Novel cystamine-core dendrimer-formulation rescues ΔF508-CFTR and inhibits Pseudomonas aeruginosa infection by augmenting autophagy

Background: Cystic fibrosis (CF) is challenged with pathophysiological barriers for effective airway drug-delivery. Hence, we standardized the therapeutic efficacy of the novel dendrimer-based autophagy-inducing anti-oxidant drug, cysteamine.

Research design and methods: Human primary-CF epithelial-cells, CFBE41o-cells were used to standardize the efficacy of the dendrimer-cystamine in correcting impaired-autophagy, rescuing ΔF508-CFTR and Pseudomonas-aeruginosa (Pa) infection.

Results: We first designed a novel cystamine-core dendrimer formulation (G4-CYS) that significantly increases membrane-ΔF508CFTR expression in CFBE41o-cells (p < 0.05) by forming its reduced-form cysteamine, in vivo. Additionally, G4-CYS treatment corrects ΔF508-CFTR-mediated impaired-autophagy as observed by a significant decrease (p < 0.05) in Ub-LC3-positive aggresome-bodies. Next, we verified that in non-permeabilized CFBE41o-cells, G4-CYS significantly (p < 0.05) induces ΔF508-CFTR’s forward-trafficking to the plasma membrane. Furthermore, cysteamine’s known antibacterial and anti-biofilm properties against Pa were enhanced as our findings demonstrate that both G4-CYS and its control DAB-core dendrimer, G4-DAB, exhibited significant (p < 0.05) bactericidal-activity against Pa. We also found that both G4-CYS and G4-DAB exhibit marked mucolytic-activity against porcine-mucus (p < 0.05). Finally, we demonstrate that G4-CYS not only corrects the autophagy-impairment by rescuing ΔF508-CFTR in CFBE41o-cells but also corrects the intrinsic phagocytosis defect (p < 0.05).

Conclusions: Overall, our data demonstrates the efficacy of novel cystamine-dendrimer formulation in rescuing ΔF508-CFTR to the plasma membrane and inhibiting Pa bacterial-infection by augmenting autophagy.     

The Course of Eating Disorders Involving Bingeing and Purging Among Adolescent Girls: Prevalence,Stability, and Transitions

Purpose

To quantify eating disorder (ED) stability and diagnostic transition among a community-based sample of adolescents and young adult females in the United States.

Subsystem macroarchitecture of the intrinsic midbrain neural network and its tectal and tegmental subnetworks

The midbrain is the smallest of three primary vertebrate brain divisions. Here we use network science tools to reveal the global organizing principles of intramidbrain axonal circuitry before adding extrinsic connections with the remaining nervous system. Curating the experimental neuroanatomical literature yielded 17,248 connection reports for 8,742 possible connections between the 94 gray matter regions forming the right and left midbrain. Evidence for the existence of 1,676 connections suggests a 19.2% connection density for this network, similar to that for the intraforebrain network [L. W. Swanson et al., Proc. Natl. Acad. Sci. U.S.A. 117, 31470–31481 (2020)]. Multiresolution consensus cluster analysis parceled this network into a hierarchy with 6 top-level and 30 bottom-level subsystems. A structure–function model of the hierarchy identifies midbrain subsystems that play specific functional roles in sensory–motor mechanisms, motivation and reward, regulating complex reproductive and agonistic behaviors, and behavioral state control. The intramidbrain network also contains four bilateral region pairs designated putative hubs. One pair contains the superior colliculi of the tectum, well known for participation in visual sensory–motor mechanisms, and the other three pairs form spatially compact right and left units (the ventral tegmental area, retrorubral area, and midbrain reticular nucleus) in the tegmentum that are implicated in motivation and reward mechanisms. Based on the core hypothesis that subsystems form functionally cohesive units, the results provide a theoretical framework for hypothesis-driven experimental analysis of neural circuit mechanisms underlying behavioral responses mediated in part by the midbrain.

