavy body weight on joint loading, subjects weighing
·spandidos-publications.com·
Evaluation of the effect of N-acetyl-glucosamine administration on bio (...)
Evaluation of the effect of N-acetyl-glucosamine
Evaluation of the effect of N-acetyl-glucosamine
Background: To evaluate the chondroprotective action of an N-acetyl-glucosamine (GlcNAc)-containing supplement on the joint health of healthy individuals without symptoms of arthritis, we conducted a randomized double-blind placebo-controlled clinical trial.  Methods: Subjects (n=100, 51.3 ± 1.0 years (mean ± SE)) without symptoms of arthritis were randomly assigned to receive a 1000 mg GlcNAc-containing diet (GlcNAc group) or a placebo diet (placebo group) once a day for 16 weeks, and the effect on the cartilage metabolism was evaluated by analyzing the ratio of type II collagen degradation to synthesis using type II collagen degradation (C2C) and synthesis (PIICP) markers. Results: The results indicated that the changes in the C2C/PIICP ratios from the baseline were slightly suppressed in the GlcNAc group compared with those in the placebo group at weeks 16 during the intervention and 4 weeks after the intervention. However, there was no significant difference between the two groups. To make the effect of GlcNAc even more clear, the subjects with joint loading and impaired cartilage metabolism were evaluated. Interestingly, the changes in the C2C/PIICP ratios from the baseline were significantly suppressed in the GlcNAc group compared with the placebo group at weeks 16 during the intervention and 4 weeks after the intervention. Moreover, test supplement-related adverse events were not essentially observed during and after the intervention. Conclusions: These observations suggest that the oral administration of GlcNAc at a dose of 1000 mg/day exerts a chondroprotective action on the healthy individuals by lowering the C2C/PIICP ratio, which indicates relative reduction of type II collagen degradation and increase of type II collagen synthesis, without apparent adverse effect.  Key words: N-acetyl-glucosamine, biomarker, cartilage metabolism, joint health
·ffhdj.com·
Evaluation of the effect of N-acetyl-glucosamine
Evaluation of the effect of the administration of an N-acetyl-glucosam (...)
Evaluation of the effect of the administration of an N-acetyl-glucosam (...)
Background: To evaluate the chondroprotective action of an N-acetyl-glucosamine (GlcNAc)-containing supplement on the joint health of healthy individuals without symptoms of arthritis, we conducted a randomized double-blind placebo-controlled clinical trial.  Methods: Subjects (n=100, 51.3 ± 1.0 years (mean ± SE)) without symptoms of arthritis were randomly assigned to receive a 1000 mg GlcNAc-containing diet (GlcNAc group) or a placebo diet (placebo group) once a day for 16 weeks, and the effect on the cartilage metabolism was evaluated by analyzing the ratio of type II collagen degradation to synthesis using type II collagen degradation (C2C) and synthesis (PIICP) markers. Results: The results indicated that the changes in the C2C/PIICP ratios from the baseline were slightly suppressed in the GlcNAc group compared with those in the placebo group at weeks 16 during the intervention and 4 weeks after the intervention. However, there was no significant difference between the two groups. To make the effect of GlcNAc even more clear, the subjects with joint loading and impaired cartilage metabolism were evaluated. Interestingly, the changes in the C2C/PIICP ratios from the baseline were significantly suppressed in the GlcNAc group compared with the placebo group at weeks 16 during the intervention and 4 weeks after the intervention. Moreover, test supplement-related adverse events were not essentially observed during and after the intervention. Conclusions: These observations suggest that the oral administration of GlcNAc at a dose of 1000 mg/day exerts a chondroprotective action on the healthy individuals by lowering the C2C/PIICP ratio, which indicates relative reduction of type II collagen degradation and increase of type II collagen synthesis, without apparent adverse effect.  Key words: N-acetyl-glucosamine, biomarker, cartilage metabolism, joint health
·ffhdj.com·
Evaluation of the effect of the administration of an N-acetyl-glucosam (...)
Geroprotectors Glucosamine – LEAF
Geroprotectors Glucosamine – LEAF
What is glucosamine? Glucosamine is a polysaccharide that naturally occurs in cartilaginous joint tissues and is involved in protein and lipid synthesis. […]
·leafscience.org·
Geroprotectors Glucosamine – LEAF
Glucosamine LEAF
Glucosamine LEAF
What is glucosamine? Glucosamine is a polysaccharide that naturally occurs in cartilaginous joint tissues and is involved in protein and lipid synthesis. […]
·leafscience.org·
Glucosamine LEAF
Glucosamine and Its Analogues as Modulators of Amyloid-ß Toxicity ACS Medicinal Chemistry Letters
Glucosamine and Its Analogues as Modulators of Amyloid-ß Toxicity ACS Medicinal Chemistry Letters
In Alzheimer’s disease (AD), amyloid-β (Aβ) oligomers are considered key mediators of synaptic dysfunction and cognitive impairment. These unstable intermediate Aβ species can interfere with different cellular organelles, leading to neuronal cell death, through the formation of Ca2+-permeable membrane pores, impairment in the levels of acetylcholine neurotransmitters, increased insulin resistance, promotion of pro-inflammatory cascades, among others. Based on a series of evidences that indicate the key role of glycosaminoglycans (GAGs) in amyloid plaque formation, we evaluated the capacity of four monosaccharides, i.e., glucosamine (GlcN), N-acetyl glucosamine (GlcNAc), glucosamine-6-sulfate (GlcN6S), and glucosamine-6-phosphate (GlcN6P), to reduce the Aβ-mediated pathological hallmarks. The tested monosaccharides, in particular, GlcN6S and GlcN6P, were able to interact with Aβ aggregates, reducing neuronal cell death, Aβ-mediated damage to the cellular membrane, acetylcholinesterase activity, insulin resistance, and pro-inflammation levels.
