Coordination of cell cycle and morphogenesis during organ formation.

Organ formation requires precise regulation of cell cycle and morphogenetic events. Using the Drosophila embryonic salivary gland (SG) as a model, we uncover the role of the SP1/KLF transcription factor Huckebein (Hkb) in coordinating cell cycle regulation and morphogenesis. The hkb mutant SG exhibits defects in invagination positioning and organ size due to the abnormal death of SG cells. Normal SG development involves distal-to-proximal progression of endoreplication (endocycle), whereas hkb mutant SG cells undergo abnormal cell division, leading to cell death. Hkb represses the expression of key cell cycle and pro-apoptotic genes in the SG. Knockdown of cyclin E or cyclin-dependent kinase 1, or overexpression of fizzy-related rescues most of the morphogenetic defects observed in the hkb mutant SG. These results indicate that Hkb plays a critical role in controlling endoreplication by regulating the transcription of key cell cycle effectors to ensure proper organ formation.

Multifunctional role of GPCR signaling in epithelial tube formation.

Epithelial tube formation requires Rho1-dependent actomyosin contractility to generate the cellular forces that drive cell shape changes and rearrangement. Rho1 signaling is activated by G-protein-coupled receptor (GPCR) signaling at the cell surface. During Drosophila embryonic salivary gland (SG) invagination, the GPCR ligand Folded gastrulation (Fog) activates Rho1 signaling to drive apical constriction. The SG receptor that transduces the Fog signal into Rho1-dependent myosin activation has not been identified. Here, we reveal that the Smog GPCR transduces Fog signal to regulate Rho kinase accumulation and myosin activation in the medioapical region of cells to control apical constriction during SG invagination. We also report on unexpected Fog-independent roles for Smog in maintaining epithelial integrity and organizing cortical actin. Our data support a model wherein Smog regulates distinct myosin pools and actin cytoskeleton in a ligand-dependent manner during epithelial tube formation.

Tctp regulates the level and localization of Foxo for cell growth in Drosophila.

Regulation of cell size is crucial for organ development. Insulin signaling regulates organ size by antagonizing the subgroup O of forkhead box transcription factor (Foxo) through 14-3-3 in Drosophila. However, mechanisms for controlling the level and the nuclear localization of Foxo in developing organs are not well understood. Here, we investigate the role of Drosophila Translationally controlled tumor protein (Tctp) and its interacting partner 14-3-3 in Foxo regulation during organ development. Foxo overexpression in the developing eye disc results in growth inhibition. We show that Tctp overexpression antagonizes the Foxo effect by downregulating the Foxo level in the eye disc. Foxo overexpression or knockdown of Tctp in the larval salivary gland results in reduced gland size, mainly due to reduced cell size by defects in endoreplication. Whereas 14-3-3ζ knockdown has a negligible effect, knockdown of 14-3-3ε mimics the effect of Foxo overexpression or Tctp knockdown, suggesting an isoform-specific role of 14-3-3. Unlike nuclear enrichment of the endogenous Foxo in the salivary gland, overexpressed Foxo protein is largely distributed in the cytoplasm, and this mislocalization is restored by Tctp overexpression. Opposite to the effect of Tctp overexpression, Tctp knockdown increases cytoplasmic Foxo levels while decreasing nuclear Foxo levels. Together, our data suggest that Tctp and 14-3-3ε play critical roles in cell growth by reducing cytoplasmic Foxo levels. Knockdown of human TCTP also elevates the level of cytoplasmic FOXO1 in HeLa cells, suggesting that human TCTP may have a conserved role in downregulating FOXO in human cells.

Survey of current retinopathy of prematurity practices in China.

AIM: To understand retinopathy of prematurity (ROP) screening and treatment preferences among Chinese ophthalmologists. METHODS: A Chinese language survey was administered anonymously using WebQ (Catalyst, Seattle, WA, USA) among Chinese ROP screeners from December 2016 to January 2017. RESULTS: Among 70 ophthalmologists contacted, 65 responded (93%; 78% female, mean age 40y, 57% pediatric ophthalmologists and 25% retina specialists). Most used screening criteria of birth weight ≤2 kg (62%) with variation in cut-off gestational age (≤37wk, 34%; ≤34wk, 22%; ≤32wk, 31%). RetCam (Natus Medical Incorporated, Pleasanton, CA, USA) wide-field fundus photography assisted most screeners (72%) and was exclusively used by many (29%). Among 55 ophthalmologists treating ROP, anti-vascular endothelial growth factor (VEGF) was preferred over laser for both zone I (76% vs 24%) and zone II ROP (58% vs 42%). Retina specialists (P=0.004) and ophthalmologists with >3mo of training (P=0.03) were more likely to use anti-VEGF over laser for zone I ROP. Lack of laser training (8/20, 40%), access (6/20, 30%) and anesthesia (4/20, 20%) were common barriers to laser treatment. CONCLUSION: Chinese ROP screeners favor anti-VEGF injection and RetCam imaging for ROP management. A better understanding of ROP screening and treatment informs future research and education efforts in China.

