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Developmental Cell Dec 2023The extrahepatic branches of the biliary tree have glands that connect to the surface epithelium through narrow pits. The duct epithelia undergo homeostatic renewal, yet...
The extrahepatic branches of the biliary tree have glands that connect to the surface epithelium through narrow pits. The duct epithelia undergo homeostatic renewal, yet the identity and multiplicity of cells that maintain this tissue is unknown. Using marker-free and targeted clonal fate mapping in mice, we provide evidence that the extrahepatic bile duct is compartmentalized. Pit cholangiocytes of extramural glands renewed the surface epithelium, whereas basally oriented cholangiocytes maintained the gland itself. In contrast, basally positioned cholangiocytes replenished the surface epithelium in mural glands. Single-cell sequencing identified genes enriched in the base and surface epithelial populations, with trajectory analysis showing graded gene expression between these compartments. Epithelia were plastic, changing cellular identity upon fasting and refeeding. Gain of canonical Wnt signaling caused basal cell expansion, gastric chief cell marker expression, and a decrease in surface epithelial markers. Our results identify the cellular hierarchy governing extrahepatic biliary epithelial renewal.
Topics: Animals; Mice; Biliary Tract; Bile Ducts, Extrahepatic; Epithelium; Epithelial Cells; Cell Proliferation
PubMed: 37909044
DOI: 10.1016/j.devcel.2023.10.004 -
Tidsskrift For Den Norske Laegeforening... Sep 2009Sleep problems are a frequent cause for contacting primary care services. Knowledge of basic mechanisms behind sleep and wakefulness is essential for giving adequate... (Review)
Review
BACKGROUND
Sleep problems are a frequent cause for contacting primary care services. Knowledge of basic mechanisms behind sleep and wakefulness is essential for giving adequate information and correct patients' frequent misperception of sleep.
MATERIAL AND METHODS
The present review is based on literature identified through a non-systematic search of Pub-med as well as the authors' own research experience.
RESULTS
Sleep need (homeostatic factor), circadian rhythm and behaviour regulate sleepiness, sleep depth and sleep duration. Falling asleep requires central-nervous deactivation. Sleep depth depends on the length of wakefulness beforehand, while duration of sleep mainly depends on timing in relation to the circadian phase of activation. Activation and wakefulness are the combined result of activating several different parts of the brain: thalamus, the reticular activation system, basal forebrain, hypothalamus and monoaminergic cell groups in the brainstem. Falling asleep is a dynamic process and is primarily a consequence of behaviourally induced deactivation. Sleep is especially modulated by GABAergic neurons in the thalamus and basal forebrain, but several neurotransmitters and endogenous substances modulate sleep and wakefulness. Sleep and wakefulness are complex phenomena, and the activity in different brain regions is markedly different depending on whether you are awake or asleep. Hence, a manipulation of these, e.g. by use of certain medications, may cause sleep problems.
INTERPRETATION
Knowledge of sleep is essential for adequate evaluation and treatment of sleep disturbances.
Topics: Central Nervous System Stimulants; Circadian Rhythm; Homeostasis; Humans; Signal Transduction; Sleep; Sleep Wake Disorders; Sleep, REM; Wakefulness
PubMed: 19756059
DOI: 10.4045/tidsskr.08.0465 -
Basal and apical regulation of VEGF-A and placenta growth factor in the RPE/choroid and primary RPE.Molecular Vision 2015Members of the vascular endothelial growth factor (VEGF) family are strongly involved in pathological processes in the retina, such as age-related macular degeneration...
PURPOSE
Members of the vascular endothelial growth factor (VEGF) family are strongly involved in pathological processes in the retina, such as age-related macular degeneration and diabetic retinopathy. Cells of the retinal pigment epithelium (RPE) constitutively secrete VEGF-A, and the secretion of placental growth factor (PlGF) has also been described. RPE cells are strongly polarized cells with different secretome at the apical and basal side. In this study, we evaluated the basal and apical regulation of VEGF-A and PlGF secretion in RPE/choroid explants and primary RPE cells.
