Safety and efficacy of elexacaftor/tezacaftor/ivacaftor in people with Cystic Fibrosis following liver transplantation: A systematic review.

BACKGROUND & AIMS: Cystic Fibrosis (CF) liver disease progresses to liver failure requiring transplantation in about 3 % of patients, 0.7 % of CF patients are post liver transplant. The prognosis of CF has improved with the introduction of elexacaftor/tezacaftor/ivacaftor (ETI). Due to the paucity of data and concerns regarding interactions with immunosuppressive drug regimens, there is no general consensus on use of ETI post liver transplantation. The aim of this review is to report the safety and efficacy of ETI in CF patients who underwent liver transplantation. METHODS: A systematic review was conducted through MEDLINE/Pubmed and EMBASE databases. English-written articles reporting clinical data on liver transplanted CF patients treated with ETI were included. Article quality was evaluated using the Critical Appraisal Checklist for Case Reports. RESULTS: Twenty cases were retrieved from 6 reports. Temporary discontinuation and/or dose reduction due to elevated transaminases was required in 5 cases. ETI restarted on a reduced dose was tolerated in 3 out of 5 patients, 1 patient tolerated full dose. Tacrolimus dose change was required in 14 cases, in 1 case ETI was discontinued due to tacrolimus toxicity. Improvement in percentage predicted FEV1 was noted in 15/19 patients (median +17 %, range 8 %-38 %). CONCLUSIONS: In the majority of liver transplanted patients ETI is well tolerated, although adverse events and liver function abnormalities may occur. Close monitoring of liver function and tacrolimus level is warranted. Significant improvement in lung function after ETI initiation is confirmed, highlighting the importance of accessing this medication for this group of patients.

Association of viral load with TRAIL, IP-10, CRP biomarker signature and disease severity in children with respiratory tract infection or fever without source: A prospective, multicentre cohort study.

BACKGROUND: To investigate the association of viral load (VL) with (i) tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), interferon gamma-induced protein-10, C-reactive protein, and a combinatorial score (BV score), and (ii) clinical severity. STUDY DESIGN: In this prospective, multicentre cohort substudy, children with respiratory tract infection or fever without source were enrolled. VL for influenza virus, rhinovirus, respiratory syncytial virus, and adenovirus was measured from nasopharyngeal swabs. The reference standard diagnosis was established based on expert panel adjudication. RESULTS: Of 1140 recruited patients, 333 had a virus monodetection. VL for the aggregated data set correlated with TRAIL and IP-10 levels, with the length of oxygen therapy, and inversely with the BV score. At a single viral level, only the influenza VL yielded a correlation with TRAIL, IP-10 levels, and the BV score. Children with a viral reference standard diagnosis had significantly higher VL than those with bacterial infection (p = 0.0005). Low TRAIL (incidence rate ratio [IRR] 0.6, 95% confidence interval [CI] 0.39-0.91) and young age (IRR 0.62, 95% CI 0.49-0.79) were associated with a longer hospital stay, while young age (IRR 0.33, 95% CI 0.18-0.61), low TRAIL (IRR 0.25, 95% CI 0.08-0.76), and high VL (IRR 1.16, 95% CI 1.00-1.33) were predictive of longer oxygen therapy. CONCLUSION: These findings indicate that VL correlates with biomarkers and may serve as a complementary tool pertaining to disease severity.

Probiotics Administration in Cystic Fibrosis: What Is the Evidence?

In the last 20 years, gut microbiota in patients with cystic fibrosis (CF) has become an object of interest. It was shown that these patients had gut dysbiosis and this could explain not only the intestinal manifestations of the disease but also part of those involving the respiratory tract. The acquisition of previously unknown information about the importance of some bacteria, i.e., those partially or totally disappeared in the gut of CF patients, in the regulation of the activity and function of the gut and the lung was the base to suggest the use of probiotics in CF patients. The main aim of this paper is to discuss the biological basis for probiotic administration to CF patients and which results could be expected. Literature analysis showed that CF intestinal dysbiosis depends on the same genetic mutations that condition the clinical picture of the diseases and is aggravated by a series of therapeutic interventions, such as dietary modifications, the use of antibiotics, and the administration of antacids. All this translates into a significant worsening of the structure and function of organs, including the lung and intestine, already deeply penalized by the genetic alterations of CF. Probiotics can intervene on dysbiosis, reducing the negative effects derived from it. However, the available data cannot be considered sufficient to indicate that these bacteria are essential elements of CF therapy. Further studies that take into account the still unsolved aspects on how to use probiotics are absolutely necessary.

