Sialoglycan recognition is a common connection linking acidosis, zinc, and HMGB1 in sepsis.

Blood pH is tightly maintained between 7.35 and 7.45, and acidosis (pH <7.3) indicates poor prognosis in sepsis, wherein lactic acid from anoxic tissues overwhelms the buffering capacity of blood. Poor sepsis prognosis is also associated with low zinc levels and the release of High mobility group box 1 (HMGB1) from activated and/or necrotic cells. HMGB1 added to whole blood at physiological pH did not bind leukocyte receptors, but lowering pH with lactic acid to mimic sepsis conditions allowed binding, implying the presence of natural inhibitor(s) preventing binding at normal pH. Testing micromolar concentrations of divalent cations showed that zinc supported the robust binding of sialylated glycoproteins with HMGB1. Further characterizing HMGB1 as a sialic acid-binding lectin, we found that optimal binding takes place at normal blood pH and is markedly reduced when pH is adjusted with lactic acid to levels found in sepsis. Glycan array studies confirmed the binding of HMGB1 to sialylated glycan sequences typically found on plasma glycoproteins, with binding again being dependent on zinc and normal blood pH. Thus, HMGB1-mediated hyperactivation of innate immunity in sepsis requires acidosis, and micromolar zinc concentrations are protective. We suggest that the potent inflammatory effects of HMGB1 are kept in check via sequestration by plasma sialoglycoproteins at physiological pH and triggered when pH and zinc levels fall in late stages of sepsis. Current clinical trials independently studying zinc supplementation, HMGB1 inhibition, or pH normalization may be more successful if these approaches are combined and perhaps supplemented by infusions of heavily sialylated molecules.

Rutin ameliorates metabolic acidosis and fibrosis in alloxan induced diabetic nephropathy and cardiomyopathy in experimental rats.

Diabetic nephropathy and cardiomyopathy are two major causes of mortality among patients with diabetes mellitus (DM). Since current diabetic medications are associated with various side effects, the naturally occurring plant-derived compounds are in demand. Bioflavonoids originating from vegetables and medicinal plants have beneficial effects on diabetes by improving glycemic control, lipid metabolism, and anti-oxidant status. The present study is focused on the effect of rutin against alloxan induced diabetic nephropathy and cardiomyopathy. Male albino Wistar rats were divided into four groups, each of six rats. Group I control rats received 0.9% saline as a single dose intraperitoneally. Group II rats were induced diabetes with a single dose of alloxan monohydrate (150 mg/kg body weight in 0.9% saline) intraperitoneally. Group III rats received 0.28 M of NH4Cl in drinking water for 3 days for the experimental induction of metabolic acidosis. Group IV rats were injected with a single dose of alloxan monohydrate (150 mg/kg bodyweight) and administered rutin hydrate (100 mg/kg) for a period of 4 weeks by oral gavage. Administration of rutin prevented urinary ketone body formation and decreased serum creatinine and urea levels in alloxan induced diabetic rats. Rutin supplementation reduced the levels of serum triglycerides and cholesterol in diabetic rats. Gene expression profiling of metabolic acidosis related genes (AQP2, AQP3 and V2R) and also histopathological results demonstrated the protective effect of rutin against diabetic ketoacidodis and fibrosis. The results of the present study revealed rutin administration prevents the progression of diabetic nephropathy and cardiomyopathy through amelioration of fibrosis and metabolic acidosis.

Thiamine ameliorates inflammation of the ruminal epithelium of Saanen goats suffering from subacute ruminal acidosis.

