scholarly journals The Artemiside-artemisox-artemisone-M1 Tetrad: Efficacies Against Blood Stage P. falciparum Parasites, DMPK Properties, and the Case for Artemiside

2021 ◽  
Author(s):  
Liezl Gibhard ◽  
Dina Coertzen ◽  
Janette Reader ◽  
Mariëtte E. van der Watt ◽  
Lyn-Marie Birkholtz ◽  
...  
Keyword(s):  
Active Drug ◽  
Early Stage ◽  
Blood Stage ◽  
Combination Therapies ◽  
Model Following ◽  
Synthetic Accessibility ◽  
Exposure Levels ◽  
Artemisinin Combination Therapies

Because of the need to replace the current clinical artemisinins in artemisinin combination therapies, we are evaluating fitness of amino-artemisinins for this purpose. These include the thiomorpholine derivative artemiside obtained in one scalable synthetic step from dihydroartemisinin (DHA) and the derived sulfone artemisone. We have recently shown that artemiside undergoes facile metabolism via the sulfoxide artemisox into artemisone and thence into the unsaturated metabolite M1; DHA is not a metabolite. Artemisox and M1 are now found to be approximately equipotent with artemiside and artemisone in vitro against asexual P. falciparum (Pf) blood stage parasites (IC50 1.5 – 2.6 nM). Against Pf NF54 blood stage gametocytes, artemisox is potently active (IC50 18.9 nM early-stage, 2.7 nM late-stage). Comparative drug metabolism and pharmacokinetic (DMPK) properties were assessed via po and iv administration of artemiside, artemisox and artemisone in a murine model. Following oral administration, the composite Cmax value of artemiside plus its metabolites artemisox and artemisone formed in vivo is some 2.6-fold higher than that attained following administration of artemisone alone. Given that efficacy of short half-life rapidly-acting antimalarial drugs such as the artemisinins is associated with Cmax, it is apparent that artemiside will be more active than artemisone in vivo, due to additive effects of the metabolites. As is evident from earlier data, artemiside indeed possesses appreciably greater efficacy in vivo against murine malaria. Overall, the higher exposure levels of active drug following administration of artemiside coupled with its synthetic accessibility indicate it is much the preferred drug for incorporation into rational new artemisinin combination therapies.

scholarly journals The Artemiside-Artemisox-Artemisone-M1 Tetrad: Efficacies against Blood Stage P. falciparum Parasites, DMPK Properties, and the Case for Artemiside

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2066
Author(s):  
Liezl Gibhard ◽  
Dina Coertzen ◽  
Janette Reader ◽  
Mariëtte E. van der Watt ◽  
Lyn-Marie Birkholtz ◽  
...  
Keyword(s):  
Late Stage ◽  
Early Stage ◽  
Blood Stage ◽  
Combination Therapies ◽  
Prolonged Incubation ◽  
Model Following ◽  
Synthetic Accessibility ◽  
Artemisinin Combination Therapies

Because of the need to replace the current clinical artemisinins in artemisinin combination therapies, we are evaluating fitness of amino-artemisinins for this purpose. These include the thiomorpholine derivative artemiside obtained in one scalable synthetic step from dihydroartemisinin (DHA) and the derived sulfone artemisone. We have recently shown that artemiside undergoes facile metabolism via the sulfoxide artemisox into artemisone and thence into the unsaturated metabolite M1; DHA is not a metabolite. Artemisox and M1 are now found to be approximately equipotent with artemiside and artemisone in vitro against asexual P. falciparum (Pf) blood stage parasites (IC50 1.5–2.6 nM). Against Pf NF54 blood stage gametocytes, artemisox is potently active (IC50 18.9 nM early-stage, 2.7 nM late-stage), although against the late-stage gametocytes, activity is expressed, like other amino-artemisinins, at a prolonged incubation time of 72 h. Comparative drug metabolism and pharmacokinetic (DMPK) properties were assessed via po and iv administration of artemiside, artemisox, and artemisone in a murine model. Following oral administration, the composite Cmax value of artemiside plus its metabolites artemisox and artemisone formed in vivo is some 2.6-fold higher than that attained following administration of artemisone alone. Given that efficacy of short half-life rapidly-acting antimalarial drugs such as the artemisinins is associated with Cmax, it is apparent that artemiside will be more active than artemisone in vivo, due to additive effects of the metabolites. As is evident from earlier data, artemiside indeed possesses appreciably greater efficacy in vivo against murine malaria. Overall, the higher exposure levels of active drug following administration of artemiside coupled with its synthetic accessibility indicate it is much the preferred drug for incorporation into rational new artemisinin combination therapies.

