Changes in social behavior with MAPK2 and KCTD13/CUL3 pathways alterations in two new outbred rat models for the 16p11.2 syndromes with autism spectrum disorders

Copy number variations (CNVs) of the human 16p11.2 locus are associated with several developmental/neurocognitive syndromes. Particularly, deletion and duplication of this genetic interval are found in patients with autism spectrum disorders, intellectual disability and other psychiatric traits. The high gene density associated with the region and the strong phenotypic variability of incomplete penetrance, make the study of the 16p11.2 syndromes extremely complex. To systematically study the effect of 16p11.2 CNVs and identify candidate genes and molecular mechanisms involved in the pathophysiology, mouse models were generated previously and showed learning and memory, and to some extent social deficits. To go further in understanding the social deficits caused by 16p11.2 syndromes, we engineered deletion and duplication of the homologous region to the human 16p11.2 genetic interval in two rat outbred strains, Sprague Dawley (SD) and Long Evans (LE). The 16p11.2 rat models displayed convergent defects in social behavior and in the novel object test in male carriers from both genetic backgrounds. Interestingly major pathways affecting MAPK1 and CUL3 were found altered in the rat 16p11.2 models with additional changes in males compared to females. Altogether, the consequences of the 16p11.2 genetic region dosage on social behavior are now found in three different species: humans, mice and rats. In addition, the rat models pointed to sexual dimorphism with lower severity of phenotypes in rat females compared to male mutants. This phenomenon is also observed in humans. We are convinced that the two rat models will be key to further investigating social behavior and understanding the brain mechanisms and specific brain regions that are key to controlling social behavior.

Increased On-Target Rate and Risk of Concatemerization after CRISPR-Enhanced Targeting in ES Cells

The French mouse clinic (Institut Clinique de la Souris; ICS) has produced more than 2000 targeting vectors for 'à la carte' mutagenesis in C57BL/6N mice. Although most of the vectors were used successfully for homologous recombination in murine embryonic stem cells (ESCs), a few have failed to target a specific locus after several attempts. We show here that co-electroporation of a CRISPR plasmid with the same targeting construct as the one that failed previously allows the systematic achievement of positive clones. A careful validation of these clones is, however, necessary as a significant number of clones (but not all) show a concatemerization of the targeting plasmid at the locus. A detailed Southern blot analysis permitted characterization of the nature of these events as standard long-range 5' and 3' PCRs were not able to distinguish between correct and incorrect alleles. We show that a simple and inexpensive PCR performed prior to ESC amplification allows detection and elimination of those clones with concatemers. Finally, although we only tested murine ESCs, our results highlight the risk of mis-validation of any genetically modified cell line (such as established lines, induced pluripotent stem cells or those used for ex vivo gene therapy) that combines the use of CRISPR/Cas9 and a circular double-stranded donor. We strongly advise the CRISPR community to perform a Southern blot with internal probes when using CRISPR to enhance homologous recombination in any cell type, including fertilized oocytes.

CRISMERE Chromosome Engineering in Mouse and Rat

CRISPR/Cas9 technology is a versatile tool for engineering biology that has dramatically transformed our ability to manipulate genomes. In this protocol, we use its capacity to generate two double-strand breaks simultaneously, at precise positions in the genome, to generate mouse or rat lines with deletion, inversion, and duplication of a specific genomic segment. The technic is called CRISMERE for CRISpr-MEdiated REarrangement. This protocol describes the different steps to generate and validate the different chromosomal rearrangements that can be obtained with the technology. These new genetic configurations can be useful to model rare diseases with copy number variation, understand the genomic organization, or provide genetic tools (like balancer chromosome) to keep lethal mutations.

AB0952 Characterization of patients with psoriatic arthritis in dermatologic and rheumatologic care: an analysis of two disease registries

Background

Psoriatic arthritis (PsA) is a chronic inflammatory disease affecting the musculoskeletal system, skin and nails. Therapeutic management in Germany is usually provided by a dermatologist or rheumatologist.

Objectives

The aim is to characterize the socioeconomic and clinical patient profiles in dermatologic and rheumatologic settings.