·pubs.acs.org·
Glucosamine and Its Analogues as Modulators of Amyloid-ß Toxicity ACS Medicinal Chemistry Letters
Glucosamine and mortality a note of caution Annals of the Rheumatic Diseases
Glucosamine and mortality a note of caution Annals of the Rheumatic Diseases
I read with interest the paper by Li et al 1 reporting the association of regular glucosamine use with lower mortality. The authors report significantly lower all-cause mortality HR 0.85 (95% CI 0.82 to 0.89), cardiovascular mortality HR 0.82 (95% CI 0.74 to 0.90), cancer mortality HR 0.94 (95% CI 0.88 to 0.99), respiratory mortality HR 0.73 (95% CI 0.66 to 0.81) and digestive mortality HR 0.74 (95% CI 0.62 to 0.90). The magnitude of the reported reduction in mortality is striking, as is the consistency across major disease categories. The results reported by the authors are consistent with other prior epidemiological studies looking at glucosamine and mortality.2–4 The biological plausibility for glucosamine having such pronounced causative effects …
·ard.bmj.com·
Glucosamine and mortality a note of caution Annals of the Rheumatic Diseases
Glucosamine as a Pain Reliving Agent in Planter Fasciitis Tiwari Research & Reviews A Journal of Health Professions
Glucosamine as a Pain Reliving Agent in Planter Fasciitis Tiwari Research & Reviews A Journal of Health Professions
Plantar fasciitis is the most common cause of the plantar heel pain. Its main features are a pain, tenderness mostly on the medial aspect of the calcaneum near the sole of heel. There are many conservative methods for treatment of the lantar fasciitis which include rest, massage, night splints, orthoses, injections, cast NSAID, shock wave therapy. The glucosamine is one of the nutritional product which has a good anti- properties and is already in use for arthritis knee. Depending on anti-inflammatory analgesic property can also be used in planter fasciitis. In this study 17 patients were studied after giving fixed dose of 1200 mg of glucosamine. The evaluation was done on linkert pain score. The p-value in studied group was
·medicaljournals.stmjournals.in·
Glucosamine as a Pain Reliving Agent in Planter Fasciitis Tiwari Research & Reviews A Journal of Health Professions
Glucosamine decreases the stemness of human ALDH+ breast cancer stem cells by inactivating STAT3
Glucosamine decreases the stemness of human ALDH+ breast cancer stem cells by inactivating STAT3
Cancer stem cells (CSCs) are a subpopulation of cancer cells responsible for tumor maintenance and relapse due to their ability to resist various anticancer effects. Owing to the resistance of CSCs to the effects of targeted therapy, an alternative strategy that targets post‑translational glycosylation may be an improved approach to treat cancer as it disrupts multiple coordinated signaling that maintains the stemness of CSCs. Glucosamine acts as an anticancer agent possibly by inhibiting N‑linked glycosylation. The aim of the present study was to investigate the effect of glucosamine on the stemness of breast CSCs, which is regulated by signal transducer and activator of transcription 3 (STAT3) signaling. Human aldehyde dehydrogenase‑positive (ALDH+) breast CSCs and MCF7 cells were treated with various concentrations (0.25, 1 or 4 mM) of glucosamine for 24 h. Subsequently, cell viability was determined by performing a trypan blue exclusion assay, pluripotency gene [ALDH 1 family member A1 (ALDH1A1), octamer‑binding transcription factor 4 (OCT‑4), and Krüppel‑like factor 4 (KLF4)] expression was determined using the reverse transcription‑quantitative polymerase chain reaction, and STAT3 and phosphorylated STAT3 (pSTAT3) levels were determined by performing western blot analysis. Furthermore, the number of mammosphere‑forming units (MFUs) in ALDH+ breast CSCs and MCF7 cells was determined. It was determined that glucosamine treatment decreased the viability of ALDH+ breast CSCs. Glucosamine treatment also decreased the stemness of ALDH+ breast CSCs and MCF7 cells, as indicated by decreased ALDH1A1, OCT‑4 and KLF4 expression level, and a decreased number of MFUs. This effect of glucosamine may be associated with a decreased pSTAT3/STAT3 ratio, indicating that glucosamine inhibited STAT3 activation; therefore, the results of the present study indicated that glucosamine treatment may be an improved approach to target the stemness of CSCs.
