Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 99
Filter
1.
Mol Pharm ; 21(5): 2473-2483, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38579335

ABSTRACT

In recent years, the drainage of fluids, immune cells, antigens, fluorescent tracers, and other solutes from the brain has been demonstrated to occur along lymphatic outflow pathways to the deep cervical lymph nodes in the neck. To the best of our knowledge, no studies have evaluated the lymphatic transport of therapeutics from the brain. The objective of this study was to determine the lymphatic transport of model therapeutics of different molecular weights and lipophilicity from the brain using cervical lymph cannulation and ligation models in rats. To do this, anesthetized Sprague-Dawley rats were cannulated at the carotid artery and cannulated, ligated, or left intact at the cervical lymph duct. Rats were administered 14C-ibuprofen (206.29 g/mol, logP 3.84), 3H-halofantrine HCl (536.89 g/mol, logP 8.06), or 3H-albumin (∼65,000 g/mol) via direct injection into the brain striatum at a rate of 0.5 µL/min over 16 min. Plasma or cervical lymph samples were collected for up to 6-8 h following dosing, and brain and lymph nodes were collected at 6 or 8 h. Samples were subsequently analyzed for radioactivity levels via scintillation counting. For 14C-ibuprofen, plasma concentrations over time (plasma AUC0-6h) were >2 fold higher in lymph-ligated rats than in lymph-intact rats, suggesting that ibuprofen is cleared from the brain primarily via nonlymphatic routes (e.g., across the blood-brain barrier) but that this clearance is influenced by changes in lymphatic flow. For 3H-halofantrine, >73% of the dose was retained at the brain dosing site in lymph-intact and lymph-ligated groups, and plasma AUC0-8h values were low in both groups (<0.3% dose.h/mL), consistent with the high retention in the brain. It was therefore not possible to determine whether halofantrine undergoes lymphatic transport from the brain within the duration of the study. For 3H-albumin, plasma AUC0-8h values were not significantly different between lymph-intact, lymph-ligated, and lymph-cannulated rats. However, >4% of the dose was recovered in cervical lymph over 8 h. Lymph/plasma concentration ratios of 3H-albumin were also very high (up to 53:1). Together, these results indicate that 3H-albumin is transported from the brain not only via lymphatic routes but also via the blood. Similar to other tissues, the lymphatics may thus play a significant role in the transport of macromolecules, including therapeutic proteins, from the brain but are unlikely to be a major transport pathway from the brain for small molecule drugs that are not lipophilic. Our rat cervical lymph cannulation model can be used to quantify the lymphatic drainage of different molecules and factors from the brain.


Subject(s)
Brain , Ibuprofen , Lymph Nodes , Rats, Sprague-Dawley , Animals , Rats , Brain/metabolism , Male , Lymph Nodes/metabolism , Ibuprofen/pharmacokinetics , Ibuprofen/administration & dosage , Ibuprofen/chemistry , Phenanthrenes/pharmacokinetics , Phenanthrenes/chemistry , Phenanthrenes/administration & dosage , Biological Transport/physiology , Albumins/pharmacokinetics , Albumins/metabolism
2.
ACS Biomater Sci Eng ; 10(5): 2894-2910, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38556768

ABSTRACT

Over the past decades, evidence has consistently shown that treatment of central nervous system (CNS)-related disorders, including Alzheimer's disease, Parkinson's disease, stroke, multiple sclerosis, and brain cancer, is limited due to the presence of the blood-brain barrier (BBB). To assist with the development of new therapeutics, it is crucial to engineer a drug delivery system that can cross the BBB efficiently and reach target cells within the brain. In this study, we present a potentially efficient strategy for targeted brain delivery through utilization of folic acid (FA)-conjugated brush polymers, that specifically target the reduced folate carrier (RFC, SLC19A1) expressed on brain endothelial cells. Here, azide (N3)-decorated brush polymers were prepared in a straightforward manner coupling a heterotelechelic α-NH2, ω-N3-poly(2-ethyl-2-oxazoline) (NH2-PEtOx-N3) to N-acylated poly(amino ester) (NPAE)-based brushes. Strain-promoted azide-alkyne cycloaddition (SPAAC) 'click chemistry' with DBCO-folic acid (FA) yielded FA-brush polymers. Interestingly, while azide functionalization of the brush polymers dramatically reduced their association to brain microvascular endothelial cells (hCMEC/D3), the introduction of FA to azide led to a substantial accumulation of the brush polymers in hCMEC/D3 cells. The ability of the polymeric brush polymers to traverse the BBB was quantitatively assessed using different in vitro BBB models including static Transwell and microfluidic platforms. FA-brush polymers showed efficient transport across hCMEC/D3 cells in a manner dependent on FA composition, whereas nonfunctionalized brush polymers exhibited limited trafficking under the same conditions. Further, cellular uptake inhibition studies suggested that the interaction and transport pathway of FA-brush polymers across BBB relies on the RFC-mediated pathways. The potential application of the developed FA-brush polymers in brain cancer delivery was also investigated in a microfluidic model of BBB-glioblastoma. Brush polymers with more FA units successfully presented an enhanced accumulation into U-87 MG glioma cells following its BBB crossing, compared to controls. These results demonstrate that FA-modified brush polymers hold a great potential for more efficient delivery of future brain therapeutics.


