Lysosomal storage, impaired autophagy and innate immunity in Gaucher and Parkinson's diseases: insights for drug discovery

Impairment of autophagic-lysosomal pathways is increasingly being implicated in Parkinson's disease (PD). GBA1 mutations cause the lysosomal storage disorder Gaucher disease (GD) and are the commonest known genetic risk factor for PD. GBA1 mutations have been shown to cause autophagic-lysosomal impairment. Defective autophagic degradation of unwanted cellular constituents is associated with several pathologies, including loss of normal protein homeostasis, particularly of α-synuclein, and innate immune dysfunction. The latter is observed both peripherally and centrally in PD and GD. Here, we will discuss the mechanistic links between autophagy and immune dysregulation, and the possible role of these pathologies in communication between the gut and brain in these disorders. Recent work in a fly model of neuronopathic GD (nGD) revealed intestinal autophagic defects leading to gastrointestinal dysfunction and immune activation. Rapamycin treatment partially reversed the autophagic block and reduced immune activity, in association with increased survival and improved locomotor performance. Alterations in the gut microbiome are a critical driver of neuroinflammation, and studies have revealed that eradication of the microbiome in nGD fly and mouse models of PD ameliorate brain inflammation. Following these observations, lysosomal-autophagic pathways, innate immune signalling and microbiome dysbiosis are discussed as potential therapeutic targets in PD and GD. This article is part of a discussion meeting issue 'Understanding the endo-lysosomal network in neurodegeneration'.

Autophagic dysfunction and gut microbiota dysbiosis cause chronic immune activation in a Drosophila model of Gaucher disease

Mutations in the GBA1 gene cause the lysosomal storage disorder Gaucher disease (GD) and are the greatest known genetic risk factors for Parkinson's disease (PD). Communication between the gut and brain and immune dysregulation are increasingly being implicated in neurodegenerative disorders such as PD. Here, we show that flies lacking the Gba1b gene, the main fly orthologue of GBA1, display widespread NF-kB signalling activation, including gut inflammation, and brain glial activation. We also demonstrate intestinal autophagic defects, gut dysfunction, and microbiome dysbiosis. Remarkably, modulating the microbiome of Gba1b knockout flies, by raising them under germ-free conditions, partially ameliorates lifespan, locomotor and immune phenotypes. Moreover, we show that modulation of the immune deficiency (IMD) pathway is detrimental to the survival of Gba1 deficient flies. We also reveal that direct stimulation of autophagy by rapamycin treatment achieves similar benefits to germ-free conditions independent of gut bacterial load. Consistent with this, we show that pharmacologically blocking autophagosomal-lysosomal fusion, mimicking the autophagy defects of Gba1 depleted cells, is sufficient to stimulate intestinal immune activation. Overall, our data elucidate a mechanism whereby an altered microbiome, coupled with defects in autophagy, drive chronic activation of NF-kB signaling in a Gba1 loss-of-function model. It also highlights that elimination of the microbiota or stimulation of autophagy to remove immune mediators, rather than prolonged immunosuppression, may represent effective therapeutic avenues for GBA1-associated disorders.

Enhanced insulin signalling ameliorates C9orf72 hexanucleotide repeat expansion toxicity in Drosophila

G4C2 repeat expansions within the C9orf72 gene are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The repeats undergo repeat-associated non-ATG translation to generate toxic dipeptide repeat proteins. Here, we show that insulin/IGF signalling is reduced in fly models of C9orf72 repeat expansion using RNA sequencing of adult brain. We further demonstrate that activation of insulin/IGF signalling can mitigate multiple neurodegenerative phenotypes in flies expressing either expanded G4C2 repeats or the toxic dipeptide repeat protein poly-GR. Levels of poly-GR are reduced when components of the insulin/IGF signalling pathway are genetically activated in the diseased flies, suggesting a mechanism of rescue. Modulating insulin signalling in mammalian cells also lowers poly-GR levels. Remarkably, systemic injection of insulin improves the survival of flies expressing G4C2 repeats. Overall, our data suggest that modulation of insulin/IGF signalling could be an effective therapeutic approach against C9orf72 ALS/FTD.