This study aimed to examine the role of thiamine in the local inflammation of ruminal epithelium caused by high-concentrate diets. Eighteen mid-lactating (148 ± 3 d in milk; milk yield = 0.71 ± 0.0300 kg/d) Saanen goats (body weight = 36.5 ± 1.99 kg; body condition score = 2.73 ± 0.16, where 0 = emaciated and 5 = obese) in parity 1 or 2 were selected. The goats were randomly divided into 3 groups (n = 6/group): (1) control diet (concentrate:forage 30:70), (2) high-concentrate diet (HC; concentrate:forage 70:30), and (3) high-concentrate diet with 200 mg of thiamine/kg of dry matter intake (THC; concentrate:forage 70:30). Goats remained on experimental diets for 8 wk. On the last day of 8 wk, ruminal and blood samples were collected to determine ruminal parameters, endotoxin lipopolysaccharide, and blood inflammatory cytokines. Goats were slaughtered to collect ruminal tissue to determine gene and protein expression of toll-like receptor 4 (TLR4) signaling pathways. Thiamine supplementation increased ruminal pH (6.03 vs. 5.42) compared with the HC group. Propionate (21.08 vs. 31.61 mM), butyrate (12.08 vs. 19.39 mM), lactate (0.52 vs. 0.71 mM), and free lipopolysaccharide (42.16 vs. 55.87 × 103 endotoxin units/mL) concentrations in ruminal fluid were lower in THC goats compared with HC goats. Similar to plasma interleukin 1ß (IL-1ß) concentration (209.31 vs. 257.23 pg/mL), blood CD8+ percentage (27.57 vs. 34.07%) also decreased in response to thiamine. Compared with HC goats, THC goats had lower ruminal epithelium activity of the enzymes myeloperoxidase and matrix metalloproteinase (MMP) 2 and 9. In contrast to HC, THC had downregulated mRNA expression of nuclear factor-κB (NFKB), TLR4, IL1B, MMP2, and MMP9 in ruminal epithelium. Thiamine supplementation led to lower relative protein expression of IL-1ß, NF-κB unit p65, and phosphorylated NF-κB unit p65 in ruminal epithelium. Taken together, these results suggest that thiamine supplementation mitigates HC-induced local inflammation and ruminal epithelial disruption.

Clinical, biochemical and genetic spectrum of 70 patients with ACAD9 deficiency: is riboflavin supplementation effective?

BACKGROUND: Mitochondrial acyl-CoA dehydrogenase family member 9 (ACAD9) is essential for the assembly of mitochondrial respiratory chain complex I. Disease causing biallelic variants in ACAD9 have been reported in individuals presenting with lactic acidosis and cardiomyopathy. RESULTS: We describe the genetic, clinical and biochemical findings in a cohort of 70 patients, of whom 29 previously unpublished. We found 34 known and 18 previously unreported variants in ACAD9. No patients harbored biallelic loss of function mutations, indicating that this combination is unlikely to be compatible with life. Causal pathogenic variants were distributed throughout the entire gene, and there was no obvious genotype-phenotype correlation. Most of the patients presented in the first year of life. For this subgroup the survival was poor (50% not surviving the first 2 years) comparing to patients with a later presentation (more than 90% surviving 10 years). The most common clinical findings were cardiomyopathy (85%), muscular weakness (75%) and exercise intolerance (72%). Interestingly, severe intellectual deficits were only reported in one patient and severe developmental delays in four patients. More than 70% of the patients were able to perform the same activities of daily living when compared to peers. CONCLUSIONS: Our data show that riboflavin treatment improves complex I activity in the majority of patient-derived fibroblasts tested. This effect was also reported for most of the treated patients and is mirrored in the survival data. In the patient group with disease-onset below 1 year of age, we observed a statistically-significant better survival for patients treated with riboflavin.

NOD1/NF-κB signaling pathway inhibited by sodium butyrate in the mammary gland of lactating goats during sub-acute ruminal acidosis.

Animals nurtured with a high-concentrate diet for a more extended period can cause subacute ruminal acidosis (SARA). In this study, twelve mid-lactating goats were separated into two groups (n = 6): a high concentrate diet (HC) control and a high concentrate with buffer (HCB) treatment group. Rumen fistula was installed in all lactating goats in the 14th week of the experiment. Goats were slaughtered in the 24th week. Our results showed that a pH value < 5.8 sustained at different periods of time for more than 3 h/day in the group HC, which confirms that SARA was prompted efficiently. Additionally, the group HCB exhibited lower concentration of LPS in peripheral blood than the group HC. Radioimmunoassay revealed a substantial reduction in the concentration level of proinflammatory cytokines in the lacteal blood of the group HCB compared to group HC. The transcriptional profiles in mammary gland following different treatments showed a significant decrease in the expression of NOD1, IKß, and NF-κB in HCB group, followed by a decreased transcriptional level of (TNF-α, IL-1ß and IL-6). Our research explores that HC diet nurtured to lactating goats for a more extended period can induce SARA by increasing the LPS and proinflammatory cytokine concentrations in plasma, that ultimately triggers the NOD1/NF-κB inflammatory pathway and induce mammary cell inflammation. Additionally, oral supplementation of sodium butyrate can decrease the concentrations of LPS and proinflammatory cytokines and inhibits NOD1/NF-κB inflammatory pathway.

Interleukin-1ß and tumor necrosis factor-α augment acidosis-induced rat articular chondrocyte apoptosis via nuclear factor-kappaB-dependent upregulation of ASIC1a channel.