Subject(s)
Blood-Brain Barrier , Brain Neoplasms , Folic Acid , Polymers , Folic Acid/chemistry , Folic Acid/metabolism , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/drug effects , Humans , Brain Neoplasms/drug therapy , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Polymers/chemistry , Drug Delivery Systems/methods , Cell Line, Tumor , Endothelial Cells/metabolism , Endothelial Cells/drug effects , Drug Carriers/chemistry
3.
Mol Pharm ; 21(4): 1756-1767, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38415587

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is characterized by death and dysfunction of motor neurons that result in a rapidly progressing loss of motor function. While there are some data on alterations at the blood-brain barrier (BBB) in ALS and their potential impact on CNS trafficking of drugs, little is reported on the impact of this disease on the expression of drug-handling proteins in the small intestine and liver. This may impact the dosing of the many medicines that individuals with ALS are prescribed. In the present study, a proteomic evaluation was performed on small intestine and liver samples from postnatal day 120 SOD1G93A mice (a model of familial ALS that harbors a human mutant form of superoxide dismutase 1) and wild-type (WT) littermates (n = 7/genotype/sex). Untargeted, quantitative proteomics was undertaken using either label-based [tandem mass tag (TMT)] or label-free [data-independent acquisition (DIA)] acquisition strategies on high-resolution mass spectrometric instrumentation. Copper chaperone for superoxide dismutase (CCS) was significantly higher in SOD1G93A samples compared to the WT samples for both sexes and tissues, therefore representing a potential biomarker for ALS in this mouse model. Relative to WT mice, male SOD1G93A mice had significantly different proteins (Padj < 0.05, |fold-change|>1.2) in the small intestine (male 22, female 1) and liver (male 140, female 3). This included an up-regulation of intestinal transporters for dietary glucose [solute carrier (SLC) SLC5A1] and cholesterol (Niemann-Pick c1-like 1), as well as for several drugs (e.g., SLC15A1), in the male SOD1G93A mice. There was both an up-regulation (e.g., SLCO2A1) and down-regulation (ammonium transporter rh type b) of transporters in the male SOD1G93A liver. In addition, there was both an up-regulation (e.g., phosphoenolpyruvate carboxykinase) and down-regulation (e.g., carboxylesterase 1) of metabolizing enzymes in the male SOD1G93A liver. This proteomic data set identified male-specific changes to key small intestinal and hepatic transporters and metabolizing enzymes that may have important implications for the bioavailability of nutrients and drugs in individuals with ALS.


Subject(s)
Amyotrophic Lateral Sclerosis , Organic Anion Transporters , Animals , Female , Humans , Male , Mice , Amyotrophic Lateral Sclerosis/genetics , Disease Models, Animal , Liver/metabolism , Mice, Transgenic , Organic Anion Transporters/metabolism , Proteomics , Superoxide Dismutase/metabolism , Superoxide Dismutase-1/genetics , Superoxide Dismutase-1/metabolism
4.
Pharmaceutics ; 15(8)2023 Aug 03.
Article in English | MEDLINE | ID: mdl-37631298

ABSTRACT

P-glycoprotein (P-gp), expressed at the blood-brain barrier (BBB), is critical in preventing brain access to substrate drugs and effluxing amyloid beta (Aß), a contributor to Alzheimer's disease (AD). Strategies to regulate P-gp expression therefore may impact central nervous system (CNS) drug delivery and brain Aß levels. As we have demonstrated that the copper complex copper diacetyl bis(4-methyl-3-thiosemicarbazone) (Cu(ATSM)) increases P-gp expression and function in human brain endothelial cells, the present study assessed the impact of Cu(ATSM) on expression and function of P-gp in mouse brain endothelial cells (mBECs) and capillaries in vivo, as well as in peripheral organs. Isolated mBECs treated with Cu(ATSM) (100 nM for 24 h) exhibited a 1.6-fold increase in P-gp expression and a 20% reduction in accumulation of the P-gp substrate rhodamine 123. Oral administration of Cu(ATSM) (30 mg/kg/day) for 28 days led to a 1.5 & 1.3-fold increase in brain microvascular and hepatic expression of P-gp, respectively, and a 20% reduction in BBB transport of [3H]-digoxin. A metallomic analysis showed a 3.5 and 19.9-fold increase in Cu levels in brain microvessels and livers of Cu(ATSM)-treated mice. Our findings demonstrate that Cu(ATSM) increases P-gp expression and function at the BBB in vivo, with implications for CNS drug delivery and clearance of Aß in AD.

