Involvement of the tumour necrosis factor receptor system in glioblastoma cell death induced by palbociclib-heptamethine cyanine dye conjugate.

Glioblastoma is the most common and aggressive primary brain tumour in adults. The development of anti-brain cancer agents are challenged by the blood-brain barrier and the resistance conferred by the local tumour microenvironment. Heptamethine cyanine dyes (HMCDs) are a class of near-infrared fluorescence compounds that have recently emerged as promising agents for drug delivery. We conjugated palbociclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor, to an HMCD, MHI-148, and conducted drug activity analysis on primary patient-derived glioblastoma cell lines. In addition to the expected cytostatic activity, our in vitro studies revealed that palbociclib-MHI-148 conjugate resulted in an almost 100-fold increase in cytotoxicity compared to palbociclib alone. This shift of palbociclib from cytostatic to cytotoxic when conjugated to MHI-148 was due to increased DNA damage, as indicated by an increase in γH2AX foci, followed by an increased expression of key extrinsic apoptosis genes, including TP53, TNFR1, TRAIL, FADD and caspase 8. In addition, we observed a time-dependent increase in the cell surface expression of TNFR1, consistent with an observed increase in the secretion TNFα, followed by TNFR1 endocytosis at 48 h. The treatment of patient GBM cells with the palbociclib-MHI-148 conjugate prevented TNFα-induced NFκB translocation, suggesting conjugate-induced TNFR1 signalling favoured the TNFR1-mediated apoptotic response rather than the pro-inflammatory response pathway. Notably, pharmacological inhibition of endocytosis of TNFR1, and siRNA-knockdown of TNFR1 reversed the palbociclib-MHI-148-induced cell death. These results show a novel susceptibility of glioblastoma cells to TNFR1-dependent apoptosis, dependent on inhibition of canonical NFκB signalling using our previously reported palbociclib-HMCD conjugate. Video Abstract.

PSA-NCAM Regulatory Gene Expression Changes in the Alzheimer's Disease Entorhinal Cortex Revealed with Multiplexed in situ Hybridization.

BACKGROUND: Alzheimer's disease (AD) is the most common form of dementia and is characterized by a substantial reduction of neuroplasticity. Our previous work demonstrated that neurons involved in memory function may lose plasticity because of decreased protein levels of polysialylated neural cell adhesion molecule (PSA-NCAM) in the entorhinal cortex (EC) of the human AD brain, but the cause of this decrease is unclear. OBJECTIVE: To investigate genes involved in PSA-NCAM regulation which may underlie its decrease in the AD EC. METHODS: We subjected neurologically normal and AD human EC sections to multiplexed fluorescent in situ hybridization and immunohistochemistry to investigate genes involved in PSA-NCAM regulation. Gene expression changes were sought to be validated in both human tissue and a mouse model of AD. RESULTS: In the AD EC, a cell population expressing a high level of CALB2 mRNA and a cell population expressing a high level of PST mRNA were both decreased. CALB2 mRNA and protein were not decreased globally, indicating that the decrease in CALB2 was specific to a sub-population of cells. A significant decrease in PST mRNA expression was observed with single-plex in situ hybridization in middle temporal gyrus tissue microarray cores from AD patients, which negatively correlated with tau pathology, hinting at global loss in PST expression across the AD brain. No significant differences in PSA-NCAM or PST protein expression were observed in the MAPT P301S mouse brain at 9 months of age. CONCLUSION: We conclude that PSA-NCAM dysregulation may cause subsequent loss of structural plasticity in AD, and this may result from a loss of PST mRNA expression. Due PSTs involvement in structural plasticity, intervention for AD may be possible by targeting this disrupted plasticity pathway.

Elucidating the cellular uptake mechanisms of heptamethine cyanine dye analogues for their use as an anticancer drug-carrier molecule for the treatment of glioblastoma.

