Motility Function Research Articles

Identification of Two Novel DNAAF2 Variants in Two Consanguineous Families with Primary Ciliary Dyskinesia.

BackgroundDynein axonemal assembly factor 2 (DNAAF2) is involved in the early preassembly of dynein in the cytoplasm, which is essential for motile cilia function. Primary ciliary dyskinesia (PCD) associated with DNAAF2 variants has rarely been reported in females with infertility. Moreover, there is no report linking DNAAF2 to scoliosis in human.Materials and MethodsWe recruited patients from two consanguineous families with a clinical diagnosis of PCD and collected their clinical history, laboratory tests, and radiographic data. Sequencing and bioinformatics analysis were then performed. Immunofluorescence and high-speed microscope analysis were used to support the pathogenicity of the variant.ResultsProband 1, a 26-year-old female from family I, exhibited scoliosis, bronchiectasis, sinusitis, situs inversus, and infertility. We found a novel homozygous missense variant in DNAAF2, c.491T>C, p.(Leu164Pro) in this patient. Subsequent immunofluorescence indicated the absence of outer dynein arm and inner dynein arm of cilia, and high-speed microscopy analysis showed that the most of the cilia are static, which support the pathogenicity of this variant. Proband 2, a 53-year-old female, presented with bronchiectasis, sinusitis, and infertility. In this patient, a new homozygous frameshift variant DNAAF2, c.822del, p.(Ala275Profs*10) was identified. The disease-causing variants mentioned above are not included in the current authorized genetic databases.ConclusionOur findings expand the spectrum of DNAAF2 variants and link DNAAF2 to female infertility and likely scoliosis in patients with PCD.

Implications of Phosphoinositide 3-Kinase-Akt (PI3K-Akt) Pathway in the Pathogenesis of Alzheimer's Disease.

Alzheimer's disease (AD) is the foremost type of dementia that afflicts considerable morbidity and mortality in aged population. Several transcription molecules, pathways, and molecular mechanisms such as oxidative stress, inflammation, autophagy, and immune system interact in a multifaceted way that disrupt physiological processes (cell growth, differentiation, survival, lipid and energy metabolism, endocytosis) leading to apoptosis, tauopathy, β-amyloidopathy, neuron, and synapse loss, which play an important role in AD pathophysiology. Despite of stupendous advancements in pathogenic mechanisms, treatment of AD is still a nightmare in the field of medicine. There is compelling urgency to find not only symptomatic but effective disease-modifying therapies. Recently, phosphoinositide 3-kinase (PI3K) and Akt are identified as a pathway triggered by diverse stimuli, including insulin, growth factors, cytokines, and cellular stress, that link amyloid-β, neurofibrillary tangles, and brain atrophy. The present review aims to explore and analyze the role of PI3K-Akt pathway in AD and agents which may modulate Akt and have therapeutic prospects in AD. The literature was researched using keywords "PI3K-Akt" and "Alzheimer's disease" from PubMed, Web of Science, Bentham, Science Direct, Springer Nature, Scopus, and Google Scholar databases including books. Articles published from 1992 to 2021 were prioritized and analyzed for their strengths and limitations, and most appropriate ones were selected for the purpose of review. PI3K-Akt pathway regulates various biological processes such as cell proliferation, motility, growth, survival, and metabolic functions, and inhibits many neurotoxic mechanisms. Furthermore, experimental data indicate that PI3K-Akt signaling might be an important therapeutic target in treatment of AD.

Improvement of conditions for boundedness in a chemotaxis consumption system with density-dependent motility

This work considers the chemotaxis model with density-dependent motility ut=Δ(ϕ(v)u),x∈Ω,t>0,vt=Δv−uv,x∈Ω,t>0under homogeneous Neumann boundary conditions in a smooth bounded domain Ω⊂R2, with the nonnegative initial data (u0,v0)∈[W1,∞(Ω)]2. The motility function ϕ(v) satisfies ϕ(v)∈C3([0,∞)) with ϕ(v)>0 and ϕ′(v)<0 for all v≥0. For all suitably regular initial data, we prove that this system has a unique global bounded classical solution. The purpose of this work is to remove the smallness assumption on ‖v0‖L∞(Ω) in Li and Zhao (2021).

