High K+ intake alleviates experimental autoimmune encephalomyelitis (EAE) and increases T regulatory cells.

Multiple sclerosis is believed to be triggered by the interplay between the environmental and genetic factors. In contrast to the Paleolithic diet, the modern Western diet is high in Na+ and low in K+. The present study was undertaken to determine whether high K+ intake alleviated experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis. Treatment of C57BL/6 or SJL mice for 7 days with a 5 % K+ diet prior to induction of EAE and maintaining mice on the diet until the end of experiments delayed the onset, reduced the peak, and accelerated the recovery of EAE in both strains compared with mice on a control diet (0.7 % K+), whereas feeding C57BL/6 mice with a 0.1 % K+ diet did the opposite. High K+ intake increased the splenic Treg cell frequency in the pretreatment and peak EAE. Thus, high K+ intake attenuates EAE, possibly by increasing the Treg cells.

NFAT5 contributes to the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and decrease of T regulatory cells in female mice.

Multiple sclerosis disproportionally affects women. The present study was undertaken to determine whether NFAT5 contributed to the pathogenesis of experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis, and if it did, whether the impact was sex associated. NFAT5 haplodeficiency reduced the disease severity only in female mice. This effect was associated with significant increases in frequency of T regulatory (Treg) cells in the CNS (from 1.45 ± 0.39% to 3.73 ± 0.94%) and spleen from (0.31 ± 0.06% to 0.94 ± 0.29%) without significantly affecting the CNS CD4+ subsets frequency. NFAT5 haploinsufficiency also significantly reduced the frequency of CD11c+CD8α+ dendritic cells in the female CNS. However, increase of their frequency in the CNS via intraperitoneal Flt3L injection at peak EAE had no significant effect on the disease courses. We conclude that NFAT5 contributes to pathogenesis of EAE in female mice, possibly through decreasing tissue specific frequency of Treg cells.

Impact of fibrinogen and prothrombin complex concentrate on clotting time in a model of obstetric hemorrhage.

STUDY OBJECTIVE: Determine the impact of varying doses of fibrinogen concentrate and 4-factor prothrombin complex concentrate on clotting time as measured by thromboelastometry in an in-vitro model of dilutional coagulopathy. DESIGN: In-Vitro Study. SETTING: Tertiary academic center. PATIENTS: 31 healthy term singleton gestation patients. INTERVENTIONS: Blood was analyzed and diluted 95% with crystalloid. Washed red blood cells were added to simulate red blood cell transfusion. Two levels of fibrinogen repletion were then added to samples to simulate fibrinogen repletion in massive transfusion. Finally, 4-factor prothrombin complex concentrate (10 U/kg, 15 U /kg, or 25 U/kg) adjusted for body weight and estimated blood volume was added. MEASUREMENTS: Samples were analyzed by thromboelastometry, and the main outcome was a FIBTEM clotting time > 80s. MAIN RESULTS: FIBTEM clotting times were prolonged after dilution. After repletion with fibrinogen and prothrombin complex concentrates 7/31 (22.5%) of samples had a prolonged FIBTEM clotting time (> 80s) in the 50% fibrinogen repletion arm and 0 (0%) had a prolonged clotting time in the 100% fibrinogen repletion arm. FIBTEM clotting times approached their baseline levels at each dose of prothrombin complex concentrate. Median clotting time in the 100% fibrinogen repletion arm was under 80s prior to the administration of prothrombin complex concentrate. CONCLUSIONS: Commonly cited doses for prothrombin complex concentrates in hemorrhage might be too high for the obstetric patient. After fibrinogen correction alone, several samples required no further correction, highlighting the importance of frequent testing at the point of care. Limitations of this study include the in vitro study design and ability to directly apply findings to patient care. Further studies are needed to elucidate the ideal dose of prothrombin complex concentrate for obstetric hemorrhage. TWEETABLE ABSTRACT: Fibrinogen concentrate and low dose 4-factor PCC corrected coagulopathy in in-vitro obstetric hemorrhage.

Dexamethasone upregulates mitochondrial Tom20, Tom70, and MnSOD through SGK1 in the kidney cells.

Dexamethasone augments mitochondrial protein abundance. The translocase of the outer membrane (Tom) of mitochondria plays a major role in importing largely cytosolically synthesized proteins into mitochondria. We hypothesize that dexamethasone upregulates the Tom transport system, leading to increase of mitochondrial protein localization. Tom20 and Tom70 are the two major subunits. Dexamethasone increased Tom20 and Tom70 mRNA levels by 53 ± 11% and 25 ± 9% and mitochondrial protein abundance by 27 ± 7% and 25 ± 4% (p < 0.05 for all), respectively, in HEK293 cells. In parallel, dexamethasone elevated the SGK1 mRNA by 79 ± 17% and activity by 190 ± 42%, and mitochondrial protein level by 41 ± 2% (all p < 0.05) without significantly affecting the cytosol counterpart. The discovery of the effect of dexamethasone on SGK1 protein restricted in the mitochondria attracted us to examine the effect of the hormone on MnSOD, an enzyme with known mitochondrial localization and function. Similarly, dexamethasone significantly increased MnSOD transcripts by 67 ± 15% and protein level only in the mitochondria dose-dependently. Inhibition of SGK1 by GSK650394 and RNAi significantly attenuated the effects of the hormone on Tom20, Tom70, and MnSOD, indicating that SGK1 relays the effects of dexamethasone. Catalase inhibited the effects of dexamethasone on SGK1 and the subsequent effects of SGK1 on Tom20, Tom70, and MnSOD. Finally, knock-down of Tom20 and Tom70 by their siRNAs reduced dexamethasone-induced increases in the mitochondrial localization of SGK1 and MnSOD proteins. In conclusion, dexamethasone upregulates Tom20, Tom70, and MnSOD, and these effects are dependent on reactive oxygen species and SGK1. Dexamethasone-induced increases of SGK1 and MnSOD mitochondrial localization requires Tom20 and Tom70.

EAE-induced upregulation of mitochondrial MnSOD is associated with increases of mitochondrial SGK1 and Tom20 protein in the mouse kidney cortex.

Our previous demonstration that severe experimental autoimmune encephalomyelitis (EAE) increases MnSOD protein abundance in the mouse kidney cortex led this study to elucidate the underlying mechanism with monensin-treated HEK293 cells as a model. Severe EAE increases mitochondrial protein abundance of SGK1 kinase and Tom20, a critical subunit of mitochondrial translocase in the renal cortex. In HEK293 cells, catalase inhibits monensin-induced increases of mitochondrial SGK1 and Tom20 protein levels. Further, GSK650394, a specific inhibitor of SGK1 reduces monensin-induced increase of mitochondrial protein abundance of Tom20 and MnSOD. Finally, RNAi of Tom20 reduces the effect of monensin on MnSOD. MnSOD and Tom20 physically associate with each other. In conclusion, in HEK293 cells, mitochondrial reactive oxygen species increase protein abundance of mitochondrial SGK1, which leads to a rise of mitochondrial Tom20, resulting in importing MnSOD protein into the mitochondria. This could be a mechanism by which severe EAE up-regulates mitochondrial MnSOD in the kidney cortex.