ABSTRACT
The authors wish to make the following correction to this paper [...].
ABSTRACT
Recent work indicates that there are distinct response habituation mechanisms that can be recruited by different stimulation rates and that can underlie different components (e.g., the duration or speed) of a single behavioral response. These findings raise the question: why is "the simplest form of learning" so complicated mechanistically? Beyond evolutionary selection for robustness of plasticity in learning to ignore, it is proposed in this article that multiple mechanisms of habituation have evolved to streamline shifts in ongoing behavioral strategy. Then, speculations are offered regarding the implications of this reconceptualization of habituation for approaching the analysis of mechanisms of more complex forms of learning and memory.
Subject(s)
Caenorhabditis elegans/physiology , Habituation, Psychophysiologic , Nociception/physiology , Adaptation, Biological , Animals , Behavior , Behavior, Animal/physiology , Humans , Mental Disorders/psychology , Zebrafish/physiologyABSTRACT
The engineering of vascular regeneration still involves barriers that need to be conquered. In the current study, a novel nanocomposite comprising of fibronectin (denoted as FN) and a small amount of silver nanoparticles (AgNP, ~15.1, ~30.2 or ~75.5 ppm) was developed and its biological function and biocompatibility in Wharton's jelly-derived mesenchymal stem cells (MSCs) and rat models was investigated. The surface morphology as well as chemical composition for pure FN and the FN-AgNP nanocomposites incorporating various amounts of AgNP were firstly characterized by atomic force microscopy (AFM), UV-Visible spectroscopy (UV-Vis), and Fourier-transform infrared spectroscopy (FTIR). Among the nanocomposites, FN-AgNP with 30.2 ppm silver nanoparticles demonstrated the best biocompatibility as assessed through intracellular ROS production, proliferation of MSCs, and monocytes activation. The expression levels of pro-inflammatory cytokines, TNF-α, IL-1ß, and IL-6, were also examined. FN-AgNP 30.2 ppm significantly inhibited pro-inflammatory cytokine expression compared to other materials, indicating superior performance of anti-immune response. Mechanistically, FN-AgNP 30.2 ppm significantly induced greater expression of vascular endothelial growth factor (VEGF) and stromal-cell derived factor-1 alpha (SDF-1α) and promoted the migration of MSCs through matrix metalloproteinase (MMP) signaling pathway. Besides, in vitro and in vivo studies indicated that FN-AgNP 30.2 ppm stimulated greater protein expressions of CD31 and von Willebrand Factor (vWF) as well as facilitated better endothelialization capacity than other materials. Furthermore, the histological tissue examination revealed the lowest capsule formation and collagen deposition in rat subcutaneous implantation of FN-AgNP 30.2 ppm. In conclusion, FN-AgNP nanocomposites may facilitate the migration and proliferation of MSCs, induce endothelial cell differentiation, and attenuate immune response. These finding also suggests that FN-AgNP may be a potential anti-inflammatory surface modification strategy for vascular biomaterials.
Subject(s)
Anti-Inflammatory Agents/administration & dosage , Cell Differentiation/drug effects , Fibronectins/administration & dosage , Mesenchymal Stem Cells/drug effects , Mesenchymal Stem Cells/metabolism , Metal Nanoparticles , Silver , Animals , Cell Proliferation , Cells, Cultured , Cytoskeleton , Endothelial Cells/metabolism , Immunohistochemistry , Matrix Metalloproteinases/metabolism , Mesenchymal Stem Cells/cytology , Metal Nanoparticles/ultrastructure , Particle Size , Rats , Reactive Oxygen Species/metabolism , Spectroscopy, Fourier Transform InfraredABSTRACT
Krüppel-like factor 4 (KLF4) is a zinc finger transcription factor critical for the regulation of many cellular functions in both normal and neoplastic cells. Here, using human glioblastoma cells, we investigated KLF4's effects on cancer cell metabolism. We found that forced KLF4 expression promotes mitochondrial fusion and induces dramatic changes in mitochondrial morphology. To determine the impact of these changes on the cellular functions following, we analyzed how KLF4 alters glioblastoma cell metabolism, including glucose uptake, glycolysis, pentose phosphate pathway, and oxidative phosphorylation. We did not identify significant differences in baseline cellular metabolism between control and KLF4-expressing cells. However, when mitochondrial function was impaired, KLF4 significantly increased spare respiratory capacity and levels of reactive oxygen species in the cells. To identify the biological effects of these changes, we analyzed proliferation and survival of control and KLF4-expressing cells under stress conditions, including serum and nutrition deprivation. We found that following serum starvation, KLF4 altered cell cycle progression by arresting the cells at the G2/M phase and that KLF4 protected cells from nutrition deprivation-induced death. Finally, we demonstrated that methylation-dependent KLF4-binding activity mediates mitochondrial fusion. Specifically, the downstream targets of KLF4-mCpG binding, guanine nucleotide exchange factors, serve as the effector of KLF4-induced mitochondrial fusion, cell cycle arrest, and cell protection. Our experimental system provides a robust model for studying the interactions between mitochondrial morphology and function, mitochondrial dynamics and metabolism, and mitochondrial fusion and cell death during tumor initiation and progression.