Differential effect of polysaccharide and nonpolysaccharide components in Sijunzi decoction on spleen deficiency syndrome and their mechanisms

Sijunzi decoction (SJZD), reported in "Tai Ping Hui Min He Ji Ju Fang" of the Song dynasty, is the basic prescription for the treatment of spleen deficiency syndrome (SDS) in traditional Chinese medicine (TCM). It is composed of Ginseng Radix et Rhizoma, Atractylodisa Macricephalae Rhizoma, Poria and Glycyrrhizae Radix et Rhizoma Praeparata Cum Melle. This study sought to explore the effects of different components in SJZD (including nonpolysaccharide NPS and active polysaccharide S-3) on SDS rats and their underlying mechanisms. First, SDS model rats were established by reserpine injection and then treated with SJZD, NPS and S-3. To clarify their effect on GI motility and immune function, the gastrointestinal (GI) hormone levels in rat serum and their related receptor expressions in rat intestine were detected by enzyme-linked immunosorbent assay (ELISA) and western blot, and the intestinal T lymphocyte expression were quantified by flow cytometry. The levels of SCFAs in feces and serum were measured by gas chromatography-mass spectrometry (GC-MS), and the gut microbiota composition was determined by 16S RNA sequencing. Furthermore, pseudo-germ-free (pGF) and gut microbiota dysbiosis (GMD) model rats were established to verify the key role of the gut microbiota in the treatment of SDS with SJZD, NPS and S-3. SJZD has a stronger therapeutic effect on intestinal immune and GI hormone secretion in SDS rats, while the efficacy of NPS and S-3 showed slight differences. NPS mainly regulated the secretion of GI hormones in SDS rats and directly improved intestinal immunity by increasing the expression of T lymphocyte cells, while S-3 mainly enhanced intestinal immune function by increasing the expression of T lymphocyte cells and repairing the intestinal barrier in both direct and indirect ways. Additionally, experiments in pGF and GMD rats have proven that the immune-enhancing effects of SJZD, NPS, and S-3 on SDS rats and the regulation of GI hormones of S-3 are related to modulation of the gut microbiota composition, while the regulation of GI hormones by SJZD and NPS is not completely dependent on this modulation. In particular, Lactobacillus, SMB53, Blautia, Dorea, Collinsella and Adlercreutzia were significantly modulated by SJZD, and 3 genera (including Lactobacillus, Dorea and SMB53) were also remarkably regulated by NPS. S-3 significantly increased the abundance of Butyricimonas and Collinsella, which were different from altered genera in the SJZD group. This study uncovered that NPS and S-3 are inseparable effective substances for SJZD in the treatment of SDS rats, in which NPS mainly improves intestinal motility dysfunction and S-3 mainly enhances intestinal immunity. The mediation effect of the gut microbiota is extremely important, but the regulating effect of NPS on gastrointestinal hormones has nothing to do with the gut microbiota.

An updated SYSCILIA gold standard (SCGSv2) of known ciliary genes, revealing the vast progress that has been made in the cilia research field.

Cilia are microtubule-based organelles with important functions in motility and sensation. They contribute to a broad spectrum of developmental disorders called ciliopathies and have recently been linked to common conditions such as cancers and congenital heart disease. There has been increasing interest in the biology of cilia and their contribution to disease over the past two decades. In 2013 we published a “Gold Standard” list of genes confirmed to be associated with cilia. This was published as part of the SYSCILIA consortium for systems biology study dissecting the contribution of cilia to human health and disease, and was named the Syscilia Gold Standard (SCGS). Since this publication, interest in cilia and understanding of their functions have continued to grow, and we now present an updated SCGS version 2. This includes an additional 383 genes, more than doubling the size of SCGSv1. We use this dataset to conduct a review of advances in understanding of cilia biology 2013– 2021 and offer perspectives on the future of cilia research. We hope that this continues to be a useful resource for the cilia community.