The acute-phase proinflammatory cytokines interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) demonstrate high-level expression and pleiotropic biological effects, and contribute to the progression and persistence of rheumatoid arthritis (RA). Acid hydrarthrosis is also an important pathological characteristic of RA, and the acid-sensing ion channel 1a (ASIC1a) plays a critical role in acidosis-induced chondrocyte cytotoxicity. However, the roles of IL-1ß and TNF-α in acid-induced apoptosis of chondrocytes remain unclear. Rat adjuvant arthritis and primary articular chondrocytes were used as in vivo and in vitro model systems, respectively. ASIC1a expression in articular cartilage was increased and highly colocalized with nuclear factor (NF)-κB expression in vivo. IL-1ß and TNF-α could upregulate ASIC1a expression. These cytokines activated mitogen-activated protein kinase and NF-κB pathways in chondrocytes, while the respective inhibitors of these signaling pathways could partially reverse the ASIC1a upregulation induced by IL-1ß and TNF-α. Dual luciferase and gel-shift assays and chromatin immunoprecipitation-polymerase chain reaction demonstrated that IL-1ß and TNF-α enhanced ASIC1a promoter activity in chondrocytes by increasing NF-κB DNA-binding activities, which was in turn prevented by the NF-κB inhibitor ammonium pyrrolidinedithiocarbamate. IL-1ß and TNF-α also decreased cell viability but enhanced LDH release, intracellular Ca2+ concentration elevation, loss of mitochondrial membrane potential, cleaved PARP and cleaved caspase-3/9 expression, and apoptosis in acid-stimulated chondrocytes, which effects could be abrogated by the specific ASIC1a inhibitor psalmotoxin-1 (PcTX-1), ASIC1a-short hairpin RNA or calcium chelating agent BAPTA-AM. These results indicate that IL-1ß and TNF-α can augment acidosis-induced cytotoxicity through NF-κB-dependent up-regulation of ASIC1a channel expression in primary articular chondrocytes.

Update on inflammation in chronic kidney disease.

BACKGROUND: Despite recent advances in chronic kidney disease (CKD) and end-stage renal disease (ESRD) management, morbidity and mortality in this population remain exceptionally high. Persistent, low-grade inflammation has been recognized as an important component of CKD, playing a unique role in its pathophysiology and being accountable in part for cardiovascular and all-cause mortality, as well as contributing to the development of protein-energy wasting. SUMMARY: The variety of factors contribute to chronic inflammatory status in CKD, including increased production and decreased clearance of pro-inflammatory cytokines, oxidative stress and acidosis, chronic and recurrent infections, including those related to dialysis access, altered metabolism of adipose tissue, and intestinal dysbiosis. Inflammation directly correlates with the glomerular filtration rate (GFR) in CKD and culminates in dialysis patients, where extracorporeal factors, such as impurities in dialysis water, microbiological quality of the dialysate, and bioincompatible factors in the dialysis circuit play an additional role. Genetic and epigenetic influences contributing to inflammatory activation in CKD are currently being intensively investigated. A number of interventions have been proposed to target inflammation in CKD, including lifestyle modifications, pharmacological agents, and optimization of dialysis. Importantly, some of these therapies have been recently tested in randomized controlled trials. KEY MESSAGES: Chronic inflammation should be regarded as a common comorbid condition in CKD and especially in dialysis patients. A number of interventions have been proven to be safe and effective in well-designed clinical studies. This includes such inexpensive approaches as modification of physical activity and dietary supplementation. Further investigations are needed to evaluate the effects of these interventions on hard outcomes, as well as to better understand the role of inflammation in selected CKD populations (e.g., in children).

Mitochondrial bioenergetics and dynamics interplay in complex I-deficient fibroblasts.

BACKGROUND: Complex I (CI) deficiency is the most frequent cause of OXPHOS disorders. Recent studies have shown increases in reactive oxygen species (ROS) production and mitochondrial network disturbances in patients' fibroblasts harbouring mutations in CI subunits. OBJECTIVES: The present work evaluates the impact of mutations in the NDUFA1 and NDUFV1 genes of CI on mitochondrial bioenergetics and dynamics, in fibroblasts from patients suffering isolated CI deficiency. RESULTS: Decreased oxygen consumption rate and slow growth rate were found in patients with severe CI deficiency. Mitochondrial diameter was slightly increased in patients' cells cultured in galactose or treated with 2'-deoxyglucose without evidence of mitochondrial fragmentation. Expression levels of the main proteins involved in mitochondrial dynamics, OPA1, MFN2, and DRP1, were slightly augmented in all patients' cells lines. The study of mitochondrial dynamics showed delayed recovery of the mitochondrial network after treatment with the uncoupler carbonyl cyanide m-chlorophenyl hydrazone (cccp) in patients with severe CI deficiency. Intracellular ROS levels were not increased neither in glucose nor galactose medium in patients' fibroblasts. CONCLUSION: Our main finding was that severe CI deficiency in patients harbouring mutations in the NDUFA1 and NDUFV1 genes is linked to a delayed mitochondrial network recovery after cccp treatment. However, the CI deficiency is neither associated with massive mitochondrial fragmentation nor with increased ROS levels. The different genetic backgrounds of patients with OXPHOS disorders would explain, at least partially, differences in the pathophysiological manifestations of CI deficiency.