The development of chemotherapies for glioblastoma is hindered by their limited bioavailability and toxicity on normal brain function. To overcome these limitations, we investigated the structure-dependent activity of heptamethine cyanine dyes (HMCD), a group of tumour-specific and BBB permeable near-infrared fluorescent dyes, in both commercial (U87MG) and patient-derived GBM cell lines. HMCD analogues with strongly ionisable sulphonic acid groups were not taken up by patient-derived GBM cells, but were taken up by the U87MG cell line. HMCD uptake relies on a combination of transporter uptake through organic anion-transporting polypeptides (OATPs) and endocytosis into GBM cells. The uptake of HMCDs was not affected by p-glycoprotein efflux in GBM cells. Finally, we demonstrate structure-dependent cytotoxic activity at high concentrations (EC50 : 1-100 µM), likely due to mitochondrial damage-induced apoptosis. An in vivo orthotopic glioblastoma model highlights tumour-specific accumulation of our lead HMCD, MHI-148, for up to 7 days following a single intraperitoneal injection. These studies suggest that strongly ionisable groups like sulphonic acids hamper the cellular uptake of HMCDs in patient-derived GBM cell lines, highlighting cell line-specific differences in HMCD uptake. We envisage these findings will help in the design and structural modifications of HMCDs for drug-delivery applications for glioblastoma.

Primary intraventricular synovial sarcoma of the brain with recurrence - case presentation.

BACKGROUND: We report a case of recurrent primary intraventricular synovial sarcoma of the brain with no extracranial primary, initially reported as a haemangiopericytoma. We believe this is the first reported case of primary intraventricular synovial sarcoma at this site. CASE PRESENTATION: A 27-year-old male presented to hospital with a new onset of seizures. Imaging revealed a left ventricular trigone mass with surrounding oedema. He underwent a left occipito-temporal craniotomy and resection with the histology reported as haemangiopericytoma. Resection was followed by adjuvant radiation treatment. Seven years later follow-up imaging revealed a 4 mm contrast enhancing lesion in the previous surgical bed. The patient underwent resection. Histological analysis of the recurrence revealed a spindle cell tumour with a SS18 gene rearrangement consistent with synovial sarcoma. Retrospective fluorescent in-situ hybridisation analysis of original histology also revealed a SS18 gene rearrangement consistent with a diagnosis of synovial sarcoma. CONCLUSION: Synovial sarcoma should be included as part of the differential diagnosis for patients presenting with intraventricular spindle cell tumours in the brain.

Single-cell image analysis reveals over-expression of organic anion transporting polypeptides (OATPs) in human glioblastoma tissue.

Background: Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults. Whilst the role of the efflux transporters are well established in GBM, the expression and function of uptake transporters, such as the organic anion transporting polypeptide (OATP) family, are not well understood. OATPs possess broad substrate specificity that includes anti-cancer agents; therefore, we sought to investigate the expression of four OATP isoforms in human GBM cell types using patient tumor tissue. Methods: We used fluorescent immunohistochemical labeling of paraffin-embedded surgically resected tissues and single-cell image analysis methods to explore the expression of the OATP isoforms in different tumor cell types through co-labeling with cell-type specific markers, such as IBA1 (pan-myeloid), GFAP (tumor cell), PDGFRß (stromal cell), and UEA-1-lectin (endothelial). Results: We found significant over-expression of all the OATP isoforms (OATP1A2, 2B1, 1C1 and 4A1) in GBM tumor sections when compared to non-neoplastic brain. A single-cell image analysis revealed that OATPs were significantly upregulated throughout the tumor parenchyma, with significantly higher expression found on lectin-positive blood vessels and IBA1-positive myeloid cells in GBM compared to non-tumor brain tissue. Qualitative analysis of the four OATP isoforms demonstrated greater expression of OATP4A1 in peri-necrotic regions of GBM tissue, which correlated with hypoxia-related markers within the Ivy GAP RNAseq dataset. Conclusion: Here, we demonstrate, for the first time, the protein expression of four OATPs in human GBM tissue, including upregulation within the tumor microenvironment by myeloid cells and tumor vasculature, and isoform-specific upregulation within hypoxic niches.

Characterization of volumetric growth of intracranial meningiomas in Maori and Pasifika populations in New Zealand.