Methods

Baseline data of patients with PsA from [1] the dermatological German Psoriasis Registry PsoBest (PB) and [2] the rheumatological German disease register RABBIT-SpA (RS) [2] were analyzed. For this purpose, comparable anamnestic and clinical variables collected in the period 10/2017 to 12/2020 were identified and descriptively analyzed. The analysis was carried out in each of the data-holding registers.

Results

1066 RS patients and 704 PB patients were included in the analysis (Table 1). The proportion of women was higher in the rheumatology setting (RS) (60% vs. 49%). Disease duration of psoriasis was longer in the dermatology setting (PB). Cutaneous severity was higher in PB, including affected body surface area and nail psoriasis. However, more patients in RS had tender joints and swollen joints. The physician-reported global disease activity was higher in RS. The mean DLQI (Dermatology Life Quality Index) was higher in PB and the mean HAQ (Health Assessment Questionnaire) was higher in RS. Patient reported global disease activity and pain were lower in PB.

Table 1.

Baseline data of patients with PsA from the registers PsoBest and RABBIT-SpA included 10/2017 to 12/2020.

RABBIT-SpA(Rheumatology setting)PsoBest(Dermatology setting)N1066704Age, mean (SD)51.9 (12.2)51.7 (13.2)Female, n (%)637 (60)346 (49)Disease duration skin, mean (SD)14.3 (13.9)21.6 (16.0)Body surface area, mean (SD)8.5 (15.0)20.8 (19.8)Nail psoriasis, n (%)434 (41)407 (58)Tender joints, n (%)905 (85)498 (71)Swollen joints, n (%)708 (67)387 (55)Physician reported disease activity, mean (SD)5.2 (1.9)4.6 (2.7)DLQI, mean (SD)5.6 (6.2)12.2 (7.6)HAQ, mean (SD)0.9 (0.7)0.7 (0.6)Patient reported disease activity, mean (SD)5.7 (2.4)4.9 (2.9)Patient reported pain, mean (SD)5.5 (2.4)5.2 (2.8)bDMARD, n (%)751 (71)514 (73)TNF, n (%)346 (46)117 (23)IL17, n (%)351 (47)246 (48)IL23, n (%)54 (7)151 (29)tsDMARD, n (%)109 (10)47 (7)csDMARD, n (%)195 (18)142 (20)

Most of the patients received biologics at inclusion (RS: 71% and PB: 73%). In the dermatology setting IL23 inhibitors were used more frequently, whereas TNF inhibitors were used more frequently in the rheumatology setting.

Conclusion

The clinical specialization of the treating physician was associated with a different treatment and clinical status of patients with PsA. Our analysis showed that patients in the rheumatology setting more frequently had joint affections and lower functional status, whereas skin severity was worse in the dermatology setting, indicating selection effects of health care access. We hypothesize out that these differences may be biased due to different diagnostic and therapeutic routines in the specialized health care settings. Psoriatic arthritis should be treated in a multidisciplinary approach to take into account all facets of this complex disease.

References

[1]PMID: 24393314

[2]PMID: 30874933

Disclosure of Interests

Lisa Lindner Grant/research support from: RABBIT-SpA is supported by a joint, unconditional grant from AbbVie, Amgen, Biogen, Hexal, Janssen-Cilag, Lilly, MSD, Novartis, Pfizer, UCB and Viatris., Matthias Augustin Grant/research support from: The PsoBest registry is/was supported by AbbVie, Almirall Hermal, Amgen, Biogen, BMS, Celgene, Hexal, Janssen-Cilag, LEO Pharma, Eli Lilly, Medac, Novartis, Pfizer, UCB and Viatris. These companies do not have influence on the design of the registry, data collection, analyses, the publication decisions or development., Laura Kühl Grant/research support from: The PsoBest registry is/was supported by AbbVie, Almirall Hermal, Amgen, Biogen, BMS, Celgene, Hexal, Janssen-Cilag, LEO Pharma, Eli Lilly, Medac, Novartis, Pfizer, UCB and Viatris. These companies do not have influence on the design of the registry, data collection, analyses, the publication decisions or development., Anja Weiß Grant/research support from: RABBIT-SpA is supported by a joint, unconditional grant from AbbVie, Amgen, Biogen, Hexal, Janssen-Cilag, Lilly, MSD, Novartis, Pfizer, UCB and Viatris., Stephan Jeff Rustenbach Grant/research support from: The PsoBest registry is/was supported by AbbVie, Almirall Hermal, Amgen, Biogen, BMS, Celgene, Hexal, Janssen-Cilag, LEO Pharma, Eli Lilly, Medac, Novartis, Pfizer, UCB and Viatris. These companies do not have influence on the design of the registry, data collection, analyses, the publication decisions or development., Frank Behrens: None declared, Martin Feuchtenberger: None declared, Ilka Schwarze: None declared, Ulrich Mrowietz: None declared, Diamant Thaçi: None declared, Kristian Reich Grant/research support from: The PsoBest registry is/was supported by AbbVie, Almirall Hermal, Amgen, Biogen, BMS, Celgene, Hexal, Janssen-Cilag, LEO Pharma, Eli Lilly, Medac, Novartis, Pfizer, UCB and Viatris. These companies do not have influence on the design of the registry, data collection, analyses, the publication decisions or development., Anja Strangfeld Grant/research support from: RABBIT-SpA is supported by a joint, unconditional grant from AbbVie, Amgen, Biogen, Hexal, Janssen-Cilag, Lilly, MSD, Novartis, Pfizer, UCB and Viatris., Anne Regierer Grant/research support from: RABBIT-SpA is supported by a joint, unconditional grant from AbbVie, Amgen, Biogen, Hexal, Janssen-Cilag, Lilly, MSD, Novartis, Pfizer, UCB and Viatris.

