Seizures are associated with adverse outcome in infants with hypoxic-ischemic encephalopathy. We hypothesized that early administration of the anticonvulsant phenobarbital after cerebral hypoxia ischemia could enhance the neuroprotective efficacy of delayed-onset hypothermia. We tested this hypothesis in a neonatal rodent model. Seven-d-old rats (n ϭ 104) underwent right carotid ligation, followed by 90 min 8% O 2 exposure; 15 min later, they received injections of phenobarbital (40 mg/kg) or saline. One or 3 h later, all were treated with hypothermia (30°C, 3 h). Function and neuropathology were evaluated after 7 d (early outcomes) or 1 mo (late outcomes). Early outcome assessment demonstrated better sensorimotor performance and less cortical damage in phenobarbital-treated groups; there were no differences between groups in which the hypothermia delay was shortened from 3 to 1 h. Late outcome assessment confirmed sustained benefits of phenobarbital ϩ hypothermia treatment; sensorimotor performance was better (persistent attenuation of contralateral forepaw placing deficits and absence of contralateral forepaw neglect); neuropathology scores were lower (median, phenobarbital 2 and saline 8.5, p Ͻ 0.05); and less ipsilateral cerebral hemisphere %Damage (mean Ϯ SD, 11 Ϯ 17 versus 28 Ϯ 22, p Ͻ 0.05). These results suggest that early posthypoxia-ischemia administration of phenobarbital may augment the neuroprotective efficacy of therapeutic hypothermia. T he results of four clinical trials support the safety and efficacy of hypothermia to decrease death and disability in infants with hypoxic-ischemic encephalopathy (HIE) (1-4). However, in these trials Ͼ40% of hypothermia-treated infants died or had poor neurologic outcomes. Thus, there is a need for strategies to improve the neuroprotective efficacy of hypothermia. One possible approach is to combine hypothermia with pharmacotherapy.In experimental models of neonatal hypoxic-ischemic brain injury, several agents enhance the neuroprotective efficacy of hypothermia; these include topiramate, an anticonvulsant (5); xenon, an anesthetic (6); and N-acetylcysteine, an antioxidant (7). There is minimal neonatal clinical experience with these drugs (8). Nevertheless, many neuroactive drugs are commonly administered to encephalopathic neonates, and an important question is whether any of these drugs could augment hypothermic neuroprotection.Anticonvulsants are an attractive group of drugs to study in combination with hypothermia. Many have neuroprotective properties in cerebral ischemia models, although it is uncertain whether these effects are attributable to seizure cessation (9). Seizures are common in encephalopathic neonates, in whom they may exacerbate hypoxic-ischemic brain injury (10,11). In one hypothermia trial, seizures were an independent predictor of adverse outcome (12). Phenobarbital is currently the anticonvulsant used most commonly to treat neonatal seizures (13). Moreover, in a small randomized trial, treatment of infants with HIE with phenobarb...

The etiology of diabetic neuropathy is multifactorial and not fully elucidated, although oxidative stress and mitochondrial dysfunction are major factors. We reported previously that complement-inactivated sera from type 2 diabetic patients with neuropathy induce apoptosis in cultured neuronal cells, possibly through an autoimmune immunoglobulinmediated pathway. Recent evidence supports an emerging role for autophagy in a variety of diseases. Here we report that exposure of human neuroblastoma SH-SY5Y cells to sera from type 2 diabetic patients with neuropathy is associated with increased levels of autophagosomes that is likely mediated by increased titers of IgM or IgG autoimmune immunoglobulins. The increased presence of macroautophagic vesicles was monitored using a specific immunohistochemical marker for autophagosomes, anti-LC3-II immunoreactivity, as well as the immunohistochemical signal for beclin-1, and was associated with increased co-localization with mitochondria in the cells exposed to diabetic neuropathic sera. We also report that dorsal root ganglia removed from streptozotocin-induced diabetic rats exhibit increased levels of autophagosomes and co-localization with mitochondria in neuronal soma, concurrent with enhanced binding of IgG and IgM autoimmune immunoglobulins. To our knowledge, this is the first evidence that the presence of autophagosomes is increased by a serum factor, likely autoantibody(ies) in a pathological condition. Stimulation of autophagy by an autoantibody-mediated pathway can provide a critical link between the immune system and the loss of function and eventual demise of neuronal tissue in type 2 diabetes.