Identification of electroporation sites in the complex lipid organization of the plasma membrane.

The plasma membrane of a biological cell is a complex assembly of lipids and membrane proteins, which tightly regulate transmembrane transport. When a cell is exposed to strong electric field, the membrane integrity becomes transiently disrupted by formation of transmembrane pores. This phenomenon termed electroporation is already utilized in many rapidly developing applications in medicine including gene therapy, cancer treatment, and treatment of cardiac arrhythmias. However, the molecular mechanisms of electroporation are not yet sufficiently well understood; in particular, it is unclear where exactly pores form in the complex organization of the plasma membrane. In this study, we combine coarse-grained molecular dynamics simulations, machine learning methods, and Bayesian survival analysis to identify how formation of pores depends on the local lipid organization. We show that pores do not form homogeneously across the membrane, but colocalize with domains that have specific features, the most important being high density of polyunsaturated lipids. We further show that knowing the lipid organization is sufficient to reliably predict poration sites with machine learning. Additionally, by analysing poration kinetics with Bayesian survival analysis we show that poration does not depend solely on local lipid arrangement, but also on membrane mechanical properties and the polarity of the electric field. Finally, we discuss how the combination of atomistic and coarse-grained molecular dynamics simulations, machine learning methods, and Bayesian survival analysis can guide the design of future experiments and help us to develop an accurate description of plasma membrane electroporation on the whole-cell level. Achieving this will allow us to shift the optimization of electroporation applications from blind trial-and-error approaches to mechanistic-driven design.

Genetically encoded photo-switchable molecular sensors for optoacoustic and super-resolution imaging.

Reversibly photo-switchable proteins are essential for many super-resolution fluorescence microscopic and optoacoustic imaging methods. However, they have yet to be used as sensors that measure the distribution of specific analytes at the nanoscale or in the tissues of live animals. Here we constructed the prototype of a photo-switchable Ca2+ sensor based on GCaMP5G that can be switched with 405/488-nm light and describe its molecular mechanisms at the structural level, including the importance of the interaction of the core barrel structure of the fluorescent protein with the Ca2+ receptor moiety. We demonstrate super-resolution imaging of Ca2+ concentration in cultured cells and optoacoustic Ca2+ imaging in implanted tumor cells in mice under controlled Ca2+ conditions. Finally, we show the generalizability of the concept by constructing examples of photo-switching maltose and dopamine sensors based on periplasmatic binding protein and G-protein-coupled receptor-based sensors.

Gut Dysbiosis in Children with Cystic Fibrosis: Development, Features and the Role of Gut-Lung Axis on Disease Progression.

Cystic fibrosis (CF) is the most common autosomal recessive disease among Caucasians. Over the last 20 years, culture-independent analysis, including next-generation sequencing, has paired with culture-based microbiology, offering deeper insight into CF lung and gut microbiota. The aim of this review is to analyse the features of gut microbiota in patients with CF and its possible role in the progression of the disease, establishing the basis for a potential role in microbe-based therapies. The literature analysis showed that the gut environment in CF patients has unique features due to the characteristics of the disease, such as decreased bicarbonate secretion, increased luminal viscosity, and an acidic small intestinal environment, which, due to the treatment, includes regular antibiotic use or a high-energy and fat-dense diet. As a result, the gut microbial composition appears altered, with reduced richness and diversity. Moreover, the population of pro-inflammatory bacteria is higher, while immunomodulatory genera, such as Bacteroides and Bifidobacterium, are scarcer. The imbalanced gut microbial population has a potential role in the development of systemic inflammation and may influence clinical outcomes, such as respiratory exacerbations, spirometry results, and overall growth. Although a better understanding of the pathophysiology behind the gut-lung axis is needed, these findings support the rationale for considering gut microbiota manipulation as a possible intervention to regulate the severity and progression of the disease.