Droplet digital PCR or quantitative PCR for in-depth genomic and functional validation of genetically altered rodents

Gene targeting and additive (random) transgenesis have proven to be powerful technologies with which to decipher the mammalian genome. With the advent of CRISPR/Cas9 genome editing, the ability to inactivate or modify the function of a gene has become even more accessible. However, the impact of each generated modification may be different from what was initially desired. Minimal validation of mutant alleles from genetically altered (GA) rodents remains essential to guarantee the interpretation of experimental results. The protocol described here combines design strategies for genomic and functional validation of genetically modified alleles with droplet digital PCR (ddPCR) or quantitative PCR (qPCR) for target DNA or mRNA quantification. In-depth analysis of the results obtained with GA models through the analysis of target DNA and mRNA quantification is also provided, to evaluate which pitfalls can be detected using these two methods, and we propose recommendations for the characterization of different type of mutant allele (knock-out, knock-in, conditional knock-out, FLEx, IKMC model or transgenic). Our results also highlight the possibility that mRNA expression of any mutated allele can be different from what might be expected in theory or according to common assumptions. For example, mRNA analyses on knock-out lines showed that nonsense-mediated mRNA decay is generally not achieved with a critical-exon approach. Likewise, comparison of multiple conditional lines crossed with the same CreER^T2 deleter showed that the inactivation outcome was very different for each conditional model. DNA quantification by ddPCR of G0 to G2 generations of transgenic rodents generated by pronuclear injection showed an unexpected variability, demonstrating that G1 generation rodents cannot be considered as established lines.

Reliable and robust droplet digital PCR (ddPCR) and RT-ddPCR protocols for mouse studies

Droplet digital PCR (ddPCR) is a recent method developed for the quantification of nucleic acids sequences. It is an evolution of PCR methodology incorporating two principal differences: a PCR reaction is performed in thousands of water-oil emulsion droplets and fluorescence is measured at the end of PCR amplification. It leads to the precise and reproducible quantification of DNA and RNA sequences. Here, we present quantitative methods for DNA and RNA analysis using Bio-Rad QX100 or QX200 systems, respectively. The aim of these methods is to provide useful molecular tools for validating genetically altered animal models such as those subject to CRISPR/Cas9 genome editing, as well for expression or CNV studies. A standard procedure for simultaneous DNA and RNA extraction adapted for mouse organs is also described. These methods were initially designed for mouse studies but also work for samples from other species like rat or human. In our lab, thousands of samples and hundreds of target genes from genetically altered lines were examined using these methods. This large dataset was analyzed to evaluate technical optimizations and limitations. Finally, we propose additional recommendations to be included in dMIQE (Minimum information for publication of quantitative digital PCR experiments) guidelines when using ddPCR instruments.