The controllability beliefs scale used with carers of people with intellectual disabilities: psychometric properties

BACKGROUND

Beliefs about the controllability of behaviour have been consistently shown to be important in understanding the responses of carers to the challenging behaviour of people with intellectual disabilities (IDs). This paper reports the reliability and validity of the controllability beliefs scale (CBS), a 15-item measure of beliefs regarding the controllability of challenging behaviour when used with carers of people with IDs.

METHODS

Two hundred and sixty-four carers of people with IDs completed the CBS, 74 people also completed the modified attributional style questionnaire and the self-injury behavioural understanding questionnaire scale to determine concurrent and convergent validity and 34 people completed the scale twice within a 2- to 4-week period to determine test-retest reliability.

RESULTS

The scale has a two-factor structure and has adequate internal reliable. The scale is significantly correlated with the controllability, internality and stability items from the Modified Attributional Style Questionnaire, showed expected associations with behavioural and internal emotional understanding items from the self-injury behavioural understanding questionnaire. The scale has good test-retest reliability.

CONCLUSIONS

The data support use of the CBS in clinical practice and research to assess carers' beliefs regarding challenging behaviour of people with IDs.

The PRaCTICaL study of nurse led, intensive care follow-up programmes for improving long term outcomes from critical illness: a pragmatic randomised controlled trial

OBJECTIVES

To test the hypothesis that nurse led follow-up programmes are effective and cost effective in improving quality of life after discharge from intensive care.

DESIGN

A pragmatic, non-blinded, multicentre, randomised controlled trial.

SETTING

Three UK hospitals (two teaching hospitals and one district general hospital).

PARTICIPANTS

286 patients aged >or=18 years were recruited after discharge from intensive care between September 2006 and October 2007.

INTERVENTION

Nurse led intensive care follow-up programmes versus standard care. Main outcome measure(s) Health related quality of life (measured with the SF-36 questionnaire) at 12 months after randomisation. A cost effectiveness analysis was also performed.

RESULTS

286 patients were recruited and 192 completed one year follow-up. At 12 months, there was no evidence of a difference in the SF-36 physical component score (mean 42.0 (SD 10.6) v 40.8 (SD 11.9), effect size 1.1 (95% CI -1.9 to 4.2), P=0.46) or the SF-36 mental component score (effect size 0.4 (-3.0 to 3.7), P=0.83). There were no statistically significant differences in secondary outcomes or subgroup analyses. Follow-up programmes were significantly more costly than standard care and are unlikely to be considered cost effective.

CONCLUSIONS

A nurse led intensive care follow-up programme showed no evidence of being effective or cost effective in improving patients' quality of life in the year after discharge from intensive care. Further work should focus on the roles of early physical rehabilitation, delirium, cognitive dysfunction, and relatives in recovery from critical illness. Intensive care units should review their follow-up programmes in light of these results.

TRIAL REGISTRATION

ISRCTN 24294750.

RIZ1 repression is associated with insulin-like growth factor-1 signaling activation in chronic myeloid leukemia cell lines

RIZ1 is a histone methyltransferase whose expression and activity are reduced in many cancers. In chronic myelogenous leukemia (CML), blastic transformation is associated with loss of heterozygosity in the region where RIZ1 is located and with decreased RIZ1 expression. Forced RIZ1 expression in model CML blast crisis (BC) cell lines decreases proliferation, increases apoptosis and enhances differentiation. We characterized molecular mechanisms that may contribute to potential CML tumor suppressor properties of RIZ1. Several RIZ1-regulated genes involved in insulin-like growth factor-1 (IGF-1) signaling were identified using cDNA microarrays. RIZ1 was shown to associate with promoter regions of IGF-1 and to increase histone H3 lysine 9 methylation using chromatin immunoprecipitation assays. IGF-1-blocking antibody was used to demonstrate the importance of autocrine IGF-1 signaling in CML-BC cell line viability. Forced RIZ1 expression in CML-BC cell lines decreases IGF-1 receptor activation and activation of downstream signaling components extracellular signal-regulated kinase 1/2 and AKT. These results highlight the therapeutic potential of inhibiting IGF-1 pathway in the acute phase of CML.