METHODS
RPE/choroid tissue explants were prepared from porcine eyes and cultivated in modified Ussing chambers, separating apical (RPE) and basal (choroid) supernatant. Primary RPE cells were also prepared from porcine eyes and cultivated on Transwell plates. Explants and cells were treated with inhibitors for VEGFR-2 (SU1498), p38 (SB203580), and the transcription factors nuclear factor-kappa B (NF-κB) and SP-1 (mithramycin), respectively. VEGF-A and PlGF content was evaluated with enzyme-linked immunosorbent assay (ELISA). In addition, western blots were performed.
RESULTS
In the RPE/choroid, VEGF-A can initially be found on the apical and basal sides with significantly more pronounced secretion on the basal side. VEGF-A secretion is differentially regulated on the apical and basal sides, with the inhibition of SP-1 and NF-κB showing strong effects apically and basally after 24 h and 48 h, the inhibition of p38 displaying its effect mainly on the basal side with some effect apically after 48 h, and the inhibition of VEGFR-2 reducing the secretion of VEGF only on the apical side at 24 h and 48 h. In the RPE cell culture, similar effects were found, with inhibition of NF-κB or SP-1 displaying a strong decrease in VEGF-A on both sides, and p38 inhibition displaying only an inhibitory effect on the basal side. In contrast, an apical effect of VEGFR-2 inhibition was not found. However, the western blot experiments exhibited a significant decrease in the VEGF-A protein under SU1498 treatment. In the RPE/choroid organ cultures, PlGF was initially found mainly on the basal site with only minute amounts of PlGF found apically. NF-κB and SP-1 were strongly involved in PlGF regulation apically and basally, while VEGFR2 and to a lesser degree p38 displayed some regulation at the basal site. In the primary RPE cell culture, PlGF was not found on the apical or basal side.
CONCLUSIONS
VEGF-A and PlGF were constitutively secreted and regulated by the RPE/choroid complex, with PlGF secreted mainly by the choroid. Although the transcription factors NF-κB and SP-1 were involved in apical and basal regulation of both growth factors, VEGFR-2 displayed a strong polarity, with regulation of apical VEGF-A and basal PlGF secretion.
Topics: Animals; Cells, Cultured; Choroid; NF-kappa B; Organ Culture Techniques; Placenta Growth Factor; Pregnancy Proteins; Retinal Pigment Epithelium; Sp1 Transcription Factor; Sus scrofa; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2; p38 Mitogen-Activated Protein Kinases
PubMed: 26167115
DOI: No ID Found -
Development (Cambridge, England) Oct 2020Between embryonic days 10.5 and 14.5, active proliferation drives rapid elongation of the murine midgut epithelial tube. Within this pseudostratified epithelium, nuclei...
Between embryonic days 10.5 and 14.5, active proliferation drives rapid elongation of the murine midgut epithelial tube. Within this pseudostratified epithelium, nuclei synthesize DNA near the basal surface and move apically to divide. After mitosis, the majority of daughter cells extend a long, basally oriented filopodial protrusion, building a path along which their nuclei can return to the basal side. WNT5A, which is secreted by surrounding mesenchymal cells, acts as a guidance cue to orchestrate this epithelial pathfinding behavior, but how this signal is received by epithelial cells is unknown. Here, we have investigated two known WNT5A receptors: ROR2 and RYK. We found that epithelial ROR2 is dispensable for midgut elongation. However, loss of phenocopies the phenotype, perturbing post-mitotic pathfinding and leading to apoptosis. These studies reveal that the ligand-receptor pair WNT5A-RYK acts as a navigation system to instruct filopodial pathfinding, a process that is crucial for continuous cell cycling to fuel rapid midgut elongation.