Elevated 80K-H Protein in Breast Cancer: A Role for FGF-1 Stimulation of 80K-H

An increase in fibroblast growth factor-1 (FGF-1) is established as part of the cause of several important cancers including breast cancer, but the mechanisms by which it induces malignant behavior are not known. We now report that the protein 80K-H, a substrate for PKC, appears to be part of this mechanism and that it is increased in breast cancer and localizes to the nucleus as part of the mechanism. Our conclusion is based on an examination of a total of 58 biopsy specimens from human breast cancer patients for the presence of relationships between the 80K-H protein and the following: fibroblast growth factor receptor-1 (FGFR-1), tumor grade, microvessel counts (MVC), estrogen receptor (ER) and progesterone receptor (PgR) status. Based on histological grading and immunohistochemical (IHC) assays, we found strong direct relationships between 80K-H and FGFR-1 (r=0.49, p=0.003) and tumor grade (r=0.42, p=0.006). A trend for a direct relationship was observed with PgR (r=0.27, p=0.087). Notably, 80K-H immunostaining was largely limited to the epithelial cells of the mammary ducts.

Subsequently, we studied the effects of FGF-1 on 80K-H in cultured human mammary carcinoma epithelial cells in order to establish a more direct relationship between these two molecules. We observed that FGF-1 treatment of MCF-7 cells stimulated translocation of 80K-H protein to the cell nucleus, as demonstrated by subcellular fractionation studies. Maximal intranuclear 80K-H was observed approximately 30 minutes following FGF-1 treatment. In addition, FGF-1 treatment of MCF-7 cells increased growth and invasion of MCF-7 cells, as demonstrated by cell proliferation and a modified Boyden chamber assay, respectively. Further support for 80K-H nuclearization was provided by the immunostaining of human breast cancer specimens and computer-assisted identification of a putative nuclear localization signal (NLS) near the amino terminus of 80K-H protein structure.

These data support the existence of a previously unrecognized FGF-1/80K-H nuclear pathway in progression of human breast cancer and suggest that 80K-H may be useful for the assessment of breast tumor progression.

Aneuploidy screening of embryonic stem cell clones by metaphase karyotyping and droplet digital polymerase chain reaction

BACKGROUND

Karyotypic integrity is essential for the successful germline transmission of alleles mutated in embryonic stem (ES) cells. Classical methods for the identification of aneuploidy involve cytological analyses that are both time consuming and require rare expertise to identify mouse chromosomes.

RESULTS

As part of the International Mouse Phenotyping Consortium, we gathered data from over 1,500 ES cell clones and found that the germline transmission (GLT) efficiency of clones is compromised when over 50 % of cells harbour chromosome number abnormalities. In JM8 cells, chromosomes 1, 8, 11 or Y displayed copy number variation most frequently, whilst the remainder generally remain unchanged. We developed protocols employing droplet digital polymerase chain reaction (ddPCR) to accurately quantify the copy number of these four chromosomes, allowing efficient triage of ES clones prior to microinjection. We verified that assessments of aneuploidy, and thus decisions regarding the suitability of clones for microinjection, were concordant between classical cytological and ddPCR-based methods. Finally, we improved the method to include assay multiplexing so that two unstable chromosomes are counted simultaneously (and independently) in one reaction, to enhance throughput and further reduce the cost.

CONCLUSION

We validated a PCR-based method as an alternative to classical karyotype analysis. This technique enables laboratories that are non-specialist, or work with large numbers of clones, to precisely screen ES cells for the most common aneuploidies prior to microinjection to ensure the highest level of germline transmission potential. The application of this method allows early exclusion of aneuploid ES cell clones in the ES cell to mouse conversion process, thus improving the chances of obtaining germline transmission and reducing the number of animals used in failed microinjection attempts. This method can be applied to any other experiments that require accurate analysis of the genome for copy number variation (CNV).

[21-year-old patient with myocardial infarct, transient cerebral ischemia and thrombocytopenia]

We report on a case of a young female soccer player who first experienced a transient ischemic attack at the age of 21 and then suffered an acute myocardial infarction accompanied by thrombocytopenia 6 months later. The underlying cause was antiphospholipid syndrome. This clinical picture is caused by a very heterogeneous group of antiphospholipid antibodies, which interfere with plasmatic coagulation at various sites and are able to activate thrombocytes, endothelial cells, and monocytes. This leads to a thrombophilic condition with clinical manifestation of recurrent venous thromboses, arterial embolisms, or premature birth or miscarriage. The main therapeutic options are thus anticoagulation, heparins, and aspirin. Steroids are recommended for cases of pronounced thrombocytopenias; if treatment fails, immunosuppressants are also advisable. The antiphospholipid syndrome should be kept in mind especially in cases of young patients with thromboembolic events since the presence of antiphospholipid antibodies can be detected in 10-20% of this patient group and effective therapy after diagnosis lowers the rate of recurrence.