BACKGROUND: Maori and Pasifika populations in New Zealand have a higher incidence and prevalence of intracranial meningioma (IM). We sought to evaluate the volumetric growth rate of meningiomas under surveillance in these populations. METHODS: From July 2002 to October 2020, 336 patients with a total of 408 IM underwent conservative management with serial radiological surveillance at Auckland City Hospital and met the criteria for the study. Inclusion criteria included: age >16 at diagnosis, ≥2 appropriate scans one or more years apart. Exclusion criteria included previous cranial irradiation, a diagnosis of Neurofibromatosis and prior treatment of meningioma. Demographic and clinical data were obtained from the electronic medical records. Imaging data were recorded from the first and last scans. We utilized open-source image processing software (3D Slicer) for semi-automated segmentation and volume calculation. Consistent with previous literature, we calculated the relative growth rate (RGR, %/year) and annual volume change (AVC, cm3 /year) over time. RESULTS: Four hundred and eight meningiomas were volumetrically characterized for a mean duration of 6.2 years. The Maori and Pasifika populations (n = 134/393) demonstrated a higher RGR (31.41 versus 14.33%/year) (P = 0.026) and AVC (2.05 versus 0.95 cm3 ) (P = 0.025) compared to the control population. They also presented at a younger age and had a higher rate of tumour multiplicity. Males represented only 17.6% of the cohort but exhibited a higher growth rate (AVC = 2.52 cm3 /year) than females (AVC = 0.99 cm3 /year) (P = 0034). CONCLUSIONS: Maori and Pasifika populations in New Zealand have a higher incidence and volumetric growth rate of IM compared to a control population. This warrants further clinical, histopathological and genomic analysis.

Tumour infiltrating lymphocyte density differs by meningioma type and is associated with prognosis in atypical meningioma.

Tumour infiltrating lymphocyte (TIL) density is prognostically significant in various tumours, but few studies have investigated its significance in meningioma. This study aimed to investigate how TIL density differs by meningioma histology and whether it is a predictor of meningioma recurrence. We studied CD3, CD8, CD4, FOXP3 and PD-1 positive (+) TIL density in a continuous cohort of 476 meningiomas resected at Auckland Hospital between 2002 and 2011 using tissue microarrays and computer assisted image analysis. TILs were identified in all meningiomas except one (median CD3+ TIL density across entire cohort 53.0 cells/mm2). Most TILs were CD8+ (median 33.6 cells/mm2) with smaller numbers of CD4+ TILs (median 2.9 cells/mm2). PD-1+ (median 0.32 cells/mm2) and FOXP3+ (median 0.0 cells/mm2) TILs were scarce. Reduced CD3+ (p=0.0066), CD8+ (p=0.0029) and PD-1+ (p=0.0375) TIL density was seen in WHO grade II/III meningioma compared with WHO grade I. Pairwise comparison confirmed statistically significant differences in TIL density existed between meningioma types (CD3, CD8, CD4, p<0.0001; FOXP3, p=0.0096; PD-1, p=0.0090) with chordoid meningioma having the lowest overall CD3+ TIL density (median 12.5 cells/mm2). Despite its low TIL density, chordoid meningioma had a higher FOXP3:CD8 ratio than several meningioma types. Atypical meningioma had a higher FOXP3:CD8 ratio than transitional meningioma (p=0.0045). No association between TIL density and recurrence was seen across the entire cohort or by WHO grade. However, CD3+ and CD8+ TIL density was associated with recurrence in atypical meningioma on multivariable analysis (CD3, p=0.0012; CD8, p=0.0071). A higher CD3+ and CD8+ TIL density was associated with improved recurrence free survival. Our findings suggest CD3+ and CD8+ TIL density is prognostically significant in atypical meningioma. Further investigation of this observation and its biological basis is warranted. The differences in TIL density by meningioma histology may be of relevance in studies of therapeutic immune checkpoint inhibition.

Oligosarcomas, IDH-mutant are distinct and aggressive.