5.
J Neuroimmune Pharmacol ; 18(3): 448-461, 2023 09.
Article in English | MEDLINE | ID: mdl-37555918

ABSTRACT

Prolonged activation of microglia leads to excessive release of proinflammatory mediators, which are detrimental to brain health. Therefore, there are significant efforts to identify pathways mediating microglial activation. Recent studies have demonstrated that fatty acid-binding protein 4 (FABP4), a lipid binding protein, is a critical player in macrophage-mediated inflammation. Given that we have previously identified FABP4 in microglia, the aim of this study was to assess whether FABP4 activity contributed to inflammation, metabolism and immune function (i.e. immunometabolism) in immortalised mouse microglia (BV-2 cells) using the proinflammatory stimulus lipopolysaccharide (LPS) to induce general microglial activation. Microglial FABP4 expression was significantly increased following exposure to LPS, an outcome associated with a significant increase in microglial proliferation rate. LPS-stimulated BV-2 microglia demonstrated a significant increase in the production of reactive oxygen species (ROS) and tumour necrosis factor-alpha (TNF-α), phosphorylation of c-Jun N-terminal kinase (JNK), increased expression of Toll-like receptor 4 (TLR4), and reduced expression of uncoupling protein 2 (UCP2), all of which were reversed following FABP4 genetic silencing and chemical inhibition with BMS309403. The oxidation rate of 3H-oleic acid and microglial uptake of 3H-2-deoxy-D-glucose were modulated with LPS activation, processes which were restored with genetic and chemical inhibition of FABP4. This is the first study to report on the critical role of FABP4 in mediating the deleterious effects of LPS on microglial immunometabolism, suggesting that FABP4 may present as a novel therapeutic target to alleviate microglia-mediated neuroinflammation, a commonly reported factor in multiple neurodegenerative diseases.


Subject(s)
Lipopolysaccharides , Microglia , Animals , Mice , Brain/metabolism , Fatty Acid-Binding Proteins , Inflammation/chemically induced , Inflammation/metabolism , Lipopolysaccharides/toxicity
6.
Neurotherapeutics ; 20(4): 1198-1214, 2023 07.
Article in English | MEDLINE | ID: mdl-37226029

ABSTRACT

Increased expression of the voltage-gated potassium channel Kv1.3 in activated microglia, and the subsequent release of pro-inflammatory mediators, are closely associated with the progression of Alzheimer's disease (AD). Studies have shown that reducing neuroinflammation through the non-selective blockade of microglial Kv1.3 has the potential to improve cognitive function in mouse models of familial AD. We have previously demonstrated that a potent and highly-selective peptide blocker of Kv1.3, HsTX1[R14A], not only entered the brain parenchyma after peripheral administration in a lipopolysaccharide (LPS)-induced mouse model of inflammation, but also significantly reduced pro-inflammatory mediator release from activated microglia. In this study, we show that microglial expression of Kv1.3 is increased in senescence accelerated mice (SAMP8), an animal model of sporadic AD, and that subcutaneous dosing of HsTX1[R14A] (1 mg/kg) every other day for 8 weeks provided a robust improvement in cognitive deficits in SAMP8 mice. The effect of HsTX1[R14A] on the whole brain was assessed using transcriptomics, which revealed that the expression of genes associated with inflammation, neuron differentiation, synapse function, learning and memory were altered by HsTX1[R14A] treatment. Further study is required to investigate whether these changes are downstream effects of microglial Kv1.3 blockade or a result of alternative mechanisms, including any potential effect of Kv1.3 blockade on other brain cell types. Nonetheless, these results collectively demonstrate the cognitive benefits of Kv1.3 blockade with HsTX1[R14A] in a mouse model of sporadic AD, demonstrating its potential as a therapeutic candidate for this neurodegenerative disease.