Isoform-specific roles of the Drosophila filamin-type protein Jitterbug (Jbug) during development.

Filamins are highly conserved actin-crosslinking proteins that regulate organization of the actin cytoskeleton. As key components of versatile signaling scaffolds, filamins are implicated in developmental anomalies and cancer. Multiple isoforms of filamins exist, raising the possibility of distinct functions for each isoform during development and in disease. Here, we provide an initial characterization of jitterbug (jbug), which encodes one of the two filamin-type proteins in Drosophila. We generate Jbug antiserum that recognizes all of the spliced forms and reveals differential expression of different Jbug isoforms during development, and a significant maternal contribution of Jbug protein. To reveal the function of Jbug isoforms, we create new genetic tools, including a null allele that deletes all isoforms, hypomorphic alleles that affect only a subset, and UAS lines for Gal4-driven expression of the major isoforms. Using these tools, we demonstrate that Jbug is required for viability and that specific isoforms are required in the formation of actin-rich protrusions including thoracic bristles in adults and ventral denticles in the embryo. We also show that specific isoforms of Jbug show differential localization within epithelia and that maternal and zygotic loss of jbug disrupts Crumbs (Crb) localization in several epithelial cell types.

Monitoring Unfractionated Heparin in Adult Patients Undergoing Extracorporeal Membrane Oxygenation (ECMO): ACT, APTT, or ANTI-XA?

BACKGROUND: During ECMO, anticoagulants, in particular, unfractionated heparin (UFH), are commonly used and monitored by laboratory tests, including ACT, APTT, and anti-Xa level. METHOD: A single-center retrospective observational study was conducted on adult patients undergoing ECMO between January 2019 and January 2020 at a tertiary hospital. The correlations between ACT, APTT, anti-Xa, antithrombin, and UFH dose were assessed. RESULTS: 129 sets of measurements from 37 patients were obtained including ACT, APTT, anti-Xa, antithrombin, and UFH dose measured simultaneously. 102 out of 129 sets of values were interpreted as antithrombin deficiencies. The correlation coefficient between APTT and anti-Xa; ACT and anti-Xa are 0.72 and 0.33, respectively, p < 0.001. The patients with normal antithrombin levels exhibited a significant correlation between APTT and anti-Xa (r = 0.80, p < 0.001). ACT, on the other hand, was poorly correlated with UFH dose, whether there is AT deficiency or not. Anti-Xa and APTT are only moderately correlated with UFH dose in the group without antithrombin deficiency, with correlation coefficients of 0.62 and 0.57, respectively, p < 0.05. CONCLUSION: APTT value is strongly correlated with anti-Xa value, particularly in patients with normal antithrombin levels. However, the ACT value was poorly correlated with anti-Xa and not with the UFH dose. In groups without antithrombin deficiency, APTT and anti-Xa values only moderately correlated with UFH dose.

Regulation of apical constriction via microtubule- and Rab11-dependent apical transport during tissue invagination.

The formation of an epithelial tube is a fundamental process for organogenesis. During Drosophila embryonic salivary gland (SG) invagination, Folded gastrulation (Fog)-dependent Rho-associated kinase (Rok) promotes contractile apical myosin formation to drive apical constriction. Microtubules (MTs) are also crucial for this process and are required for forming and maintaining apicomedial myosin. However, the underlying mechanism that coordinates actomyosin and MT networks still remains elusive. Here, we show that MT-dependent intracellular trafficking regulates apical constriction during SG invagination. Key components involved in protein trafficking, such as Rab11 and Nuclear fallout (Nuf), are apically enriched near the SG invagination pit in a MT-dependent manner. Disruption of the MT networks or knockdown of Rab11 impairs apicomedial myosin formation and apical constriction. We show that MTs and Rab11 are required for apical enrichment of the Fog ligand and the continuous distribution of the apical determinant protein Crumbs (Crb) and the key adherens junction protein E-Cadherin (E-Cad) along junctions. Targeted knockdown of crb or E-Cad in the SG disrupts apical myosin networks and results in apical constriction defects. Our data suggest a role of MT- and Rab11-dependent intracellular trafficking in regulating actomyosin networks and cell junctions to coordinate cell behaviors during tubular organ formation.

