Nacc1 Mutation in Mice Models Rare Neurodevelopmental Disorder with Underlying Synaptic Dysfunction

A missense mutation in the transcription repressor Nucleus accumbens-associated 1 (NACC1) gene at c.892C>T (p.Arg298Trp) on chromosome 19 causes severe neurodevelopmental delay ( Schoch et al., 2017). To model this disorder, we engineered the first mouse model with the homologous mutation (Nacc1+/R284W ) and examined mice from E17.5 to 8 months. Both genders had delayed weight gain, epileptiform discharges and altered power spectral distribution in cortical electroencephalogram, behavioral seizures, and marked hindlimb clasping; females displayed thigmotaxis in an open field. In the cortex, NACC1 long isoform, which harbors the mutation, increased from 3 to 6 months, whereas the short isoform, which is not present in humans and lacks aaR284 in mice, rose steadily from postnatal day (P) 7. Nuclear NACC1 immunoreactivity increased in cortical pyramidal neurons and parvalbumin containing interneurons but not in nuclei of astrocytes or oligodendroglia. Glial fibrillary acidic protein staining in astrocytic processes was diminished. RNA-seq of P14 mutant mice cortex revealed over 1,000 differentially expressed genes (DEGs). Glial transcripts were downregulated and synaptic genes upregulated. Top gene ontology terms from upregulated DEGs relate to postsynapse and ion channel function, while downregulated DEGs enriched for terms relating to metabolic function, mitochondria, and ribosomes. Levels of synaptic proteins were changed, but number and length of synaptic contacts were unaltered at 3 months. Homozygosity worsened some phenotypes including postnatal survival, weight gain delay, and increase in nuclear NACC1. This mouse model simulates a rare form of autism and will be indispensable for assessing pathophysiology and targets for therapeutic intervention.

Toward a comprehensive catalog of regulatory elements

Regulatory elements are the genomic regions that interact with transcription factors to control cell-type-specific gene expression in different cellular environments. A precise and complete catalog of functional elements encoded by the human genome is key to understanding mammalian gene regulation. Here, we review the current state of regulatory element annotation. We first provide an overview of assays for characterizing functional elements, including genome, epigenome, transcriptome, three-dimensional chromatin interaction, and functional validation assays. We then discuss computational methods for defining regulatory elements, including peak-calling and other statistical modeling methods. Finally, we introduce several high-quality lists of regulatory element annotations and suggest potential future directions.

Selective Neuronal Uptake and Distribution of AAVrh8, AAV9, and AAVrh10 in Sheep After Intra-Striatal Administration

BACKGROUND

Transgenic sheep are currently the only large animal model of Huntington's disease expressing full-length mutant human huntingtin. These transgenic sheep provide an opportunity to test adeno associated virus (AAV) therapies directly targeting the huntingtin gene. A recent study demonstrated that self-complementary (sc) AAV with artificial miRNA against human huntingtin reduced mutant human huntingtin in caudate and putamen after a single injection near the internal capsule.

OBJECTIVE

To identify an AAV serotype among AAVrh8, AAV9 and AAVrh10 with the highest neuronal uptake and distribution, with no obvious cell loss in the neostriatum of the sheep.

METHODS

We tested AAVrh8, AAV9 and AAVrh10 by stereotactic direct unilateral injection into the neostriatum of sheep, near the internal capsule. Four weeks after administration, we examined the viral spread and neuronal uptake of each serotype of AAV containing GFP. We compared single stranded (ss) and scAAVs. Further, we measured the distribution of AAVrh8 and AAV9 to a variety of tissues outside the brain.

RESULTS

Sc AAV9 had the best combination of neuronal uptake and distribution throughout the neostriatum. scAAVrh10 demonstrated good spread, but was not taken up by neurons. scAAVrh8 demonstrated good spread, but had less neuronal uptake than AAV9. Six hours after convection-enhanced administration to the neostriatum, both AAVrh8 and AAV9 viral genomes were detected in blood, saliva, urine, feces and wool. By four weeks, viral genomes were detected in wool only. Administration of AAVrh8, AAV9 and AAVrh10 was not associated with loss of neostriatal, medium spiny neuron number as measured by DARPP32 immunohistochemistry.

CONCLUSIONS

Altogether, we found scAAV9 had the best neuronal uptake and spread, showed no loss of neurons at one-month post-injection, and was not measurable in body fluids one month after injection. This information will guide future clinical experiments requiring brain injection of AAV for therapeutics for gene or miRNA deliveries in sheep transgenic for the human huntingtin gene.

