Curcumin Prevents Cerebellar Hypoplasia and Restores the Behavior in Hyperbilirubinemic Gunn Rat by a Pleiotropic Effect on the Molecular Effectors of Brain Damage

Bilirubin toxicity to the central nervous system (CNS) is responsible for severe and permanent neurologic damage, resulting in hearing loss, cognitive, and movement impairment. Timely and effective management of severe neonatal hyperbilirubinemia by phototherapy or exchange transfusion is crucial for avoiding permanent neurological consequences, but these therapies are not always possible, particularly in low-income countries. To explore alternative options, we investigated a pharmaceutical approach focused on protecting the CNS from pigment toxicity, independently from serum bilirubin level. To this goal, we tested the ability of curcumin, a nutraceutical already used with relevant results in animal models as well as in clinics in other diseases, in the Gunn rat, the spontaneous model of neonatal hyperbilirubinemia. Curcumin treatment fully abolished the landmark cerebellar hypoplasia of Gunn rat, restoring the histological features, and reverting the behavioral abnormalities present in the hyperbilirubinemic rat. The protection was mediated by a multi-target action on the main bilirubin-induced pathological mechanism ongoing CNS damage (inflammation, redox imbalance, and glutamate neurotoxicity). If confirmed by independent studies, the result suggests the potential of curcumin as an alternative/complementary approach to bilirubin-induced brain damage in the clinical scenario.

Bilirubin-Induced Oxidative Stress Leads to DNA Damage in the Cerebellum of Hyperbilirubinemic Neonatal Mice and Activates DNA Double-Strand Break Repair Pathways in Human Cells

Unconjugated bilirubin is considered a potent antioxidant when present at moderate levels. However, at high concentrations, it produces severe neurological damage and death associated with kernicterus due to oxidative stress and other mechanisms. While it is widely recognized that oxidative stress by different toxic insults results in severe damage to cellular macromolecules, especially to DNA, no data are available either on DNA damage in the brain triggered by hyperbilirubinemia during the neonatal period or on the activation of DNA repair mechanisms. Here, using a mouse model of neonatal hyperbilirubinemia, we demonstrated that DNA damage occurs in vivo in the cerebellum, the brain region most affected by bilirubin toxicity. We studied the mechanisms associated with potential toxic action of bilirubin on DNA in in vitro models, which showed significant increases in DNA damage when neuronal and nonneuronal cells were treated with 140 nM of free bilirubin (Bf), as determined by γH2AX Western blot and immunofluorescence analyses. Cotreatment of cells with N-acetyl-cysteine, a potent oxidative-stress inhibitor, prevented DNA damage by bilirubin, supporting the concept that DNA damage was caused by bilirubin-induced oxidative stress. Bilirubin treatment also activated the main DNA repair pathways through homologous recombination (HR) and nonhomologous end joining (NHEJ), which may be adaptive responses to repair bilirubin-induced DNA damage. Since DNA damage may be another important factor contributing to neuronal death and bilirubin encephalopathy, these results contribute to the understanding of the mechanisms associated with bilirubin toxicity and may be of relevance in neonates affected with severe hyperbilirubinemia.

Short Term Development and Fate of MGE-Like Neural Progenitor Cells in Jaundiced and Non-Jaundiced Rat Brain

Neonatal hyperbilirubinemia targets specific brain regions and can lead to kernicterus. One of the most debilitating symptoms of kernicterus is dystonia, which results from bilirubin toxicity to the globus pallidus (GP). Stem cell transplantation into the GP to replace lost neurons and restore basal ganglia circuits function is a potential therapeutic strategy to treat dystonia in kernicterus. In this study we transplanted human medial ganglionic eminence (MGE)-like neural progenitor cells (NPCs) that we differentiated into a primarily gamma-aminobutyric acid (GABA)ergic phenotype, into the GP of non-immunosuppressed jaundiced (jj) and non-jaundiced (Nj) rats. We assessed the survival and development of graft cells at three time-points post-transplantation. While grafted MGE-like NPCs survived and generated abundant fibers in both jj and Nj brains, NPC survival was greater in the jj brain. These results were consistent with our previous finding that excitatory spinal interneuron-like NPCs exhibited a higher survival rate in the jj brain than in the Nj brain. Our findings further support our hypothesis that slightly elevated bilirubin levels in the jj brain served as an antioxidant and immunosuppressant to protect the transplanted cells. We also identified graft fibers growing toward brain regions that receive projections from the GP, as well as host fibers extending toward the graft. These promising findings suggest that MGE-like NPCs may have the capacity to restore the circuits connecting GP and other nuclei.