Whole genome sequencing in the diagnosis of primary ciliary dyskinesia

BackgroundIt is estimated that 1–13% of cases of bronchiectasis in adults globally are attributable to primary ciliary dyskinesia (PCD) but many adult patients with bronchiectasis have not been investigated for PCD. PCD is a disorder caused by mutations in genes required for motile cilium structure or function, resulting in impaired mucociliary clearance. Symptoms appear in infancy but diagnosis is often late or missed, often due to the lack of a “gold standard” diagnostic tool and non-specific symptoms. Mutations in > 50 genes account for around 70% of cases, with additional genes, and non-coding, synonymous, missense changes or structural variants (SVs) in known genes presumed to account for the missing heritability.MethodsUK patients with no identified genetic confirmation for the cause of their PCD or bronchiectasis were eligible for whole genome sequencing (WGS) in the Genomics England Ltd 100,000 Genomes Project. 21 PCD probands and 52 non-cystic fibrosis (CF) bronchiectasis probands were recruited in Wessex Genome Medicine Centre (GMC). We carried out analysis of single nucleotide variants (SNVs) and SVs in all families recruited in Wessex GMC.Results16/21 probands in the PCD cohort received confirmed (n = 9), probable (n = 4) or possible (n = 3) diagnosis from WGS, although 13/16 of these could have been picked up by current standard of care gene panel testing. In the other cases, SVs were identified which were missed by panel testing. We identified variants in novel PCD candidate genes (IFT140 and PLK4) in 2 probands in the PCD cohort. 3/52 probands in the non-CF bronchiectasis cohort received a confirmed (n = 2) or possible (n = 1) diagnosis of PCD. We identified variants in novel PCD candidate genes (CFAP53 and CEP164) in 2 further probands in the non-CF bronchiectasis cohort.ConclusionsGenetic testing is an important component of diagnosing PCD, especially in cases of atypical disease history. WGS is effective in cases where prior gene panel testing has found no variants or only heterozygous variants. In these cases it may detect SVs and is a powerful tool for novel gene discovery.

153 THE CLINICAL SIGNIFICANCE OF INCOMPLETE BOLUS CLEARANCE IN PATIENTS WITH DYSPHAGIA

Abstract The primary function of the esophagus is to facilitate bolus transport to the stomach. High-resolution manometry assesses the functions of esophageal motility, but not the clearance of bolus transit through the esophagus. The development of combined multichannel intraluminal impedance and manometry (MII-EM) has enabled simultaneous measurement of bolus transport and manometry. This study investigated the effects of bolus transit on esophageal motility disorders and its effect on the quality of life of patients with dysphagia. Methods A total of 810 wet swallows were reviewed and analyzed in 81 patients with dysphagia who underwent MII-EM. Incomplete bolus clearance (IBC) was defined based on impedance measurement. IBC was classified into four types (A: normal, B: incomplete clearance in the upper esophagus, C: incomplete clearance in the lower esophagus, D: incomplete clearance of the whole esophagus), and was also evaluated according to the appearance rate of complete bolus transit. Then, the clinical significance of IBC was determined by our previously validated dysphagia symptom score and the SF8 quality of life instrument (physical component summary and mental component summary). Results There were 16 cases of esophageal achalasia (Ach), 9 of esophagogastric junction outflow obstruction (EGJOO), 8 of distal esophageal spasm (DES), 7 of Jackhammer esophagus (JE), 2 of absent contractility (AC), 10 of ineffective esophageal motility (IEM) and 29 normal cases. The figure shows the breakdown of IBC for each disorder. Complete bolus transit was found in 27.8% in EGJOO, 52.5% in DES, 14.2% in JE, 4.0% in IEM, and 83.3% in normal; no CBT was found in Ach and AC. Patients with IBC had significantly higher dysphagia symptom scores (p &amp;lt; 0.05) and lower mental component summaries (p &amp;lt; 0.05) than those without. Conclusion Patients with dysphagia with esophageal dysmotility were classified into two groups: those with and without IBC. Assessment of bolus transport is an important clinical marker for patients with dysphagia, because those with IBC had a significantly higher dysphagia symptom scores and impaired quality of life.