Subject(s)
Cell Division , G2 Phase , Glioblastoma/metabolism , Kruppel-Like Transcription Factors/metabolism , Mitochondrial Dynamics , Neoplasm Proteins/metabolism , Oxygen Consumption , Cell Line, Tumor , Cell Survival , Glioblastoma/genetics , Glioblastoma/pathology , Humans , Kruppel-Like Factor 4 , Kruppel-Like Transcription Factors/genetics , Neoplasm Proteins/geneticsABSTRACT
Peroxiredoxins (PRDXs) are antioxidant enzymes proven to control the levels of reactive oxygen species (ROS) and to avoid oxidative damage in the spermatozoon. Previously, we have shown that low amounts of PRDXs are associated with male infertility and that PRDX6 is the primary antioxidant defense in human spermatozoa, maintaining survival and DNA integrity (Gong et al., 2012, Fernandez and O'Flaherty, 2018). Oxidative stress can trigger different pathway cascades in the spermatozoa, including truncated apoptosis. It has been reported that the phosphorylation status of phosphoinositide 3-kinase (PI3K) and its target AKT (protein kinase B) prevent the spermatozoon from entering the truncated apoptotic cascade. Here, we aim to study the regulation of the PI3K/AKT pathway by PRDX6 and assess its role in maintaining sperm viability. Human semen samples were obtained over 1 year from 20 healthy non-smoking volunteers aged 22-30 years. Sperm viability, lipid peroxidation and apoptosis-like changes were determined by flow cytometry while phosphorylation of PI3K and AKT substrates were assessed by immunoblotting using anti-phospho-PI3K and anti-phospho-AKT substrates antibodies. We found that the addition of arachidonic acid and lysophosphatidic acid, products of PRDX6 calcium-independent phospholipase A2 (Ca2+-iPLA2), prevented loss of sperm viability and maintained the phosphorylation of PI3K. Antioxidant compounds such as D-penicillamine partially prevented the oxidative damage on spermatozoa that led to a reduction of their viability. Thus, other pathways can also participate in sperm survival and be regulated by PRDXs. In conclusion, PRDX6 contributes to the regulation of ROS production and the PI3K/AKT pathway for the maintenance of sperm survival.
Subject(s)
Oxidative Stress/physiology , Peroxiredoxin VI/metabolism , Phosphatidylinositol 3-Kinase/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Sperm Motility/physiology , Spermatozoa/metabolism , Adult , Antioxidants/pharmacology , Apoptosis/physiology , Arachidonic Acid/pharmacology , Cell Survival/physiology , Humans , Infertility, Male/physiopathology , Lysophospholipids/pharmacology , Male , Penicillamine/pharmacology , Peroxiredoxin VI/antagonists & inhibitors , Phosphorylation , Reactive Oxygen Species/metabolism , Young AdultABSTRACT
nab-Paclitaxel ( nab-P), an albumin-bound formulation of paclitaxel, was developed to improve the tolerability and antitumor activity of taxanes. The neonatal Fc receptor (FcRn) is a transport protein that can bind to albumin and regulate the homeostasis of circulating albumin. Therefore, the pharmacokinetics and pharmacodynamics of nab-P may be impacted by FcRn expression. This study aimed to investigate the effects of FcRn on nab-P elimination and distribution to targeted tissues. Wild-type and FcRn-knockout (FcRn-KO) mice were treated with nab-P, mouse-specific nab-P (distribution experiments only), and solvent-based paclitaxel (pac-T). Blood and tissue samples were collected for distribution analyses. Organ, urine, and fecal samples were collected for elimination analyses. The nab-P tissue penetration in the pancreas, fat pad, and kidney of wild-type mice, as reflected by the ratio of tissue/plasma concentration, was significantly higher (ranging from 5 to 80 fold) than that of FcRn-KO mice. In contrast, the tissue penetration of pac-T in these organs of FcRn-KO mice was similar to that of wild-type mice. More importantly, the excretion of nab-P in feces of FcRn-KO mice (45-68%) was significantly higher than that of wild-type mice (26-46%) from 8 to 48 h post treatment. In comparison, the difference of excretion of pac-T in feces between FcRn-KO mice and wild-type mice was smaller than that of nab-P. Furthermore, greater tissue penetration and fecal excretion were observed with nab-P than pac-T in both FcRn-KO and wild-type mice. These findings suggest that FcRn enhances the tissue distribution and penetration of nab-P in the targeted organs, while FcRn prevents excretion of nab-P to feces in the intestinal lumen. The findings support the notion that albumin nanoparticle delivery alters drug distribution and elimination through an FcRn-mediated process to impact drug efficacy and toxicity.