Epidemiological transition to mortality and refracture following an initial fracture.

This study sought to redefine the concept of fracture risk that includes refracture and mortality, and to transform the risk into "skeletal age". We analysed data obtained from 3521 women and men aged 60 years and older, whose fracture incidence, mortality, and bone mineral density (BMD) have been monitored since 1989. During the 20-year follow-up period, among 632 women and 184 men with a first incident fracture, the risk of sustaining a second fracture was higher in women (36%) than in men (22%), but mortality risk was higher in men (41%) than in women (25%). The increased risk of mortality was not only present with an initial fracture, but was accelerated with refractures. Key predictors of post-fracture mortality were male gender (hazard ratio [HR] 2.4; 95% CI, 1.79-3.21), advancing age (HR 1.67; 1.53-1.83), and lower femoral neck BMD (HR 1.16; 1.01-1.33). A 70-year-old man with a fracture is predicted to have a skeletal age of 75. These results were incorporated into a prediction model to aid patient-doctor discussion about fracture vulnerability and treatment decisions.

Familial retinal arteriolar tortuosity and quantification of vascular tortuosity using swept-source optical coherence tomography angiography.

PURPOSE: Familial retinal arteriolar tortuosity (FRAT) is a rare autosomal dominant disorder that is characterized by tortuosity of the second and higher order retinal arterioles. We implement swept-source optical coherence tomography angiography (SS-OCTA) to quantify vessel tortuosity in patients with FRAT. We hypothesize that patients with FRAT will have higher retinal arteriole tortuosity when compared to controls. METHODS: Patients were scanned with a SS-OCTA device (Plex Elite 9000, Carl Zeiss Meditec, Dublin, CA). Images of a 12 × 12 mm2 area centered on the fovea were processed, and retinal vessels >23.5 µm in diameter were identified. An automatic tortuosity measurement program written in MATLAB was used to assess vessel tortuosity. Branch points in the vessels were detected and used to separate the vasculature into individual segments. The tortuosity was measured by calculating the arc-chord ratio of each vessel segment, where a minimum value of 1 indicated a straight vessel and higher values corresponded to increasing tortuosity. RESULTS: Two patients (4 eyes) with a known history of FRAT and six controls (12 eyes) were enrolled in the study. The mean tortuosity of all vessel segments (MTVS) in scans of FRAT eyes was on average 1.1244 [range: 1.1044-1.1438] while for control eyes it was 1.0818 [range: 1.0746-1.0872]. Average MTVS of FRAT eyes was significantly higher compared to control eyes (p = 0.03). CONCLUSIONS AND IMPORTANCE: Our results are consistent with the hypothesis that patients with FRAT have higher objective measurements of tortuosity compared to controls. Broader applications of this method may be of benefit in other retinal diseases with changes in retinal vessel configuration.

Association between pre- and intraorbital soft tissue volumes and the risk of orbital blowout fractures using CT-based volumetric measurements.

Orbital blowout fractures result from trauma which breaks the bony orbital wall while sparing the rim. Previous research into fracture mechanism has focused on bony anatomy. This study evaluates the role of preorbital and intraorbital soft tissue volume in fracture risk. A retrospective case-control study was conducted on 51 cases of adults with unilateral orbital blowout fracture, matched to 51 controls who had experienced orbital trauma by comparable mechanisms without sustaining a fracture. Axial Computed Tomography (CT) images with orbital fine cuts were assessed on a 3D post-processing workstation to measure the volume of the pre- and intraorbital soft tissues, then compared between the two groups using Mann-Whitney U analysis. In the case group, there were 40 males (78%), injured by assault (66%), fall (12%), motor vehicle collision (10%), or other cause (12%). The control group included 33 males (65%), injured by assault (55%), fall (22%), motor vehicle (4%), or other cause (20%). There was no significant difference in mechanism rates between case and control groups. Median preorbital volumes were 12.5 cm3 in the case group and14.1 cm3 in controls (p = 0.02). Median intraorbital volumes were 24.4 cm3 in the case group and 25.9 cm3 in controls (p = 0.003). CT volumetric analysis shows that patients who sustained blowout fractures have lower preorbital and intraorbital soft tissue volume than those who did not fracture. This underscores the significant role that soft tissues play in dissipating impact forces, both anterior to the orbital rim and within the orbit itself.

Association of psychosis with antiphospholipid antibody syndrome: A systematic review of clinical studies.

