Suppression of lymphocyte spontaneous proliferative response by proteolipid protein peptide in patients with HAM/TSP

To understand the immune mechanism suggested in HTLV-I-associated myelopathy (HAM/TSP), we investigated T cell response to proteolipid protein (PLP). Because of high autologous proliferative response (APR) of peripheral blood mononuclear cells (PBMC) in culture, the lymphocyte proliferation assay was not useful in this disease. Unexpectedly, however, APR was profoundly (70–98%) suppressed in 6 of 9 cases when PLP peptide 105-124 was added in the culture. PLP peptide 85-104 or 145-159 also suppressed APR in a few cases. Time course study showed that the peptide-mediated suppression became apparent after day 4 in culture. The results can be interpreted as that suppressor cells recognizing the PLP peptides were present in the PBMC of HAM/TSP patients and suppressed the APR as the consequence of antigen specific response. This may indicate that a T cell response to certain PLP determinants is involved in the pathomechanism of HAM/TSP at least in part. Molecular mimicry between PLP and HTLV-I mayaccount for the T cell sensitization to PLP in HAM/TSP.Special issue dedicated to Dr. Marjorie B. Lees.     

Immunological signature of the different clinical stages of the HTLV-1 infection: establishing serum biomarkers for HTLV-1-associated disease morbidity

Abstract

This study aimed at establishing the immunological signature and an algorithm for clinical management of the different clinical stages of the HTLV-1-infection based on serum biomarkers. A panel of serum biomarkers was evaluated by four sets of innovative/non-conventional data analysis approaches in samples from 87 HTLV-1 patients: asymptomatic carriers (AC), putative HTLV-1 associated myelopathy/tropical spastic paraparesis (pHAM/TSP) and HAM/TSP. The analysis of cumulative curves and molecular signatures pointed out that HAM/TSP presented a pro-inflammatory profile mediated by CXCL10/LTB-4/IL-6/TNF-α/IFN-γ, counterbalanced by IL-4/IL-10. The analysis of biomarker networks showed that AC presented a strongly intertwined pro-inflammatory/regulatory net with IL-4/IL-10 playing a central role, while HAM/TSP exhibited overall immune response toward a predominant pro-inflammatory profile. At last, the classification and regression trees proposed for clinical practice allowed for the construction of an algorithm to discriminate AC, pHAM and HAM/TSP patients with the elected biomarkers: IFN-γ, TNF-α, IL-10, IL-6, IL-4 and CysLT. These findings reveal a complex interaction among chemokine/leukotriene/cytokine in HTLV-1 infection and suggest the use of the selected but combined biomarkers for the follow-up/diagnosis of disease morbidity of HTLV-1-infected individuals.     

A metabonomic investigation of the effects of 60 days exposure of rats to two types of pyrethroid insecticides

Type I and II pyrethroid insecticides display different neurotoxicity. To investigate the long-term (60 days exposure) metabolic effect of the two types of pyrethroid insecticides deltamethrin and permethrin, ¹H nuclear magnetic resonance (NMR) spectroscopy-based metabonomics was used to analyze the biochemical composition of urine and serum samples from rats administrated daily with deltamethrin or permethrin for 60 consecutive days, and principal component analysis used to visualize similarities and differences in the resultant biochemical profiles. Rats treated with either deltamethrin or permethrin displayed increased levels of urinary acetate, dimethylamine, dimethylglycine, trimethylamine and serum free amino acids, and decreased urinary 2-oxoglutarate, all of which are indicative of kidney lesions and nephrotoxicity. The reduced excretion of tricarboxylic acid cycle intermediates, together with increased 3-D-hydroxybutyrate, acetate, and lactate in treated rats could suggest disturbance of the energy metabolism, including an increased rate of anaerobic glycolysis, enhanced fatty acid β-oxidation and ketogenesis. These results show that these two types of insecticides have similarities in the urine and serum spectra, indicating that similar metabolic pathways are perturbed by the insecticides, which induced hepatotoxicity and nephrotoxicity. This approach may lead to the discovery of novel biomarkers of pyrethroids toxicity and thereby provide new insights into the toxicological mechanisms of pesticides pyrethroids.     