Spatial Regulation of T-Cell Signaling by Programmed Death-Ligand 1 on Wireframe DNA Origami Flat Sheets.

Programmed Death-1 (PD-1) is a coinhibitory receptor expressed on activated T cells that suppresses T-cell signaling and effector functions. It has been previously shown that binding to its ligand PD-L1 induces a spatial reorganization of PD-1 receptors into microclusters on the cell membrane. However, the roles of the spatial organization of PD-L1 on PD-1 clustering and T-cell signaling have not been elucidated. Here, we used DNA origami flat sheets to display PD-L1 ligands at defined nanoscale distances and investigated their ability to inhibit T-cell activation in vitro. We found that DNA origami flat sheets modified with CD3 and CD28 activating antibodies (FS-α-CD3-CD28) induced robust T-cell activation. Co-treatment with flat sheets presenting PD-L1 ligands separated by ∼200 nm (FS-PD-L1-200), but not 13 nm (FS-PD-L1-13) or 40 nm (FS-PD-L1-40), caused an inhibition of T-cell signaling, which increased with increasing molar ratio of FS-PD-L1-200 to FS-α-CD3-CD28. Furthermore, FS-PD-L1-200 induced the formation of smaller PD-1 nanoclusters and caused a larger reduction in IL-2 expression compared to FS-PD-L1-13. Together, these findings suggest that the spatial organization of PD-L1 determines its ability to regulate T-cell signaling and may guide the development of future nanomedicine-based immunomodulatory therapies.

Apparent stiffness of vimentin intermediate filaments in living cells and its relation with other cytoskeletal polymers.

The cytoskeleton is a complex network of interconnected biopolymers intimately involved in the generation and transmission of forces. Several mechanical properties of microtubules and actin filaments have been extensively explored in cells. In contrast, intermediate filaments (IFs) received comparatively less attention despite their central role in defining cell shape, motility and adhesion during physiological processes as well as in tumor progression. Here, we explored relevant biophysical properties of vimentin IFs in living cells combining confocal microscopy and a filament tracking routine that allows localizing filaments with ~20 nm precision. A Fourier-based analysis showed that IFs curvatures followed a thermal-like behavior characterized by an apparent persistence length (lp*) similar to that measured in aqueous solution. Additionally, we determined that certain perturbations of the cytoskeleton affect lp* and the lateral mobility of IFs as assessed in cells in which either the microtubule dynamic instability was reduced or actin filaments were partially depolymerized. Our results provide relevant clues on how vimentin IFs mechanically couple with microtubules and actin filaments in cells and support a role of this network in the response to mechanical stress.

Protect, promote and support: a warm chain of breastfeeding for oncological women-results from a survey of young Italian cancer mothers.

The topic of lactation following cancer diagnosis will become increasingly more current. Although oncological research confirms that breastfeeding after cancer might be possible, there is a lack of guidelines and a good recommendation for oncological women. In the absence of specific recommendations, women with past cancer may be at higher risk for psychological distress related to breastfeeding. The objective of this article was to analyse the experience of breastfeeding in new mothers with a history of cancer compared to women without a cancer diagnosis. First, we explored the impact of the cancer diagnosis on the breastfeeding choice. Second, we evaluated the relationship between different feeding methods and the mother's mood states in women with and without a history of cancer. The sample was composed of 74 mothers divided into two groups: 34 with a cancer history (clinical sample) and 40 without a cancer diagnosis (control group). Participants were requested to complete a questionnaire three months after childbirth which assessed: socio-demographic and clinical data, feeding modes (breastfeeding, formula and mixed feeding) and the profile of mood states (POMS). Results showed that women in the clinical group breastfeed significantly less and use formula more than those in the control group. Moreover, in the clinical group, women who breastfeed feel reported higher levels of confusion (according to POMS) than mothers who bottle-feed or use a mixed feeding method. On the contrary, in the control sample, women who breastfeed feel significantly more vigorous than puerperae who bottle-feed or use mixed methods according to POMS. Our findings suggest the need for a specific warm chain of support and the development of guidelines with clear and specific information for women with a cancer diagnosis in order to reduce their confusion around breastfeeding.