·spandidos-publications.com·
Glucosamine decreases the stemness of human ALDH+ breast cancer stem cells by inactivating STAT3
Glucosamine Hydrochloride and N-Acetylglucosamine Influence the Response of Bovine Chondrocytes
Glucosamine Hydrochloride and N-Acetylglucosamine Influence the Response of Bovine Chondrocytes
Background: Glucosamine hydrochloride (GlcN·HCl) has been shown to inhibit cell growth and matrix synthesis, but not with N-acetyl-glucosamine (GlcNAc) supplementation. This effect might be related to an inhibition of critical growth factors (GF), or to a different metabolization of the two glucosamine derivatives. The aim of the present study was to evaluate the synergy between GlcN·HCl, GlcNAc, and GF on proliferation and cartilage matrix synthesis. Method: Bovine chondrocytes were cultivated in monolayers for 48 h and in three-dimensional (3D) chitosan scaffolds for 30 days in perfusion bioreactors. Serum-free (SF) medium was supplemented with either growth factors (GF) TGF-β (5 ng mL−1) and IGF-I (10 ng mL−1), GlcN·HCl or GlcNAc at 1mM each or both. Six groups were compared according to medium supplementation: (a) SF control; (b) SF + GlcN·HCl; (c) SF + GlcNAc; (d) SF + GF; (e) SF + GF + GlcN·HCl; and (f) SF + GF + GlcNAc. Cell proliferation, proteoglycan, collagen I (COL1), and collagen II (COL2) synthesis were evaluated. Results: The two glucosamines showed opposite effects in monolayer culture: GlcN·HCl significantly reduced proliferation and GlcNAc significantly augmented cellular metabolism. In the 30 days 3D culture, the GlcN·HCl added to GF stimulated cell proliferation more than when compared to GF only, but the proteoglycan synthesis was smaller than GF. However, GlcNAc added to GF improved the cell proliferation and proteoglycan synthesis more than when compared to GF and GF/GlcN·HCl. The synthesis of COL1 and COL2 was observed in all groups containing GF. Conclusion: GlcN·HCl and GlcNAc increased cell growth and stimulated COL2 synthesis in long-time 3D culture. However, only GlcNAc added to GF improved proteoglycan synthesis.
·link.springer.com·
Glucosamine Hydrochloride and N-Acetylglucosamine Influence the Response of Bovine Chondrocytes
Glucosamine impedes transforming growth factor ß1-mediated corneal fibroblast differentiation by targeting Krüppel-like factor 4 SpringerLink
Glucosamine impedes transforming growth factor ß1-mediated corneal fibroblast differentiation by targeting Krüppel-like factor 4 SpringerLink
Background Transforming growth factor (TGF) family members play important roles in the regulation of corneal integrity, and the pathogenesis of corneal fibrosis. Currently, there are no effective agents targeting TGF-β signaling to diminish corneal fibrosis. Glucosamine (GlcN), which is widely used in the treatment of osteoarthritis, abrogates the morphologic effects of TGF-β2 on retinal pigmented epithelial cells in a mouse disease model. Here, we sought to determine whether GlcN would exert beneficial effects against TGF-β1-induced corneal fibrosis. Methods In human corneal fibroblasts (HCFs) treated with GlcN, the expression of Krüppel-like factor 4 (KLF4) and its downstream signaling effects were determined in the presence and absence of TGF-β1 using immunoblot analysis. We further explored GlcN inhibition of fibroblast-to-myofibroblast differentiation via KLF4 siRNA. The effect of cycloheximide on KLF4 protein levels with or without GlcN administration was assessed to determine whether GlcN affects the stability of the KLF4 protein. Results In HCFs, GlcN induced the expression of KLF4, which regulated the maturation and maintenance of the ocular surface. GlcN partially suppressed the TGF-β1-induced expression of alpha-smooth muscle actin (α-SMA) and reduced the collagen contraction capacity in HCFs, suggesting a decrease in fibroblast-to-myofibroblast differentiation. This effect appeared to be mediated through suppression of Smad2 phosphorylation and ERK-dependent signaling. The levels of KLF4 mRNA were increased by GlcN and decreased by TGF-β1 and the TGF-β1-induced α-SMA mRNA expression was upregulated when the KLF4 gene was silenced. GlcN also appeared to stabilize the KLF4 protein, reducing its turnover in corneal fibroblasts. Conclusion These findings shed light on a novel mechanism by which GlcN suppresses TGF-β1-induced fibroblast-to-myofibroblast differentiation through the upregulation of KLF4 expression. Current strategies for treating corneal fibrosis were not effective. Elevating KLF4 levels through the use of GlcN might provide an effective alternative to alleviate the development and progression of corneal fibrosis.
·link.springer.com·
Glucosamine impedes transforming growth factor ß1-mediated corneal fibroblast differentiation by targeting Krüppel-like factor 4 SpringerLink