Prenatal detection of associated anomalies in fetuses diagnosed with cleft lip with or without cleft palate in utero

OBJECTIVE

The aim of this study was to determine the prenatal detection rate of associated anomalies in fetuses with a suspected cleft lip with or without cleft palate.

METHODS

Fetuses with a suspected cleft lip with or without cleft palate, determined by prenatal ultrasound, were prospectively enrolled. Additional anomalies suspected by ultrasound or genetic testing were recorded. Postnatal outcome was obtained.

RESULTS

Forty-five fetuses with a cleft lip with or without cleft palate, diagnosed prenatally with either two-dimensional and/or three-dimensional ultrasound, were studied. Postnatal follow-up revealed that 16 (35.6%) of these 45 fetuses had an additional structural or syndromic abnormality. Of the 37 fetuses with prenatally determined 'isolated' cleft lip with or without cleft palate, eight (21.6%) had an additional malformation identified after delivery.

CONCLUSION

In pregnancies complicated by a cleft lip with or without cleft palate, patients should be informed of the risks of associated anomalies, some of which may be undetected prenatally.

A monkey model for enterohemorrhagic Escherichia coli infection

Adult Macaca radiata (n=22) were infected intragastrically with 10(12) Escherichia coli O157:H7 strain 84-01, which produces Shiga toxins 1 and 2. Clinical symptoms and bacterial excretion were documented in each monkey for a specified time period before they were killed. At necropsy, samples were obtained for culture and histologic and ultrastructural examination. Seventeen monkeys had diarrhea: E. coli O157 was isolated from postinfection stool samples from all monkeys and from autopsy cultures for 14 of 22 monkeys. Histologic examination showed attaching-effacing lesions, which appeared at 12 h and persisted for 7 days, in 12 monkeys. Widening of the intercellular spaces, degeneration and vacuolization of the epithelial cells, epithelial tufting, extrusion of epithelial cells, and neutrophilic infiltration were characteristic features seen in 20 of the 22 infected monkeys but not in 4 control monkeys. This monkey model closely parallels the early stages of the disease produced by E. coli O157:H7 and would be useful in the further study of pathogenic mechanisms and prevention methods in enterohemorrhagic E. coli infections.

Hector's house: Sir Hector Hetherington and the academicization of Glasgow Hospital Medicine before the NHS

Images

Placental pathology casebook. Complete hydatidiform mole with coexistent term twin pregnancy

A case of twin pregnancy consisting of a complete hydatidiform mole with a coexistent, viable fetus is presented. The case is distinctive for its presentation on ultrasound, its unusually low levels of serum hCG, its remarkable histology, and its term delivery.

Sources and impact of artifacts on clinical three-dimensional ultrasound imaging

The purpose of this paper is to investigate, identify and discuss artifacts and their sources arising in three-dimensional ultrasound (3D US) in clinical practice in order to increase the awareness of clinicians and sonographers with respect to common 3D US artifacts and to use this increased awareness to avoid or reduce the occurrence of misdiagnosis in 3D US studies. Patient 3D US data were acquired using several different scanners and reviewed interactively on the scanner and graphics workstations. Artifacts were catalogued according to artifact origin. Two-dimensional ultrasound (2D US) artifacts were classified whether they were of a B-mode or color/power Doppler origin and their presentation in the original scan planes and the resulting volume re-sliced planes and rendered images was identified. Artifacts unique to 3D US were observed, noted and catalogued on the basis of whether they arose during acquisition, rendering or volume editing operations. Acoustic artifacts identified included drop-out, shadowing, etc. whose presentation depended on the relationship between slice and imaging plane orientation. Color/power Doppler artifacts were related to gain, aliasing, and flash which could add apparent structure or confusion to the volume images. Rendered images also demonstrated artifacts due to shadowing and motion of adjacent structures, cardiac motion or pulsatility of the cardiac septum or vessel walls. Editing artifacts potentially removed important structures. Three-dimensional ultrasound is prone to the same types of artifacts encountered in 2D US imaging plus others unique to volume acquisition and visualization. The consequences of these diagnostically significant artifacts include mimicking of abnormal development, masses, or missing structures thus requiring careful study before reaching a diagnosis.