Subject(s)
Alzheimer Disease , Neurodegenerative Diseases , Mice , Animals , Peptides/pharmacology , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Disease Models, Animal , Inflammation , Cognition
7.
Mol Pharm ; 20(5): 2686-2701, 2023 05 01.
Article in English | MEDLINE | ID: mdl-37066621

ABSTRACT

Microglia-mediated neuroinflammation is commonly associated with neurodegeneration and has been implicated in several neurological disorders, such as Alzheimer's disease and Parkinson's disease. Therefore, it is crucial to develop a detailed understanding of the interaction of potential nanocarriers with microglial cells to efficiently deliver anti-inflammatory molecules. In this study, we applied brush polymers as a modular platform to systematically investigate their association with murine (BV-2) and human (HMC3) microglial cell lines in the presence and absence of the pro-inflammatory inducer lipopolysaccharide (LPS) using flow cytometry. Brush polymers of different sizes and shapes, ranging from ellipsoid to worm-like cylinders, were prepared through a combination of the two building blocks carboxylated N-acylated poly(aminoester)s (NPAEs)-based polymers and poly(2-ethyl-2-oxazoline)-NH2 (PEtOx-NH2) and characterized by 1H NMR spectroscopy, size exclusion chromatography, and small-angle neutron scattering. Generally, ellipsoidal particles showed the highest cellular association. Moreover, while no significant differences in murine cell association were observed, the brush polymers revealed a significant accumulation in LPS-activated human microglia compared to resting cells, emphasizing their higher affinity to activated HMC3 cells. Brush polymers with the highest cell association were further modified with the anti-inflammatory agent N-acetyl cysteine (NAC) in a reversible manner. The brush polymer-NAC conjugates were found to significantly attenuate the production of interleukin 6 (p < 0.001) in LPS-activated HMC3 cells compared to LPS-activated BV-2 cells. Thus, the presented brush polymer-NAC conjugates showed a high anti-inflammatory activity in human microglia, suggesting their potential for disease-targeted therapy of microglial-mediated neuroinflammation in the future.


Subject(s)
Microglia , Polymers , Mice , Humans , Animals , Microglia/metabolism , Polymers/metabolism , Lipopolysaccharides/pharmacology , Neuroinflammatory Diseases , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/metabolism , Acetylcysteine/chemistry
9.
Front Pharmacol ; 14: 1111617, 2023.
Article in English | MEDLINE | ID: mdl-36744256

ABSTRACT

Background: Fluids, solutes and immune cells have been demonstrated to drain from the brain and surrounding structures to the cervical lymph vessels and nodes in the neck via meningeal lymphatics, nasal lymphatics and/or lymphatic vessels associated with cranial nerves. A method to cannulate the efferent cervical lymph duct for continuous cervical lymph fluid collection in rodents has not been described previously and would assist in evaluating the transport of molecules and immune cells from the head and brain via the lymphatics, as well as changes in lymphatic transport and lymph composition with different physiological challenges or diseases. Aim: To develop a novel method to cannulate and continuously collect lymph fluid from the cervical lymph duct in rats and to analyze the protein, lipid and immune cell composition of the collected cervical lymph fluid. Methods: Male Sprague-Dawley rats were cannulated at the carotid artery with or without cannulation or ligation at the cervical lymph duct. Samples of blood, whole lymph and isolated lipoprotein fractions of lymph were collected and analyzed for lipid and protein composition using commercial kits. Whole lymph samples were centrifuged and isolated pellets were stained and processed for flow cytometry analysis of CD3+, CD4+, CD8a+, CD45R+ (B220) and viable cell populations. Results: Flow rate, phospholipid, triglyceride, cholesterol ester, free cholesterol and protein concentrations in cervical lymph were 0.094 ± 0.014 mL/h, 0.34 ± 0.10, 0.30 ± 0.04, 0.07 ± 0.02, 0.02 ± 0.01 and 16.78 ± 2.06 mg/mL, respectively. Protein was mostly contained within the non-lipoprotein fraction but all lipoprotein types were also present. Flow cytometry analysis of cervical lymph showed that 67.1 ± 7.4% of cells were CD3+/CD4+ T lymphocytes, 5.8 ± 1.6% of cells were CD3+/CD8+ T lymphocytes, and 10.8 ± 4.6% of cells were CD3-/CD45R+ B lymphocytes. The remaining 16.3 ± 4.6% cells were CD3-/CD45- and identified as non-lymphocytes. Conclusion: Our novel cervical lymph cannulation method enables quantitative analysis of the lymphatic transport of immune cells and molecules in the cervical lymph of rats for the first time. This valuable tool will enable more detailed quantitative analysis of changes to cervical lymph composition and transport in health and disease, and could be a valuable resource for discovery of biomarkers or therapeutic targets in future studies.