Assessing different liquid-storage temperatures for rooster spermatozoa

Although liquid-storage is extensively used in poultry, there are still questions on how sperm physiology is affected and to what extent sperm functions are disrupted by storage temperature and time. There, therefore, was investigation of storage temperature and durations on multiple semen variables. The storage at 37 °C was the most damaging, affecting values for several variables within 4 h of storage, whereas most differences occurred between 5 and 25 °C after 8 h. Progressive motility and mitochondrial function started to decrease within 2 h at 25 and 37 °C, and within 4 h at 5 °C. Acrosomal damage only occurred in samples at 37 °C. Eosin-negrosin staining indicated there was damage to the plasma membrane at 37 °C, however, with use of propidium iodide there were differences between 5 and 25 °C following 24 h. Temperatures of 5 and 25 °C resulted in similar curves for chromatin dispersion although chromatin integrities differed with storage for periods longer than 4 h. At 37 °C, results using both chromatin evaluations indicated there was damage after 2 h of incubation. Oxidative stress at 5 and 25 °C was similar when there was 24 h of storage. Intriguingly, there were no interaction between temperature and storage duration for peroxidized sperm membrane and total peroxidation status. These findings indicated that with a prolonged storage at 5 °C there were not marked changes in chicken spermatozoa, whereas at 25 °C there did not appear to be sperm damage occurring as a result of short-term storage.

Functional difference of ATP-generating pathways in rooster sperm (Gallus gallus domesticus)

Adenosine triphosphate (ATP) production via glycolysis and oxidative phosphorylation is essential for the maintenance of flagellar motility in sperm; however, the primary energy production pathways supporting fertilization vary among species. Inconsistency in thought exists regarding which pathways maintain ATP production and sperm motility in poultry. Glycolysis and mitochondrial oxidation contribute to flagellar motion in chicken sperm, but the relative dependence on these pathways for motility and penetrability into the inner perivitelline layer remains unclear. In the present study, there was use of various inhibitors and energy substrates to evaluate the relative contribution of anaerobic glycolysis and mitochondrial oxidation to chicken sperm flagellar motility, ATP production, and penetrating capacity through the perivitelline layer. Although both pathways contributed to these processes to varying extent, glucose was the primary substrate for sperm penetration into the inner perivitelline layer in chickens. Furthermore, results from metabolic stress analyses indicated that there was less perivitelline penetrability in response to pyruvate that was not due to changes in reactive oxygen species or intracellular pH. Overall, results from the present study indicate glycolysis and mitochondrial oxidation pathways have distinct functions in the flagellar motility and penetrability of the perivitelline membrane by rooster sperm. There, therefore, are new insights as a result of findings in the present study into the energy production system of sperm through which there is utilization of extracellular metabolic substrates for maintaining sperm fertilization capacity.

Bioconvection Reiner-Rivlin Nanofluid Flow between Rotating Circular Plates with Induced Magnetic Effects, Activation Energy and Squeezing Phenomena

This article deals with the unsteady flow in rotating circular plates located at a finite distance filled with Reiner-Rivlin nanofluid. The Reiner-Rivlin nanofluid is electrically conducting and incompressible. Furthermore, the nanofluid also accommodates motile gyrotactic microorganisms under the effect of activation energy and thermal radiation. The mathematical formulation is performed by employing the transformation variables. The finalized formulated equations are solved using a semi-numerical technique entitled Differential Transformation Method (DTM). Padé approximation is also used with DTM to present the solution of nonlinear coupled ordinary differential equations. Padé approximation helps to improve the accuracy and convergence of the obtained results. The impact of several physical parameters is discussed and gives analysis on velocity (axial and tangential), magnetic, temperature, concentration field, and motile gyrotactic microorganism functions. The impact of torque on the lower and upper plates are deliberated and presented through the tabular method. Furthermore, numerical values of Nusselt number, motile density number, and Sherwood number are given through tabular forms. It is worth mentioning here that the DTM-Padé is found to be a stable and accurate method. From a practical point of view, these flows can model cases arising in geophysics, oceanography, and in many industrial applications like turbomachinery.

