Faculty Bibliography

Sepsis, a complex disorder characterized by immune, metabolic, and neurological dysregulation, is the number one killer in the intensive care unit. Mortality remains alarmingly high even in among sepsis survivors discharged from the hospital. There is no clear strategy for managing this lethal chronic sepsis illness, which is associated with severe functional disabilities and cognitive deterioration. Providing insight into the underlying pathophysiology is desperately needed to direct new therapeutic approaches. Previous studies have shown that brain cholinergic signaling importantly regulates cognition and inflammation. Here, we studied the relationship between peripheral immunometabolic alterations and brain cholinergic and inflammatory states in mouse survivors of cecal ligation and puncture (CLP)-induced sepsis. Within 6 days, CLP resulted in 50% mortality vs. 100% survival in sham-operated controls. As compared to sham controls, sepsis survivors had significantly lower body weight, higher serum TNF, interleukin (IL)-1β, IL-6, CXCL1, IL-10, and HMGB1 levels, a lower TNF response to LPS challenge, and lower serum insulin, leptin, and plasminogen activator inhibitor-1 levels on day 14. In the basal forebrain of mouse sepsis survivors, the number of cholinergic [choline acetyltransferase (ChAT)-positive] neurons was significantly reduced. In the hippocampus and the cortex of mouse sepsis survivors, the activity of acetylcholinesterase (AChE), the enzyme that degrades acetylcholine, as well as the expression of its encoding gene were significantly increased. In addition, the expression of the gene encoding the M1 muscarinic acetylcholine receptor was decreased in the hippocampus. In parallel with these forebrain cholinergic alterations, microglial activation (in the cortex) and increased Il1b and Il6 gene expression (in the cortex), and Il1b gene expression (in the hippocampus) were observed in mouse sepsis survivors. Furthermore, microglial activation was linked to decreased cortical ChAT protein expression and increased AChE activity. These results reinforce the notion of persistent inflammation-immunosuppression and catabolic syndrome in sepsis survivors and characterize a previously unrecognized relationship between forebrain cholinergic dysfunction and neuroinflammation in sepsis survivors. This insight is of interest for new therapeutic approaches that focus on brain cholinergic signaling for patients with chronic sepsis illness, a problem with no specific treatment.

An incidental finding of napsin A-positive breast carcinoma with apocrine features during workup for metastatic cancer in an axillary lymph node led to our investigation of the incidence of napsin A expression in breast carcinomas, focusing on those with apocrine features. We included 97 cases of breast carcinomas and performed immunohistochemistry with napsin A, GATA-3, thyroid transcription factor-1, and GCDFP-15. There was a statistically significant difference between apocrine and nonapocrine cases with respect to polyclonal napsin A H-scores (P < .00152), monoclonal napsin A H-scores (P < .00631), GATA-3 H-scores (P < .00029), and GCDFP-15 H-scores (P < .00251). Of the 49 cases of apocrine carcinoma, monoclonal napsin A antibody was positive in 66.7% of cases, including in 7 (14.6%) that showed 3+ staining. The majority of nonapocrine cases were negative (62.5%) or weakly (1+) positive (29.2%), with none exhibiting 3+ strength. It is important for pathologists to be aware that breast carcinomas with apocrine features can express napsin A.

Inflammatory conditions characterized by excessive peripheral immune responses are associated with diverse alterations in brain function, and brain-derived neural pathways regulate peripheral inflammation. Important aspects of this bidirectional peripheral immune - brain communication, including the impact of peripheral inflammation on brain region-specific cytokine responses, and brain cholinergic signaling (which plays a role in controlling peripheral cytokine levels) remain unclear. To provide insight, we studied gene expression of cytokines, immune cell markers and brain cholinergic system components in the cortex, cerebellum, brainstem, hippocampus, hypothalamus, striatum, and thalamus in mice following an intraperitoneal lipopolysaccharide injection. Endotoxemia was accompanied by elevated serum levels of IL-1beta, IL-6 and other cytokines, and brain region-specific increases in Il1b (highest, relative to basal level increase - in cortex, lowest increase- in cerebellum) and Il6 (highest increase - in cerebellum, lowest increase - in striatum) mRNA expression. Gene expression of brain Gfap (astrocyte marker) was also differentially increased. However, Iba1 (microglia marker) mRNA expression was decreased in the cortex, hippocampus and other brain regions in parallel with morphological changes, indicating microglia activation. Brain choline acetyltransferase (Chat) mRNA expression was decreased in the striatum; acetylcholinesterase (Ache) mRNA expression was decreased in the cortex and increased in the hippocampus; and M1 muscarinic acetylcholine receptor (Chrm1) mRNA expression was decreased in the cortex and the brainstem. These results reveal a previously unrecognized regional specificity in brain immunoregulatory and cholinergic system gene expression in the context of peripheral inflammation, and are of interest for designing future anti-inflammatory approaches.