Test of a Model to Assess the Condition of Lodgepole Pine Stands

/ A predictive model for assessing stand condition as a function of suitability for achieving specified management objectives was originally developed using a data set for only 28 stands. In this study, we evaluate the model using an operational-sized data set composed of currently collected stand inventory data for 238 stands in the Snowy Range of the Medicine Bow National Forest in southern Wyoming. We compared its predictions of old growth suitability to results of a separate special old growth survey. Stands were characterized as profiles of variables derived from stand inventory data, and plotted as points in two-dimensional space where similarity between stands was reflected by the distance between their points. Results suggest the model is useful for classifying stand condition using relatively large sets of data currently collected during routine stand inventories.

[Long term biokinetics of 169Yb following injection as citrate, hydroxyethylethylenediaminetetraacetate and nitrilotriacetate]

169Yb complexes with known biokinetics in tumour-bearing mice up to 48 h p.i. were injected into healthy mice to study the radionuclide biodistribution in various organs and tissues for 672 h after injection, in order to obtain reliable biokinetic data in an animal model, not affected by tumour-growth, as a basis for the calculation of biological half-life and dose distribution. The results demonstrated the existence of at least two components with different biological half-lives in the organs and tissues investigated. The effective half-lives of these components decreased with increasing stability of the complexes administered. The effective half-life of the fast component was a few hours and that of the slow one between about 200 and 800 h.

[The effect of bone-seeking metal salts on the biodistribution of tumor-seeking heavy metal complexes]

This work attempted to overcome the problem of unwanted bone radioactivity after injection of tumour-affine heavy-metal compounds (prototype 169Yb-citrate) by pre-application of stable yttrium- and calcium-compounds into tumour-bearing mice in doses of 1 mg metal/kg body weight. The pre-application of stable yttrium and calcium resulted in a smaller bone radioactivity. The most favourable results were achieved by injecting the metal salts simultaneously at or within 5 h before the 169Yb-citrate. On the other hand a strong radioactivity increase in the RES (liver and spleen) by a factor of 2 to 4 was observed after yttrium-preapplication.

Langzeitbiokinetik des 169Yb nach Injektion als Zitrat, Hydroxyethylethylen- diamintetraazetat und Nitrilotriazetat

169Yb-Komplexe mit bekannter Biokinetik in tumortragenden Mäusen bis zu 48 h nach Injektion wurden gesunden Mäusen intravenös injiziert und die Bioverteilung in Organen und Geweben bis zu 672 h nach Injektion untersucht. Durch diese Langzeituntersuchungen in einem durch Tumorwachstum unbeeinflußten Tiermodell sollten zuverlässige biokinetische Daten als Basis für Berechnungen der biologischen Halbwertszeit und der Dosisverteilung in verschiedenen Organen und Geweben erhalten werden. Die Ergebnisse der Radionuklidelimination aus Organen und Geweben bzw. der -exkretion mit dem Urin zeigten, daß mindestens zwei Komponenten vorliegen, deren effektive Halbwertszeiten mit zunehmender Stabilität der verabreichten Komplexe kürzer werden. Sie liegen für die »schnelle« Komponente bei wenigen Stunden und für die »langsame« Komponente zwischen 200 und 800 h.

Der Einfluß von knochenaffinen Metallsalzen auf die Bioverteilung tumoraffiner Schwermetallkomplexe

Diese Arbeit versucht, das Problem der unerwünschten Knochenradioaktivität nach Injektion tumoraffiner, radioaktiver Schwermetallverbindungen (Prototyp: 169Yb-Zitrat) durch Prämedikation mit stabilen Yttrium-oder Kalziumverbindungen in tumortragenden Mäusen in Dosen von 1 mg/kg Körpergewicht zu überwinden. Die Prämedikation mit stabilem Yttrium oder Kalzium resultiert in geringeren Knochenradioaktivitäten. Die besten Ergebnisse wurden erreicht, wenn die Metallsalze gleichzeitig oder bis 5 h vor 169Yb-Zitrat injiziert wurden. Andererseits wurde eine starke Radioaktivitätserhöhung um den Faktor 2-4 im RES (Leber, Milz) nach Prämedikation mit Yttrium beobachtet.