Topics: Animals; Apoptosis; Cell Nucleus; Digestive System; Epithelial Cells; Epithelium; Female; Male; Mesoderm; Mice, Inbred C57BL; Pseudopodia; Receptor Protein-Tyrosine Kinases; Receptor Tyrosine Kinase-like Orphan Receptors
PubMed: 32994164
DOI: 10.1242/dev.195388 -
Insect Biochemistry and Molecular... Jul 2023Salivary glands are vital to tick feeding success and also play a crucial role in tick-borne pathogen transmission. In previous studies of Ixodes scapularis salivary...
Salivary glands are vital to tick feeding success and also play a crucial role in tick-borne pathogen transmission. In previous studies of Ixodes scapularis salivary glands, we demonstrated that saliva-producing type II and III acini are innervated by neuropeptidergic axons which release different classes of neuropeptides via their terminals (Šimo et al., 2009b, 2013). Among these, the neuropeptide SIFamide-along with its cognate receptor-were postulated to control the basally located acinar valve via basal epithelial and myoepithelial cells (Vancová et al., 2019). Here, we functionally characterized a second SIFamide receptor (SIFa_R2) from the I. scapularis genome and proved that it senses a low nanomolar level of its corresponding ligand. Insect SIFamide paralogs, SMYamides, also activated the receptor but less effectively compared to SIFamide. Bioinformatic and molecular dynamic analyses suggested that I. scapularis SIFamide receptors are class A GPCRs where the peptide amidated carboxy-terminus is oriented within the receptor binding cavity. The receptor was found to be expressed in Ixodes ricinus salivary glands, synganglia, midguts, trachea, and ovaries, but not in Malpighian tubules. Investigation of the temporal expression patterns suggests that the receptor transcript is highly expressed in unfed I. ricinus female salivary glands and then decreases during feeding. In synganglia, a significant transcript increase was detected in replete ticks. In salivary gland acini, an antibody targeting the SIFa_R2 recognized basal epithelial cells, myoepithelial cells, and basal granular cells in close proximity to the SIFamide-releasing axon terminals. Immunoreactivity was also detected in specific neurons distributed throughout various I. ricinus synganglion locations. The current findings, alongside previous reports from our group, indicate that the neuropeptide SIFamide acts via two different receptors that regulate distinct or common cell types in the basal region of type II and III acini in I. ricinus salivary glands. Our study investigates the peptidergic regulation of the I. ricinus salivary gland in detail, emphasizing the complexity of this system.
Topics: Female; Animals; Ixodes; Salivary Glands; Neurons; Saliva; Neuropeptides
PubMed: 37257628
DOI: 10.1016/j.ibmb.2023.103963 -
Canadian Journal of Diabetes Jun 2023Our aim in this study was to compare the efficacy and safety of commercially available fixed-ratio combinations (FRCs) of glucagon-like peptide-1 receptor agonists... (Meta-Analysis)
Meta-Analysis
Comparison of Efficacy and Safety of Commercially Available Fixed-Ratio Combinations of Insulin Degludec/Liraglutide and Insulin Glargine/Lixisenatide: A Network Meta-analysis.
OBJECTIVES
Our aim in this study was to compare the efficacy and safety of commercially available fixed-ratio combinations (FRCs) of glucagon-like peptide-1 receptor agonists (GLP-1RAs) and basal insulins by a network meta-analysis of randomized controlled trials (RCTs) of people with type 2 diabetes.
METHODS
We present a systematic review and network meta-analyses of RCTs of individuals with type 2 diabetes randomized to FRCs or to their components for ≥24 weeks. All reports were obtained from PubMed or ClinicalTrials.gov up to February 28, 2022. The primary outcome was glycated hemoglobin (A1C) level attained. Secondary outcomes included fasting plasma glucose, change in body weight, and incident hypoglycemia. Treatment effects were estimated as mean difference (MD) and standard error (SE), or as odds ratio (OR) with 95% confidence interval (CI) using the fixed combination of insulin glargine 100 IU/mL and lixisenatide (iGlarLixi) as reference.