Curcumin increased the expression of c-FLIP in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients

Human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) disease is a chronic neuroinflammatory disease, which is associated with HTLV-1 infection. There is no effective and satisfactory treatment of HAM/TSP. It has been shown that curcumin exhibits modulatory effects on apoptosis and cytotoxicity-related molecules in HAM/TSP patients. In the present study, we examined the effect of curcumin on the gene expression of caspase-8, caspase-10, and anti-apoptotic protein c-FLIP, in HAM/TSP patients. Furthermore, we compared the expression of these molecules between HAM/TSP and asymptomatic carriers. Real-time PCR was performed to examine the mRNA expression of caspase-8, caspase-10, and c-FLIP in studied groups. The mRNA expression of caspase-8 and caspase-10 was similar before and after curcumin treatment in HAM/TSP patients (P > 0.05). The mRNA expression of c-FLIPL and c-FLIPs was higher after curcumin treatment compared with before treatment and significant differences were observed between the two groups (P = 0.004 and P = 0.044, respectively). The mRNA expression levels of caspase-8, caspase-10, c-FLIPL, and c-FLIPs were not statistically significant between HAM/TSP patients and asymptomatic carriers (P < 0.05). In conclusion, our results showed that curcumin increased the expression of c-FLIP in HAM/TSP patients which might suggest that, this molecule is involved in the apoptosis of HTLV-1-infected cells. Further studies with large sample size could be useful to clarify the role of this supplement in HAM/TSP patients.     

Uncoupling the BMP receptor antagonist function from the WNT agonist function of R-spondin 2 using the inhibitory peptide dendrimer RWd

Signaling by bone morphogenetic proteins (BMPs) plays pivotal roles in embryogenesis, adult tissue homeostasis, and disease. Recent studies revealed that the well-established WNT agonist R-spondin 2 (RSPO2) is also a BMP receptor (BMP receptor type 1A) antagonist, with roles in early Xenopus embryogenesis and human acute myeloid leukemia (AML). To uncouple the BMP antagonist function from the WNT agonist function and to promote development of AML therapeutics, here we identified a 10-mer peptide (RW) derived from the thrombospondin 1 domain of RSPO2, which specifically prevents binding between RSPO2 and BMP receptor type 1A without altering WNT signaling. We also show that a corresponding RW dendrimer (RW^d) exhibiting improved half-life relieves inhibition of BMP receptor signaling by RSPO2 in human AML cells, reduces cell growth, and induces differentiation. Moreover, microinjection of RW^d in Xenopus embryos ventralizes the dorsoventral embryonic patterning by upregulating BMP signaling without affecting WNT signaling. Our study corroborates the function of RSPO2 as a BMP receptor antagonist and provides a proof of concept for pharmacologically uncoupling BMP antagonist from WNT agonist functions of RSPO2 using the inhibitor peptide RW^d with enhanced target selectivity and limited side effects.     

Drosophila type XV/XVIII collagen, Mp, is involved in Wingless distribution

Multiplexin (Mp) is the Drosophila orthologue of vertebrate collagens XV and XVIII. Like them, Mp is widely distributed in the basement membranes of the developing embryos, including those of neuroblasts in the central and peripheral nervous systems, visceral muscles of the gut, and contractile cardioblasts. Here we report the identification of mutant larvae bearing piggyBac transposon insertions that exhibit decrease Mp production associated with abdominal cuticular and wing margin defects, malformation of sensory organs and impaired sensitivity to physical stimuli. Additional findings include the abnormal ultrastructure of fatbody associated with abnormal collagen IV deposition, and reduced Wingless deposition. Collectively, these findings are consistent with the notion that Mp is required for the proper formation and/or maintenance of basement membrane, and that Mp may be involved in establishing the Wingless signaling gradients in the Drosophila embryo.     