10.
Pharm Res ; 40(3): 651-660, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36539667

ABSTRACT

PURPOSE: The ATP-binding cassette (ABC) transport protein ABCG2 (also known as breast cancer resistance protein (BCRP)) is expressed at the luminal face of the blood-brain barrier (BBB), where it limits the brain uptake of a number of therapeutic drugs. We recently reported that the ABC efflux transporter P-glycoprotein (P-gp) was downregulated in human immortalised brain endothelial (hCMEC/D3) cells treated with ferric ammonium citrate (FAC). The aim of the present study, therefore, was to assess whether BCRP expression is also affected by FAC and identify any signalling mechanisms involved. METHODS: ABCG2 mRNA was assessed by RT-qPCR. Protein levels of BCRP, phosphorylated extracellular-regulated kinases 1 and 2 (p-ERK1/2) and total ERK 1/2 were assessed by Western blot. Reactive oxygen species (ROS) levels were determined using 2',7'-dichlorofluorescin diacetate. RESULTS: Treatment of hCMEC/D3 cells with FAC (250 µM, 72 h) significantly reduced ABCG2 mRNA levels (32.2 ± 3.7%) without a concomitant reduction in BCRP protein expression. ABCG2 mRNA levels were restored to control levels when co-treated with the antioxidant N-acetylcysteine (NAC), suggesting the effect of FAC was mediated by a ROS-sensitive pathway. We also found that FAC-treatment was associated with increased levels of p-ERK1/2, suggesting involvement of the ERK1/2 signalling pathway in the observed ABCG2 mRNA downregulation. The ERK1/2 signalling pathway inhibitor U0126 restored p-ERK1/2 levels and partially attenuated the FAC-induced reduction in ABCG2 mRNA. CONCLUSIONS: This study suggests that FAC-induced downregulation of ABCG2 mRNA is driven by ROS and ERK1/2 signalling, mechanisms which may be exploited to modulate BCRP expression at the BBB.


Subject(s)
Endothelial Cells , MAP Kinase Signaling System , Humans , ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics , ATP Binding Cassette Transporter, Subfamily G, Member 2/metabolism , ATP-Binding Cassette Transporters/metabolism , Brain/metabolism , Endothelial Cells/metabolism , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , Reactive Oxygen Species/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism
11.
Mol Pharm ; 20(1): 255-266, 2023 01 02.
Article in English | MEDLINE | ID: mdl-36331024

ABSTRACT

The voltage-gated potassium channel Kv1.3 regulates the pro-inflammatory function of microglia and is highly expressed in the post-mortem brains of individuals with Alzheimer's and Parkinson's diseases. HsTX1[R14A] is a selective and potent peptide inhibitor of the Kv1.3 channel (IC50 ∼ 45 pM) that has been shown to decrease cytokine levels in a lipopolysaccharide (LPS)-induced mouse model of inflammation. Central nervous system exposure to HsTX1[R14A] was previously detected in this mouse model using liquid chromatography with tandem mass spectrometry, but this technique does not report on the spatial distribution of the peptide in the different brain regions or peripheral organs. Herein, the in vivo distribution of a [64Cu]Cu-labeled DOTA conjugate of HsTX1[R14A] was observed for up to 48 h by positron emission tomography (PET) in mice. After subcutaneous administration to untreated C57BL/6J mice, considerable uptake of the radiolabeled peptide was observed in the kidney, but it was undetectable in the brain. Biodistribution of a [68Ga]Ga-DOTA conjugate of HsTX1[R14A] was then investigated in the LPS-induced mouse model of neuroinflammation to assess the effects of inflammation on uptake of the peptide in the brain. A control peptide with very weak Kv1.3 binding, [68Ga]Ga-DOTA-HsTX1[R14A,Y21A,K23A] (IC50 ∼ 6 µM), was also tested. Significantly increased uptake of [68Ga]Ga-DOTA-HsTX1[R14A] was observed in the brains of LPS-treated mice compared to mice treated with control peptide, implying that the enhanced uptake was due to increased Kv1.3 expression rather than simply increased blood-brain barrier disruption. PET imaging also showed accumulation of [68Ga]Ga-DOTA-HsTX1[R14A] in inflamed joints and decreased clearance from the kidneys in LPS-treated mice. These biodistribution data highlight the potential of HsTX1[R14A] as a therapeutic for the treatment of neuroinflammatory diseases mediated by overexpression of Kv1.3.


Subject(s)
Lipopolysaccharides , Neuroinflammatory Diseases , Mice , Animals , Tissue Distribution , Gallium Radioisotopes/metabolism , Mice, Inbred C57BL , Peptides/chemistry , Brain/diagnostic imaging , Brain/metabolism , Inflammation/metabolism , Positron-Emission Tomography
12.
Pharmaceutics ; 14(12)2022 Dec 14.
Article in English | MEDLINE | ID: mdl-36559296