According to the classical view, early in vertebrate development the neural plate invaginates to form the neural tube, which immediately displays three sequential swellings that were called the primary forebrain, midbrain (MB), and hindbrain vesicles by von Baer in 1837 (1) and that are followed by the presumptive spinal cord caudally. Together, these four differentiations or morphogenetic units of the neural tube go on to generate the entire adult central nervous system (2, 3). As a major part of a systematic research program to analyze the organizing principles of mammalian nervous system macroconnectivity, we recently completed a study of forebrain intrinsic circuitry (4), and here we present a similar study of MB intrinsic circuitry.Based on developmental and adult topographic features, the MB can be divided into two great parts: tectum (TC) dorsally and tegmentum (TG) ventrally (5, 6). In mammals, the TC in turn has two parts, the superior and inferior colliculi, which are important nodes in circuitry related to visual and auditory functions, respectively (3). The TG, in contrast, is much more differentiated structurally and functionally, with a variety of gray matter regions that have been intensively analyzed over the last 75 y. Among the most prominent are three cranial nerve nuclei (oculomotor nucleus, trochlear nucleus, and midbrain nucleus of the trigeminal nerve), as well as the pretectal region, red nucleus, substantia nigra and ventral tegmental area, midbrain raphe nuclei, periaqueductal gray, and midbrain reticular nucleus (3).This topographic approach to biological structure–function organization is like dividing the body in human anatomy into head, neck, trunk, and upper and lower limbs with hands and feet. Topographic anatomy is particularly useful for describing and mapping structure–function spatial relationships of body parts and for surgical procedures. For example, the hand is an obvious body part with especially important and intricate functions in humans. Systems anatomy, however, is an equally valid and complementary way of describing global principles of body organization. In human biology, the body is conveniently and systematically divided into about a dozen interrelated systems (skeletal, digestive, respiratory, nervous, and so on), and components of each typically play a role in topographic parts such as the hand. The systems approach is particularly useful for organizing vast amounts of data into simplified, readily understandable conceptual frameworks or models of how the body works as a whole.The nervous system can also be treated from the complementary topographic and systems perspectives (7), and it is the only bodily system remaining without a relatively simple global systems model, largely because its cellular network architecture is much more complex than the other systems. However, general network analysis tools, which can be applied to any complex system, from the internet to social interactions in a human population, offer one promising approach (8, 9). Basic requirements include a systematic parts list for the network, an understanding of how each part works, and an account of how the parts are connected to form a functional system (10). Our long-term strategy for the rat nervous system follows the time-honored approach to solving any difficult problem, that is, to proceed from coarser-grained to finer-grained analyses, analogous to the strategy used to sequence the human genome (11). Thus, using a nested approach, we have started at the coarse-grained macro level of analysis (axonal macroconnections from one gray matter region to another gray matter region), as a prelude and framework for analyses at the finer-grained meso level (connections between neuron types making up each gray matter region), micro level (connections between individual neurons making up each neuron type), and nano level (the set of synapses formed by each neuron) (12).     

PRRX‐NCOA1/2 rearrangement characterizes a distinctive fibroblastic neoplasm

Fibroblastic/myofibroblastic neoplasms represent a broad, and occasionally diagnostically challenging, category of soft tissue neoplasms. A subset of these tumors defy conventional classification. However, with the advent of next‐generation sequencing, the identification of disease‐defining molecular alterations is gradually improving their subclassification. Following identification of two index cases of a distinctive fibroblastic neoplasm with a fusion gene involving PRRX1 and NCOA1, we performed a retrospective review to further characterize this entity. We identified two additional cases, including one with a fusion between PRRX1 and NCOA2. The average patient age was 38 years, and three patients were female. Two tumors occurred on the neck, and the others involved the groin and thigh. Tumors were centered in the subcutis and ranged from 2.3 to 14.0 cm (average 5.8 cm). Morphologically, they were predominantly hypocellular, with focal hypercellularity. They were composed of monomorphic spindle‐stellate cells with a vague fascicular pattern. The nuclei were bland with only rare mitotic activity, and occasional multinucleation. The intervening stroma was typically abundant and ranged from myxoid to collagenous, with frequent rope‐like collagen bundles. Three of the cases had a prominent vasculature ranging from numerous small curvilinear vessels to ectatic and branching staghorn‐like vessels. Immunohistochemistry was negative for desmin, smooth muscle actin, S100, CD34, keratin, and epithelial membrane antigen. Each of the patients was treated by simple excision and none of the tumors were associated with local recurrence or metastasis. Based on their unique morphological and molecular attributes, we believe this represents a novel fibroblastic tumor for which we have tentatively proposed the name “PRRX‐NCOAx‐rearranged fibroblastic tumor.”