The relationship of gastrointestinal complications and ventilator related status with gastric residual volume in intensive care patients

Aim: Our study aimed primarily to determine whether there was a relationship between total gastric residual volume (GRV) amounts and two different GRV thresholds and the development of gastrointestinal intolerance in patients on mechanical ventilation in the intensive care unit (ICU) and secondarily, to determine the effects of different GRV quantities on ventilator-related conditions (VAC).Methods: Seventy patients above the age of 18 who were scheduled to be fed with enteral nutrition (EN) for at least three days, were divided into two groups including 35 patients according to GRV threshold values of 250 ml and 500 ml. The total amounts of GRV of the patients who did not exceed any of the two GRV thresholds during the follow-up period of 72 hours were recorded and calculated. For all patients, necessary data was recorded and high gastric residual volume rates (HGRV), times to reach target calories, mean GRV amounts, abdominal distension, vomiting, diarrhea, VAC and infection-related ventilator-related complications (IVAC) were all observed.Results: Although there were statistically significant differences between the groups in terms of the HGRV rates and the HGRV rates exceeding the determined threshold values [p &amp;lt;0.05], there was no significant difference between the groups in terms of abdominal distension, vomiting, diarrhea, VAC and IVAC (p&amp;gt; 0.05).Conclusion: The results of this study suggest that measuring the amount of GRV in intensive care patients fed by EN via the nasogastric tube in order to decide on gastrointestinal motility function and to reduce the complication rate, is not necessary.

Traveling wave solutions to the density-suppressed motility model

To understand the “self-trapping” mechanism inducing spatio-temporal pattern formations observed in the experiment of [21] for bacterial motion, the following density-suppressed motility model{ut=Δ(γ(v)u)+u(a−bu),vt=Δv+u−v, was proposed in [6,21], where u(x,t) and v(x,t) represent the densities of bacteria and the chemical emitted by the bacteria, respectively; γ(v) is called the motility function satisfying γ′(v)<0 and a,b>0 are positive constants accounting for the growth and death rates of bacterial cells. The analysis of the above system is highly non-trivial due to the cross-diffusion and possible degeneracy resulting from the nonlinear motility function γ(v) and mathematical progresses on the global well-posedness and asymptotics of solutions were just made recently. Among other things, the purpose of this paper is to consider the above system with motility function γ(v)=1(1+v)m(m>0) and investigate the traveling wave solutions which are genuine patterns observed in the experiment of [21]. By introducing an auxiliary parabolic problem to which the comparison principle applies and constructing relaxed super- and sub-solutions with spatially inhomogeneous decay rates, we show that there exist two constants b⁎(m,a) and K(m,a), for b>b⁎(m,a) and K(m,a)<1, the above density-suppressed motility model admits traveling wave solutions (u,v)(x,t)=:(U,V)(x⋅ξ−ct) in RN along the direction ξ∈SN−1 for all wave speed c≥2a connecting the equilibrium (a/b,a/b) to (0,0), while positive traveling wave solutions will not exist if c<2a. As m→0, we have b⁎(m,a)→0 and K(m,a)→0, our results are well consistent with the relevant results for the well-known Fisher-KPP equation (i.e. the first equation of the above system with γ(v)=1). The main novel idea in the analysis of this paper is the construction of super- and sub-solutions with spatially inhomogeneous (i.e. non-constant) decay rates, in contrast to the constant decay rates used in the literature for reaction-diffusion equations, which was developed to cope with the difficulty caused by the density-dependent nonlinear diffusion in the system. We further discuss the selection of wave patterns and wave speeds for given initial value and use numerical simulations to illustrate that both monotone and non-monotone traveling wavefronts exist depending on whether the motility function γ(v) changes its convexity at v=a/b. Two-dimensional simulations demonstrate that the system can generate outward expanding ring (strip) pattern as observed in the experiment.

Nanocarried antioxidants in freezing extenders for boar spermatozoa.

Post-thawing cryoinjuries in boar spermatozoa due to oxidative stress may be reduced by adding nanoencapsulated antioxidants to freezing extenders. This study evaluated post-thawing kinetics, structural and biochemical functions of boar spermatozoa frozen with extenders including resveratrol and vitamin E loaded into polymeric nanocapsules. Resveratrol was added at 0 (control), 5, 10, 20, 40 and 80µg/ml, whereas Vitamin E was added at 0 (control), 50, 100, 200 and 400µg/ml. Both antioxidants were tested in free and nanoencapsulated presentations. In contact with empty nanocapsules, some sperm kinetics parameters were impaired compared to the control (p<.05), whereas lipoperoxidation declined (p<.05). With inclusion of 40µg/ml nanoencapsulated resveratrol, some sperm kinetics parameters were improved (p<.01), but sperm motility, structural and biochemical functions did not differ from the control (p>.05). No improvement in sperm quality occurred with inclusion of vitamin E, although sperm kinetics with 400µg/ml nanoencapsulated vitamin E was reduced compared to the control (p<.01). Inclusion of 40µg/ml nanoencapsulated resveratrol benefitted boar sperm kinetics after thawing, but no improvement resulted from inclusion of vitamin E.