RESULTS
We included 29 RCTs from among the 1,404 articles identified. No direct comparisons between FRCs were found. After excluding some insulin-capped trials to reach model consistency, both FRCs were more efficacious regarding A1C than their components, but no difference between FRCs was found (MD, -0.10%; SE, 0.10%). The effect of the fixed combination of insulin degludec and liraglutide (IDegLira) (MD, -0.47 mmol/L; SE, 0.24 mmol/L) and basal insulins was similar to that of iGlarLixi (reference) on fasting glucose, whereas GLP-1RAs had lower efficacy than iGlarLixi. Weight gain was lower with GLP-1RAs and IDegLira (MD, -0.72 kg; SE, 0.32 kg) than with iGlarLixi (reference) and higher with basal insulins. Incident hypoglycemia (based on different definitions) was least frequent with GLP-1RAs, followed by IDegLira (OR, 0.78; 95% CI, 0.39 to 1.57), iGlarLixi (reference), and basal insulins.
CONCLUSIONS
For A1C, both FRCs were more efficacious over their individual components, with similar efficacies of the 2 FRCs.
Topics: Humans; Liraglutide; Insulin Glargine; Network Meta-Analysis; Glycated Hemoglobin; Blood Glucose; Drug Combinations; Hypoglycemic Agents; Diabetes Mellitus, Type 2; Hypoglycemia; Randomized Controlled Trials as Topic
PubMed: 36963632
DOI: 10.1016/j.jcjd.2023.03.002 -
Developmental Dynamics : An Official... May 2011The development of the tetrapod limb during skeletogenesis follows a highly conservative pattern characterized by a general proximo-distal progression in the... (Review)
Review
The development of the tetrapod limb during skeletogenesis follows a highly conservative pattern characterized by a general proximo-distal progression in the establishment of skeletal elements and a postaxial polarity in digit development. Salamanders represent the only exception to this pattern and display an early establishment of distal autopodial structures, specifically the basale commune, an amalgamation of distal carpal and tarsal 1 and 2, and a distinct preaxial polarity in digit development. This deviance from the conserved tetrapod pattern has resulted in a number of hypotheses to explain its developmental basis and evolutionary history. Here we summarize the current knowledge of salamander limb development under consideration of the fossil record to provide a deep time perspective of this evolutionary pathway and highlight what data will be needed in the future to gain a better understanding of salamander limb development specifically and tetrapod limb development and evolution more broadly.
Topics: Animals; Biological Evolution; Extremities; Fossils; Regeneration; Urodela
PubMed: 21465623
DOI: 10.1002/dvdy.22629 -
Journal of Veterinary Diagnostic... May 2022Senecavirus A (SVA) infection in pigs causes vesicular disease and results in a short viremia and transient shedding of the virus, mainly in oral fluids and feces. Here...
Senecavirus A (SVA) infection in pigs causes vesicular disease and results in a short viremia and transient shedding of the virus, mainly in oral fluids and feces. Here we describe the consistent prolonged shedding of SVA in the semen of 2 boars, and persistence of SVA within the tonsils and testes of 3 adult boars. Two SVA-infected boars that were identified on a Minnesota sow farm in 2017 shed SVA RNA in semen for >3 mo after an outbreak of vesicular disease had occurred on the farm. SVA was isolated from 1 semen sample collected 9 d after clinical disease began on the farm. The third SVA-infected boar was identified on an Indiana sow farm in 2020. All boars had SVA RNA detected in the testes and tonsils by RT-rtPCR, with lower Ct values obtained for the testes than from the tonsils. All boars had multifocal lymphocytic orchitis with segmental degeneration and atrophy of the germinal epithelium within the seminiferous tubules. One boar also had areas of seminiferous tubule collapse and interstitial fibrosis within the testes. In all boars, in situ hybridization demonstrated the presence of SVA mRNA within cells located basally in the seminiferous tubules of the testes, and within the basal surface epithelial cells, crypt epithelial cells, and subepithelial and parafollicular lymphocytes and histiocytes of the tonsil.