We examined the hypothesis that activation of the apoptosis cascade occurs relatively early in diabetes mellitus affecting three distinct neuronal populations that are involved in regulating gut function: (i) dorsal root ganglion (DRG), (ii) vagus nodose ganglion and (iii) colon myenteric plexus. A validated streptozotocin-induced diabetic rat model and age-matched healthy controls were studied. After 4-8 weeks of diabetes the animals were anaesthetized, fixed in situ and the relevant tissues removed. After 1 month of diabetes some animals were treated with insulin for 2 weeks to restore euglycaemia. Apoptosis was measured using immunohistochemical detection of activated caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL)-positive cells in adjacent sections in neurones (PGP 9.5-positive cells). The level of apoptosis was confirmed using double-label assessment of caspase-3 and TUNEL in DRG preparations. Caspase-3 immunoreactive neurones demonstrated a range in staining intensity. When all grades of staining were included, 6-8% of the DRG, nodose ganglia and myenteric neurones were immunoreactive in the preparations from diabetic rats compared with 0.2-0.5% in controls. Neurones staining positive for both caspase-3 and TUNEL accounted for 1-2% of the total neuronal population in all three preparations in diabetic rats compared with 0.1-0.2% in controls (P < 0.05). Insulin treatment reversed the percentage of TUNEL-positive neurones in diabetic rats to control levels. Activation of the apoptosis cascade occurs relatively early in diabetic autonomic neuropathy and may contribute to the pathophysiology of this disorder.

The NaKCl cotransporter NKCC1 facilitates intraneuronal chloride accumulation in the developing brain. Bumetanide, a clinically available diuretic, inhibits this chloride transporter, and augments the antiepileptic effects of phenobarbital in neonatal rodents. In a neonatal cerebral hypoxia-ischemia (HI) model, elicited by right carotid ligation, followed by 90 min 8% O2 exposure in 7-day-old(P7) rats, phenobarbital(PB) increases the neuroprotective efficacy of hypothermia. We evaluated whether bumetanide influenced the neuroprotective efficacy of combination treatment with PB and hypothermia(HT). P7 rats underwent HI lesioning; 15 min later, all received PB (30 mg/kg). 10 min later, half received bumetanide (10 mg/kg, PB-HT+BUM) and half received saline (PB-HT+SAL). One hour after HI, all were cooled (30°C, 3h). Contralateral forepaw sensorimotor function and brain damage were evaluated 1 to 4 weeks later. Forepaw functional measures were close to normal in the PB-HT+BUM group, while deficits persisted in PB-HT+SAL controls; there were corresponding reductions in right cerebral hemisphere damage (at P35, % damage: PB-HT+BUM, 21±16 versus 38±20 in controls). These results provide evidence that NKCC1 inhibition amplifies phenobarbital bioactivity in the immature brain, and suggest that co-administration of phenobarbital and bumetanide may represent a clinically feasible therapy to augment the neuroprotective efficacy of therapeutic hypothermia in asphyxiated neonates.

Protein post‐translational modifications (PTMs) of histones are ubiquitous regulatory mechanisms involved in many biological processes, including replication, transcription, DNA damage repair and ontogenesis. Recently, many short‐chain acylation histone modifications have been identified by mass spectrometry (MS). Lysine succinylation (Ksuc or Ksucc) is a newly identified histone PTM that changes the chemical environment of histones and is similar to other acylation modifications; lysine succinylation appears to accumulate at transcriptional start sites and to correlate with gene expression. Although numerous studies are ongoing, there is a lack of reviews on the Ksuc of histones. Here, we review lysine succinylation sites on histones, including the chemical characteristics and the mechanism by which lysine succinylation influences nucleosomal structure, chromatin dynamics and several diseases and then discuss lysine succinylation regulation to identify theoretical and experimental proof of Ksuc on histones and in diseases to inspire further research into histone lysine succinylation as a target of disease treatment in the future.