Magnetized and non-magnetized Casson fluid flow with gyrotactic microorganisms over a stratified stretching cylinder

This study presents the magnetized and non-magnetized Casson fluid flow with gyrotactic microorganisms over a stratified stretching cylinder. The mathematical modeling is presented in the form of partial differential equations and then transformed into ordinary differential equations (ODEs) utilizing suitable similarity transformations. The analytical solution of the transformed ODEs is presented with the help of homotopy analysis method (HAM). The convergence analysis of HAM is also presented by mean of figure. The present analysis consists of five phases. In the first four phases, we have compared our work with previously published investigations while phase five is consists of our new results. The influences of dimensionless factors like a magnetic parameter, thermal radiation, curvature parameter, Prandtl number, Brownian motion parameter, Schmidt number, heat generation, chemical reaction parameter, thermophoresis parameter, Eckert number, and concentration difference parameter on physical quantities of interests and flow profiles are shown through tables and figures. It has been established that with the increasing Casson parameter (i.e. beta to infty), the streamlines become denser which results the increasing behavior in the fluid velocity while on the other hand, the fluid velocity reduces for the existence of Casson parameter (i.e. beta = 1.0). Also, the streamlines of stagnation point Casson fluid flow are highly wider for the case of magnetized fluid as equated to non-magnetized fluid. The higher values of bioconvection Lewis number, Peclet number, and microorganisms’ concentration difference parameter reduces the motile density function of microorganisms while an opposite behavior is depicted against density number.

P–048 Effects of bisphenol S and bisphenol F on human spermatozoa: an in vitro study

Abstract Study question Are plasticizers bisphenol S (BPS) and bisphenol F (BPF) safer alternatives to bisphenol A (BPA) for human sperm function? Summary answer Unlike BPA, the analogues BPS and BPF do not significantly affect human sperm mitochondrial functions, motility and viability What is known already The widespread distribution of BPA, along with its reputation to be an endocrine disruptor has generated concerns about possible adverse effects for human health, thus prompting the European Food Safety Authority and the Food and Drug Administration to ban the use of this chemical in many plastic products. Following such restrictions, several substitutes have been developed, with BPS and BPF representing the main replacements to BPA. While it has been demonstrated that BPA promotes oxidative damages in spermatozoa from different species, including human, the possible effects exerted by BPS and BPF on human sperm, have not yet been investigated. Study design, size, duration We explored the effect of 4 h in vitro exposure to scalar concentrations of BPS and BPF (from 10 to 400 μM), and to 400 μM BPA on sperm motility, viability, mitochondrial membrane potential (Δm) and mitochondrial generation of reactive oxygen species (ROS). In a set of experiments, the effect of a combination of both BPF (400 μM) and BPS (400 μM) on ΔΨm and mitochondrial ROS generation was also assessed. Participants/materials, setting, methods Sperm Δm was analyzed by flow cytometry with the fluorescent lipophilic cationic dye JC–1. Flow cytometric assessment of mitochondrial generation of ROS was carried out using the lipid soluble cation MitoSOX red (MSR). Sperm motility and viability were evaluated by Computer-Aided Semen Analysis (CASA) and eosin assay, respectively. Main results and the role of chance The exposure to scalar concentration of BPS did not significantly affect sperm motility and viability with respect to untreated controls. A lower, albeit not significant, sperm motility was registered in samples exposed to the highest concentrations of BPF (300 μM and 400 μM). As expected, 400 μM BPA produced a complete sperm immobilization along with a dramatically loss in sperm viability. No significant differences were observed in sperm Δm and ROS generation after exposure to scalar concentration of BPS compared to untreated controls and the trend towards lower Δm and higher mitochondrial ROS generation at the highest concentrations of BPF did not reach statistical significance. On the contrary, after 4 h exposure to 400 μM BPA a significant lower Δm and higher mitochondrial ROS generation were observed. Finally, the exposure to a combination of BPF and BPS at high concentrations (400 μM) did not significantly affect sperm Δm, or mitochondrial ROS generation, when compared to 400 μM BPA, used as positive control. Limitations, reasons for caution: The present study only evaluated BPS and BPF effects, but in daily-life people are exposed to several plasticizers containing different bisphenols at different concentrations. Therefore, adverse effects of synergic exposure to BPA analogues other than BPS and BPF, alone or in combination with BPA, cannot be ruled out. Wider implications of the findings: The analogues BPS and BPF, alone or in combination, appeared to be safer alternatives to BPA on sperm biology as they exert a neutral effect on sperm motility, viability, and mitochondrial functions even at high concentrations. These results could be useful to identify more secure plasticizer components. Trial registration number Not applicable