Extracellular superoxide dismutase (EC-SOD) is an isoform of SOD normally found both intra- and extra-cellularly and accounting for most SOD activity in blood vessels. Here we explored the role of EC-SOD in protecting against brain damage induced by chronic hypoxia. EC-SOD Transgenic mice, were exposed to hypoxia (FiO2.1%) for 10 days (H-KI) and compared to transgenic animals housed in room air (RA-KI), wild type animals exposed to hypoxia (H-WT or wild type mice housed in room air (RA-WT). Overall brain metabolism evaluated by positron emission tomography (PET) showed that H-WT mice had significantly higher uptake of 18FDG in the brain particularly the hippocampus, hypothalamus, and cerebellum. H-KI mice had comparable uptake to the RA-KI and RA-WT groups. To investigate the functional state of the hippocampus, electrophysiological techniques in ex vivo hippocampal slices were performed and showed that H-KI had normal synaptic plasticity, whereas H-WT were severely affected. Markers of oxidative stress, GFAP, IBA1, MIF, and pAMPK showed similar values in the H-KI and RA-WT groups, but were significantly increased in the H-WT group. Caspase-3 assay and histopathological studies showed significant apoptosis/cell damage in the H-WT group, but no significant difference in the H-KI group compared to the RA groups. The data suggest that EC-SOD has potential prophylactic and therapeutic roles in diseases with compromised brain oxygenation.

Of the 74 immunocompetent patients diagnosed between July 2004 and June 2011 at the North Shore University Hospital and Long Island Jewish Medical Center with primary central nervous system lymphoma, 71 (95.9%) had diffuse large B-cell lymphomas (DLBCL). The median patient age was 68 years (range: 19-87 years) with a slight male preponderance (1.1:1). The overall median survival time was 21 months. For patients older than 70 years, the median survival time was 8 months while for those 70 years or younger, the median survival time was 27 months (p<0.01). Female patients had a worse prognosis than male patients (p<0.05, median survival time, 17 months compared to 23 months). We had enough data from 52 of these 71 patients to define the lymphomas as either germinal center B-cell-like (GCB) or activated B-cell-like (ABC) DLBCL. Of these 52 patients, 42 (80.8%) had ABC DLBCL while only 10 (19.2%) had GCB DLBCL. The patients in the GCB subgroup seemed to survive longer than the patients in the ABC subgroup, although the difference did not reach statistical significance. No statistically significant difference in overall survival was seen between patients with BCL-6 positive or negative DLBCL; or between patients with BCL-2 positive or negative DLBCL.

There is increasing evidence that hyperoxia, particularly at the time of birth, may result in neurological injury, in particular to the susceptible vasculature of these tissues. This study was aimed at determining whether overexpression of extracellular superoxide dismutase (EC-SOD) is protective against brain injury induced by hyperoxia. Transgenic (TG) mice (with an extra copy of the human extracellular superoxide dismutase gene) and wild-type (WT) neonate mice were exposed to hyperoxia (95% of F(i) o(2) ) for 7 days after birth versus the control group in room air. Brain positron emission tomography (PET) scanning with fludeoxyglucose (FDG) isotope uptake was performed after exposure. To assess apoptosis induced by hyperoxia exposure, caspase 3 ELISA and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were performed. Quantitative western blot for the following inflammatory markers was performed: glial fibrillary acidic protein, ionized calcium-binding adaptor molecule 1, macrophage-inhibiting factor, and phospho-AMP-activated protein kinase. PET scanning with FDG isotope uptake showed significantly higher uptake in the WT hyperoxia neonate brain group (0.14 ± 0.03) than in both the TG group (0.09 ± 0.01) and the control group (0.08 ± 0.02) (P< 0.05). Histopathological investigation showed more apoptosis and dead neurons in hippocampus and cerebellum brain sections of WT neonate mice after exposure to hyperoxia than in TG mice; this finding was also confirmed by TUNEL staining. The caspase 3 assay confirmed the finding of more apoptosis in WT hyperoxia neonates (0.814 ± 0.112) than in the TG hyperoxic group (0.579 ± 0.144) (P < 0.05); this finding was also confirmed by TUNEL staining. Quantitative western blotting for the inflammatory and metabolic markers showed significantly higher expression in the WT group than in the TG and control groups. Thus, overexpression of EC-SOD in the neonate brain offers significant protection against hyperoxia-induced brain damage.