scholarly journals Towards new transmission-blocking combination therapies - pharmacokinetics of 10-amino-artemisinins and 11-aza-artemisinin, and comparison with DHA and artemether

2021 ◽  
Author(s):  
Daniel J. Watson ◽  
Lizahn Laing ◽  
Liezl Gibhard ◽  
Ho Ning Wong ◽  
Richard K. Haynes ◽  
...  
Keyword(s):  
Relative Bioavailability ◽  
Total Plasma ◽  
Combination Therapies ◽  
Total Plasma Clearance ◽  
Efficacy Data ◽  
Liver Clearance ◽  
First Time ◽  
Artemisinin Combination Therapies

As artemisinin combination therapies (ACTs) are compromised by resistance, we are evaluating triple combination therapies (TACTs) comprising an amino-artemisinin, a redox drug and third drug with different mode of action. Thus, here we briefly review efficacy data on artemisone, artemiside, other amino-artemisinins and 11-aza-artemisinin, and conduct ADME profiling in vitro and PK profiling in vivo via iv and po administration to mice. The sulfamide derivative has a notably long murine microsomal half-life ( t 1/2 >150 min), low intrinsic liver clearance and total plasma clearance rates ( CL int 189.4, CL tot 32.2 mL/min/kg), and high relative bioavailability (F 59%). Kinetics are somewhat similar for 11-aza-artemisinin ( t 1/2 >150 min, CL int 576.9, CL tot 75.0 mL/min/kg), although bioavailability is lower (F 14%). In contrast, artemether is rapidly metabolized to DHA ( t 1/2 17.4 min) and eliminated ( CL int 855.0, CL tot 119.7 mL/min/kg), and has low oral bioavailability F of 2%. Whilst artemisone displays low t 1/2 of <10 min and high CL int of 302.1, it displays a low CL tot of 42.3 mL/min/kg, and moderate bioavailability F of 32%. Its active metabolite M1 displays a much improved t 1/2 of >150 min and a reduced CL int of 37.4 mL/min/kg. Artemiside has t 1/2 12.4 min and CL int 673.9 and CL tot 129.7 mL/kg/min, likely a reflection of its surprisingly rapid metabolism to artemisone, reported here for the first time. DHA is not formed from any amino-artemisinin. Overall, the efficacy and PK data strongly support the development of selected amino-artemisinins as components of new TACTs.

scholarly journals Upregulations of Clcn3 and P-Gp Provoked by Lens Osmotic Expansion in Rat Galactosemic Cataract

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Lixia Ji ◽  
Lixia Cheng ◽  
Zhihong Yang
Keyword(s):  
Osmotic Stress ◽  
Early Stage ◽  
Lens Epithelial Cells ◽  
Anterior Capsule ◽  
Glycoprotein P ◽  
Protein Levels ◽  
P Glycoprotein ◽  
Sugar Cataract

Objective.Lens osmotic expansion, provoked by overactivated aldose reductase (AR), is the most essential event of sugar cataract. Chloride channel 3 (Clcn3) is a volume-sensitive channel, mainly participating in the regulation of cell fundamental volume, and P-glycoprotein (P-gp) acts as its modulator. We aim to study whether P-gp and Clcn3 are involved in lens osmotic expansion of galactosemic cataract.Methods and Results.In vitro, lens epithelial cells (LECs) were primarily cultured in gradient galactose medium (10–60 mM), more and more vacuoles appeared in LEC cytoplasm, and mRNA and protein levels of AR, P-gp, and Clcn3 were synchronously upregulated along with the increase of galactose concentration. In vivo, we focused on the early stage of rat galactosemic cataract, amount of vacuoles arose from equatorial area and scattered to the whole anterior capsule of lenses from the 3rd day to the 9th day, and mRNA and protein levels of P-gp and Clcn3 reached the peak around the 9th or 12th day.Conclusion. Galactosemia caused the osmotic stress in lenses; it also markedly leads to the upregulations of AR, P-gp, and Clcn3 in LECs, together resulting in obvious osmotic expansion in vitro and in vivo.

scholarly journals Metabolism and Pharmacokinetic Study of the Boron-Containing Prodrug of Belinostat (ZL277), a Pan HDAC Inhibitor with Enhanced Bioavailability