Childhood Asymmetry Labium Majus Enlargement (CALME): Description of Two Cases.

Background: Childhood asymmetry labium majus enlargement (CALME) is an uncommon, benign condition that occurs in pre- and early pubertal girls and is characterized by a painless, fluctuating, non-tender labial swelling with normal overlying skin. Recognition of this benign condition is essential. Differentiation with several other diseases that mimic CALME and require different diagnostic and therapeutic approaches is mandatory. Two cases of CALME are described in this report. Differential diagnoses and therapeutic approaches are highlighted. Case presentation: The first case was an 11-year-old Caucasian girl referred to our hospital for the evaluation of right labium majus, which showed a palpable, painless, soft, non-tender, non-erythematous enlargement measuring approximately 2 cm with indistinct borders. Ultrasound showed a mass 23 × 18 × 12 mm in diameter. Surgical excision of the mass was performed and in the histopathological evaluation, the tissue specimens were composed of haphazardly arranged vascular channels, adipose tissue and nervous elements that were components of the vulvar soft tissue and were compatible with the diagnosis of CALME. Case 2 was a 6-year-old Caucasian girl who presented a post-traumatic painless mass of left labium majus swelling that progressively increased in volume. Ultrasound study evidenced an ill-defined heterogeneous echotexture mass 26 × 15 × 10 mm in diameter and magnetic resonance imaging confirmed these findings. Histopathological examination was performed after bioptic sampling evidencing normal constituents of vulvar soft tissue, including fibroblast, collagen, adipose tissue, blood vessels and nerves compatible with CALME. Conclusions: CALME is a particular clinical condition that occurs mainly in pre-pubertal girls and has a benign course but poses numerous problems in differential diagnosis that can be solved only with careful clinical observation and with a careful use of radiological imaging techniques. Our cases, in agreement with recent literature, suggest that radical excision is not recommended and that surgical biopsy should be taken into consideration only in cases of doubt.

Inflamed Phylloides Tumour in a Girl: A Challenging Diagnosis in Paediatric Breast Lesions.

Introduction: Phylloides tumours (PTs) are rare fibroepithelial neoplasms that account for 0.3⁻0.9% of all breast tumours. These tumours typically occur in women aged 30⁻70 years. The occurrence of these tumours in older children and adolescents poses particular diagnostic and therapeutic problems. However, early diagnosis is mandatory because although most of the cases of PTs in children are benign, the borderline and malignant cases with potential negative outcomes cannot be excluded. Case presentation: A 12-year-old girl presented at the Paediatric Emergency Department for hyperaemia and warmth of the left breast that occurred a few days prior without fever. The girl experienced menarche 8 months previously. She experienced no previous trauma and she had no family history of breast cancer. On physical examination, the left breast was painful, enlarged and tender. The overlying skin was erythematous and warm. A breast ultrasonography (US) revealed a large mass with features of an abscess, including a hyperechoic wall, scattered internal echoes and hypoechoic peripheral lacunae of apparent colliquative nature. After 4 days of unsuccessful antibiotic therapy, surgical drainage was performed due to the suspicion of a mammary abscess. At the surgical incision site, the lesion was not-well circumscribed and lacked a capsule. In addition, purulent material was not detected. Histological examination revealed that the tissue alterations were compatible with benign PT. With this diagnosis, the girl underwent definitive surgical removal of the lesion. The postoperative period passed without negative events. An US performed 6 months later revealed that no new mass was present at this time, suggesting no recurrence of the tumour. Conclusion: This case shows that in the presence of a clinical picture suggesting the inflammation of the breast in adolescent females, PT should be considered as a possible diagnosis and US-guided core biopsy should be considered to confirm this suspicion. Thereafter, when surgical excision is performed, particular attention must be paid to both the preservation of all the normal breast parenchyma and future aesthetic problems.

Glyoxal as an alternative fixative to formaldehyde in immunostaining and super-resolution microscopy.