OBJECTIVE: In this systematic review, we reviewed the association between Antiphospholipid antibody syndrome (APS) and psychosis and focused on the prevalence, clinical presentation, immunologic and neurological workup, treatment options, and clinical outcomes. METHODOLOGY: We performed this systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)'s guidelines. We searched eight databases for potential articles and manually searched references and relevant articles of included studies. We included all articles reporting psychotic symptoms in patients with APS. Article quality was assessed using an adapted version of the Cancer Council Australia tool for case-series. RESULTS: We included 23 articles of 454 articles found. The mean patient age at presentation was 39years and most patients were women. Delusions and hallucinations were the common clinical manifestations of APS-associated psychosis. Findings on neuroimaging were attributed to APS-associated thrombosis in most cases. Most patients had a complete resolution of psychotic symptoms. CONCLUSION: APS-associated psychosis is rare. Later age of onset for psychosis, sudden onset, female sex, and comorbid medical and psychiatric symptoms should raise the suspicions for the presence of APS. APS-associated psychosis may have a favorable prognosis. However, further studies need to validate this conclusion.

Function of Translationally Controlled Tumor Protein in Organ Growth: Lessons from Drosophila Studies.

Regulation of cell growth and proliferation is crucial for development and function of organs in all animals. Genetic defects in growth control can lead to developmental disorders and cancers. Translationally controlled tumor protein (TCTP) is a family of evolutionarily conserved proteins implicated in cancer. Recent studies have revealed multiple roles of TCTP in diverse cellular events, but TCTP functions in vivo are poorly understood in vertebrate systems. We have used Drosophila melanogaster, the fruit fly, as a model organism for genetic dissection of Tctp function. Our studies have shown that Tctp is essential for organ development by regulating growth signaling. Furthermore, it is required for genome stability by promoting DNA repair and chromatin remodeling in the nucleus. Thus, Tctp acts as a multifaceted cytosolic and nuclear factor for regulating organ growth and genome stability. In this chapter, we describe an overview of our findings on Tctp functions in Drosophila and discuss their implications in cancer.

14-3-3 proteins regulate Tctp-Rheb interaction for organ growth in Drosophila.

14-3-3 family proteins regulate multiple signalling pathways. Understanding biological functions of 14-3-3 proteins has been limited by the functional redundancy of conserved isotypes. Here we provide evidence that 14-3-3 proteins regulate two interacting components of Tor signalling in Drosophila, translationally controlled tumour protein (Tctp) and Rheb GTPase. Single knockdown of 14-3-3ɛ or 14-3-3ζ isoform does not show obvious defects in organ development but causes synergistic genetic interaction with Tctp and Rheb to impair tissue growth. 14-3-3 proteins physically interact with Tctp and Rheb. Knockdown of both 14-3-3 isoforms abolishes the binding between Tctp and Rheb, disrupting organ development. Depletion of 14-3-3s also reduces the level of phosphorylated S6 kinase, phosphorylated Thor/4E-BP and cyclin E (CycE). Growth defects from knockdown of 14-3-3 and Tctp are suppressed by CycE overexpression. This study suggests a novel mechanism of Tor regulation mediated by 14-3-3 interaction with Tctp and Rheb.

Effect of autologous fat injection on lower eyelid position.

PURPOSE: To evaluate the effect of autologous periorbital fat injections on lower eyelid position. METHODS: Retrospective review of patients treated with autologous periorbital (malar/eyelid tear trough) fat injections for aesthetic purposes by a single surgeon (S.N.) between March 2007 and June 2011. The primary outcome, lower eyelid position as defined by marginal reflex distance 2 and inferior scleral show, was measured by standardizing and comparing pretreatment and posttreatment follow-up digital photos. Photographs were randomized and measured by 2 masked investigators. RESULTS: Seventy patients (5 male; mean age, 53; range, 33 to 77 years) were treated with autologous fat injections to the malar and lower eyelid tear trough for aesthetic purposes. A mean decrease in marginal reflex distance 2 of 0.5 mm in both OS and OD was found when pre- and posttreatment measurements were compared. Primary and secondary mean follow-up period was at 117 and 316 days, respectively. The effect of the autologous periorbital fat injection was not diminished (n=21) between follow-up periods. A mean change in scleral show of 0.5 mm was found when pre- and posttreatment measurements were compared. The overall mean follow-up period for scleral show was 125 days. Minor complications occurred in 7% (n=5) of patients who had postinjection subcutaneous induration. CONCLUSION: Autologous fat injections are well tolerated and have potential to be an effective adjuvant or primary treatment for mild lower eyelid retraction.