R-lipoic acid overdosing affects platelet life span via ROS mediated autophagy

α-Lipoic Acid as Adjunctive Treatment for Schizophrenia: A Randomized Double-Blind Study

BACKGROUND/PURPOSE

There is evidence for low endogenous antioxidant levels and oxidative imbalance in patients with schizophrenia. A previous open-label study with α-lipoic acid (ALA), a potent antioxidant, improved patients' negative and cognitive symptoms and markers of lipid peroxidation. Here we report the results of a randomized double-blind, placebo-controlled study to verify the response of patients with schizophrenia to adjunctive treatment with ALA (100 mg/d) in a 4-month follow-up.

METHODS

We conducted a 16-week, double-blind, placebo-controlled study of ALA at 100 mg/d dosages. We compared negative and positive symptoms, cognitive function, extrapyramidal symptoms, body mass index, and oxidative/inflammatory parameters between placebo and control groups.

RESULTS

We found no significant improvement in body mass index, cognition, psychopathology, antipsychotic adverse effects, or oxidative stress and inflammation in the experimental group compared with placebo. The whole group of patients improved in several measures, indicating a strong placebo effect in this population. A surprising finding was a significant decrease in red blood cells, white blood cells, and platelets in the group treated with ALA.

CONCLUSIONS

The decrease in red blood cells, white blood cells, and platelet counts requires further investigation and attention when prescribing ALA for patients with schizophrenia.

Autophagy Ameliorates Reactive Oxygen Species-Induced Platelet Storage Lesions

Platelet transfusion is a life-saving therapy to prevent bleeding; however, the availability of platelets for transfusion is limited by the markedly short shelf life owing to the development of platelet storage lesions (PSLs). The mechanism of PSLs remains obscure. Dissection of the intracellular biological changes in stored platelets may help to reduce PSLs and improve platelet transfusion efficiency. In the present study, we explore the changes of stored platelets at room temperature under constant agitation. We found that platelets during storage showed an increased reactive oxygen species (ROS) generation accompanied with receptor shedding, apoptosis, and diminished platelet aggregation. ROS scavenger reduced platelet shedding but also impaired platelet aggregation. Autophagy is a conserved catabolic process that sequesters protein aggregates and damaged organelles into lysosomes for degradation and platelets’ own intact autophagic system. We revealed that there exist a stable autophagic flux in platelets at the early stage of storage, and the autophagic flux in platelets perished after long-term storage. Treatment stored platelets with rapamycin, which stimulates autophagy in eukaryotic cells, markedly ameliorated PSLs, and improved platelet aggregation in response to extracellular stimuli.

Long-Term Alpha-Lipoic Acid (ALA) Antioxidant Therapy Reduces Damage in the Cardiovascular System of Streptozotocin-Induced Diabetic Rats

Cellular damage, lipid oxidation and the action of inflammatory cytokines are implicated in the evolution of vascular complications associated with diabetes mellitus (DM) hyperglycemia. In contrast, alpha-lipoic acid (ALA) is a supplement with antioxidant and anti-inflammatory effects. This study aims to evaluate the overall effects of ALA supplementation by assessing its long-term systemic action on the vascular morphology of rats with induced diabetes. A total of 28 male rats were divided into 4 groups with seven animals each. For diabetes induction, two groups received streptozotocin. The animals in the lipoic and diabetic lipoic groups received ALA supplement. After 8 weeks the animals were anesthetized and blood collected was for hematological, biochemical and serological analyses. The thoracic aorta was removed, processed for paraffin and histological sections were stained for morphometric analysis. In diabetic groups, an improvement in hematological profile was observed, with platelet reduction in the diabetic lipoic group. ALA addition to the diet attenuated the negative effects in lipid profile; moreover, renal, hepatic and inflammatory parameters reduced or displayed values close to the values of the normal control. The anti-inflammatory effect of ALA was observed in diabetic animals, with a reduction of inflammatory citokines, accompanied by the improvement of morphological parameters in the aorta. In conclusion, long-term supplementation with ALA promoted systemic improvement, thus reducing the risk of vascular diseases. The changes in the renal and hepatic parameters without any negative impact in the hematological profile also show that ALA can be indicated as a low-risk prophylaxis or complementary therapy.

Transient Howell-Jolly-body-like cytoplasmic inclusions in neutrophils after severe intoxication with alpha-lipoic acid

After intravenous supplementation of an unintentionally high dose of the antioxidant alpha-lipoic acid (ALA), a 53-year-old female complained of myalgia, chills and nausea, and showed signs of haemorrhagic diathesis. The laboratory findings were excessive hyperferritinemia, leukoerythroblastosis, severe thrombocytopenia, elevated liver enzymes and impaired coagulation. The toxicological tests resulted in an ALA serum concentration of 10 280 µg/L. The peripheral blood film of the patient showed some neutrophil dysplasia with unusual small dark-blue stained round cytoplasmic inclusions resembling 'Howell-Jolly-body-like' (HJBL) cytoplasmic inclusions, aptly named due to the morphologic similarity to their erythrocytic counterparts. Such HJBL inclusions are occasionally associated with acquired immunodeficiency, or immunosuppressive or cytostatic treatment. An association with ALA intoxication has not been described before. There are only a few reports on unintentional, harmful and lethal intoxications with ALA. The underlying molecular background of its toxicity on liver function or haematopoiesis is not yet known in detail, but ALA seems to interact with enzyme functions, e.g. with mitochondrial enzyme-complexes, possibly due to its pro-oxidant potential at high doses.