Paraformaldehyde (PFA) is the most commonly used fixative for immunostaining of cells, but has been associated with various problems, ranging from loss of antigenicity to changes in morphology during fixation. We show here that the small dialdehyde glyoxal can successfully replace PFA Despite being less toxic than PFA, and, as most aldehydes, likely usable as a fixative, glyoxal has not yet been systematically tried in modern fluorescence microscopy. Here, we tested and optimized glyoxal fixation and surprisingly found it to be more efficient than PFA-based protocols. Glyoxal acted faster than PFA, cross-linked proteins more effectively, and improved the preservation of cellular morphology. We validated glyoxal fixation in multiple laboratories against different PFA-based protocols and confirmed that it enabled better immunostainings for a majority of the targets. Our data therefore support that glyoxal can be a valuable alternative to PFA for immunostaining.

Vimentin Levels and Serine 71 Phosphorylation in the Control of Cell-Matrix Adhesions, Migration Speed, and Shape of Transformed Human Fibroblasts.

Metastasizing tumor cells show increased expression of the intermediate filament (IF) protein vimentin, which has been used to diagnose invasive tumors for decades. Recent observations indicate that vimentin is not only a passive marker for carcinoma, but may also induce tumor cell invasion. To clarify how vimentin IFs control cell adhesions and migration, we analyzed the nanoscale (30-50 nm) spatial organization of vimentin IFs and cell-matrix adhesions in metastatic fibroblast cells, using three-color stimulated emission depletion (STED) microscopy. We also studied whether wild-type and phospho-deficient or -mimicking mutants of vimentin changed the size and lifetime of focal adhesions (FAs), cell shape, and cell migration, using live-cell total internal reflection imaging and confocal microscopy. We observed that vimentin exists in fragments of different lengths. Short fragments were mostly the size of a unit-length filament and were mainly localized close to small cell-matrix adhesions. Long vimentin filaments were found in the proximity of large FAs. Vimentin expression in these cells caused a reduction in FAs size and an elongated cell shape, but did not affect FA lifetime, or the speed or directionality of cell migration. Expression of a phospho-mimicking mutant (S71D) of vimentin increased the speed of cell migration. Taken together, our results suggest that in highly migratory, transformed mesenchymal cells, vimentin levels control the cell shape and FA size, but not cell migration, which instead is linked to the phosphorylation status of S71 vimentin. These observations are consistent with the possibility that not only levels, but also the assembly status of vimentin control cell migration.

rsEGFP2 enables fast RESOLFT nanoscopy of living cells.

The super-resolution microscopy called RESOLFT relying on fluorophore switching between longlived states, stands out by its coordinate-targeted sequential sample interrogation using low light levels. While RESOLFT has been shown to discern nanostructures in living cells, the reversibly photoswitchable green fluorescent protein (rsEGFP) employed in these experiments was switched rather slowly and recording lasted tens of minutes. We now report on the generation of rsEGFP2 providing faster switching and the use of this protein to demonstrate 25-250 times faster recordings.DOI:http://dx.doi.org/10.7554/eLife.00248.001.

Endocytic trafficking of Rac is required for the spatial restriction of signaling in cell migration.

The small GTPases, Rab5 and Rac, are essential for endocytosis and actin remodeling, respectively. Coordination of these processes is critical to achieve spatial restriction of intracellular signaling, which is essential for a variety of polarized functions. Here, we show that clathrin- and Rab5-mediated endocytosis are required for the activation of Rac induced by motogenic stimuli. Rac activation occurs on early endosomes, where the RacGEF Tiam1 is also recruited. Subsequent recycling of Rac to the plasma membrane ensures localized signaling, leading to the formation of actin-based migratory protrusions. Thus, membrane trafficking of Rac is required for the spatial resolution of Rac-dependent motogenic signals. We further demonstrate that a Rab5-to-Rac circuitry controls the morphology of motile mammalian tumor cells and primordial germinal cells during zebrafish development, suggesting that this circuitry is relevant for the regulation of migratory programs in various cells, in both in vitro settings and whole organisms.