Oligodendrogliomas are defined at the molecular level by the presence of an IDH mutation and codeletion of chromosomal arms 1p and 19q. In the past, case reports and small studies described gliomas with sarcomatous features arising from oligodendrogliomas, so called oligosarcomas. Here, we report a series of 24 IDH-mutant oligosarcomas from 23 patients forming a distinct methylation class. The tumors were recurrences from prior oligodendrogliomas or developed de novo. Precursor tumors of 12 oligosarcomas were histologically and molecularly indistinguishable from conventional oligodendrogliomas. Oligosarcoma tumor cells were embedded in a dense network of reticulin fibers, frequently showing p53 accumulation, positivity for SMA and CALD1, loss of OLIG2 and gain of H3K27 trimethylation (H3K27me3) as compared to primary lesions. In 5 oligosarcomas no 1p/19q codeletion was detectable, although it was present in the primary lesions. Copy number neutral LOH was determined as underlying mechanism. Oligosarcomas harbored an increased chromosomal copy number variation load with frequent CDKN2A/B deletions. Proteomic profiling demonstrated oligosarcomas to be highly distinct from conventional CNS WHO grade 3 oligodendrogliomas with consistent evidence for a smooth muscle differentiation. Expression of several tumor suppressors was reduced with NF1 being lost frequently. In contrast, oncogenic YAP1 was aberrantly overexpressed in oligosarcomas. Panel sequencing revealed mutations in NF1 and TP53 along with IDH1/2 and TERT promoter mutations. Survival of patients was significantly poorer for oligosarcomas as first recurrence than for grade 3 oligodendrogliomas as first recurrence. These results establish oligosarcomas as a distinct group of IDH-mutant gliomas differing from conventional oligodendrogliomas on the histologic, epigenetic, proteomic, molecular and clinical level. The diagnosis can be based on the combined presence of (a) sarcomatous histology, (b) IDH-mutation and (c) TERT promoter mutation and/or 1p/19q codeletion, or, in unresolved cases, on its characteristic DNA methylation profile.

Fatal disseminated Anncaliia algerae myositis mimicking polymyositis in an immunocompromised patient.

We report the first New Zealand case of Anncaliia algerae myositis in a 55-year-old man with a history of psoriatic arthritis, treated with long-term immunosuppressive therapy. He resided in the city of Rotorua, which is famous for geothermal hot springs. A vastus lateralis muscle biopsy was performed to investigate the cause of an unexplained myositis. Light microscopy demonstrated a necrotizing myositis with scattered clusters of ovoid spores within the myocyte cytoplasm resembling microsporidia. DNA analysis by PCR and electron microscopy confirmed microsporidial myositis with features characteristic of A. algerae. Immunosuppressive drugs were stopped and the patient was treated with cholestyramine wash and albendazole. The patient deteriorated with involvement of bulbar and respiratory muscles requiring intensive care and ventilation. He died 3 weeks after diagnosis. Post-mortem examination of skeletal muscle from tongue and intercostal muscles also revealed numerous organisms confirming disseminated disease.

Cytoprotective agent troxipide-cyanine dye conjugate with cytotoxic and antiproliferative activity in patient-derived glioblastoma cell lines.

Cytoprotective agents are mainly used to protect the gastrointestinal tract linings and in the treatment of gastric ulcers. These agents are devoid of appreciable cytotoxic or cytostatic effects, and medicinal chemistry efforts to modify them into anticancer agents are rare. A drug repurposing campaign initiated in our laboratory with the primary focus of discovering brain cancer drugs resulted in drug-dye conjugate 1, a combination of the cytoprotective agent troxipide and heptamethine cyanine dye MHI 148. The drug-dye conjugate 1 was evaluated in three different patient-derived adult glioblastoma cell lines, commercially available U87 glioblastoma, and one paediatric glioblastoma cell line. In all cases, the conjugate 1 showed potent cytotoxic activity with nanomolar potency (EC50: 267 nM). Interestingly, troxipide alone does not show any cytotoxic and cytostatic activity in the above cell lines. We also observe a synergistic effect of 1 with temozolomide (TMZ), the standard drug used for glioblastoma treatment, even though the cell lines we used in this study were resistant to TMZ treatment. Herein we disclose the synthesis and in vitro activity of drug-dye conjugate 1 for treatment of difficult-to-treat brain cancers such as glioblastoma.

Single-cell image analysis reveals a protective role for microglia in glioblastoma.