2019 ◽  
Vol 12 (4) ◽  
pp. 180 ◽  
Author(s):  
Changde Zhang ◽  
Shanchun Guo ◽  
Qiu Zhong ◽  
Qiang Zhang ◽  
Ahamed Hossain ◽  
...  
Keyword(s):  
Pharmacokinetic Study ◽  
Hdac Inhibitor ◽  
Active Drug ◽  
Hydrolysis Product ◽  
Liver Microsomes ◽  
Tumor Model ◽  
Maximum Plasma ◽  
Metabolic Products

ZL277 is a prodrug of belinostat with enhanced bioavailability and efficacy as a pan histone deacetylase (HDAC) inhibitor. In this study, we investigated the metabolism and pharmacokinetics of ZL277 in liver S9 fractions, liver microsomes, liver cytosol, and in mice. Metabolic products were identified and quantified by a combination of liquid chromatography and tandem mass spectrometry. The in vitro metabolic profile of ZL277 includes ZL277-B(OH)2-452, the major oxidative metabolite ZL277-OH-424, the active ingredient belinostat, belinostat amide, belinostat acid, and methylated belinostat in liver S9 fractions. Both ZL277-OH-424 and belinostat underwent further glucuronidation in liver microsome, whereas only ZL277-OH-424, but not belinostat, underwent some level of sulfation in rat liver cytosols. These metabolites were examined in plasma and in a breast tumor model in vivo. They were also examined in urine and feces from mice treated with ZL277. The pharmacokinetic study of ZL277 showed the parameters of active drug belinostat with a half-life (t1/2) of 10.7 h, an area under curve value (AUC) of 1506.9 ng/mL*h, and a maximum plasma concentration (Cmax) of 172 ng/mL, reached 3 h after a single dose of 10 mg/kg. The hydrolysis product of the prodrug, ZL277-B(OH)2-452 showed an AUC of 8306 ng/mL*h and Cmax of 931 ng/mL 3 h after drug administration.

scholarly journals Rationally Designing Simple Rod-Like Amphiphilic NIR-Emissive AIE Probes for Precise In-Vivo Detection of Aβ Fibrils/Plaques at A Super-Early Stage

2021 ◽  
Author(s):  
Yipu Wang ◽  
Dong Mei ◽  
Xinyi Zhang ◽  
Da-Hui Qu ◽  
Ju Mei ◽  
...  
Keyword(s):  
High Performance ◽  
Ex Vivo ◽  
Early Stage ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
In Vivo Detection ◽  
Different Strains ◽  
Aβ Fibrils

With increase of social aging, Alzheimer's disease (AD) has been one of the serious diseases threatening human health. The occurrence of A<i>β </i>fibrils<i> </i>or plaques is recognized as the hallmark of AD.<i> </i>Currently, optical imaging has stood out to be a promising technique for the imaging of A<i>β</i> fibrils/plaques and the diagnosis of AD. However, restricted by their poor blood-brain barrier (BBB) penetrability, short-wavelength excitation and emission, and aggregation-caused quenching (ACQ) effect, the clinically used gold-standard optical probes such as <a>thioflavin</a> T (ThT) and thioflavin S (ThS), are not effective enough in the early diagnosis of AD <i>in vivo</i>. Herein, we put forward an “all-in-one” design principle and demonstrate its feasibility in developing high-performance fluorescent probes which are specific to A<i>β</i> fibrils/plaques and promising for super-early <i>in</i>-<i>vivo</i> diagnosis of AD. As a proof of concept, a simple rod-like amphiphilic NIR fluorescent AIEgen, i.e., AIE-CNPy-AD, is developed by taking the specificity, BBB penetration ability, deep-tissue penetration capacity, high signal-to-noise ratio (SNR) into consideration. AIE-CNPy-AD is constituted by connecting the electron-donating and accepting moieties through single bonds and tagging with a propanesulfonate tail, giving rise to the NIR fluorescence, aggregation-induced emission (AIE) effect, amphiphilicity, and rod-like structure, which in turn result in high binding-affinity and excellent specificity to A<i>β</i> fibrils/plaques, satisfactory ability to penetrate BBB and deep tissues, ultrahigh SNR and sensitivity, and high-fidelity imaging capability. <i>In-vitro, ex-vivo,</i> and <i>in-vivo</i> <a>identifying of A<i>β</i> fibrils/plaques</a> in different strains of mice indicate that AIE-CNPy-AD holds the universality to the detection of A<i>β</i> fibrils/plaques. It is noteworthy that AIE-CNPy-AD is even able to trace the small and sparsely distributed A<i>β</i> fibrils/plaques in very young AD model mice such as 4-month-old APP/PS1 mice which are reported to be the youngest mice to have A<i>β</i> deposits in brains, suggesting its great potential in diagnosis and intervention of AD at a super-early stage.