Subject(s)
Histocompatibility Antigens Class I/metabolism , Paclitaxel/metabolism , Receptors, Fc/metabolism , Albumins/chemistry , Animals , Mice , Mice, Knockout , Nanoparticles/chemistry , Tissue DistributionABSTRACT
Previous studies have shown that different paclitaxel formulations produce distinct anticancer efficacy and safety profiles in animals and humans. This study aimed to investigate the distinct pharmacokinetics and tissue distribution of various nanoformulations of paclitaxel, which may translate into potential differences in safety and efficacy. Four nanoparticle formulations ( nab-paclitaxel, mouse albumin nab-paclitaxel [m -nab-paclitaxel], micellar paclitaxel, and polymeric nanoparticle paclitaxel) as well as solvent-based paclitaxel were intravenously administered to mice. Seventeen blood and tissue samples were collected at different time points. The total paclitaxel concentration in each tissue specimen was measured with liquid chromatography-tandem mass spectrometry. Compared with solvent-based paclitaxel, all four nanoformulations demonstrated decreased paclitaxel exposure in plasma. All nanoformulations were associated with paclitaxel blood-cell accumulation in mice; however, m- nab-paclitaxel was associated with the lowest accumulation. Five minutes after dosing, the total paclitaxel in the tissues and blood was approximately 44% to 57% of the administered dose of all paclitaxel formulations. Paclitaxel was primarily distributed to liver, muscle, intestine, kidney, skin, and bone. Compared with solvent-based paclitaxel, the different nanocarriers altered the distribution of paclitaxel in all tissues with distinct paclitaxel concentration-time profiles. nab-paclitaxel was associated with increased delivery efficiency of paclitaxel in the pancreas compared with the other formulations, consistent with the demonstrated efficacy of nab-paclitaxel in pancreatic cancer. All the nanoformulations led to high penetration in the lungs and fat pad, which potentially points to efficacy in lung and breast cancers. Micellar paclitaxel and polymeric nanoparticle paclitaxel were associated with high paclitaxel accumulation in the heart; thus, the risk of cardiovascular toxicity with these formulations may warrant further investigation. The solvent-based formulation was associated with the poorest paclitaxel penetration in all tissues and the lowest tissue-to-plasma ratio. The different nanocarriers of paclitaxel were associated with distinct pharmacokinetics and tissue distribution, which largely align with the observed efficacy and toxicity profiles in clinical trials.
Subject(s)
Antineoplastic Agents, Phytogenic/metabolism , Antineoplastic Agents, Phytogenic/pharmacokinetics , Paclitaxel/metabolism , Paclitaxel/pharmacokinetics , Animals , Docetaxel/chemistry , Drug Compounding , Female , Mice , Nanoparticles/chemistry , Tandem Mass SpectrometryABSTRACT
The goal of this project was to explore and to statistically evaluate the responsible gastrointestinal (GI) factors that are significant factors in explaining the systemic exposure of ibuprofen, between and within human subjects. In a previous study, we determined the solution and total concentrations of ibuprofen as a function of time in aspirated GI fluids, after oral administration of an 800 mg IR tablet (reference standard) of ibuprofen to 20 healthy volunteers in fasted state conditions. In addition, we determined luminal pH and motility pressure recordings that were simultaneously monitored along the GI tract. Blood samples were taken to determine ibuprofen plasma levels. In this work, an in-depth statistical and pharmacokinetic analysis was performed to explain which underlying GI variables are determining the systemic concentrations of ibuprofen between (inter-) and within (intra-) subjects. In addition, the obtained plasma profiles were deconvoluted to link the fraction absorbed with the fraction dissolved. Multiple linear regressions were performed to explain and quantitatively express the impact of underlying GI physiology on systemic exposure of the drug (in terms of plasma Cmax/AUC and plasma Tmax). The exploratory analysis of the correlation between plasma Cmax/AUC and the time to the first phase III contractions postdose (TMMC-III) explains â¼40% of the variability in plasma Cmax for all fasted state subjects. We have experimentally shown that the in vivo intestinal dissolution of ibuprofen is dependent upon physiological variables like, in this case, pH and postdose phase III contractions. For the first time, this work presents a thorough statistical analysis explaining how the GI behavior of an ionized drug can explain the systemic exposure of the drug based on the individual profiles of participating subjects. This creates a scientifically based and rational framework that emphasizes the importance of including pH and motility in a predictive in vivo dissolution methodology to forecast the in vivo performance of a drug product. Moreover, as no extensive first-pass metabolism is considered for ibuprofen, this study demonstrates how intraluminal drug behavior is reflecting the systemic exposure of a drug.