Colonization with enteroadherent, enterotoxigenic and enterohemorrhagic Escherichia coli among day-care center attendees in New Orleans, Louisiana

BACKGROUND

E. coli strains producing specific virulence factors are frequently cited as causes of pediatric diarrhea in developing areas, although many well children from the same areas are colonized with these organisms. The role of these Escherichia coli in day-care center (DCC)-associated diarrhea in the United States has not been evaluated.

METHODS

A cohort of 112 DCC attendees from 5 DCC in urban New Orleans were followed longitudinally with demographic data, biweekly routine stool samples and additional stool samples with episodes of diarrhea. E. coli isolates were routinely saved; diarrhea stool samples were tested to detect enterotoxigenic, enterohemorrhagic and enteroadherent strains; and the prevalence of these E. coli in children with and without diarrhea was investigated.

RESULTS

During 225 child months of observation 21 episodes of diarrhea were documented and microbiologic data were available for 18. HEp-2 cell enteroadherent E. coli [mostly enteroaggregative (EAggEC) pattern] were identified in 6 of 18 (33.3%) diarrhea cases vs. 6 of 36 (16.6%) age-matched controls. However, the prevalence of EAggEC was very DCC-specific, with EAggEC found in 12 of 22 routine specimens from a DCC with recent EAggEC-related diarrhea vs. 0 of 11 routine specimens from age-matched children in another DCC without EAggEC-related diarrhea (P=0.002). Enterotoxigenic E. coli were uncommon in both ill and well children, and no enterohemorrhagic E. coli were detected.

CONCLUSION

EAggEC were commonly isolated from children with and without diarrhea in certain DCC settings, although we cannot determine whether these strains caused diarrhea. Diarrhea-producing E. coli were not associated with diarrhea in this DCC population.

Structural and functional analysis of the human neutrophil 1-15 antigen, an Mr 65,000 to 70,000 activation-associated membrane proteinase

Previous studies with the anti-neutrophil/antichymotrypsin mAb 1-15 have identified an activation-associated, chymotrypsin-like activity within the membrane fraction of isolated human neutrophils (PMN). In the present study, the molecular and biochemical characteristics of mAb 1-15 Ag/proteinase were determined. On casein/acrylamide sizing gels, PMN membrane preparations were found to contain an Mr 58,000 to 84,000 band of Ca2(+)-dependent proteinase activity. Reducing and nonreducing SDS-PAGE of mAb 1-15-affinity-purified membrane proteins demonstrated specific recovery of an enzymatically active Mr 65,000 to 70,000 chymotrypsin-like Ag. The presence of a distinct membrane serine esterase of isoelectric point 6.3/Mr 65,000 to 70,000 was confirmed in active site-labeling experiments with the serine proteinase inhibitor [3H]diisopropylfluorophosphate (DFP). Substrate-affinity chromatography with phe-Sepharose or FMLP-Sepharose provided partial purification of enzyme activity among Mr 65,000 to 70,000 FMLP- or phe-binding proteins. Enzyme inhibition was obtained by incubation with mAb 1-15, DFP, N-carbobenzoxyl-phe-chlormethyl ketone, or PMSF, but not tosyl-amide-phenylethylchlormethyl ketone, bestatin, aprotinin, or phosphoramidon. In HPLC analysis, [3H]DFP labeled proteinase was found to comigrate with one of three FMLP-affinity-labeled membrane peaks, but unlike the FMLP surface receptor the DFP-labeling membrane proteinase was not modified by endoglycosidase F. We conclude that the mAb 1-15 Ag, which appears to play a role in PMN activation, is a distinct, active, Mr 65,000 to 70,000 serine proteinase with affinity for substrate sites containing aromatic amino acids.