BACKGROUND: Microglia and tumor-associated macrophages (TAMs) constitute up to half of the total tumor mass of glioblastomas. Despite these myeloid populations being ontogenetically distinct, they have been largely conflated. Recent single-cell transcriptomic studies have identified genes that distinguish microglia from TAMs. Here we investigated whether the translated proteins of genes enriched in microglial or TAM populations can be used to differentiate these myeloid cells in immunohistochemically stained human glioblastoma tissue. METHODS: Tissue sections from resected low-grade, meningioma, and glioblastoma (grade IV) tumors and epilepsy tissues were immunofluorescently triple-labeled for Iba1 (pan-myeloid marker), CD14 or CD163 (preferential TAM markers), and either P2RY12 or TMEM119 (microglial-specific markers). Using a single-cell-based image analysis pipeline, we quantified the abundance of each marker within single myeloid cells, allowing the identification and analysis of myeloid populations. RESULTS: P2RY12 and TMEM119 successfully discriminated microglia from TAMs in glioblastoma. In contrast, CD14 and CD163 expression were not restricted to invading TAMs and were upregulated by tumor microglia. Notably, a higher ratio of microglia to TAMs significantly correlated with increased patient survival. CONCLUSIONS: We demonstrate the validity of previously defined microglial-specific genes P2RY12 and TMEM119 as robust discriminators of microglia and TAMs at the protein level in human tissue. Moreover, our data suggest that a higher proportion of microglia may be beneficial for patient survival in glioblastoma. Accordingly, this tissue-based method for myeloid population differentiation could serve as a useful prognostic tool.

The mutational landscape of melanoma brain metastases presenting as the first visceral site of recurrence.

Brain metastases are a major cause of melanoma-related mortality and morbidity. We undertook whole-exome sequencing of 50 tumours from patients undergoing surgical resection of brain metastases presenting as the first site of visceral disease spread and validated our findings in an independent dataset of 18 patients. Brain metastases had a similar driver mutational landscape to cutaneous melanomas in TCGA. However, KRAS was the most significantly enriched driver gene, with 4/50 (8%) of brain metastases harbouring non-synonymous mutations. Hotspot KRAS mutations were mutually exclusive from BRAFV600, NRAS and HRAS mutations and were associated with a reduced overall survival from the resection of brain metastases (HR 10.01, p = 0.001). Mutations in KRAS were clonal and concordant with extracranial disease, suggesting that these mutations are likely present within the primary. Our analyses suggest that KRAS mutations could help identify patients with primary melanoma at higher risk of brain metastases who may benefit from more intensive, protracted surveillance.

The epidemiology of patients undergoing meningioma resection in Auckland, New Zealand, 2002 to 2011.

The incidence of meningioma is known to vary by gender and ethnicity. This study aimed to describe the epidemiological characteristics of a 10-year cohort of patients undergoing meningioma resection at Auckland City Hospital, Auckland, New Zealand. Of particular interest was whether there was any difference in meningioma incidence and recurrence rates between New Zealand Maori and Pacific Island patients compared with other ethnic groups. The study was a retrospective analysis of 493 patients with pathologically confirmed meningioma over the period 1 January 2002 to 31 December 2011. Based on this neurosurgical cohort, the minimum incidence of meningioma in the Auckland region was 3.39 per 100,000 population per year (95% C.I. 3.02-3.80) for the study period. Meningioma was significantly more common in women than men by a ratio of 4.2:1. New Zealand Maori and Pacific Island patients had a significantly higher incidence of meningioma than other ethnic groups. New Zealand Maori had a meningioma incidence 2.74 times that of Europeans (95% C.I. 2.01-3.73, p < 0.001). Pacific Island patients had 2.03 times higher incidence of meningioma than Europeans (95% C.I. 1.42 - 2.89, p < 0.001). The overall meningioma recurrence rate was 21.6% with a mean follow-up of 77 months. Recurrence rates for meningioma among Pacific Island patients were significantly higher than for other ethnic groups (hazard ratio 1.73, p = 0.008). Multivariate analysis of clinical variables confirmed the significance of traditional prognostic factors such as WHO tumour grade and Simpson grade of surgical excision in predicting meningioma recurrence.

PARP inhibitor cyanine dye conjugate with enhanced cytotoxic and antiproliferative activity in patient derived glioblastoma cell lines.

We describe the synthesis and in vitro activity of drug-dye conjugate 1, which is a combination of the PARP inhibitor rucaparib and heptamethine cyanine dye IR-786. The drug-dye conjugate 1 was evaluated in three different patient-derived glioblastoma cell lines and showed strong cytotoxic activity with nanomolar potency (EC50: 128 nM), which was a 780 fold improvement over rucaparib itself. We also observe a synergistic effect of 1 with temozolomide (TMZ), the standard drug for treatment for glioblastoma even though these cell lines were resistant to TMZ treatment. We envisage such conjugates to be worth exploring for their utility in the treatment of various brain cancers.