Subject(s)
Drug Liberation , Fasting/physiology , Gastrointestinal Absorption/physiology , Gastrointestinal Tract/physiology , Ibuprofen/pharmacokinetics , Administration, Oral , Adult , Area Under Curve , Biological Availability , Biological Variation, Individual , Biological Variation, Population/physiology , Datasets as Topic , Female , Healthy Volunteers , Humans , Hydrogen-Ion Concentration , Ibuprofen/administration & dosage , Male , Middle Aged , Models, Biological , Solubility , Tablets , Young AdultABSTRACT
Exploring the intraluminal behavior of an oral drug product in the human gastrointestinal (GI) tract remains challenging. Many in vivo techniques are available to investigate the impact of GI physiology on oral drug behavior in fasting state conditions. However, little is known about the intraluminal behavior of a drug in postprandial conditions. In a previous report, we described the mean solution and total concentrations of ibuprofen after oral administration of an immediate-release (IR) tablet in fed state conditions. In parallel, blood samples were taken to assess systemic concentrations. The purpose of this work was to statistically evaluate the impact of GI physiology (e.g., pH, contractile events) within and between individuals (intra and intersubject variability) for a total of 17 healthy subjects. In addition, a pharmacokinetic (PK) analysis was performed by noncompartmental analysis, and PK parameters were correlated with underlying physiological factors (pH, time to phase III contractions postdose) and study parameters (e.g., ingested amount of calories, coadministered water). Moreover, individual plasma profiles were deconvoluted to assess the fraction absorbed as a function of time, demonstrating the link between intraluminal and systemic behavior of the drug. The results demonstrated that the in vivo dissolution of ibuprofen depends on the present gastric pH and motility events at the time of administration. Both intraluminal factors were responsible for explaining 63% of plasma Cmax variability among all individuals. For the first time, an in-depth analysis was performed on a large data set derived from an aspiration/motility study, quantifying the impact of physiology on systemic behavior of an orally administered drug product in fed state conditions. The data obtained from this study will help us to develop an in vitro biorelevant dissolution approach and optimize in silico tools in order to predict the in vivo performance of orally administered drug products, especially in fed state conditions.
Subject(s)
Drug Liberation , Gastric Absorption/physiology , Ibuprofen/pharmacokinetics , Postprandial Period/physiology , Stomach/physiology , Administration, Oral , Adult , Area Under Curve , Biological Availability , Biological Variation, Individual , Biological Variation, Population/physiology , Computer Simulation , Datasets as Topic , Female , Food-Drug Interactions/physiology , Gastric Emptying/physiology , Healthy Volunteers , Humans , Hydrogen-Ion Concentration , Ibuprofen/administration & dosage , Male , Middle Aged , Models, Biological , Solubility , Tablets , Young AdultABSTRACT
In vivo drug dissolution in the gastrointestinal (GI) tract is largely unmeasured. The purpose of this clinical study was to evaluate the in vivo drug dissolution and systemic absorption of the BCS class IIa drug ibuprofen under fed and fasted conditions by direct sampling of stomach and small intestinal luminal content. Expanding current knowledge of drug dissolution in vivo will help to establish physiologically relevant in vitro models predictive of drug dissolution. A multilumen GI catheter was orally inserted into the GI tract of healthy human subjects. Subjects received a single oral dose of ibuprofen (800 mg tablet) with 250 mL of water under fasting and fed conditions. The GI catheter facilitated collection of GI fluid from the stomach, duodenum, and jejunum. Ibuprofen concentration in GI fluid supernatant and plasma was determined by LC-MS/MS. A total of 23 subjects completed the study, with 11 subjects returning for an additional study visit (a total of 34 completed study visits). The subjects were primarily white (61%) and male (65%) with an average age of 30 years. The subjects had a median [min, max] weight of 79 [52, 123] kg and body mass index of 25.7 [19.4, 37.7] kg/m2. Ibuprofen plasma levels were higher under fasted conditions and remained detectable for 28 h under both conditions. The AUC0-24 and Cmax were lower in fed subjects vs fasted subjects, and Tmax was delayed in fed subjects vs fasted subjects. Ibuprofen was detected immediately after ingestion in the stomach under fasting and fed conditions until 7 h after dosing. Higher levels of ibuprofen were detected in the small intestine soon after dosing in fasted subjects compared to fed. In contrast to plasma drug concentration, overall gastric concentrations remained higher under fed conditions due to increased gastric pH vs fasting condition. The gastric pH increased to near neutrality after feedingbefore decreasing to acidic levels after 7 h. Induction of the fed state reduced systemic levels but increased gastric levels of ibuprofen, which suggest that slow gastric emptying and transit dominate the effect for plasma drug concentration. The finding of high levels of ibuprofen in stomach and small intestine 7 h post dosing was unexpected. Future work is needed to better understand the role of various GI parameters, such as motility and gastric emptying, on systemic ibuprofen levels in order to improve in vitro predictive models.