Prolonged function and optimization of actomyosin motility for upscaled network-based biocomputation

Significant advancements have been made towards exploitation of naturally available molecular motors and their associated cytoskeletal filaments in nanotechnological applications. For instance, myosin motors and actin filaments from muscle have been used with the aims to establish new approaches in biosensing and network-based biocomputation. The basis for these developments is a version of the in vitro motility assay (IVMA) where surface-adsorbed myosin motors propel the actin filaments along suitably derivatized nano-scale channels on nanostructured chips. These chips are generally assembled into custom-made microfluidic flow cells. For effective applications, particularly in biocomputation, it is important to appreciably prolong function of the biological system. Here, we systematically investigated potentially critical factors necessary to achieve this, such as biocompatibility of different components of the flow cell, the degree of air exposure, assay solution composition and nanofabrication methods. After optimizing these factors we prolonged the function of actin and myosin in nanodevices for biocomputation from <20 min to >60 min. In addition, we demonstrated that further optimizations could increase motility run times to >20 h. Of great importance for the latter development was a switch of glucose oxidase in the chemical oxygen scavenger system (glucose oxidase–glucose–catalase) to pyranose oxidase, combined with the use of blocking actin (non-fluorescent filaments that block dead motors). To allow effective testing of these approaches we adapted commercially available microfluidic channel slides, for the first time demonstrating their usefulness in the IVMA. As part of our study, we also demonstrate that myosin motor fragments can be stored at −80 °C for more than 10 years before use for nanotechnological purposes. This extended shelf-life is important for the sustainability of network-based biocomputation.

SARS-CoV-2 infection induces the dedifferentiation of multiciliated cells and impairs mucociliary clearance

Understanding how SARS-CoV-2 spreads within the respiratory tract is important to define the parameters controlling the severity of COVID-19. Here we examine the functional and structural consequences of SARS-CoV-2 infection in a reconstructed human bronchial epithelium model. SARS-CoV-2 replication causes a transient decrease in epithelial barrier function and disruption of tight junctions, though viral particle crossing remains limited. Rather, SARS-CoV-2 replication leads to a rapid loss of the ciliary layer, characterized at the ultrastructural level by axoneme loss and misorientation of remaining basal bodies. Downregulation of the master regulator of ciliogenesis Foxj1 occurs prior to extensive cilia loss, implicating this transcription factor in the dedifferentiation of ciliated cells. Motile cilia function is compromised by SARS-CoV-2 infection, as measured in a mucociliary clearance assay. Epithelial defense mechanisms, including basal cell mobilization and interferon-lambda induction, ramp up only after the initiation of cilia damage. Analysis of SARS-CoV-2 infection in Syrian hamsters further demonstrates the loss of motile cilia in vivo. This study identifies cilia damage as a pathogenic mechanism that could facilitate SARS-CoV-2 spread to the deeper lung parenchyma.

Structure of the trypanosome paraflagellar rod and insights into non-planar motility of eukaryotic cells