ABSTRACT

For peripherally administered drugs to reach the central nervous system (CNS) and treat amyotrophic lateral sclerosis (ALS), they must cross the blood-brain barrier (BBB). As mounting evidence suggests that the ultrastructure of the BBB is altered in individuals with ALS and in animal models of ALS (e.g., SOD1G93A mice), we characterized BBB transporter expression and function in transgenic C9orf72 BAC (C9-BAC) mice expressing a hexanucleotide repeat expansion, the most common genetic cause of ALS. Using an in situ transcardiac brain perfusion technique, we identified a 1.4-fold increase in 3H-2-deoxy-D-glucose transport across the BBB in C9-BAC transgenic (C9) mice, relative to wild-type (WT) mice, which was associated with a 1.3-fold increase in brain microvascular glucose transporter 1 expression, while other general BBB permeability processes (passive diffusion, efflux transporter function) remained unaffected. We also performed proteomic analysis on isolated brain microvascular endothelial cells, in which we noted a mild (14.3%) reduction in zonula occludens-1 abundance in C9 relative to WT mice. Functional enrichment analysis highlighted trends in changes to various BBB transporters and cellular metabolism. To our knowledge, this is the first study to demonstrate altered BBB function in a C9orf72 repeat expansion model of ALS, which has implications on how therapeutics may access the brain in this mouse model.

13.
Bioconjug Chem ; 33(11): 2197-2212, 2022 11 16.
Article in English | MEDLINE | ID: mdl-36330854

ABSTRACT

Upregulation of the voltage-gated potassium channel KV1.3 is implicated in a range of autoimmune and neuroinflammatory diseases, including rheumatoid arthritis, psoriasis, multiple sclerosis, and type I diabetes. Understanding the expression, localization, and trafficking of KV1.3 in normal and disease states is key to developing targeted immunomodulatory therapies. HsTX1[R14A], an analogue of a 34-residue peptide toxin from the scorpion Heterometrus spinifer, binds KV1.3 with high affinity (IC50 of 45 pM) and selectivity (2000-fold for KV1.3 over KV1.1). We have synthesized a fluorescent analogue of HsTX1[R14A] by N-terminal conjugation of a Cy5 tag. Electrophysiology assays show that Cy5-HsTX1[R14A] retains activity against KV1.3 (IC50 ∼ 0.9 nM) and selectivity over a range of other potassium channels (KV1.2, KV1.4, KV1.5, KV1.6, KCa1.1 and KCa3.1), as well as selectivity against heteromeric channels assembled from KV1.3/KV1.5 tandem dimers. Live imaging of CHO cells expressing green fluorescent protein-tagged KV1.3 shows co-localization of Cy5-HsTX1[R14A] and KV1.3 fluorescence signals at the cell membrane. Moreover, flow cytometry demonstrated that Cy5-HsTX1[R14A] can detect KV1.3-expressing CHO cells. Stimulation of mouse microglia by lipopolysaccharide, which enhances membrane expression of KV1.3, was associated with increased staining by Cy5-HsTX1[R14A], demonstrating that it can be used to identify KV1.3 in disease-relevant models of inflammation. Furthermore, the biodistribution of Cy5-HsTX1[R14A] could be monitored using ex vivo fluorescence imaging of organs in mice dosed subcutaneously with the peptide. These results illustrate the utility of Cy5-HsTX1[R14A] as a tool for visualizing KV1.3, with broad applicability in fundamental investigations of KV1.3 biology, and the validation of novel disease indications where KV1.3 inhibition may be of therapeutic value.


Subject(s)
Kv1.3 Potassium Channel , Scorpion Venoms , Mice , Animals , Cricetinae , Kv1.3 Potassium Channel/chemistry , Kv1.3 Potassium Channel/metabolism , Scorpion Venoms/chemistry , Scorpion Venoms/metabolism , Scorpion Venoms/pharmacology , Potassium Channel Blockers/chemistry , Potassium Channel Blockers/pharmacology , Cricetulus , Tissue Distribution , Peptides/chemistry
14.
Healthcare (Basel) ; 10(8)2022 Aug 08.
Article in English | MEDLINE | ID: mdl-36011146

ABSTRACT

A core competency of Australian Pharmacy graduates is to prepare and compound extemporaneous formulations. Students in our pharmacy course would traditionally formulate extemporaneous products in laboratory classes while simultaneously preparing a handwritten label, with students divorcing this laboratory activity from the entire dispensing process. As a way to incorporate the dispensing process into the preparation of extemporaneous products without adding excessive time to the laboratory, we integrated MyDispense, a virtual pharmacy simulation, in pre-laboratory activities. This meant that students could complete all the dispensing activities for prescribed extemporaneous formulations prior to attending the laboratory. Prescriptions for solutions, suspensions, creams and ointments were developed in MyDispense, including essential components for dispensing an extemporaneous formulation (e.g., formulation name, dosing instructions). These prescriptions were provided to students at least 1 week prior to their laboratory classes, whereas for the laboratory assessments, the prescription was provided at the commencement of the extemporaneous exam. Due to the implementation of dispensing via MyDispense, we found that students demonstrated pre-laboratory engagement as all students presented their printed labels upon entering the laboratory. We also observed an increase in interaction between students and laboratory facilitators, mainly focused on the principles of formulation integrated around patient outcomes. Virtual simulations such as MyDispense can therefore provide a guided realistic learning experience, whilst overcoming time pressures associated with laboratory timetabling. This approach also encourages students to engage in the dispensing process prior to extemporaneous laboratories providing more opportunity to discuss higher-level formulation principles and patient-centred outcomes during laboratory classes.