Subject(s)
Absorption, Physiological/physiology , Drug Liberation/physiology , Gastrointestinal Tract/physiology , Ibuprofen/pharmacokinetics , Administration, Oral , Adult , Biological Availability , Biopharmaceutics , Fasting/physiology , Female , Gastric Emptying/physiology , Healthy Volunteers , Humans , Intestinal Absorption/physiology , Male , Middle Aged , Postprandial Period , Solubility , Tablets , Young AdultABSTRACT
As an orally administered, locally acting gastrointestinal drug, mesalamine products are designed to achieve high local drug concentration in the gastrointestinal (GI) tract for the treatment of ulcerative colitis. The aim of this study was to directly measure and compare drug dissolution of three mesalamine formulations in human GI tract and to correlate their GI concentration with drug concentration in plasma. Healthy human subjects were orally administered Pentasa, Apriso, or Lialda. GI fluids were aspirated from stomach, duodenum, proximal jejunum, mid jejunum, and distal jejunum regions. Mesalamine (5-ASA) and its primary metabolite acetyl-5-mesalamine (Ac-5-ASA) were measured using LC-MS/MS. GI tract pH was measured from each GI fluid sample, which averaged 1.82, 4.97, 5.67, 6.17, and 6.62 in the stomach, duodenum, proximal jejunum, middle jejunum, and distal jejunum, respectively. For Pentasa, high levels of 5-ASA in solution were observed in the stomach, duodenum, proximal jejunum, mid jejunum, and distal jejunum from 1 to 7 h. Apriso had minimal 5-ASA levels in stomach, low to medium levels of 5-ASA in duodenum and proximal jejunum from 4 to 7 h, and high levels of 5-ASA in distal jejunum from 3 to 7 h. In contrast, Lialda had minimal 5-ASA levels from stomach and early small intestine. A composite appearance rate (CAR) was calculated from the deconvolution of individual plasma concentration to reflect drug release, dissolution, transit, and absorption in the GI tract. Individuals dosed with Pentasa had high levels of CAR from 1 to 10 h; individuals dosed with Apriso had low levels of CAR from 1 to 4 h and high levels of CAR from 5 to 10 h; Lialda showed minimal levels of CAR from 0 to 5 h, then increased to medium levels from 5 to 12 h, and then decreased to further lower levels after 12 h. In the colon region, Pentasa and Apriso showed similar levels of accumulated 5-ASA excreted in the feces, while Lialda showed slightly higher 5-ASA accumulation in feces. However, all three formulations showed similar levels of metabolite Ac-5-ASA in the feces. These results provide direct measurement of drug dissolution in the GI tract, which can serve as a basis for investigation of bioequivalence for locally acting drug products.
Subject(s)
Drug Liberation/physiology , Gastrointestinal Tract/metabolism , Mesalamine/metabolism , Administration, Oral , Adolescent , Adult , Chemistry, Pharmaceutical/methods , Female , Humans , Male , Middle Aged , Solubility , Young AdultABSTRACT
In this study, we determined the pH and buffer capacity of human gastrointestinal (GI) fluids (aspirated from the stomach, duodenum, proximal jejunum, and mid/distal jejunum) as a function of time, from 37 healthy subjects after oral administration of an 800 mg immediate-release tablet of ibuprofen (reference listed drug; RLD) under typical prescribed bioequivalence (BE) study protocol conditions in both fasted and fed states (simulated by ingestion of a liquid meal). Simultaneously, motility was continuously monitored using water-perfused manometry. The time to appearance of phase III contractions (i.e., housekeeper wave) was monitored following administration of the ibuprofen tablet. Our results clearly demonstrated the dynamic change in pH as a function of time and, most significantly, the extremely low buffer capacity along the GI tract. The buffer capacity on average was 2.26 µmol/mL/ΔpH in fasted state (range: 0.26 and 6.32 µmol/mL/ΔpH) and 2.66 µmol/mL/ΔpH in fed state (range: 0.78 and 5.98 µmol/mL/ΔpH) throughout the entire upper GI tract (stomach, duodenum, and proximal and mid/distal jejunum). The implication of this very low buffer capacity of the human GI tract is profound for the oral delivery of both acidic and basic active pharmaceutical ingredients (APIs). An in vivo predictive dissolution method would require not only a bicarbonate buffer but also, more significantly, a low buffer capacity of dissolution media to reflect in vivo dissolution conditions.
Subject(s)
Body Fluids/chemistry , Gastrointestinal Motility/physiology , Gastrointestinal Tract/physiology , Ibuprofen/pharmacokinetics , Intestinal Absorption/physiology , Absorption, Physiological , Administration, Oral , Adult , Body Fluids/physiology , Buffers , Drug Liberation , Healthy Volunteers , Humans , Hydrogen-Ion Concentration , Intestinal Mucosa/physiology , Manometry , Middle Aged , Solubility , Tablets , Therapeutic Equivalency , Time Factors , Young AdultABSTRACT
Habituation is a highly conserved phenomenon that remains poorly understood at the molecular level. Invertebrate model systems, like Caenorhabditis elegans, can be a powerful tool for investigating this fundamental process. Here we established a high-throughput learning assay that used real-time computer vision software for behavioral tracking and optogenetics for stimulation of the C. elegans polymodal nociceptor, ASH. Photoactivation of ASH with ChR2 elicited backward locomotion and repetitive stimulation altered aspects of the response in a manner consistent with habituation. Recording photocurrents in ASH, we observed no evidence for light adaptation of ChR2. Furthermore, we ruled out fatigue by demonstrating that sensory input from the touch cells could dishabituate the ASH avoidance circuit. Food and dopamine signaling slowed habituation downstream from ASH excitation via D1-like dopamine receptor, DOP-4. This assay allows for large-scale genetic and drug screens investigating mechanisms of nociception modulation.