BERA in Newborns with Hyperbilirubinemia

BACKGROUND: Neonatal hyperbilirubinemia is a common problem seen in the newborn period, is usually mild and transient without long-lasting sequelae. Bilirubin induced neurologic damage may occur and auditory pathway is the most sensitive past to bilirubin toxicity. Auditory brainstem response (BERA) provides an electro physiologic means of assessing ascending auditory pathway and to localise the lesion. AIMS: To assess the effect of bilirubin toxicity on brainstem auditory pathway among neonates with hyperbilirubinemia using BERA and compare with control of normal newborns. MATERIAL AND METHODS: BERA was recorded in twenty five term newborns admitted to Tertiary care hospital, with hyperbilirubinemia at level exceeding exchange transfusion (mean bilirubin level 25.4+/- 4.66 mg/dl). They were compared with 25 term normal newborns without any risk factor for hearing impairment. The results were analysed by Gaussian test (Z), student unpaired ‘t’ test, chi square test and Mann-Whitney U test. RESULTS: At least one of waves I, III and V was absent in 8% of newborn with hyperbilirubinemia. There was statistically significant prolongation of mean latencies of waves III and V and mean I-V interwave latency in hyperbilirubinemia newborn compared to normal neonates . Auditory threshold was elevated in 6 out of 25 jaundiced newborn. Significant positive correlation between BERA abnormalities and bilirubin levels was found with respect to presence of waves I, III and V and auditory threshold. No significant positive correlation was found between bilirubin levels and BERA latencies. CONCLUSION: BERA abnormalities were noted in form of absence of waves I, III, V,prolongation of latency and interwave latencies and increased auditory threshold in newborns with hyperbilirubinemia as compared to normal neonates. BERA abnormality was also found to be transient and was normal in most of these patients during follow up.

Neurosurgery (Neuro Vascular)

Background: Blood breakdown products such as bilirubin and bilirubin oxidation products damage cortex and white matter after intracerebral hemorrhage(ICH). Here, we tested whether albumin can antagonize axonal damage caused by bilirubin. Methods: The effect of albumin on white matter injury was investigated using brain slices in vitro. After CD-1 mice brain slices were cut using a vibratome, they were incubated in one of five solutions: artificial cerebral spinal fluid (ACSF), bilirubin ACSF, bilirubin and albumin ACSF, bilirubin ACSF that had albumin added 1 hour(h) later, and bilirubin and denatured albumin ACSF. All solutions were continuously aerated with 95% O2 and 5% CO2. Subsequently, electrophysiological recordings of axonal response to electrical stimulation were performed 8h after incubation of brain slices. Results: Bilirubin treatment profoundly damaged both myelinated and unmeylinated axons in brain slices, but had a greater effect on myelinated axons. Unmyelinated axons were found to be more susceptible to damage from denatured albumin. Albumin treatment at 0 h and 1 h significantly diminished bilirubin toxicity for both myelinated and unmyelinated axons, with 1 h delayed albumin treatment conferring greater neuroprotection. Conclusions: These results implicate the role of albumin in preventing bilirubin-induced axonal damage following ICH and its potential therapeutic value for hemorrhagic stroke.

Open-label prospective study of safety and efficacy of glass-based Y-90 radioembolization for infiltrative HCC with PVT.

276 Background: Safety and efficacy of Yttrium-90 (Y90) therapy for infiltrative unresectable hepatocellular carcinoma (HCC) with portal vein thrombosis (PVT) require further evaluation. Methods: A prospective single center, open-label, single arm safety and efficacy study recruited patients with unresectable (Barcelona Liver Cancer Stage C) infiltrative HCC with PVT. Safety was assessed according to Common Terminology Criteria for Adverse Events v.3.0 at 1 week and monthly thereafter for 6 months post therapy. Efficacy was assessed by overall survival (OS) as primary endpoint. Tumor response was assessed by dynamic contrast MRI according to Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST at 1, 3, and 6 months (secondary endpoint). To achieve 0.95 power (α=0.05) and predicting prolongation of mean OS by at least 50% over the best supportive care (4 months ± 2 months (SD)), the study was designed to recruit 30 patients. Survival analysis was performed using Kaplan-Meier estimation. Prognostic factors were tested using log-rank and univariate analysis. Results: Thirty (n=30) patients were enrolled and underwent Y90 therapy (median age 63). The median OS was 13 months (CI: 4.1-21.1 months). Six patients had transaminitis (70% grade 1, 30% grade 2) while 8 patients had biliary toxicity (50% grade 1, 10% grade 2, 40% grade 3). Grade 3 bilirubin toxicity occurred in the same 2 patients with grade 2 transaminase toxicity. Although all patients recovered from transient liver toxicities, grade ≥2 liver toxicity was found to be predictor of poor outcome with median OS of 3.6 months for patients with grade ≥2 toxicity vs. 13 months for those with grade 1 or no toxicity (p=0.004). Child-Pugh class B, INR ≥1.5, and grade ≥2 hepatobiliary toxicities were found to be poor prognostic factors by both log-rank and univariate analysis (p<0.05). Upon short-term imaging follow up (mean 34 days post Y90), 80% of patients were found to have complete (13%) or partial (67%) response according to targeted mRECIST criteria, with 93% stable disease according to targeted RECIST. Conclusions: In patients with unresectable infiltrative HCC and PVT, Y90 therapy is a viable and safe treatment option.