The Use of Trichostatin A to Rescue TRKA+ Neurons in a Mouse Model of Familial Dysautonomia

Familial dysautonomia is a severe, recessive disease that devastates the peripheral nervous system, culminating in death of most patients by age 40. Studies have shown that there is a reduced number of both TrkA+ neurons and acetylation in familial dysautonomia patients and our mouse model of familial dysautonomia. Another feature of familial dysautonomia is a decrease in histone acetylation. This study evaluated the ability of the histone deacetylase inhibitor, Trichostatin A, to rescue the reduced number of TrkA+ neurons in the dorsal root ganglia in our mouse model of familial dysautonomia. Pregnant dams were treated with either 1mg/kg of Trichostatin A (experimental) or vehicle alone (control), at E8.5, E10.5, and E12.5, a time frame corresponding to neurogenesis in the mouse dorsal root ganglia.  Immunohistochemistry was used to quantify the number of TrkA+ neurons at E17.5. Trichostatin A-treated knockout embryos (n=3) showed a significant increase in the number of TrkA+ neurons over vehicle only knockout embryos (n=3) (132.9% increase; p<.00001).  Trichostatin A (1mg/kg) effectively rescues the number of TrkA+ neurons in our mouse model.  Further studies will explore the cellular mechanisms via which histone deacetylase inhibition prevents neuronal cell death as well as the possible benefits of using these therapeutics for familial dysautonomia symptom management

Elongator Function in the Anterior Pituitary and Its Relevance to Familial Dysautonomia

Familial Dysautonomia (FD) is a devastating neurodegenerative childhood disease characterized by a diminished number of autonomic neurons. FD children suffer from a multitude of autonomic symptoms including cardiovascular instability, gastrointestinal incoordination, and respiratory dysfunction. FD patients also exhibit an abnormal autonomic stress response, show poor growth velocity, and have difficulty gaining and maintaining weight. Treatment with growth hormone (GH) has been shown to increase growth velocity in FD patients. FD results from a mutation in the IKBKAP gene and diminished levels of the corresponding protein IKAP, a scaffolding protein that assembles a multi-subunit complex called Elongator. Elongator functions in the modification of tRNAs that mediate translation of AA- and AG-ending codons including lysine, glutamine, and glutamic acid. In the absence of Elongator, small AG biased genes are upregulated and large AA-biased genes are downregulated. IKAP is expressed throughout the autonomic nervous system and historically FD has been considered a strictly neurological disease. Here we show that IKAP is robustly expressed in the pituitary gland, indicating a strong dependence on Elongator. We hypothesize that compromised growth in FD may actually result from dysfunction of somatotrophs in the anterior pituitary, a non-neuronal cell type. To test this hypothesis, we generated a conditional knockout (CKO) mouse where Ikbkap is selectively ablated in anterior pituitary somatotrophs. These CKO mice exhibit decreased growth compared to control littermates. Surprisingly, quantitative immunohistochemistry indicates that GH1 levels may actually be increased in the CKO pituitary. CaBP7, a calcium binding protein that negatively regulates vesicle trafficking, is also found at elevated levels in the CKO, likely because of its strong AG-bias. In combination, these results suggest that upregulation of CaBP7 may inhibit GH1 exocytosis from pituitary cells, decreasing the amount of circulating GH1 and compromising growth in FD patients

Effects of Dopamine Beta Hydroxylase Levels in a Mouse Model of FD

Familial dysautonomia is a severe, recessive disease that devastates the peripheral nervous system, culminating in death of most patients by age 40. The most debilitating feature of familial dysautonomia is the severe autonomic crises that occur. These crises, which can sometimes last for days, cause extreme vomiting and nausea, among other symptoms. The crises have been shown to coincide with an increased level of circulating dopamine following stress. The current hypothesis suggests that elevated levels of tyrosine hydroxylase cause an overproduction of dopamine. The chromaffin cells cannot convert this dopamine into norepinephrine quickly enough; therefore, this dopamine is released into the blood stream. We propose an alternate hypothesis in which the levels of dopamine beta hydroxylase are instead reduced. Reduction of dopamine beta hydroxylase, the enzyme that converts dopamine to norepinephrine, would result in a larger amount of dopamine being released from chromaffin cells during the response to stress. This reduction in enzyme levels is also seen in dopamine beta hydroxylase deficiency, a disease that shares many of the same symptoms of familial dysautonomia. In support of this hypothesis, we have shown through quantitative RT-PCR that dopamine beta hydroxylase transcript levels are decreased in Wnt1-Cre; IkbkapLoxP/ LoxP conditional knockout (CKO) embryos in which Ikbkap is ablated in the adrenal gland. Further analysis of the CKO using immunohistochemistry indicates that DBH protein levels may also be diminished as well as mis-localized within the cell

