Methyl pyruvate rescues mitochondrial damage caused by SIGMAR1 mutation related to amyotrophic lateral sclerosis

Background

Amyotrophic lateral sclerosis (ALS) is a disease caused by motor neuron degeneration. Recently, a novel SIGMAR1 gene variant (p.E102Q) was discovered in some familial ALS patients.

Methods

We address mechanisms underlying neurodegeneration caused by the mutation using Neuro2A cells overexpressing σ₁R^E102Q, a protein of a SIGMAR1 gene variant (p.E102Q) and evaluate potential amelioration by ATP production via methyl pyruvate (MP) treatment.

Results

σ₁R^E102Q overexpression promoted dissociation of the protein from the endoplasmic reticulum (ER) membrane and cytoplasmic aggregation, which in turn impaired mitochondrial ATP production and proteasome activity. Under ER stress conditions, overexpression of wild-type σ₁R suppressed ER stress-induced mitochondrial injury, whereas σ₁R^E102Q overexpression aggravated mitochondrial damage and induced autophagic cell death. Moreover, σ₁R^E102Q-overexpressing cells showed aberrant extra-nuclear localization of the TAR DNA-binding protein (TDP-43), a condition exacerbated by ER stress. Treatment of cells with the mitochondrial Ca^2 + transporter inhibitor Ru360 mimicked the effects of σ₁R^E102Q overexpression, indicating that aberrant σ₁R-mediated mitochondrial Ca^2 + transport likely underlies TDP-43 extra-nuclear localization, segregation in inclusion bodies, and ubiquitination. Finally, enhanced ATP production promoted by methyl pyruvate (MP) treatment rescued proteasome impairment and TDP-43 extra-nuclear localization caused by σ₁R^E102Q overexpression.

Conclusions

Our observations suggest that neurodegeneration seen in some forms of ALS are due in part to aberrant mitochondrial ATP production and proteasome activity as well as TDP-43 mislocalization resulting from the SIGMAR1 mutation.

General significance

ATP supplementation by MP represents a potential therapeutic strategy to treat ALS caused by SIGMAR1 mutation.     

Pain relief following stimulation of the pontomesencephalic parabrachial region in humans: brain sites for nonopiate-mediated pain control

It has been demonstrated that stimulation of the pontomesencephalic parabrachial region (PBR) by microinjection of cholinergic drugs or electricity in the cat produces potent pain suppression which is not antagonized by the opiate antagonist, naloxone. We report the application of electrical PBR stimulation in 2 patients whose pain was resistant to conventional methods of treatment including morphine administration. Intermittent use of low-frequency PBR stimulation was found to relieve pain in these patients. The present results appear to suggest that PBR stimulation, unlike periaqueductal gray stimulation, may be useful for the control of morphine-resistant pain in humans.     

Positive phototropism is accelerated in Biomphalaria glabrata snails by infection with Schistosoma mansoni

Parasite-induced behavioral changes in their hosts favor to complete the lifecycle of parasites. Schistosome infection is also known to cause physiological changes in infected freshwater snail intermediate hosts. Here, we report, a novel phenomenon in which Schistosoma mansoni, a highly debilitating worm affecting millions of people worldwide, alters the phototropic behavior of Biomphalaria glabrata, the vector snail. S. mansoni-infection enhanced positive phototropism of vector snails and infected snails spent significantly more time in light. Possibly, these behavioral changes help the parasite to be released efficiently from the infected intermediate hosts, and to infect mammalian hosts.     

Resolution ofFusarium sporotrichioides proteins by two-dimensional polyacrylamide gel electrophoresis and identification by sequence homology comparison in protein data base

Proteins fromFusarium sporotrichioides M-1-1, a T2-toxin-producing strain, were separated by two-dimensional polyacrylamide gel electrophoresis. One thousand two hundred and forty-four protein spots were resolved and 103 protein spots were subjected to N-terminal sequencing. Fifty-eight protein spots were sequenced and 48 proteins were observed to have blocked N termini. Forty out of 58 sequenced proteins were identified by homology search against the PIR protein sequence data base and protein superfamily data base, while the residual 18 sequences were not identified. Twenty-seven of the N-terminal-blocked proteins were subjected to mild anhydrous hydrazine vapor deblocking. Twenty-four spots were not deblocked indicating the presence of acyl groups at the N termini, while 3 proteins were deblocked showing the blocked group to be pyrroglutamyl carboxylic acid residues. The results can provide a more global view of cellular genetic expression than any other technique. The created data may offer a unique opportunity to link information with DNA sequence data.     