Alterations in mRNA 3' UTR Isoform Abundance Accompany Gene Expression Changes in Human Huntington's Disease Brains

The huntingtin gene has two mRNA isoforms that differ in their 3' UTR length. The relationship of these isoforms with Huntington's disease is not established. We provide evidence that the abundance of huntingtin 3' UTR isoforms differs between patient and control neural stem cells, fibroblasts, motor cortex, and cerebellum. Huntingtin 3' UTR isoforms, including a mid-3' UTR isoform, have different localizations, half-lives, polyA tail lengths, microRNA sites, and RNA-binding protein sites. Isoform shifts in Huntington's disease motor cortex are not limited to huntingtin; 11% of alternatively polyadenylated genes change the abundance of their 3' UTR isoforms. Altered expression of RNA-binding proteins may be associated with aberrant isoform abundance; knockdown of the RNA-binding protein CNOT6 in control fibroblasts leads to huntingtin isoform differences similar to those in disease fibroblasts. These findings demonstrate that mRNA 3' UTR isoform changes are a feature of molecular pathology in the Huntington's disease brain.

Cellular Analysis of Silencing the Huntington's Disease Gene Using AAV9 Mediated Delivery of Artificial Micro RNA into the Striatum of Q140/Q140 Mice

BACKGROUND

The genetic mutation in Huntington's disease (HD) is a CAG repeat expansion in the coding region of the huntingtin (Htt) gene. RNAi strategies have proven effective in substantially down-regulating Htt mRNA in the striatum through delivery of siRNAs or viral vectors based on whole tissue assays, but the extent of htt mRNA lowering in individual neurons is unknown.

OBJECTIVE

Here we characterize the effect of an AAV9-GFP-miRHtt vector on Htt mRNA levels in striatal neurons of Q140/Q140 knock-in mice.

METHODS

HD mice received bilateral striatal injections of AAV9-GFP-miRHtt or AAV9-GFP at 6 or 12 weeks and striata were evaluated at 6 months of age for levels of Htt mRNA and protein and for mRNA signal within striatal neurons using RNAscope multiplex fluorescence in situ hybridization.

RESULTS

Compared to controls, the striatum of 6-month old mice treated at 6 or 12 weeks of age with AAV9-GFP-miRHtt showed a reduction of 40-50% in Htt mRNA and lowering of 25-40% in protein levels. The number of Htt mRNA foci in medium spiny neurons (MSNs) of untreated Q140/Q140 mice varied widely per cell (0 to 34 per cell), with ∼10% of MSNs devoid of foci. AAV9-GFP-miRHtt treatment shifted the distribution toward lower numbers and the percentage of cells without foci increased to 14-20%. The average number of Htt mRNA foci per MSN was reduced by 43%.

CONCLUSIONS

The findings here show that intrastriatal infusion of an AAV9-GFP-miRHtt vector lowers mRNA expression of Htt in striatum by ∼50%, through a partial reduction in the number of copies of mutant Htt mRNAs per cell. These findings demonstrate at the neuronal level the variable levels of Htt mRNA expression in MSNs and the neuronal heterogeneity of RNAi dependent Htt mRNA knockdown.

Safety of Striatal Infusion of siRNA in a Transgenic Huntington's Disease Mouse Model

BACKGROUND

The immune system In Huntington's disease (HD) is activated and may overreact to some therapies. RNA interference using siRNA lowers mutant huntingtin (mHTT) protein but could increase immune responses.

OBJECTIVE

To examine the innate immune response following siRNA infusion into the striatum of wild-type (WT) and HD transgenic (YAC128) mice.

METHODS

siRNAs (2'-O-methyl phosphorothioated) were infused unilaterally into striatum of four month-old WT and YAC128 mice for 28 days. Microglia number and morphology (resting (normal), activated, dystrophic), cytokine levels, and DARPP32-positive neurons were measured in striatum immediately or 14 days post-infusion. Controls included contralateral untreated striatum, and PBS and sham treated striata.

RESULTS

The striata of untreated YAC128 mice had significantly fewer resting microglia and more dystrophic microglia than WT mice, but no difference from WT in the proportion of activated microglia or total number of microglia. siRNA infusion increased the total number of microglia in YAC128 mice compared to PBS treated and untreated striata and increased the proportion of activated microglia in WT and YAC128 mice compared to untreated striata and sham treated groups. Cytokine levels were low and siRNA infusion resulted in only modest changes in those levels. siRNA infusion did not change the number of DARPP32-positive neurons.

