Blimp-1/PRDM1 and Hr3/RORß specify the blue-sensitive photoreceptor subtype in Drosophila by repressing the hippo pathway.

During terminal differentiation of the mammalian retina, transcription factors control binary cell fate decisions that generate functionally distinct subtypes of photoreceptor neurons. For instance, Otx2 and RORß activate the expression of the transcriptional repressor Blimp-1/PRDM1 that represses bipolar interneuron fate and promotes rod photoreceptor fate. Moreover, Otx2 and Crx promote expression of the nuclear receptor Nrl that promotes rod photoreceptor fate and represses cone photoreceptor fate. Mutations in these four transcription factors cause severe eye diseases such as retinitis pigmentosa. Here, we show that a post-mitotic binary fate decision in Drosophila color photoreceptor subtype specification requires ecdysone signaling and involves orthologs of these transcription factors: Drosophila Blimp-1/PRDM1 and Hr3/RORß promote blue-sensitive (Rh5) photoreceptor fate and repress green-sensitive (Rh6) photoreceptor fate through the transcriptional repression of warts/LATS, the nexus of the phylogenetically conserved Hippo tumor suppressor pathway. Moreover, we identify a novel interaction between Blimp-1 and warts, whereby Blimp-1 represses a warts intronic enhancer in blue-sensitive photoreceptors and thereby gives rise to specific expression of warts in green-sensitive photoreceptors. Together, these results reveal that conserved transcriptional regulators play key roles in terminal cell fate decisions in both the Drosophila and the mammalian retina, and the mechanistic insights further deepen our understanding of how Hippo pathway signaling is repurposed to control photoreceptor fates for Drosophila color vision.

Feasibility of tele-guided patient-administered lung ultrasound in heart failure.

BACKGROUND: Readmission rates for heart failure remain high, and affordable technology for early detection of heart failure decompensation in the home environment is needed. Lung ultrasound has been shown to be a sensitive tool to detect pulmonary congestion due to heart failure, and monitoring patients in their home environment with lung ultrasound could help to prevent hospital admissions. The aim of this project was to investigate whether patient-performed tele-guided ultrasound in the home environment using an ultraportable device is feasible.Affiliations: Journal instruction requires a country for affiliations; however, these are missing in affiliations [1, 2]. Please verify if the provided country are correct and amend if necessary.Correct METHODS: Stable ambulatory patients with heart failure received a handheld ultrasound probe connected to a smart phone or tablet. Instructions for setup were given in person during a clinic visit or over the phone. During each ultrasound session, patients obtained six ultrasound clips from the anterior and lateral chest with verbal and visual tele-guidance from an ultrasound trained clinician. Patients also reported their weight and degree of dyspnea, graded on a 5-point scale. Two independent reviewers graded the ultrasound clips based on the visibility of the pleural line and A or B lines. RESULTS: Eight stable heart failure patients each performed 10-12 lung ultrasound examinations at home under remote guidance within a 1-month period. There were no major technical difficulties. A total of 89 ultrasound sessions resulted in 534 clips of which 88% (reviewer 1) and 84% (reviewer 2) were interpretable. 91% of ultrasound sessions produced interpretable clips bilaterally from the lateral chest area, which is most sensitive for the detection of pulmonary congestion. The average time to complete an ultrasound session was 5 min with even shorter recording times for the last session. All patients were clinically stable during the study period and no false positive B-lines were observed. CONCLUSIONS: In this feasibility study, patients were able to produce interpretable lung ultrasound exams in more than 90% of remotely supervised sessions in their home environment. Larger studies are needed to determine whether remotely guided lung ultrasound could be useful to detect heart failure decompensation early in the home environment.

Initial clinical and hemodynamic results of a regional pulmonary thromboendarterectomy program.

BACKGROUND: Pulmonary thromboendarterectomy (PTE) is the treatment of choice for eligible patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, access to CTEPH and PTE care is limited. There is a paucity of published data on PTE efficacy and outcomes from alternative, regional centers of excellence in CTEPH and PTE care in the USA, outside a single national and international referral center. METHODS: We performed a retrospective review of patients undergoing PTE at our institution from June 2013 to December 2016 (42 months), and collected clinical, echocardiographic and hemodynamic data on our patients pre- and post-PTE (N.=71). RESULTS: Patients age ranged between 20-83 years (mean±SD: 56±16), with 54% of patients female and 61% Caucasians. The predominant symptom was shortness of breath with a median duration of symptoms of 17 months. Following PTE, clinical improvements included a reduction in NYHA class from 3.1±1.1 to 2.2±1.2. There were major improvements in hemodynamics and echocardiographic parameters pre- versus post-PTE: mean pulmonary artery pressure (mmHg) 45±11 to 24±8, cardiac index (L/min/m2) 2.1±0.5 to 2.8±0.5, pulmonary vascular resistance (mmHg/L/min) 8.9±4.5 to 2.8±1.8, ratio of right ventricle (RV): left ventricle (LV) 1.2±0.3 to 0.9±0.2, RV fractional area change (%) 23±14 to 44±13, reduction in the incidence of RV outflow tract Doppler notching and improved pulmonary artery acceleration time (96% to 30%, and 74±19 to 111±21). In-hospital mortality was 4.2% (3 patients). CONCLUSIONS: Herein, we report for the first time, the improvements in patient functionality, hemodynamics, right heart function and outcomes at a major regional PTE program.

Single-base pair differences in a shared motif determine differential Rhodopsin expression.

The final identity and functional properties of a neuron are specified by terminal differentiation genes, which are controlled by specific motifs in compact regulatory regions. To determine how these sequences integrate inputs from transcription factors that specify cell types, we compared the regulatory mechanism of Drosophila Rhodopsin genes that are expressed in subsets of photoreceptors to that of phototransduction genes that are expressed broadly, in all photoreceptors. Both sets of genes share an 11-base pair (bp) activator motif. Broadly expressed genes contain a palindromic version that mediates expression in all photoreceptors. In contrast, each Rhodopsin exhibits characteristic single-bp substitutions that break the symmetry of the palindrome and generate activator or repressor motifs critical for restricting expression to photoreceptor subsets. Sensory neuron subtypes can therefore evolve through single-bp changes in short regulatory motifs, allowing the discrimination of a wide spectrum of stimuli.