T Cell-Dependent Activation of Macrophages and Enhancement of Their Phagocytic Activity in the Lungs of Mice Inoculated with Heat-Killed Cryptococcus neoformans: Involvement of IFN-γ and Its Protective Effect against Cryptococcal Infection

Previous investigations have demonstrated that macrophages play a critical role in the first-line cellular defense mechanism against infection with Cryptococcus neoformans. In the present study, to elucidate the way in which anticryptococcal activity of macrophages is regulated at the site of infection, pulmonary intraparenchymal macrophages were directly analyzed for expression of their surface molecules and their phagocytic activities against the organism, and the effects of depletion of T cells and endogenous IFN-γ in vivo on these parameters were examined. In the lungs of mice intratracheally inoculated with heat-killed C. neoformans, macrophages were activated, as indicated by augmented expression of MHC class II, intercellular adhesion molecule-1 (ICAM-1) and Fc receptor (FcR), and about two-thirds of macrophages were found to have ingested an average of 3.77 ± 0.12 yeast cells per macrophage. In mice depleted of both CD4⁺ and CD8⁺ T cells by injecting the specific monoclonal antibodies (mAbs) or anti-IFN-γ mAb, not only augmentation of the expression of macrophage activation markers but also phagocytosis of C. neoformans was significantly reduced. These results suggest that anticryptococcal activity of macrophages is regulated by IFN-γ endogenously produced by T cells. Additionally, treatment with IFN-γ were shown to significantly prolong the survival time of mice infected with viable C. neoformans. Additionally, preimmunization with heat-killed C. neoformans significantly prolonged the survival time of mice which received the following infection.     

Occurrence of two different endorphins in the salmon pituitary

Two endorphins have been identified in the teleost pituitary, $\text{Oncorhynchus}\text{keta}$ (chum salmon). Endorphin I is a nonacosa peptide and the primary structure was reported previously. Endorphin II has been elucidated to be a triaconta peptide with the following primary structure: Ac-Tyr-Gly-Gly- Phe-Met-Lys-Ser-Trp-Asn-Glu-Arg-Ser-Gln-Lys-Pro-Leu-Leu-Thr- Leu-Phe-Lys-Asn-Val-Ile-Ile-Lys-Asp-Gly-Gln-Gln-OH. It is evident that these endorphins are highly homologous to each other, but are different molecules, and that endorphin II is much more similar to the mammalian endorphins than endorphin I.     

Solid state fermentation,storage and viability of Streptomyces similanensis 9X166 using agro-industrial substrates against Phytophthora palmivora-induced black rot disease in orchids

Streptomyces similanensis 9X166 is known to be an antagonist of the black rot pathogen of orchids, Phytophthora palmivora. In this study, we investigated the production of highly viable S. similanensis 9X166 cells by solid state fermentation using agro-industrial substrates, and the shelf life of a S. similanensis 9X166 dried solid. Rice bran was found to be the most appropriate raw material for production of both viable cells and β-1,3-glucanase. A medium containing 12?g of rice bran and coconut husks at a ratio of 10:2, supplemented with 10?mL of mineral salts produced the highest number of viable cells and greatest level of β-1,3-glucanase. Ammonium sulfate was the most suitable nitrogen source, and an initial moisture content of 65% and a temperature of 30°C were found to be optimal conditions for the production of viable cells and β-1,3-glucanase. Storing the dried fermented solid under non-vacuum conditions resulted in the highest cell viability. The specific rate of degradation on viability increased as the temperature increased to 37°C, according to the Arrhenius equation. There was no difference between the storage time estimated by the Arrhenius equation from the specific rate of degradation compared to the validated storage time of S. similanensis 9X166 dried solids when maintained at the ambient temperature in Thailand. At 60 days, the product retained 10⁶ CFU/g of S. similanensis 9X166 in dried solid, which was the minimal effective amount for 100% inhibition of P. palmivora in living orchids.