Early detection of duodenal cancer by upper gastrointestinal-endoscopy in Lynch syndrome

Small bowel cancer (SBC) is the malignancy with the highest standardized incidence ratio in Lynch syndrome (LS) patients. Of all SBCs, about 50% are duodenal cancers (DCs), therefore being accessible by esophago-gastro-duodenoscopy (EGD) for surveillance. We asked whether early detection of DC is possible for LS patients undergoing surveillance by EGD and if surveillance should be limited to specific subgroups. Data for LS patients with DC were retrieved from the registry of the German Consortium for Familial Intestinal Cancer. Patients undergoing active surveillance by EGDs (surveillance group) were compared to those who did not (nonsurveillance group) regarding tumor stage at diagnosis. Union for International Cancer Control stages I-IIA were defined as early stage disease and IIB-IV as advanced stage disease. Statistical analysis was performed using Fisher's exact test. Among 2015 patients with pathogenic variants in any mismatch-repair-gene, 47 patients with 49 DCs were identified. In 10% of cases, patients were under 35 years at diagnosis; family and personal tumor history did not correlate with DC diagnosis. Pathogenic germline variants in MSH6, PMS2 or EPCAM were present in 10% of patients. Statistical analysis could be performed on 13 DC patients in the surveillance group and 14 in the nonsurveillance group. Early detection was possible for 71% of patients in the surveillance group and 29% of patients in the nonsurveillance group (P = .021). Early detection of DC by EGD in LS patients is feasible regardless of family history, mutational status and should start no later than 25 years of age

The next generation of training for arabidopsis researchers: Bioinformatics and Quantitative Biology

It has been more than 50 years since Arabidopsis (Arabidopsis thaliana) was first introduced as a model organism to understand basic processes in plant biology. A well-organized scientific community has used this small reference plant species to make numerous fundamental plant biology discoveries (Provart et al., 2016). Due to an extremely well-annotated genome and advances in high-throughput sequencing, our understanding of this organism and other plant species has become even more intricate and complex. Computational resources, including CyVerse,3 Araport,4 The Arabidopsis Information Resource (TAIR),5 and BAR,6 have further facilitated novel findings with just the click of a mouse. As we move toward understanding biological systems, Arabidopsis researchers will need to use more quantitative and computational approaches to extract novel biological findings from these data. Here, we discuss guidelines, skill sets, and core competencies that should be considered when developing curricula or training undergraduate or graduate students, postdoctoral researchers, and faculty. A selected case study provides more specificity as to the concrete issues plant biologists face and how best to address such challenges

Kommunale Energieversorgung - Ausweg aus der Klimakatastrophe?

SIGLEAvailable from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Early detection of duodenal cancer by upper gastrointestinal-endoscopy in Lynch syndrome

Small bowel cancer (SBC) is the malignancy with the highest standardized incidence ratio in Lynch syndrome (LS) patients. Of all SBCs, about 50% are duodenal cancers (DCs), therefore being accessible by esophago-gastro-duodenoscopy (EGD) for surveillance. We asked whether early detection of DC is possible for LS patients undergoing surveillance by EGD and if surveillance should be limited to specific subgroups. Data for LS patients with DC were retrieved from the registry of the German Consortium for Familial Intestinal Cancer. Patients undergoing active surveillance by EGDs (surveillance group) were compared to those who did not (nonsurveillance group) regarding tumor stage at diagnosis. Union for International Cancer Control stages I-IIA were defined as early stage disease and IIB-IV as advanced stage disease. Statistical analysis was performed using Fisher's exact test. Among 2015 patients with pathogenic variants in any mismatch-repair-gene, 47 patients with 49 DCs were identified. In 10% of cases, patients were under 35 years at diagnosis; family and personal tumor history did not correlate with DC diagnosis. Pathogenic germline variants in MSH6, PMS2 or EPCAM were present in 10% of patients. Statistical analysis could be performed on 13 DC patients in the surveillance group and 14 in the nonsurveillance group. Early detection was possible for 71% of patients in the surveillance group and 29% of patients in the nonsurveillance group (P = .021). Early detection of DC by EGD in LS patients is feasible regardless of family history, mutational status and should start no later than 25 years of age