Structural and functional analysis of the human neutrophil 1-15 antigen, an Mr 65,000 to 70,000 activation-associated membrane proteinase

Previous studies with the anti-neutrophil/antichymotrypsin mAb 1-15 have identified an activation-associated, chymotrypsin-like activity within the membrane fraction of isolated human neutrophils (PMN). In the present study, the molecular and biochemical characteristics of mAb 1-15 Ag/proteinase were determined. On casein/acrylamide sizing gels, PMN membrane preparations were found to contain an Mr 58,000 to 84,000 band of Ca2(+)-dependent proteinase activity. Reducing and nonreducing SDS-PAGE of mAb 1-15-affinity-purified membrane proteins demonstrated specific recovery of an enzymatically active Mr 65,000 to 70,000 chymotrypsin-like Ag. The presence of a distinct membrane serine esterase of isoelectric point 6.3/Mr 65,000 to 70,000 was confirmed in active site-labeling experiments with the serine proteinase inhibitor [3H]diisopropylfluorophosphate (DFP). Substrate-affinity chromatography with phe-Sepharose or FMLP-Sepharose provided partial purification of enzyme activity among Mr 65,000 to 70,000 FMLP- or phe-binding proteins. Enzyme inhibition was obtained by incubation with mAb 1-15, DFP, N-carbobenzoxyl-phe-chlormethyl ketone, or PMSF, but not tosyl-amide-phenylethylchlormethyl ketone, bestatin, aprotinin, or phosphoramidon. In HPLC analysis, [3H]DFP labeled proteinase was found to comigrate with one of three FMLP-affinity-labeled membrane peaks, but unlike the FMLP surface receptor the DFP-labeling membrane proteinase was not modified by endoglycosidase F. We conclude that the mAb 1-15 Ag, which appears to play a role in PMN activation, is a distinct, active, Mr 65,000 to 70,000 serine proteinase with affinity for substrate sites containing aromatic amino acids.

OHIO-1 beta-lactamase is part of the SHV-1 family

The OHIO-1 beta-lactamase gene was subcloned in a 1.16-kilobase TaqI fragment in the 2.4-kilobase chimeric plasmid pSK04. After directional subcloning into M13, the DNA sequence of this fragment was determined. The results showed an open reading frame of 858 base pairs (bp) encoding a protein of 286 amino acids. The structural gene showed 95, 87, and 60% DNA sequence identity with SHV-1, LEN-1, and TEM-1, respectively, and 93, 85, and 62% predicted amino acid sequence identity, respectively. The 87 bp upstream of the OHIO-1 structural gene had 96% identity with the upstream flanking sequence of SHV-1, including the -35 and -10 consensus sequences and the putative ribosomal binding site. A 223-bp DNA probe derived from a PstI-HaeII fragment in the C-terminal sequence of OHIO-1 had predicted 96, 88, and 61% sequence identity with SHV-1, LEN-1, and TEM-1, respectively. This probe hybridized to SHV-1 and poorly to LEN-1, but not to TEM-1 or a variety of other plasmid-mediated beta-lactamase genes, under stringent conditions. Screening of plasmid DNA derived from 40 ampicillin-resistant clinical isolates by Southern hybridization with the 223-bp probe uncovered no strains encoding OHIO-1. Isoelectric focusing of the same collection did identify two strains producing enzymes resembling SHV-1, however. We have also performed a kinetic comparison of OHIO-1, SHV-1, and TEM-1. OHIO-1 and SHV-1 were indistinguishable from each other but could be distinguished from TEM-1. These data clearly place OHIO-1 within the SHV-1 family of beta-lactamases.