CONCLUSION

Findings suggest that siRNA infusion may be a safe method for lowering mHTT levels in the striatum in young animals, since treatment does not produce a robust cytokine response or cause neurotoxicity. The potential long-term effects of a sustained increase in total and activated microglia after siRNA infusion in HD mice need to be explored.

[Neurotoxicity due to long-standing exposure to lead]

Using computer psychometric tests characterizing central nervous system functions, the authors proved that workers contacting lead have altered visual perception time, rate and accuracy of motor functions, weaker short-term memory. Correlation analysis revealed no relationship between the changes obtained and the acting concentration. Research obviously should be parallel to studies of health state parameters.

[Approaches to evaluation of occupational lead load in copper industry enterprise]

Evaluation of copper industry in Saxony revealed serum lead concentrations in 109 workers under the allowable level accepted in Germany for workers contacting lead, ambient lead concentrations in air of workplace rarely 2-4 times over the allowable level. The authors recommend these parameters of exposure as a basis for evaluating health state of workers.

[Inclusion of psychopathologic methods for diagnosis of early neurotoxic effects from lead and organic solvent mixtures]

To verify occupational neurotoxic effects it will be necessary to enlist the help of clinical psychologists and psychiatrists. However, no unified professional test battery exists to date. 119 healthy workers (26 lead-exposed, 45 exposed to mixed organic solvents, and 48 controls) were tested using uniformly standardised psychological and psychiatric methods. Long-term lead-exposed employees showed an increased number of psychoneurovegetative symptoms and deficits in attention performance according to the results of the Seeber-PNF and the Brickenkamp-d2-tests. There was no difference between the control group and persons exposed to the organic solvents test. Many parameters correlated to the dose of the toxic agent in the lead-exposed group. SCL-90-R, AMDP, and HAMD merely hinted at differences between the exposed subjects and the controls. Psychological and pathopsychological methods are necessary but will not suffice to detect early effects after long-term exposure to lead or organic solvents.

[Studying strain and recovery of initial cardiovascular functional state in accordance with "vegetative tone background"]

The aim of the investigation is the observation of strain during distinct physical and psychic load and particularly the recovery of the functional resting state of the cardiovascular system during restitution after load. Parameters of performance did not differ significantly between vagotonics and sympathotonics. Subjective appraisal of the ability to recover and relax after load comes off better by vagotonics than by sympathotonics. Vagotonics show a greater variability of parameters of the heart rhythm during transitional stages than sympathotonics do. This is a sign of good regulation of the tone by vagotonics during adaptation of the body to a new situation. We conclude a better come off of restitution of the functional state of the body after load, a better ability to recover and a better ability to hold out against new load.

Vegetative function diagnosis for early detection of lead intoxication

In the search for the early effects of neurotoxic lead poisoning, vegetative function diagnosis is a potential approach, focusing on the behaviour of the cardiac rhythm. Four groups of male subjects (109 copper workers exhibiting mean lead levels in blood of 31.2 micrograms/dl after long-term lead exposure; 27 control subjects having a similar job in the iron and steel industry without neurotoxic exposure; 35 reference subjects from Magdeburg University Hospital without neurotoxic exposure, and 5 subjects to whom benefits have been awarded for disability resulting from lead intoxication) were studied. All subjects underwent the same psychometric test battery. Special attention was paid to the restoration of vegetative tone after exposure. The more extensive the exposure to lead, the longer was the delay in restoration. This effect seems to be reversible, as workers heavily exposed to lead, but otherwise healthy, were more affected than the patients included in this investigation. Simply comparing the cardiac rhythm of exposed and non-exposed subjects at rest is not sufficient for early detection of lead intoxication. The behaviour of cardiac rhythm in humans at rest is the result of long-term influence by a wide range of factors, of which lead exposure is only one.

[Stress on adolescents due to forced positions in various postural loads]

To assess the strain imposed by defined static loads, eleven young males were studied in four different postures at three different loads held. In addition to the usual cardiovascular parameters of heart rate and arterial blood pressure, the long-term variability of the cardiac cycle (sinus arrhythmia) and the subjective exertion assessment according to Borg were used as strain criteria. Despite a high interindividual variability, HR arrhythmia data reflect in very good terms the strain imposed by predominantly central activation at static loads and forced postures. Such a strain assessment does not replace other modes of assessment such as biomechanical model considerations. Still, it may add to an assessment made on the basis of heart rate and blood pressure.