Subject(s)
Avoidance Learning/physiology , Caenorhabditis elegans Proteins/metabolism , Habituation, Psychophysiologic/physiology , Nociceptors/metabolism , Receptors, Dopamine D2/metabolism , Animals , Animals, Genetically Modified , Caenorhabditis elegans , Caenorhabditis elegans Proteins/genetics , Channelrhodopsins/genetics , Channelrhodopsins/metabolism , Dopamine/metabolism , Feeding Behavior/physiology , Image Processing, Computer-Assisted , Locomotion/physiology , Membrane Potentials/physiology , Mixed Function Oxygenases/genetics , Mixed Function Oxygenases/metabolism , Motor Activity/physiology , Mutation , Nociceptors/cytology , Optogenetics , Patch-Clamp Techniques , Pattern Recognition, Automated , Photic Stimulation , Receptors, Dopamine D2/genetics , Sensation/physiologyABSTRACT
BACKGROUND AIMS: Since human embryonic stem cells and human fetal neural stem cells have immune rejection and ethical issues, recent advancements in induced pluripotent stem cells (iPS cells) provide new possibilities to study autologous cell therapy for Parkinson's disease (PD). METHODS: We isolated human skin fibroblasts from normal individuals and patients with PD; we generated iPS cells by transfecting these human skin fibroblasts with retroviral reprogramming factors of OCT4, SOX2, KLF4 and c-MYC and induced iPS cells to differentiate neural stem cells (NSCs) and then into neurons and dopamine neurons in vitro. RESULTS: We found that iPS cell-derived NSC transplant into the striatum of the 6-hydroxydopamine (OHDA)-induced PD rats improved their functional defects of rotational asymmetry at 4, 8, 12 and 16 weeks after transplantation. iPS cell-derived NSCs were found to survive and integrate into the brain of transplanted PD rats and differentiated into neurons, including dopamine neurons in vivo. CONCLUSIONS: Transplantation of iPS cell-derived NSCs has therapeutic potential for PD. Our study provided experimental proof for future clinical application of iPS cells in cell-based treatment of PD.
Subject(s)
Induced Pluripotent Stem Cells/cytology , Motor Neurons/cytology , Parkinson Disease/therapy , Stem Cell Transplantation , Aged , Animals , Cell Differentiation/drug effects , Dopaminergic Neurons/drug effects , Dopaminergic Neurons/pathology , Female , Fibroblasts/metabolism , Humans , Immunohistochemistry , Kruppel-Like Factor 4 , Male , Mice , Middle Aged , Neural Stem Cells/cytology , Oxidopamine , Parkinson Disease/pathology , Pluripotent Stem Cells/drug effects , Rats, Sprague-Dawley , Skin/pathology , Tyrosine 3-Monooxygenase/metabolismABSTRACT
AIMS: SOX2 is a key regulatory gene in embryonic stem cells. Although it has been implicated in cancer progression, its role in breast carcinoma is poorly understood. MATERIALS AND METHODS: Fifty-seven ductal carcinomas in situ (DCIS), 552 invasive breast carcinomas and 107 corresponding metastatic lymph nodes were evaluated immunohistochemically for the expression of SOX2. Its correlation with clinicopathological features, other biomarker profiles and patients' outcomes were analysed. RESULTS: SOX2 was detected in 19.0% (105 of 552) of invasive breast carcinomas and 12.3% (seven of 57) of DCIS. Expression correlated with larger tumour size (P = 0.005) and higher grade (P = 0.002). It was associated negatively with ER (P = 0.015) and PR (P = 0.046) expression, but positively with Ki67 index (P = 0.013). Interestingly, it was also associated with neuroendocrine marker expression (synpatophysin and chromogranin/synaptophysin, P = 0.048 and 0.028, respectively). Expression appeared to be independent from that of common stem cell markers, namely CD44, CD24 and aldehyde dehydrogenase 1 (ALDH1). Furthermore, a higher rate of expression was observed in metastatic lymph nodes than in the corresponding primary tumours (P = 0.034). High SOX2 expression was correlated with poor disease-free survival (log-rank=9.489, P = 0.012) and was an independent prognostic factor (HR=2.918, P = 0.015) in patients with high nodal stages. CONCLUSIONS: In summary, SOX2 expression was related to adverse breast carcinoma profile and poor outcome in selected patient groups.
