The single IGF-1 partial deficiency is responsible for mitochondrial dysfunction and is restored by IGF-1 replacement therapy.

BACKGROUND & AIMS: We previously described in cirrhosis and aging, both conditions of IGF-1 deficiency, a clear hepatic mitochondrial dysfunction with increased oxidative damage. In both conditions, the hepatic mitochondrial function was improved with low doses of IGF-1. The aim of this work was to explore if the only mere IGF-1 partial deficiency, without any exogenous insult, is responsible for hepatic mitochondrial dysfunction. METHODS: Heterozygous (igf1+/-) mice were divided into two groups: untreated and treated mice with low doses of IGF-1. WT group was used as controls. Parameters of hepatic mitochondrial function were determined by flow cytometry, antioxidant enzyme activities were determined by spectrophotometry, and electron chain transport enzyme levels were determined by immunohistochemistry and immunofluorescence analyses. Liver expression of genes coding for proteins involved in mitochondrial protection and apoptosis was studied by microarray analysis and RT-qPCR. RESULTS: Hz mice showed a significant reduction in hepatic mitochondrial membrane potential (MMP) and ATPase activity, and an increase in intramitochondrial free radical production and proton leak rates, compared to controls. These parameters were normalized by IGF-1 replacement therapy. No significant differences were found between groups in oxygen consumption and antioxidant enzyme activities, except for catalase, whose activity was increased in both Hz groups. Relevant genes coding for proteins involved in mitochondrial protection and survival were altered in Hz group and were reverted to normal in Hz+IGF-1 group. CONCLUSIONS: The mere IGF-1 partial deficiency is per se associated with hepatic mitochondrial dysfunction sensitive to IGF-1 replacement therapy. Results in this work prove that IGF-1 is involved in hepatic mitochondrial protection, because it is able to reduce free radical production, oxidative damage and apoptosis. All these IGF-1 actions are mediated by the modulation of the expression of genes encoding citoprotective and antiapoptotic proteins.

Insulin-like growth factor 1 (IGF-1) therapy: Mitochondrial dysfunction and diseases.

This review resumes the association between mitochondrial function and diseases, especially neurodegenerative diseases. Additionally, it summarizes the major role of IGF-1 as a mitochondrial protector, as studied in several experimental models (cirrhosis, aging …). The contribution of mitochondrial dysfunction to impairments in insulin metabolic signaling is also suggested by gene array analysis showing that reductions in gene expression, that regulates mitochondrial ATP production, are associated with insulin resistance and type 2 diabetes mellitus. Moreover, reductions in oxidative capacity of mitochondrial electron transport chain are manifested in obese, insulin-resistant and diabetic patients. Genetic and environmental factors, oxidative stress, and alterations in mitochondrial biogenesis can adversely affect mitochondrial function, leading to insulin resistance and several pathological conditions, such as type 2 diabetes. Finally, it remains essential to know the exact mechanisms involved in mitochondrial generation and metabolism, mitophagy, apoptosis, and oxidative stress to establish new targets in order to develop potentially effective therapies. One of the newest targets to recover mitochondrial dysfunction could be the administration of IGF-1 at low doses. In the last years, it has been observed that IGF-1 therapy has several beneficial effects: restores physiological IGF-1 levels; improves insulin resistance and lipid metabolism; exerts mitochondrial protection; and has hepatoprotective, neuroprotective, antioxidant and antifibrogenic effects. In consequence, treatment of mitochondrial dysfunctions with low doses of IGF-1 could be a powerful and useful effective therapy to restore normal mitochondrial functions.

Multiple sclerosis patients with anti-lipid oligoclonal IgM show early favourable response to immunomodulatory treatment.

BACKGROUND AND PURPOSE: Interferon beta and Glatiramer acetate are safe immunomodulatory treatments (IT) for multiple sclerosis (MS), but not always effective. New drugs are available, although they show more side-effects and unknown long-term safety profile. Anti-lipid oligoclonal IgM bands (OCMB) distinguish MS patients with early aggressive course. We prospectively studied if IT are effective in these patients or if they are candidates for more aggressive drugs as first therapeutic option. METHODS: Seventy-five clinically isolated syndrome patients were studied. OCMB and conversion to MS were assessed. Patients suffering at least two demyelinating events within 3 years were considered eligible to start IT. RESULTS: Eighteen patients showed OCMB (M+) and 57 lacked them (M-). All M+ patients and only 25 M- patients were treated. The other 32 M- patients suffered less MS attacks than those required to initiate treatment. IT similarly reduced relapse rate in both treated groups (P < 0.0001) and reduced Expanded Disability Status Scale (EDSS) progression in M+ patients, whose EDSS score had significantly increased before treatment. EDSS did not change in M- patients during follow-up, regardless if they were treated or not. CONCLUSIONS: Oligoclonal IgM bands identify MS patients who are candidates for early immunomodulatory treatment as IT improves their initial aggressive disease course.