scholarly journals Defining the early stages of intestinal colonisation by whipworms

2020 ◽  
Author(s):  
María A. Duque-Correa ◽  
David Goulding ◽  
Claire Cormie ◽  
Catherine Sharpe ◽  
Judit Gali Moya ◽  
...  
Keyword(s):  
Intestinal Epithelium ◽  
Early Stage ◽  
Proximal Colon ◽  
Host Cells ◽  
Parasitic Nematodes ◽  
Metazoan Parasites ◽  
Multiple Cells ◽  
First Time

ABSTRACTHundreds of millions of people are infected with whipworms (Trichuris trichiura), large metazoan parasites that live in the caecum and proximal colon. Whipworms inhabit distinct multi-intracellular epithelial burrows that have been described as syncytial tunnels. However, the interactions between first-stage (L1) larvae and the host epithelia that determine parasite invasion and establishment in the syncytium remain unclear. In vivo experiments investigating these events have been severely hampered by the limited in situ accessibility to intracellular infective larvae at the bottom of the crypts of Lieberkühn, and the lack of genetic tools such as fluorescent organisms that are readily available for other pathogens but not parasitic nematodes. Moreover, cell lines, which do not mimic the complexity of the intestinal epithelium, have been unsuccessful in supporting infection by whipworm larvae. Here, we show that caecaloids grown in an open crypt-like conformation recapitulate the caecal epithelium. Using this system, we establish in vitro infections with T. muris L1 larvae for the first-time, and provide clear evidence that syncytial tunnels are formed at this early stage. We show that larval whipworms are completely intracellular but woven through multiple cells. Using the caecaloids, we are able to visualise the pathways taken by the larvae as they burrow through the epithelial cells. We also demonstrate that larvae degrade the mucus layers overlaying the epithelium, enabling them to access the cells below. We show that early syncytial tunnels are composed of enterocytes and goblet cells that are alive and actively interacting with the larvae during the first 24 h of the infection. Progression of infection results in damage to host cells and by 72 h post-infection, we show that desmosomes of cells from infected epithelium widen and some host cells appear to become liquified. Collectively, our work unravels processes mediating the intestinal epithelium invasion by whipworms and reveals new specific interactions between the host and the parasite that allow the whipworm to establish on its multi-intracellular niche. Our study demonstrates that caecaloids can be used as a relevant in vitro model to investigate the infection biology of T. muris during the early colonisation of its host.

scholarly journals TArget-Responsive Subcellular Catabolism Analysis for Early-stage Antibody-Drug Conjugates Screening and Assessment

2020 ◽  
Author(s):  
Hua Sang ◽  
Jiali Liu ◽  
Fang Zhou ◽  
Xiaofang Zhang ◽  
Jingwei Zhang ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Therapeutic Efficacy ◽  
High Throughput Screening ◽  
Early Stage ◽  
Cellular Level ◽  
Drug Conjugates ◽  
Therapeutic Outcomes ◽  
Lysosomal Proteolysis

<p></p><p>Key events including antibody-antigen affinity, ADC internalization, trafficking and lysosomal proteolysis-mediated payload release combinatorially determine the therapeutic efficacy and safety for ADCs. Nevertheless, a universal technology that efficiently and conveniently evaluates the involvement of these above elements to ADC payload release and hence the final therapeutic outcomes for mechanistic studies and quality assessment is lacking. Considering the plethora of ADC candidates under development owing to the ever-evolving linker and drug chemistry, we developed a TArget-Responsive Subcellular Catabolism (TARSC) approach that measures catabolites kinetics for given ADCs and elaborates how each individual step ranging from antigen binding to lysosomal proteolysis affects ADC catabolism by targeted interferences. Using a commercial and a biosimilar ado-trastuzumab emtansine (T-DM1) as model ADCs, we recorded unequivocal catabolites kinetics for the two T-DM1s in the presence and absence of the targeted interferences. Their negligible differences in TARSC profiles fitting with their undifferentiated therapeutic outcomes suggested by <i>in vitro</i> viability assays and <i>in vivo</i> tumor growth assays, highlighting TARSC analysis as a good indicator of ADC efficacy and bioequivalency. Lastly, we demonstrated the use of TARSC in assessing payload release efficiency for a new Trastuzumab-toxin conjugate. Collectively, we demonstrated the use of TARSC in characterizing ADC catabolism at (sub)cellular level, and in systematically depicting whether given target proteins affect ADC payload release and hence therapeutic efficacy. We anticipate its future use in high-throughput screening, quality assessment and mechanistic understanding of ADCs for drug R&D before proceeding to costly <i>in vivo</i> experiments.</p><br><p></p>

scholarly journals Transcriptome dynamics in early in vivo developing and in vitro produced porcine embryos