Selection of hybrid plants obtained by electrofusion of vacuolated x evacuolated plant protoplasts in hypo-osmolar solution

Vacuolated and evacuolated tobacco mesophyll protoplasts were electrically fused in hypo-osmolar media by using an alternating field of modulated amplitude for alignment. The vacuolated fusion partner was isolated from Nicotiana tabaccum L. cv Xanthi and the evacuolated one from the streptomycin-resistant strain Nicotiana tabaccum L. cv Petit Havana SR1. The field and osmolarity conditions used ensured relatively high yields of heterologous fusion products despite the differences in density and size of the parental cells. After removal of the evacuolated, streptomycin-resistant fused and unfused protoplasts by flotation of vacuole-containing cells on iso-osmolar sucrose medium, the cybrids and hybrids were cultured in 25 microliters drops of agarose. During the first 5 weeks the non-fused Xanthi-protoplasts were used as a nurse culture. After addition of streptomycin to the growth media, cybrids and hybrids were successfully selected whereas fused and unfused vacuole-containing protoplasts died within 6 days. Only the streptomycin-resistant cybrids and hybrids developed into whole plants. On average a yield of 0.025% of streptomycin-resistant plants (referred to the total number of parental cells) was obtained. Polyacrylamide gel electrophoresis of leaf extracts of these plants showed that at least 50% of the streptomycin-resistant plants had a hybrid-esterase isoenzyme pattern. The protocol can be generalised by fusion of iodoacetamide-inactivated vacuolated protoplasts with meristematic (or evacuolized) protoplasts carrying no genetic marker. Use of evacolated protoplasts for electrofusion with vacuole-containing protoplasts therefore offers a way of overcoming the lack of suitable genetic markers for hybrid selection.

[Randomized double-blind study of the analgesic effect of caerulein and morphine in chronic tumor pain]

Caerulein (CRL) (5 micrograms i.m.) and morphine (10 mg i.m.) have been tested for their analgesic activity in a double blind randomized study in a total of 36 patients with medium to severe tumor pains. A decrease of more than 20 mm on a visual analogue scale (VAS) was taken as a criterion for successful therapy. This was the case in 67% of the patients treated with morphine and 50% of those treated with CRL. This difference is statistically not significant, but CRL has significantly fewer side-effects than morphine. The present data do not permit a definitive judgement on the value of CRL in the treatment of tumor pains. Further studies with more patients and different doses and administration routes are warranted.

[Erosive gastritis: an aggravating cause of anemia in patients treated for chronic renal insufficiency]

Anemia is one of the commonest and most serious complications of chronic renal failure. The causes are multiple, while gastrointestinal blood loss is often unrecognized. Eleven hemodialyzed patients underwent esogastroduodenoscopy (OGD) to investigate anemia requiring transfusion of 4 or more blood units in a 6-month period. The same investigator performed all the endoscopies using the following scores: 0 = no lesions, 1 = focal red appearance of the mucosa, 2 = bleeding of the mucosa due to the gastroscope, 3 = erosive lesions, and 4 = presence of ulcers. Patients with a score of 1 or more were treated with ranitidine in a dose of 150-300 mg daily for 6 months. The need for transfusions before and after OGD was compared. The results were as follows: 8 of 11 patients had a score of 1-3, 1 patient scored 4 and 2 patients had no lesions. After 6 months' treatment with ranitidine no differences in hematocrit values were noted but the need for transfusions was significantly reduced (8.6 +/- 1.4 blood units before OGD vs. 4.9 +/- 1.3 blood units in the 6 months following OGD). It is concluded that minimal lesions of the esogastroduodenal mucosa are very common in hemodialyzed patients and ranitidine treatment could reduce the need for blood transfusions in these patients.

Epidemiologic study of abuse of analgesics containing phenacetin. Renal morbidity and mortality (1968-1979)

A study group of 623 working women 30 to 49 years old with objective evidence of intake of phenacetin-containing analgesics and a matched control group of 621 women without such intake in 1968 were assessed six times from 1969 to 1978 for laboratory evidence of urinary-tract disorders. The two groups did not differ in development of bacteriuria, hematuria, or proteinuria. However, a low specific gravity of urine (study group vs. control group, 23 vs. 7 per cent) and a raised level of serum creatinine (6.7 vs. 0.9 per cent) were significantly more frequent in the study group (P less than 0.001). Adjusted analyses of mortality over 11 years showed significant differences between the groups in overall mortality (study group vs. control group, 39 vs. 13 deaths; P less than 0.001), mortality due to urinary-tract disorders (P = 0.033), and cardiovascular diseases (P = 0.008). We conclude that heavy users of analgesic mixtures in the course of a decade have a higher incidence of both abnormal kidney function and kidney-related mortality than do casual users and nonusers, but the absolute incidences remain small even among heavy users.