Impact of race on renal transplant outcome

The influence of race on the outcome of cadaver renal transplantation (CRT) continues to be controversial even in the cyclosporine era. The present study examines the effect of race in 343 adult CRT performed from 1/1/82 through 10/1/88 with regard to the incidence of delayed function (DF), graft survival (GS), and patient survival (PS). Blacks constituted 38% of the patients. A history of nephrosclerosis secondary to hypertension was more common in blacks, with 51% (67/130) vs. 8% (17/213) in whites, while glomerulonephritis and Type 1 diabetes mellitus were more common in whites. There was no significant difference in the number of HLA (A,B,DR) matches or DR mismatches between whites and blacks. With azathioprine immunosuppression DF was more common in blacks than in whites, 54% (14/26) vs. 20% (11/55) respectively (P less than 0.01). The higher incidence of DF in blacks than in whites on Aza was associated with a significantly lower dose of intraoperative albumin, 0.25 g/kg vs. 0.44 g/kg, respectively (P less than 0.01). Of the Aza treated black recipients who had DF, 79% (11/14) had graft loss within three months, significantly worse than 25% (3/12) with graft loss when immediate function was present (P less than 0.005). Currently, all patients receive at least 0.80 g/kg of albumin intraoperatively and CsA quadruple induction therapy. With the current regimen, black and white recipients of primary CRT recipients have a comparable low incidence of DF of 18% and 22%, respectively. However, DF remains high among repeat black or white recipients: 33% (10/30) and 57% (8/14), respectively. The incidence of rejection within 30 days was similar for black and white recipients during the Aza and CsA eras, 62% vs. 75% and 34% vs. 42% respectively. GS and PS at three months for blacks on Aza were 54% and 89%, respectively, reflecting the corresponding high incidence of DF. This compares with 71% and 97% GS and PS for whites on Aza. Blacks and whites receiving CsA had equivalent 1-year GS and PS: 76% and 92%, respectively. We conclude that, in our center during the Aza era, blacks had a higher incidence of DF and lower GS than whites. With our current intraoperative fluid replacement and CsA immunosuppression, the incidence of DF and GS and PS are equivalent in black and white recipients.

The effect of computerized utilization review on patterns of psychiatric inpatient care

An interactive computerized utilization review system for psychiatric inpatient care was developed and tested on a 30-bed acute admission ward, where staff were trained in its use. The program permitted staff to review clinical decisions affecting length of stay and to receive immediate feedback on the cost and revenue for each case. The impact of the system was evaluated by comparing the length of stay of patients on the study unit with that of patients on a similar unit where the system was not in use, and also by comparing the length of stay for both units before and after the system was implemented. The findings showed that the length of stay on the study unit was significantly reduced after the system's implementation, and that it was well accepted by the staff. Six-month follow-up data showed no increase in symptomatology for the study patients compared with the control group.

Detection of myoglobin by radioimmmunoassay in human sera: its usefulness and limitations as an emergency room screening test for acute myocardial infarction

The results indicate that serum myoglobin determinations may be obtained by radioimmunoassay utilizing time periods for the testing which allow more useful clinical evaluation of patients. The data also demonstrate, however, that there are important temporal considerations in using serum myoglobin levels for the detection of acute myocardial infarcts and, if this test is used to determine in the Emergency Room whether patients have had acute myocardial infarcts, these limitations will have to be kept in mind. In addition, three other patient subgroups that might be expected to have elevated serum myoglobin levels by radioimmunoassay have been determined. These include patients with shock (irrespective of etiology), patients with severe renal insufficiency, i.e., those with serum creatinine levels equal to or greater than 8 mg. per cent, and possibly patients who have been on alcohol binges immediately prior to being seen in the Emergency Room.