The syndrome of irreversible acidosis after prolonged propofol infusion.

INTRODUCTION: Propofol infusion syndrome is described in the pediatric literature as metabolic acidosis, rhabdomyolysis, and bradycardia that results in death. The pathogenesis of this syndrome is thought to be activation of the systemic inflammatory response, which culminates in acidosis and muscle necrosis. MATERIALS AND METHODS: Retrospective chart review of three patients in the Neurological Critical Care Units at Hahnemann and Massachusetts General Hospitals between October 2001 and September 2004. RESULTS: Patient 1: A 27-year-old woman had seizures secondary to hemorrhage from an arteriovenous malformation. Propofol coma was induced for sedation. After initiation of propofol, she developed a metabolic acidosis, hypotension, and bradycardia and expired. Patient 2: A 64-year-old man presented in status epilepticus. After prolonged propofol administration, he developed metabolic acidosis, hypotension, and rhabdomyolysis and expired. Patient 3: A 24-year-old woman presented in status epilepticus secondary to encephalitis. Propofol was added for seizure control. She developed hypotension, metabolic acidosis, and bradyarrhythmias. Despite transvenous pacing, she expired. CONCLUSION: These data show an association between extended propofol use and metabolic acidosis, rhabdomyolysis, and death in adults, as well as children. Risk factors for propofol infusion syndrome in adults include lean body mass index, high dose, and administration of more than 24-hour duration. Creatine phosphokinase, lactic acid levels, electrolytes, and arterial blood gases should be monitored frequently. Both bacterial and fungal cultures should be obtained. If this syndrome is suspected, hemodialysis should be considered. In fatal cases, autopsy should include electron microscopy of cardiac and skeletal muscle to look for mitochondrial dysfunction. Further study is warranted.

Rumenocentesis (rumen puncture): a viable instrument in herd health diagnosis.

The use of rumenocentesis as a tool in veterinary practice is to be evaluated; this publication describes the technique and reports results of a field study. From 164 dairy cows samples of ruminal fluid have been collected by means of rumenocentesis. In order to compare reaction of the individuals towards rumenocentesis, reaction has been scored on a five-point scale. In the period after rumenocentesis, the animals were observed and examined clinically in case of any pathologic alteration. To test a possible pain-reducing treatment, two study groups received local anaesthesia, while a third group had been sampled without. About 50% of all animals examined did not show resistance during rumenocentesis, while the rest of the population reacted at different levels. In four animals ruminal fluid sampling was not carried out due too heavy resistance, while six samples showed visible contamination with blood. Local anaesthesia with 2 ml of 2 % lidocaine s. c. and i. m. had influence on reaction of the individual samples, but did not have effect on sample size collected and pathologic alterations post punctionem. In total, 5.5 % of the study population showed alterations at the puncture site as haematomas and abscess forming; in three individuals the general health status was impaired after collection. The authors consider rumenocentesis a viable diagnostic procedure in bovine health diagnostics.

Acidosis induces necrosis and apoptosis of cultured hippocampal neurons.

Acidosis, hypoxia, and hypoglycemia rapidly and transiently appear after reduction of cerebral blood flow. Acidosis also accompanies head trauma and subarachnoid hemorrhage. These insults result in necrotic and apoptotic loss of neurons. We previously demonstrated that transient acidification of intracellular pH from 7.3 to 6.5 induces delayed neuronal loss in cultured hippocampal slices (49). We now report that acidosis induced both necrotic and apoptotic loss of neurons. Necrosis and apoptosis were distinguished temporally and pharmacologically. Necrosis appeared rapidly and was dose dependent with the duration of the acidosis treatment. Apoptosis was delayed with maximal number of apoptotic cells seen with a 30-min acidosis treatment. Apoptotic neuronal loss was accompanied by DNA fragmentation and was blocked by inhibitors of protein and RNA synthesis, ectopic expression of the anti-apoptotic gene bcl-2, or an inhibitor of caspases, proteases known to be activated during apoptosis. Necrotic neuronal loss was unaffected by these treatments. Hypothermia, a treatment known to attenuate neuronal loss following a variety of insults, blocked both acidosis-induced necrosis and apoptosis. These results indicate that acidosis is neurotoxic in vitro and suggest that acidosis contributes to both necrotic and apoptotic neuronal loss in vivo.