Neurochemical Characterization of PSA-NCAM+ Cells in the Human Brain and Phenotypic Quantification in Alzheimer's Disease Entorhinal Cortex.

Polysialylated neural cell adhesion molecule (PSA-NCAM) is widely expressed in the adult human brain and facilitates structural remodeling of cells through steric inhibition of intercellular NCAM adhesion. We previously showed that PSA-NCAM immunoreactivity is decreased in the entorhinal cortex in Alzheimer's disease (AD). Based on available evidence, we hypothesized that a loss of PSA-NCAM+ interneurons may underlie this reduction. PSA-NCAM expression by interneurons has previously been described in the human medial prefrontal cortex. Here we used postmortem human brain tissue to provide further evidence of PSA-NCAM+ interneurons throughout the human hippocampal formation and additional cortical regions. Furthermore, PSA-NCAM+ cell populations were assessed in the entorhinal cortex of normal and AD cases using fluorescent double labeling and manual cell counting. We found a significant decrease in the number of PSA-NCAM+ cells per mm2 in layer II and V of the entorhinal cortex, supporting our previous description of reduced PSA-NCAM immunoreactivity. Additionally, we found a significant decrease in the proportion of PSA-NCAM+ cells that co-labeled with NeuN and parvalbumin, but no change in the proportion that co-labeled with calbindin or calretinin. These results demonstrate that PSA-NCAM is expressed by a variety of interneuron populations throughout the brain. Furthermore, that loss of PSA-NCAM expression by NeuN+ cells predominantly contributes to the reduced PSA-NCAM immunoreactivity in the AD entorhinal cortex.

Multimodal molecular analysis of astroblastoma enables reclassification of most cases into more specific molecular entities.

Astroblastoma is a rare and controversial glioma with variable clinical behavior. The diagnosis currently rests on histologic findings of a circumscribed glioma with astroblastomatous pseudorosettes and vascular hyalinization. Immunohistochemical studies have suggested different oncogenic drivers, such as BRAF p.V600E, but very few cases have been studied using genome-wide methodologies. Recent genomic profiling identified a subset of CNS embryonal tumors with astroblastoma-like morphology that harbored MN1 gene fusions, termed "CNS high-grade neuroepithelial tumors with MN1 alteration" (CNS-HGNET-MN1). To further characterize the genetic alterations that drive astroblastomas, we performed targeted next-generation sequencing (NGS) of 500 cancer-associated genes in a series of eight cases. We correlated these findings with break-apart fluorescence in situ hybridization (FISH) analysis of the MN1 locus and genome-wide DNA methylation profiling. Four cases showed MN1 alteration by FISH, including two pediatric cases that lacked other pathogenic alterations, and two adult cases that harbored other cancer-associated gene mutations or copy number alterations (eg, CDKN2A/B homozygous deletion, TP53, ATM and TERT promoter mutations). Three of these cases grouped with the CNS-HGNET-MN1 entity by methylation profiling. Two of four MN1 intact cases by FISH showed genetic features of either anaplastic pleomorphic xanthoastrocytoma (BRAF p.V600E mutation, CDKN2A/B homozygous deletion and TERT promoter mutation) or IDH-wildtype glioblastoma (trisomy 7, monosomy 10, CDK4 amplification and TP53, NRAS and TERT promoter mutations) and these cases had an aggressive clinical course. Two clinically indolent cases remained unclassifiable despite multimodal molecular analysis. We conclude that astroblastoma histology is not specific for any entity including CNS-HGNET-MN1, and that additional genetic characterization should be considered for astroblastomas, as a number of these tumors likely contain a methylation profile or genetic alterations that suggest classification as other tumor entities. Our heterogeneous molecular findings help to explain the clinical unpredictability of astroblastoma.

Cardiomyopathy as presenting sign of glycogenin-1 deficiency-report of three cases and review of the literature.