Subject(s)
Breast Neoplasms/metabolism , SOXB1 Transcription Factors/metabolism , Adult , Aged , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/genetics , Carcinoma, Ductal, Breast/metabolism , Carcinoma, Ductal, Breast/pathology , Carcinoma, Intraductal, Noninfiltrating/genetics , Carcinoma, Intraductal, Noninfiltrating/metabolism , Carcinoma, Intraductal, Noninfiltrating/pathology , Cell Differentiation , Cohort Studies , Female , Gene Expression , Gene Expression Regulation, Neoplastic , Humans , Immunohistochemistry , Lymphatic Metastasis/genetics , Lymphatic Metastasis/pathology , Middle Aged , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Prognosis , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , SOXB1 Transcription Factors/geneticsABSTRACT
BACKGROUND: Oral fat tolerance test (OFTT) has been widely used to assess the postprandial lipemia in human beings, but there is few studies concerning OFTT in nonhuman primates. This study is designed to explore the feasibility of OFTT in rhesus monkeys. METHODS: In a cross-over study, a total of 8 adult female rhesus monkeys were fed with normal monkey diet (NND), high sugar high fat diet (HHD), and extremely high fat diet (EHD), respectively. Each monkey consumed NND, HHD and EHD respectively, each weighing 60 g. Serial blood samples were collected at 1, 2, 3, 4, 5, and 6 h after ingesting each kind of food. Triglyceride, cholesterol, glucose, and insulin at each time point were measured. The area under the curve of triglyceride (TG-AUC) and triglyceride peak response (TG-PR) were also calculated. RESULTS: All monkeys ingested 3 kinds of foods within 15 minutes. TG-AUC and TG-PR of HHD group were higher than those of the other two groups. Postprandial triglyceride levels at 2, 3, 4, and 5 hours in HHD group during OFTT were also higher than those in NND and EHD group. CONCLUSIONS: HHD diet can be used in OFTT for nonhuman primates.
Subject(s)
Diagnostic Techniques, Digestive System , Dietary Fats/administration & dosage , Administration, Oral , Animals , Blood Glucose , Cholesterol/blood , Diet, High-Fat , Feasibility Studies , Female , Humans , Insulin/blood , Lipid Metabolism , Macaca mulatta , Postprandial Period , Triglycerides/bloodABSTRACT
Glucose-containing peritoneal dialysis solutions may exacerbate metabolic abnormalities and increase cardiovascular risk in diabetic patients. Here, we examined whether a low-glucose regimen improves metabolic control in diabetic patients undergoing peritoneal dialysis. Eligible patients were randomly assigned in a 1:1 manner to the control group (dextrose solutions only) or to the low-glucose intervention group (IMPENDIA trial: combination of dextrose-based solution, icodextrin and amino acids; EDEN trial: a different dextrose-based solution, icodextrin and amino acids) and followed for 6 months. Combining both studies, 251 patients were allocated to control (n=127) or intervention (n=124) across 11 countries. The primary endpoint was change in glycated hemoglobin from baseline. Mean glycated hemoglobin at baseline was similar in both groups. In the intention-to-treat population, the mean glycated hemoglobin profile improved in the intervention group but remained unchanged in the control group (0.5% difference between groups; 95% confidence interval, 0.1% to 0.8%; P=0.006). Serum triglyceride, very-low-density lipoprotein, and apolipoprotein B levels also improved in the intervention group. Deaths and serious adverse events, including several related to extracellular fluid volume expansion, increased in the intervention group, however. These data suggest that a low-glucose dialysis regimen improves metabolic indices in diabetic patients receiving peritoneal dialysis but may be associated with an increased risk of extracellular fluid volume expansion. Thus, use of glucose-sparing regimens in peritoneal dialysis patients should be accompanied by close monitoring of fluid volume status.
Subject(s)
Diabetic Nephropathies/therapy , Glucose/administration & dosage , Peritoneal Dialysis/methods , Adult , Aged , Diabetic Nephropathies/blood , Female , Glycated Hemoglobin/analysis , Humans , Lipids/blood , Male , Middle Aged , Peritoneal Dialysis/adverse effectsABSTRACT
A 240-mg single tablet has been developed with the focus of reducing the pill burden of the apalutamide daily dose of 240 mg (4 × 60-mg tablets). An open-label, randomized, single-dose phase 1 study with a 2-sequence and 2-period crossover design in healthy men determined the bioequivalence of a 240-mg single tablet versus the currently available 4 × 60-mg tablets (Part 1, N = 74) and assessed effect of a high-fat meal (Part 2, N = 21) on apalutamide maximum plasma concentration (Cmax) and the area under the plasma concentration-time curve (AUC0-72 h). The 90% confidence interval of geometric mean ratios for Cmax and AUC0-72 h fell between 80% and 125% for both Part 1 and Part 2. No new safety concerns with the 240-mg single tablet were observed. To support the use of different food vehicles as well as nasogastric (NG) tubes for alternative administration, we conducted in vitro compatibility studies to evaluate the purity, dose, and stability of 240-mg tablets dispersed in applesauce/yogurt/orange juice/green tea as well as in NG tubes (polyurethane/silicone/polyvinyl chloride). The studies confirmed the alternative administrations do not affect the purity, dose-accuracy, or stability of apalutamide. The apalutamide 240-mg tablet is bioequivalent to 4 × 60-mg tablets and compatible with the tested food vehicles and NG tubes.