Rhizosphere Acidification by Iron Deficient Bean Plants: The Role of Trace Amounts of Divalent Metal Ions: A Study on Roots of Intact Plants with the Use of C- and P-NMR

Rhizosphere acidification by Fe-deficient bean (Phaseolus vulgaris L.) plants was induced by trace amounts of divalent metal ions (Zn, Mn). The induction of this Fe-efficiency reaction was studied by (14)CO(2) and (11)CO(2) fixation experiments, and with (31)P-NMR on roots of whole plants. The starting and ending of an acidification cycle was closely coupled to parallel changes in CO(2) fixation, within the maximal resolution capacity of 20 min. (31)P-NMR experiments on intact root systems showed one peak which was ascribed to vacuolar free phosphate. At the onset of proton extrusion this peak shifted, indicating increase of pH in the cells. Proton extrusion was inhibited, with a lag period of 2 hours, by the protein synthesis inhibitors cycloheximide and hygromycin. It is assumed that Zn and Mn induce proton extrusion in Fe-deficient bean roots by activating the synthesis of a short-living polypeptide; the NMR data suggest a role for this peptide in the functioning of a proton pumping ATPase in the plasma membrane.

An investigation on lipoperoxidation mechanisms in boar spermatozoa

Aerobic incubation of washed boar spermatozoa in a heavy metal free medium at 37 degrees C results in a peroxidative breakdown of membrane phospholipids as revealed by malondialdehyde production. In the presence of iron ions, alone and with ascorbate, the amount of malondialdehyde produced increases noticeably. Alkoxy and lipoperoxy radicals are likely involved in these peroxidative processes, while OH. radical does not seem to be essential in the pathway of malondialdehyde formation.

Supramolecular organization of lysophosphatidylcholine-packaged Gramicidin A

Heat derived gramicidin A'/L-alpha-lysophosphatidylcholine complexes were separated on a sucrose gradient to form two fractions: Fraction A which had an approximately constant Gramicidin A' to phospholipid ratio of 8 to 10 lipid molecules per Gramicidin A' molecule and Fraction B which had a larger but variable ratio. Fluorescence and circular dichroism studies confirmed Fraction A to be a lipid-incorporated channel state. Electron microscopic studies, using uranyl acetate negative staining, showed fraction A to be a membranous state with the formation of bilayer vesicles, that is, the interaction of peptide and phospholipid micelles causes the lipid to reorganize into a bilayer structure. Freeze-fracture replicas of the channel incorporated state demonstrated the presence of a supramolecular organization of particles exhibiting a tendency to form rows with a 50-60 A periodicity along the row and with 70-80 A distance between rows. An idealized working model for the incorporated state is presented.

Antioxidant activity of bull semen in relation with aging

This paper reports on the findings of an antioxidant activity in whole semen from bull and its components, washed spermatozoa and seminal fluid. The antioxidant activity has been evaluated as the ability of semen or its components to inhibit the spontaneous autooxidation of epinephrine a pH 10, 2, which involves the production of superoxide radicals (0(2)). This preliminary study provides further evidence on the role of free radicals, which are well known to be dangerous to cellular life, and points to the need of a better understanding of the role of antioxidant activities as a cellular protective mechanism.

Intermolecular interactions of gramicidin A' transmembrane channels incorporated into lysophosphatidylcholine lipid systems

Fluorescence studies are reported on gramicidin A' incorporated into lysophosphatidylcholine phospholipid structures. The shift in the emission maximum during incorporation and the quenching of fluorescence by I- and by acrylamide of the incorporated state obtained after prolonged heating are consistent with the presence of the channel state comprised of two single-stranded beta 6 -helices associated head-to-head (formyl end-to-formyl end). The quantum yield for the incorporated state, when gramicidin A' is within the lipid matrix, is very low and indicates the occurrence of intermolecular Trp-Trp interactions. Possible interactions between channels within the lipid matrix are discussed utilizing Trp-Trp contacts.