We describe a new type of cardiomyopathy caused by a mutation in the glycogenin-1 gene (GYG1). Three unrelated male patients aged 34 to 52 years with cardiomyopathy and abnormal glycogen storage on endomyocardial biopsy were homozygous for the missense mutation p.Asp102His in GYG1. The mutated glycogenin-1 protein was expressed in cardiac tissue but had lost its ability to autoglucosylate as demonstrated by an in vitro assay and western blot analysis. It was therefore unable to form the primer for normal glycogen synthesis. Two of the patients showed similar patterns of heart dilatation, reduced ejection fraction and extensive late gadolinium enhancement on cardiac magnetic resonance imaging. These two patients were severely affected, necessitating cardiac transplantation. The cardiomyocyte storage material was characterized by large inclusions of periodic acid and Schiff positive material that was partly resistant to alpha-amylase treatment consistent with polyglucosan. The storage material had, unlike normal glycogen, a partly fibrillar structure by electron microscopy. None of the patients showed signs or symptoms of muscle weakness but a skeletal muscle biopsy in one case revealed muscle fibres with abnormal glycogen storage. Glycogenin-1 deficiency is known as a rare cause of skeletal muscle glycogen storage disease, usually without cardiomyopathy. We demonstrate that it may also be the cause of severe cardiomyopathy and cardiac failure without skeletal muscle weakness. GYG1 should be included in cardiomyopathy gene panels.

Distribution of PSA-NCAM in normal, Alzheimer's and Parkinson's disease human brain.

Polysialated neural cell adhesion molecule (PSA-NCAM) is a membrane bound glycoprotein widely expressed during nervous system development. While commonly described in the neurogenic niches of the adult human brain, there is limited evidence of its distribution in other brain regions. PSA-NCAM is an important regulator of cell-cell interactions and facilitates cell migration and plasticity. Recent evidence suggests these functions may be altered in neurodegenerative diseases such as Alzheimer's (AD) and Parkinson's disease (PD). This study provides a detailed description of the PSA-NCAM distribution throughout the human brain and quantitatively compares the staining load in cortical regions and sub-cortical structures between the control, AD and PD brain. Our results provide evidence of widespread, yet specific, PSA-NCAM expression throughout the human brain including regions devoid of PSA-NCAM in the rodent brain such as the caudate nucleus (CN) and cerebellum (CB). We also detected a significant reduction in PSA-NCAM load in the entorhinal cortex (EC) of cases that was inversely correlated with hyperphosphorylated tau load. These results demonstrate that PSA-NCAM-mediated structural plasticity may not be limited to neurogenic niches and is conserved in the aged brain. We also provide evidence that PSA-NCAM is reduced in the EC, a region severely affected by AD pathology.

Isolated gluteal and paravertebral muscle weakness due to anti-3-hydroxy-3-methylglutaryl-coenzyme a reductase antibody-associated necrotizing autoimmune myopathy.

INTRODUCTION: A 56-year-old man with a distant history of statin use presented with progressive isolated very proximal lower limb and truncal weakness. Electromyogram (EMG) showed isolated gluteal and lumbar paraspinal muscle involvement. METHODS: Gluteus medius muscle biopsy was performed under general anesthesia. RESULTS: The biopsy showed a pauci-inflammatory necrotizing myopathy. Serum antibodies to 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) were positive. He has since partially responded to corticosteroids and methotrexate. CONCLUSIONS: Anti-HMGCR-associated necrotizing autoimmune myopathy (NAM) can present in a restricted form after cessation of a statin. Biopsy of a symptomatic but uncommonly studied muscle is worthwhile. Muscle Nerve 54: 150-152, 2016.

Merosin-deficient congenital muscular dystrophy: A novel homozygous mutation in the laminin-2 gene.

Merosin deficient congenital muscular dystrophy (MDC1A) is an autosomal recessive disorder characterized by mutations in the LAMA2 gene at chromosome 6q22-23. This gene spans 65 exons and encodes the α2 chain subunit of laminin-2. A variety of deletions, missense, nonsense and splice site mutations have been described in the LAMA2 gene, with resultant MDC1A. We describe a novel LAMA2 homozygous sequence variant in a Samoan patient with MDC1A and confirm its pathogenic effect with merosin immunohistochemistry on skeletal muscle biopsy. The likely effect of the sequence variant is modeled using in silico analysis.