Topics: Animals; Female; Male; Picornaviridae; RNA; Swine; Swine Diseases; Viremia
PubMed: 35354385
DOI: 10.1177/10406387221084054 -
Revue Medicale de Liege Apr 2019Insulin degludec (Tresiba®) is characterized by an original mode of prolonged and continuous insulin release after its subcutaneous injection. Thereby, it has a very...
Insulin degludec (Tresiba®) is characterized by an original mode of prolonged and continuous insulin release after its subcutaneous injection. Thereby, it has a very long glucose-lowering effect, around 42 hours, and a better reproducibility from both a pharmacokinetic and pharmacodynamic point of view. Its efficacy and safety have been assessed in the phase 3 clinical programme BEGIN as compared with insulin glargine U100, in patients with type 1 diabetes (T1D) and type 2 (T2D). For a similar glucose control (reduction in glycated haemoglobin), less hypoglycaemic episodes were recorded, including severe hypoglycaemia, during the nocturnal period, with insulin degludec than with insulin glargine U100. This clinical benefit has been confirmed in the complementary SWITCH programme in T1D and T2D patients at higher risk of hypoglycaemia, in the double-blind cardiovascular outcome trial DEVOTE in T2D patients at high cardiovascular risk and in real-life conditions in the observational European EU-TREAT study in patients with T1D and T2D. Insulin degludec (Tresiba®) is indicated and reimbursed for the treatment of patients with T1D, combined with a prandial insulin, and T2D, alone or combined with oral antidiabetic agents, a glucagon-like peptide-1 receptor agonist or a short-acting insulin.
Topics: Diabetes Mellitus, Type 2; Double-Blind Method; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Observational Studies as Topic; Reproducibility of Results
PubMed: 30997973
DOI: No ID Found -
Acta Dermato-venereologica Jan 2019Deregulated Hedgehog signalling is a driver of basal cell carcinomas. One effector of the Hedgehog pathway is n-MYC. c/n-MYC proteins, NAMPT and DBC1 are linked to SIRT1...
Deregulated Hedgehog signalling is a driver of basal cell carcinomas. One effector of the Hedgehog pathway is n-MYC. c/n-MYC proteins, NAMPT and DBC1 are linked to SIRT1 in a positive feedback loop that may contribute to tumorigenesis of basal cell carcinoma. In 5 basal cell carcinoma types immunohistochemistry revealed n-MYC, NAMPT and SIRT1 expression. DBC1 was homogenously expressed in all epithelial cells. NAMPT, SIRT1 and c-MYC were expressed in the stratum basale of human and murine skin. In hair follicles NAMPT and SIRT1 were expressed together with c-MYC and n-MYC, except for the matrix, where n-MYC was strongly positive, but c-MYC expression was absent. Therefore, a common pathway connecting n-MYC, NAMPT and SIRT1 may be active in basal cell carcinomas and in their cells of origin. This pathway may contribute to the development of basal cell carcinomas. Targeting factors in the feedback loop may offer novel therapeutic options.
Topics: Adaptor Proteins, Signal Transducing; Animals; Biomarkers, Tumor; Biopsy; Carcinoma, Basal Cell; Cell Cycle Proteins; Cytokines; Humans; Immunohistochemistry; Mice; Mice, Inbred C57BL; Neoplastic Stem Cells; Nerve Tissue Proteins; Nicotinamide Phosphoribosyltransferase; Proto-Oncogene Proteins c-myc; Sirtuin 1; Skin Neoplasms
PubMed: 30182136
DOI: 10.2340/00015555-3031