Autophagic regulation of platelet biology

Platelets, developed from megakaryocytes, are characterized by anucleate and short-life span hemocyte in mammal vessel. Platelets are very important in the cardiovascular system. Studies indicate the occurrence of autophagy platelets and megakaryocytes. Moreover, abnormal autophagy decreases the number of platelets and suppresses platelet aggregation. In addition, mitophagy, as a kind of selective autophagy, could inhibit platelet aggregation under oxidative stress or hypoxic, whereas promote platelet aggregation after reperfusion. Finally, autophagy regulates hemorrhagic and thrombosis diseases by influencing the number and function of platelets. In this paper, the role of autophagy in platelets and megakaryocytes, as well as coupled with the promotive or inhibitory role of hemorrhagic and thrombosis diseases are elucidated. Therefore, autophagy may be a potentially therapeutic target in modulating the platelet-related diseases.

Nix-mediated mitophagy regulates platelet activation and life span

Platelet activation requires fully functional mitochondria, which provide a vital energy source and control the life span of platelets. Previous reports have shown that both general autophagy and selective mitophagy are critical for platelet function. However, the underlying mechanisms remain incompletely understood. Here, we show that Nix, a previously characterized mitophagy receptor that plays a role in red blood cell maturation, also mediates mitophagy in platelets. Genetic ablation of Nix impairs mitochondrial quality, platelet activation, and FeCl3-induced carotid arterial thrombosis without affecting the expression of platelet glycoproteins (GPs) such as GPIb, GPVI, and αIIbβ3 Metabolic analysis revealed decreased mitochondrial membrane potential, enhanced mitochondrial reactive oxygen species level, diminished oxygen consumption rate, and compromised adenosine triphosphate production in Nix -/- platelets. Transplantation of wild-type (WT) bone marrow cells or transfusion of WT platelets into Nix-deficient mice rescued defects in platelet function and thrombosis, suggesting a platelet-autonomous role (acting on platelets, but not other cells) of Nix in platelet activation. Interestingly, loss of Nix increases the life span of platelets in vivo, likely through preventing autophagic degradation of the mitochondrial protein Bcl-xL. Collectively, our findings reveal a novel mechanistic link between Nix-mediated mitophagy, platelet life span, and platelet physiopathology. Our work suggests that targeting platelet mitophagy Nix might provide new antithrombotic strategies.

miR-96-5p and miR-101-3p as potential intervention targets to rescue TiO2 NP-induced autophagy and migration impairment of human trophoblastic cells

Autophagy induced by titanium dioxide nanoparticles (TiO2 NPs) has been realized nowadays, but the underlying mechanisms remain largely unknown. Animal studies have confirmed that autophagy might be an important mechanism to impair placenta development, but the reversal of damage is not clear. Here, we used human HTR-8/SVneo (HTR) cells as a proper model to explore how autophagy is regulated in TiO2 NP-exposed human placenta cells. Our studies showed that TiO2 NPs could enter HTR cells and locate in cytoplasm. Although they did not affect cell viability even under 100 μg ml-1, autophagy was observed and cell migration ability was severely impaired. Further study showed that TiO2 NPs increased the expressions of both miR-96-5p and miR-101-3p and then, they targeted mTOR and decreased the expression of mTOR proteins. In addition, miR-96-5p also targeted Bcl-2 to down-regulate Bcl-2 protein level, which is also a key regulator of autophagy. We proved that when two microRNA inhibitors were added, cell autophagy was, to a greater extent, reversed compared with the result when one inhibitor was added, and the cell migration ability was also reversed to a greater degree. Our studies revealed that TiO2 NPs might impair placenta development via autophagy. Moreover, miR-96-5p as well as miR-101-3p may act as potential targets to reverse TiO2 NP-induced autophagy and placenta dysfunction.

Optimal α-lipoic acid strengthen immunity of young grass carp (Ctenopharyngodon idella) by enhancing immune function of head kidney, spleen and skin

This study was for the first time to investigate the effects of α-lipoic acid (LA) on growth and immune function of head kidney, spleen and skin in young grass carp (Ctenopharyngodon idella). A total of 540 healthy grass carp (with initial body weight at 216.59 ± 0.33 g) were randomly divided into six groups and fed six separate diets with graded dietary levels of LA for 70 days. Un-supplemented group did not find LA and its concentrations in the other five diets were 203.25, 403.82, 591.42, 781.25 and 953.18 mg kg^-1, respectively. After the growth trial, fish were challenged with A. hydrophila for 14 days. The results showed that, compared with the un-supplemented group, optimal LA improved lysozyme (LZ) and acid phosphatase (ACP) activities, enhanced complement 3 (C3), C4 and immunoglobulin (Ig) M contents and up-regulated hepcidin, liver expressed antimicrobial peptide (LEAP)-2A, LEAP-2B and β-defensin-1 mRNA levels in the head kidney, spleen and skin of young grass carp; meanwhile, optimal LA up-regulated anti-inflammatory cytokines transforming growth factor (TGF)-β1, TGF-β2, interleukin (IL)-4/13A (not IL-4/13B), IL-10 and IL-11 mRNA levels partly related to target of rapamycin (TOR) signaling and down-regulated pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interferon (IFN)-γ2, IL-1β, IL-6, IL-8, IL-12p40 (not IL-12p35), IL-15 (not in the skin) and IL-17D mRNA levels partially associated with nuclear factor-kappa B (NF-κB) signaling in the head kidney, spleen and skin of young grass carp. Above results indicated that optimal LA enhanced the immune function of head kidney, spleen and skin in fish. Interestingly, excessive LA decreased the growth and impaired the immune function of head kidney, spleen and skin in fish. Finally, on the basis of the percent weight gain (PWG), the ability against skin hemorrhage and lesion, the IgM content in the head kidney and the LZ activity in the spleen, the optimal dietary LA levels were estimated to be 315.37, 382.33, 353.19 and 318.26 mg kg^-1 diet, respectively.