2020 ◽  
Author(s):  
Vera A van der Weijden ◽  
Meret Schmidhauser ◽  
Mayuko Kurome ◽  
Johannes Knubben ◽  
Veronika L Flöter ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Early Stage ◽  
Developmental Competence ◽  
Molecular Signaling ◽  
Developmental Potential ◽  
Stage Of Development ◽  
Molecular Signaling Pathways ◽  
Canonical Pathways

Abstract Background: The transcriptional changes around the time of embryonic genome activation in pre-implantation embryos indicate that this process is highly dynamic. In vitro produced porcine blastocysts are known to be less competent than in vivo developed blastocysts. To understand the conditions that compromise developmental competence of in vitro embryos, it is crucial to evaluate the transcriptional profile of porcine embryos during pre-implantation stages. In this study, we investigated the transcriptome dynamics in in vivo developed and in vitro produced 4-cell embryos, morulae and hatched blastocysts.Results: In vivo developed and in vitro produced embryos displayed largely similar transcriptome profiles during development. Enriched canonical pathways from the 4-cell to the morula transition that were shared between in vivo developed and in vitro produced embryos included oxidative phosphorylation, tRNA charging, and EIF2 signaling. The shared canonical pathways from the morula to the hatched blastocyst transition were 14-3-3-mediated signaling, signaling of Rho family GTPases, and NRF2-mediated oxidative stress response. The in vivo developed and in vitro produced hatched blastocysts were compared to identify molecular signaling pathways indicative of lower developmental competence of in vitro produced hatched blastocysts. A higher metabolic rate and expression of the arginine transporter SLC7A1 were found in in vitro produced hatched blastocysts.Conclusions: Our findings suggest that embryos with compromised developmental potential are arrested at an early stage of development, while embryos developing to the hatched blastocyst stage display largely similar transcriptome profiles, irrespective of the embryo source. The hatched blastocysts derived from the in vitro fertilization-pipeline showed an enrichment in molecular signaling pathways associated with lower developmental competence, compared to the in vivo developed embryos.

scholarly journals CSPα reduces aggregates and rescues striatal dopamine release in αsynuclein transgenic mice

2020 ◽  
Author(s):  
L Caló ◽  
E Hidari ◽  
M Wegrzynowicz ◽  
JW Dalley ◽  
BL Schneider ◽  
...  
Keyword(s):  
Dopamine Release ◽  
Early Stage ◽  
Synaptic Function ◽  
Snare Complex ◽  
Early Event ◽  
Vesicle Recycling ◽  
Cysteine String Protein ◽  
And Function

AbstractαSynuclein aggregation at the synapse is an early event in Parkinson’s disease and is associated with impaired striatal synaptic function and dopaminergic neuronal death. The cysteine string protein (CSPα) and αsynuclein have partially overlapping roles in maintaining synaptic function and mutations in each cause neurodegenerative diseases. CSPα is a member of the DNAJ/HSP40 family of co-chaperones and like αsynuclein, chaperones the SNARE complex assembly and neurotransmitter release. αSynuclein can rescue neurodegeneration in CSPαKO mice. However, whether αsynuclein aggregation alters CSPα expression and function is unknown. Here we show that αsynuclein aggregation at the synapse induces a decrease in synaptic CSPα and a reduction in the complexes that CSPα forms with HSC70 and STGa. We further show that viral delivery of CSPα rescues in vitro the impaired vesicle recycling in PC12 cells with αsynuclein aggregates and in vivo reduces synaptic αsynuclein aggregates restoring normal dopamine release in 1-120hαsyn mice. These novel findings reveal a mechanism by which αsynuclein aggregation alters CSPα at the synapse, and show that CSPα rescues αsynuclein aggregation-related phenotype in 1-120hαsyn mice similar to the effect of αsynuclein in CSPαKO mice. These results implicate CSPα as a potential therapeutic target for the treatment of early-stage PD.

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