Iatrogenic Wernicke's encephalopathy in allogeneic bone marrow transplantation: a study of eight cases.

Wernicke's encephalopathy (WE) is a neuropsychiatric condition generally caused by acute thiamine deficiency and classically involves the triad of altered mentation, ataxia and ophthalmoplegia. It is most common among alcoholics, but several other causes have been identified, including total parenteral nutrition (TPN) use. We present eight cases of WE in patients undergoing allogeneic BMT, where thiamine deficiency was caused by a lack of vitamin supplementation during TPN administration. Clinically, WE presented as a severe refractory metabolic acidosis, preceded by 'raspberry tongue', and ophthalmologic and neurologic dysfunction. The sites most affected were the periventricular structures and the thalamus, and no mammilary bodies lesions were found.

Swelling, acidosis, and irreversible damage of glial cells from exposure to arachidonic acid in vitro.

Swelling and damage of C6 glioma cells and of primary cultured astrocytes were analyzed in vitro during incubation with arachidonic acid (AA; 20:4). The cells were suspended in a physiological medium supplemented with AA at concentrations of 0.001-1.0 mM. Cell swelling was quantified by flow cytometry with hydrodynamic focusing. Flow cytometry was also utilized for assessment of cell viability by exclusion of the fluorescent dye propidium iodide and for measurement of the intracellular pH (pHi) by 2',7'-bis-(2-carboxyethyl)-5(and -6)carboxy-fluorescein. Administration of AA caused an immediate dose-dependent swelling of C6 glioma cells, even at a concentration of 0.01 mM. At this level cell volume increased within 20 min to 105.0% of control, at 0.1 mM to 111.0%, while at 1.0 mM to 123.7%. Following a phase of rapid cell volume increase, swelling leveled off during the subsequent observation period of 70 min. Viability of the C6 glioma cells was 90% under control conditions. It remained unchanged after raising AA concentrations to 0.1 mM. At 0.5 mM, however, cell viability fell to 72.8%, and at 1.0 mM to 32.7%. pHi of the glioma cells was 7.3 under control conditions. In parallel with the early swelling phase, AA led to a dose-dependent decrease of the intracellular pH and an elevated lactate production of the cells. During incubation with 0.1 mM AA, pHi decreased to 7.06 after 5 min, but recovered to normal subsequently. In addition, swelling-inducing properties of linoleic (18:2) or stearic (18:0) acid were analyzed for evaluation of the specificity of glial swelling induced by AA. Whereas stearic acid (0.1 mM) failed to induce a swelling response, linoleic acid (0.1 mM) was found to be effective. The volume increase of the glial cells, however, was only half of that found during exposure to AA at the same concentration. Further, glial swelling from AA or linoleic acid was completely inhibited by the aminosteroid U-74389F, an antagonist of lipid peroxidation. Finally, omission of Na+ ions in the suspension medium with replacement by choline led also to inhibition of the cell volume increase by AA. Experiments using astrocytes from primary culture confirmed the swelling-inducing properties of AA at a quantitative level, whereas vulnerability of the cells to AA was increased. The present results demonstrate an important role of AA in cytotoxic swelling and irreversible damage of glial cells at concentrations that occur in vivo in cerebral ischemia or trauma.(ABSTRACT TRUNCATED AT 250 WORDS)

[The antiacidotic and cardioprotective effects of fructose-1,6-diphosphate and dehydroascorbic acid]. / Antiatsidoticheskii i kardioprotektivnyi éffekty fruktozo-1,6-difosfata i degidroaskorbinovoi kisloty.

The antiacidotic and cardioprotective effects of dehydro-L-ascorbic acid and fructose-1,6-diphosphate were compared in experiments of rats. It was found that the both compounds exhibit the antiacidotic effect on the model of metabolic acidosis in the isolated hypoxic heart, decrease the excess-lactate degree, increase ATP level in the myocardium and reduce the size of the necrosis area 4 hours after the modelling of myocardial infarction. The significance of the antiacidotic component in the mechanism of the cardioprotective action of the energy-supplying agents is concluded.

Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes with acanthocytosis: a clinicopathological study of a unique case.

A case of a unique combination of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like syndrome (MELAS) with acanthocytosis is reported. Neuropathological examination revealed pellagra-like change in Betz cells, brain-stem neurons and anterior horn cells as well as findings compatible with mitochondrial encephalomyopathies. Abnormal function of nicotinic acid-related enzymes could be the cause of the complicated clinicopathologic findings in this case. This is the first report of MELAS with acanthocytosis.