Notch signaling and Notch signaling modifiers

Originally discovered nearly a century ago, the Notch signaling pathway is critical for virtually all developmental programs and modulates an astounding variety of pathogenic processes. The DSL (Delta, Serrate, LAG-2 family) proteins have long been considered canonical activators of the core Notch pathway. More recently, a wide and expanding network of non-canonical extracellular factors has also been shown to modulate Notch signaling, conferring newly appreciated complexity to this evolutionarily conserved signal transduction system. Here, I review current concepts in Notch signaling, with a focus on work from the last decade elucidating novel extracellular proteins that up- or down-regulate signal potency.     

Restoration of ultrastructural and biochemical changes in alloxan-induced diabetic rat sciatic nerve on treatment with Na3VO4 and Trigonella—a promising antidiabetic agent

Vanadium has been reported to have broad pharmacological activity both in vitro and in vivo. Vanadium compound, sodium orthovanadate, Na₃VO₄, is well known for its hypoglycaemic effects. However, Na₃VO₄ exerts these effects at relatively high doses (0.6 mg/ml) and exhibit several toxic effects. In the present study lower doses of Na₃VO₄ (0.2 mg/ml) are combined with Trigonella foenum graecum seed powder (TSP), another hypoglycaemic agent, to reduce its toxicity without compromising its antidiabetic potential. The efficacy of the lower doses of Na₃VO₄ has been investigated in restoring the altered glucose metabolism and histological structure in the sciatic nerves in 21 and 60 days alloxan diabetic rats. A portion of the glucose was found to be channelled from the normal glycolytic route to polyol pathway, evident by the reduced hexokinase activity and increased polyol pathway enzymes aldose reductase and sorbitol dehydrogenase activity causing accumulation of sorbitol and fructose in diabetic conditions. Ultrastructural observation of the sciatic nerve showed extensive demylination and axonal loss after eight weeks of diabetes induction. Blood glucose levels increased in diabetic rats were normalized with the lower dose of vanadium and Trigonella treatment. The treatment of the diabetic rats with vanadium and Trigonella prevented the activation of the polyol pathway and sugar accumulations. The sciatic nerves were also protected against the structural abnormalities found in diabetes with Trigonella foenum graecum as well as Na₃VO₄. Results suggest that lower doses of Na₃VO₄ may be used in combination with TSP as an efficient antidiabetic agent to effectively control the long-term complications of diabetes in tissues like peripheral nerve.     

Amelioration of altered antioxidant status and membrane linked functions by vanadium andTrigonella in alloxan diabetic rat brains

Trigonella foenum graecum seed powder (TSP) and sodium orthovanadate (SOV) have been reported to have antidiabetic effects. However, SOV exerts hypoglycemic effects at relatively high doses with several toxic effects. We used low doses of vanadate in combination with TSP and evaluated their antidiabetic effects on antioxidant enzymes and membrane-linked functions in diabetic rat brains. In rats, diabetes was induced by alloxan monohydrate (15 mg/100 g body wt.) and they were treated with 2 IU insulin, 0.6 mg/ml SOV, 5% TSP and a combination of 0.2 mg/ml SOV with 5% TSP for 21 days. Blood glucose levels, activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), Na⁺/K⁺ ATPase, membrane lipid peroxidation and fluidity were determined in different fractions of whole brain after 21 days of treatment. Diabetic rats showed high blood glucose (P < 0.001), decreased activities of SOD, catalase and Na⁺/K⁺ ATPase (P < 0.01,P < 0.001 andP < 0.01), increased levels of GPx and MDA (P < 0.01 andP < 0.001) and decreased membrane fluidity (P < 0.01). Treatment with different antidiabetic compounds restored the above-altered parameters. Combined dose ofTrigonella and vanadate was found to be the most effective treatment in normalizing these alterations. Lower doses of vanadate could be used in combination with TSP to effectively counter diabetic alterations without any toxic effects.