Clinically isolated syndromes: a new oligoclonal band test accurately predicts conversion to MS.

BACKGROUND: Patients with a clinically isolated demyelinating syndrome (CIS) are at risk of developing a second attack, thus converting into clinically definite multiple sclerosis (CDMS). Therefore, an accurate prognostic marker for that conversion might allow early treatment. Brain MRI and oligoclonal IgG band (OCGB) detection are the most frequent paraclinical tests used in MS diagnosis. A new OCGB test has shown high sensitivity and specificity in differential diagnosis of MS. OBJECTIVE: To evaluate the accuracy of the new OCGB method and of current MRI criteria (MRI-C) to predict conversion of CIS to CDMS. METHODS: Fifty-two patients with CIS were studied with OCGB detection and brain MRI, and followed up for 6 years. The sensitivity and specificity of both methods to predict conversion to CDMS were analyzed. RESULTS: OCGB detection showed a sensitivity of 91.4% and specificity of 94.1%. MRI-C had a sensitivity of 74.23% and specificity of 88.2%. The presence of either OCGB or MRI-C studied simultaneously showed a sensitivity of 97.1% and specificity of 88.2%. CONCLUSIONS: The presence of oligoclonal IgG bands is highly specific and sensitive for early prediction of conversion to multiple sclerosis. MRI criteria have a high specificity but less sensitivity. The simultaneous use of both tests shows high sensitivity and specificity in predicting clinically isolated demyelinating syndrome conversion to clinically definite multiple sclerosis.

An ultrasensitive method for the detection of oligoclonal IgG bands.

We have developed an ultrasensitive isoelectrofocusing (IEF) method for the detection of oligoclonal (OGC) IgG bands in cerebrospinal fluid (CSF) and sera. In this procedure, double antibody and peroxidase immunodetection have been substituted by a single antibody labelled with alkaline phosphatase. Alkaline phosphatase immunodetection not only improves tenfold the sensitivity of the assay but also gives a sharper pattern resolution making the interpretation easier and increases the specificity of this technique. This preliminary report should be validated in a larger number of patients with and without multiple sclerosis (MS).

Tumoricidal activity of lauryl gallate towards chemically induced skin tumours in mice.

Lauryl gallate (antioxidant food additive E-312) prevents the formation of dimethylbenzanthracene-induced skin tumours in mice, and kills, selectively, tumoral cells on established tumours. This results in total remission, after topical application of the compound on the tumoral mass, without affecting the surrounding tissue.

Intrathecal IgM synthesis predicts the onset of new relapses and a worse disease course in MS.

BACKGROUND: The authors have recently described that intrathecal IgM synthesis (ITMS) correlates with a higher disability in patients with clinically definite MS (CDMS). OBJECTIVE: To follow-up a group of patients with MS in the initial stages of the disease to evaluate if the presence of ITMS correlates with a worse evolution. METHODS: Oligoclonal IgM bands were performed in 22 patients with MS with a mean of 1.14 months of evolution. Patients were followed for a period ranging from 6 to 36 months (mean, 21.4 months). During follow-up, time to conversion to CDMS, number of relapses, and changes in Expanded Disability Status Scale (EDSS) score were evaluated. RESULTS: Patients were divided into two groups according to the presence (Group 1, 10 patients) or absence (Group 2, 12 patients) of ITMS. No clinical differences were observed between the groups at inclusion in the study. During the follow-up, the probability of conversion to CDMS was greater in Group 1 (90% of the patients had converted to CDMS after 8 months of follow-up) than in Group 2 (51% of patients had converted to CDMS after 36 months of follow-up) (p = 0.0001). Patients from Group 1 had more relapses (mean, 2.0) than those from Group 2 (mean, 0.58) (p = 0.02). At the end of the study, patients from Group 1 had higher EDSS scores (mean, 1.70) than those from Group 2 (mean, 0.79) (p = 0.02). CONCLUSION: The presence of oligoclonal IgM bands in CSF can be a prognostic marker in the early phases of MS.

Intrathecal IgM synthesis in neurologic diseases: relationship with disability in MS.

The authors studied the intrathecal IgM synthesis (ITMS) in paired sera and CSF samples from 65 patients with MS, 28 with CNS infection, 40 with other neurologic diseases and eight control subjects. ITMS was found in 30 patients with MS and in 20 with CNS infection, but not in patients with other neurologic diseases or in control subjects. In infectious samples, the ITMS is likely a primary response. In MS group, it was associated with higher Expanded Disability Status Scale index (p = 0.017).