15.
J Pharm Sci ; 111(12): 3196-3205, 2022 12.
Article in English | MEDLINE | ID: mdl-35841999

ABSTRACT

This publication represents the first to report global information on characteristics and requirements of doctoral programs in the pharmaceutical sciences in schools/colleges of Pharmacy. Survey responses (140 responses) were received from doctoral programs in 23 countries, with the greatest number of responses obtained from Japan, followed by India and the United States. Program characteristics and requirements, and student and faculty information, including graduate placement, in programs in Asia, North America, Europe, Africa and Australia were compared. Survey responses indicated differences in entrance requirements for doctoral programs with minimum requirements being a bachelor's degree, pharmacy degree or master's degree, including a M.Phil. degree. Programs differed widely in size in all geographical areas, but there was a similar emphasis on core educational learning outcomes (core competencies) and Ph.D. graduation requirements including qualifying examinations, thesis defense with internal and external reviewers and requirements for peer-reviewed publications. Additionally, three-quarters of programs indicated that there was external review of their programs every 2-4 or 5-7 years. Female students and female faculty mentors represented about 50% of students/faculty in programs in most geographical areas. Placement of students after graduation indicated that the highest percentage went into the pharmaceutical industry in Asia (predominantly India) and North America, with a lower percentage in Europe, Africa and Australia.


Subject(s)
Education, Pharmacy , Female , Humans , Africa , Europe , Surveys and Questionnaires , United States , North America , Asia
16.
J Pharm Sci ; 111(12): 3206-3214, 2022 12.
Article in English | MEDLINE | ID: mdl-35842000

ABSTRACT

Information on master's programs in the pharmaceutical sciences is lacking; this manuscript addresses this gap in the literature, by reporting on the results of an international survey performed in 2021 of master's programs in the pharmaceutical sciences offered at Schools/Colleges of Pharmacy. Ninety-six responses were received from universities from 23 countries, with the greatest number of responses obtained from India, followed by the United States and Japan. Master's programs in the pharmaceutical sciences are generally full time and 2 years in duration. Only 3% of programs were reported to be examination-based, while the remaining 97% had a research component with 70% of programs having a thesis defense with external and/or internal examiners. Master's programs tended to be larger in Asia and Europe than in North America; as well, programs in North America tended to have more international students. Didactic coursework was included in 96% of master's programs in North America, but only in 38% of Asian and 58% of European programs. The predominant placement of graduates from master's programs in Asia was in the pharmaceutical industry (70%); this contrasted with programs in Europe, Africa and North America where 28-36% enter careers in the pharmaceutical industry and higher percentages enter Ph.D. programs. The major challenge identified by programs was funding of faculty and of graduate students, although decreasing career opportunities was identified as a challenge in Asia and Africa.


Subject(s)
Pharmacy , Humans , United States , Surveys and Questionnaires , Pharmaceutical Preparations , Europe , Africa
17.
Adv Drug Deliv Rev ; 185: 114282, 2022 06.
Article in English | MEDLINE | ID: mdl-35421522

ABSTRACT

Alzheimer's disease (AD) has traditionally been considered solely a neurological condition. Therefore, numerous studies have been conducted to identify the existence of pathophysiological changes affecting the brain and the blood-brain barrier in individuals with AD. Such studies have provided invaluable insight into possible changes to the central nervous system exposure of drugs prescribed to individuals with AD. However, there is now increasing recognition that extra-neurological systems may also be affected in AD, such as the small intestine, liver, and kidneys. Examination of these peripheral pathophysiological changes is now a burgeoning area of scientific research, owing to the potential impact of these changes on the absorption, distribution, metabolism, and excretion (ADME) of drugs used for both AD and other concomitant conditions in this population. The purpose of this review is to identify and summarise available literature reporting alterations to key organs influencing the pharmacokinetics of drugs, with any changes to the small intestine, liver, kidney, and circulatory system on the ADME of drugs described. By assessing studies in both rodent models of AD and samples from humans with AD, this review highlights possible dosage adjustment requirements for both AD and non-AD drugs so as to ensure the achievement of optimum pharmacotherapy in individuals with AD.