Subject(s)
Food , Thiohydantoins , Male , Humans , Therapeutic Equivalency , TabletsABSTRACT
BACKGROUND AND OBJECTIVE: The combination of niraparib and abiraterone acetate (AA) plus prednisone is under investigation for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) and metastatic castration-sensitive prostate cancer (mCSPC). Regular-strength (RS) and lower-strength (LS) dual-action tablets (DATs), comprising niraparib 100 mg/AA 500 mg and niraparib 50 mg/AA 500 mg, respectively, were developed to reduce pill burden and improve patient experience. A bioequivalence (BE)/bioavailability (BA) study was conducted under modified fasting conditions in patients with mCRPC to support approval of the DATs. METHODS: This open-label randomized BA/BE study (NCT04577833) was conducted at 14 sites in the USA and Europe. The study had a sequential design, including a 21-day screening phase, a pharmacokinetic (PK) assessment phase comprising three periods [namely (1) single-dose with up to 1-week run-in, (2) daily dose on days 1-11, and (3) daily dose on days 12-22], an extension where both niraparib and AA as single-agent combination (SAC; reference) or AA alone was continued from day 23 until discontinuation, and a 30-day follow-up phase. Patients were randomly assigned in a parallel-group design (four-sequence randomization) to receive a single oral dose of niraparib 100 mg/AA 1000 mg as a LS-DAT or SAC in period 1, and patients continued as randomized into a two-way crossover design during periods 2 and 3 where they received niraparib 200 mg/AA 1000 mg once daily as a RS-DAT or SAC. The design was powered on the basis of crossover assessment of RS-DAT versus SAC. During repeated dosing (periods 2 and 3, and extension phase), all patients also received prednisone/prednisolone 5 mg twice daily. Plasma samples were collected for measurement of niraparib and abiraterone plasma concentrations. Statistical assessment of the RS-DAT and LS-DAT versus SAC was performed on log-transformed pharmacokinetic parameters data from periods 2 and 3 (crossover) and from period 1 (parallel), respectively. Additional paired analyses and model-based bioequivalence assessments were conducted to evaluate the similarity between the LS-DAT and SAC. RESULTS: For the RS-DAT versus SAC, the 90% confidence intervals (CI) of geometric mean ratios (GMR) for maximum concentration at a steady state (Cmax,ss) and area under the plasma concentration-time curve from 0-24 h at a steady state (AUC 0-24h,ss) were respectively 99.18-106.12% and 97.91-104.31% for niraparib and 87.59-106.69 and 86.91-100.23% for abiraterone. For the LS-DAT vs SAC, the 90% CI of GMR for AUC0-72h of niraparib was 80.31-101.12% in primary analysis, the 90% CI of GMR for Cmax,ss and AUC 0-24h,ss of abiraterone was 85.41-118.34% and 86.51-121.64% respectively, and 96.4% of simulated LS-DAT versus SAC BE trials met the BE criteria for both niraparib and abiraterone. CONCLUSIONS: The RS-DAT met BE criteria (range 80%-125%) versus SAC based on 90% CI of GMR for Cmax,ss and AUC 0-24h,ss. The LS-DAT was considered BE to SAC on the basis of the niraparib component meeting the BE criteria in the primary analysis for AUC 0-72h; abiraterone meeting the BE criteria in additional paired analyses based on Cmax,ss and AUC 0-24h,ss; and the percentage of simulated LS-DAT versus SAC BE trials meeting the BE criteria for both. GOV IDENTIFIER: NCT04577833.
Subject(s)
Abiraterone Acetate , Indazoles , Piperidines , Prostatic Neoplasms, Castration-Resistant , Tablets , Therapeutic Equivalency , Humans , Indazoles/pharmacokinetics , Indazoles/administration & dosage , Male , Piperidines/pharmacokinetics , Piperidines/administration & dosage , Abiraterone Acetate/pharmacokinetics , Abiraterone Acetate/administration & dosage , Aged , Middle Aged , Prostatic Neoplasms, Castration-Resistant/drug therapy , Antineoplastic Combined Chemotherapy Protocols/pharmacokinetics , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Models, Biological , Biological Availability , Cross-Over Studies , Aged, 80 and over , Computer Simulation , Prednisone/pharmacokinetics , Prednisone/administration & dosageABSTRACT
During nervous system development, neurons send out axons, which must navigate large distances to reach synaptic targets. Axons grow out sequentially. The early outgrowing axons, pioneers, must integrate information from various guidance cues in their environment to determine the correct direction of outgrowth. Later outgrowing follower axons can at least in part navigate by adhering to pioneer axons. In Caenorhabditis elegans, the right side of the largest longitudinal axon tract, the ventral nerve cord, is pioneered by the AVG axon. How the AVG axon navigates is only partially understood. In this study, we describe the role of two members of the IgCAM family, wrk-1 and rig-5, in AVG axon navigation. While wrk-1 and rig-5 single mutants do not show AVG navigation defects, both mutants have highly penetrant pioneer and follower navigation defects in a nid-1 mutant background. Both mutations increase the fraction of follower axons following the misguided pioneer axon. We found that wrk-1 and rig-5 act in different genetic pathways, suggesting that we identified two pioneer-independent guidance pathways used by follower axons. We assessed general locomotion, mechanosensory responsiveness, and habituation to determine whether axonal navigation defects impact nervous system function. In rig-5 nid-1 double mutants, we found no significant defects in free movement behavior; however, a subpopulation of animals shows minor changes in response duration habituation after mechanosensory stimulation. These results suggest that guidance defects of axons in the motor circuit do not necessarily lead to major movement or behavioral defects but impact more complex behavioral modulation.