Eukaryotic flagella (synonymous with cilia) rely on a microtubule-based axoneme, together with accessory filaments to carryout motility and signaling functions. While axoneme structures are well characterized, 3D ultrastructure of accessory filaments and their axoneme interface are mostly unknown, presenting a critical gap in understanding structural foundations of eukaryotic flagella. In the flagellum of the protozoan parasite Trypanosoma brucei (T. brucei), the axoneme is accompanied by a paraflagellar rod (PFR) that supports non-planar motility and signaling necessary for disease transmission and pathogenesis. Here, we employed cryogenic electron tomography (cryoET) with sub-tomographic averaging, to obtain structures of the PFR, PFR-axoneme connectors (PACs), and the axonemal central pair complex (CPC). The structures resolve how the 8 nm repeat of the axonemal tubulin dimer interfaces with the 54 nm repeat of the PFR, which consist of proximal, intermediate, and distal zones. In the distal zone, stacked “density scissors” connect with one another to form a “scissors stack network (SSN)” plane oriented 45° to the axoneme axis; and ~370 parallel SSN planes are connected by helix-rich wires into a paracrystalline array with ~90% empty space. Connections from these wires to the intermediate zone, then to overlapping layers of the proximal zone and to the PACs, and ultimately to the CPC, point to a contiguous pathway for signal transmission. Together, our findings provide insights into flagellum-driven, non-planar helical motility of T. brucei and have broad implications ranging from cell motility and tensegrity in biology, to engineering principles in bionics.

Transcriptome profiles of stem-like cells from primary breast cancers allow identification of ITGA7 as a predictive marker of chemotherapy response

BackgroundBreast cancer stem cells (BCSCs) are drivers of therapy-resistance, therefore are responsible for poor survival. Molecular signatures of BCSCs from primary cancers remain undefined. Here, we identify the consistent transcriptome of primary BCSCs shared across breast cancer subtypes, and we examine the clinical relevance of ITGA7, one of the genes differentially expressed in BCSCs.MethodsPrimary BCSCs were assessed using immunohistochemistry and fluorescently labelled using Aldefluor (n = 17). Transcriptomes of fluorescently sorted BCSCs and matched non-stem cancer cells were determined using RNA-seq (n = 6). ITGA7 expression was examined in breast cancers using immunohistochemistry (n = 305), and its functional role was tested using siRNA in breast cancer cells.ResultsProportions of BCSCs varied from 0 to 9.4%. 38 genes were significantly differentially expressed in BCSCs; genes were enriched for functions in vessel morphogenesis, motility, and metabolism. ITGA7 was found to be significantly downregulated in BCSCs, and low expression significantly correlated with reduced survival in patients treated with chemotherapy, and with chemoresistance in breast cancer cells in vitro.ConclusionsThis study is the first to define the molecular profile of BCSCs from a range of primary breast cancers. ITGA7 acts as a predictive marker for chemotherapy response, in accordance with its downregulation in BCSCs.

Diabetic diarrhoea: A study on gastrointestinal motility, pH levels and autonomic function.

Chronic diarrhoea is a common, but poorly investigated diabetes complication. Autonomic neuropathy is a leading pathophysiological theory founded on old, small studies. Studies of gastrointestinal motility and pH levels are lacking. Using new diagnostic methods, we aimed to find out if diabetic diarrhoea was associated with alterations in gastrointestinal motility, pH levels and autonomic function. Fifty-seven patients (42 women, 46 with type 1 diabetes) were prospectively included. Symptoms were evaluated with the gastrointestinal symptom rating scale, defining ≥4 points as cases with diarrhoea. Patients scoring <4 were used as controls. We used the wireless motility capsule to measure gastrointestinal transit times, pH levels and contractility parameters. Autonomic function was assessed by measuring heart rate variability, baroreflex sensitivity and orthostatic hypotension. Seventeen patients (30%) had diarrhoea. Compared with controls, cases had slower gastric emptying (21:46 vs. 4:14, h:min, p = 0.03) and faster colonic transit (18:37 vs. 54:25, p < 0.001). Cases had increased intraluminal pH in the antrum (2.4 vs. 1.2, p = 0.009), caecum (7.3 vs. 6.4, p = 0.008) and entire colon (7.1 vs. 6.7, p = 0.05). They also had a decreased pH difference across the pylorus (3.3 vs. 4.9, p = 0.004) and ileocaecal junction (0.6 vs 1.0, p = 0.009). The groups did not differ in autonomic function, but diastolic blood pressure drop correlated rs = -0.34 (p = 0.04) with colonic transit time. Patients with diabetic diarrhoea had altered gastrointestinal transit and intraluminal pH levels, but minimal changes in autonomic function. Our results suggest that tests of gastrointestinal function are clinically useful in diabetic diarrhoea.