Subject(s)
Alzheimer Disease , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Biological Transport , Blood-Brain Barrier/metabolism , Brain/metabolism , Humans , Intestine, Small/metabolism
18.
J Neurochem ; 162(3): 226-244, 2022 08.
Article in English | MEDLINE | ID: mdl-35304760

ABSTRACT

P-glycoprotein (P-gp) is an efflux transporter at the blood-brain barrier (BBB) that hinders brain access of substrate drugs and clears endogenous molecules such as amyloid beta (Aß) from the brain. As biometals such as copper (Cu) modulate many neuronal signalling pathways linked to P-gp regulation, it was hypothesised that the bis(thiosemicarbazone) (BTSC) Cu-releasing complex, copper II glyoxal bis(4-methyl-3-thiosemicarbazone) (CuII [GTSM]), would enhance P-gp expression and function at the BBB, while copper II diacetyl bis(4-methyl-3-thiosemicarbazone) (CuII [ATSM]), which only releases Cu under hypoxic conditions, would not modulate P-gp expression. Following treatment with 25-250 nM CuII (BTSC)s for 8-48 h, expression of P-gp mRNA and protein in human brain endothelial (hCMEC/D3) cells was assessed by RT-qPCR and Western blot, respectively. P-gp function was assessed by measuring accumulation of the fluorescent P-gp substrate, rhodamine 123 and intracellular Cu levels were quantified by inductively coupled plasma mass spectrometry. Interestingly, CuII (ATSM) significantly enhanced P-gp expression and function 2-fold and 1.3-fold, respectively, whereas CuII (GTSM) reduced P-gp expression 0.5-fold and function by 200%. As both compounds increased intracellular Cu levels, the effect of different BTSC backbones, independent of Cu, on P-gp expression was assessed. However, only the Cu-ATSM complex enhanced P-gp expression and this was mediated partly through activation (1.4-fold) of the extracellular signal-regulated kinase 1 and 2, an outcome that was significantly attenuated in the presence of an inhibitor of the mitogen-activated protein kinase regulatory pathway. Our findings suggest that CuII (ATSM) and CuII (GTSM) have the potential to modulate the expression and function of P-gp at the BBB to impact brain drug delivery and clearance of Aß.


Subject(s)
Copper , Thiosemicarbazones , ATP Binding Cassette Transporter, Subfamily B/genetics , ATP Binding Cassette Transporter, Subfamily B/metabolism , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Amyloid beta-Peptides/metabolism , Brain/metabolism , Copper/metabolism , Endothelial Cells/metabolism , Humans , Thiosemicarbazones/chemistry , Thiosemicarbazones/pharmacology
19.
Br J Pharmacol ; 179(11): 2577-2588, 2022 06.
Article in English | MEDLINE | ID: mdl-35048358

ABSTRACT

The access of drugs into the central nervous system (CNS) is regulated by the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB). A large body of evidence supports perturbation of these barriers in neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Modifications to the BBB and BSCB are also reported in amyotrophic lateral sclerosis (ALS), albeit these modifications have received less attention relative to those in other neurodegenerative diseases. Such alterations to the BBB and BSCB have the potential to impact on CNS exposure of drugs in ALS, modulating the effectiveness of drugs intended to reach the brain and the toxicity of drugs that are not intended to reach the brain. Given the clinical importance of these phenomena, this review will summarise reported modifications to the BBB and BSCB in ALS, discuss their impact on CNS drug exposure, and suggest further research directions so as to optimise medicine use in people with ALS.


Subject(s)
Amyotrophic Lateral Sclerosis , Amyotrophic Lateral Sclerosis/drug therapy , Blood-Brain Barrier , Central Nervous System , Humans , Spinal Cord
20.
Am J Pharm Educ ; 86(3): 8670, 2022 03.
Article in English | MEDLINE | ID: mdl-34301575

ABSTRACT

Pharmacy schools are generating significant amounts of data across the training continuum, including data about student selection, performance, and job placement. However, current data practices limit the Academy's ability to effectively leverage the vast amounts of data available within and across pharmacy institutions. To improve data practices and promote the quality and reusability of data, a set of guiding principles for data management and stewardship were developed and published in 2016. The FAIR principles state that digital objects should be findable (ie, data have a unique identifier and are registered in a searchable resource), accessible (ie, data are retrievable by their identifier using an open, free, standardized protocol), interoperable (ie, data use a formal, accessible, shared, and broadly applicable language, and include qualified references to other data), and reusable (ie, data are described with accurate and relevant attributes, released with a data usage license, and meet domain-relevant community standards). This commentary advocates for improved data practices and provides recommendations for advancing FAIR data principles in pharmacy education.


Subject(s)
Education, Pharmacy , Pharmacy , Humans , School Admission Criteria , Schools, Pharmacy
SELECTION OF CITATIONS
SEARCH DETAIL
...