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Chimeric antigen receptor T (CAR T) cell therapy has shown remarkable success in treating various leukemias and lymphomas. Cellular kinetic (CK) and pharmacodynamic (PD) behavior of CAR T cell therapy is distinct from other therapies due to its living nature. CAR T CK is typically characterized by an exponential expansion driven by target binding, fast initial decline (contraction), and slow long-term decline (persistence). Due to the dependence of CK on target binding, CK and PD of CAR T therapies are inherently and bidirectionally linked. In this work, we develop a semi-mechanistic model of CAR T CK/PD, incorporating molecular-scale binding, T cell dynamics with multiple phenotypes, and tumor growth and killing. We calibrate this model to published CK and PD data for a CD19-targeting CAR T cell therapy. Using sensitivity analysis, we explore variability in response due to patient- and drug-specific properties. We further explore the impact of tumor characteristics on CAR T-cell expansion and efficacy through individual- and population-level parameter scans. [ABSTRACT FROM AUTHOR]

Introduction: In vivo T cell migration has been of interest to scientists for the past 60 years. T cell kinetics are important in the understanding of the immune response to infectious agents. More recently, adoptive T cell therapies have proven to be a most promising approach to treating a wide range of diseases, including autoimmune and cancer diseases, whereby the characterization of cellular kinetics represents an important step towards the prediction of therapeutic efficacy. Methods: Here, we developed a physiologically-based pharmacokinetic (PBPK) model that describes endogenous T cell homeostasis and the kinetics of exogenously administered T cells in mouse. Parameter calibration was performed using a nonlinear fixed-effects modeling approach based on published data on T cell kinetics and steady-state levels in different tissues of mice. The Partial Rank Correlation Coefficient (PRCC) method was used to perform a global sensitivity assessment. To estimate the impact of kinetic parameters on exogenously administered T cell dynamics, a local sensitivity analysis was conducted. Results: We simulated the model to analyze cellular kinetics following various T cell doses and frequencies of CCR7+ T cells in the population of infused lymphocytes. The model predicted the effects of T cell numbers and of population composition of infused T cells on the resultant concentration of T cells in various organs. For example, a higher percentage of CCR7+ T cells among exogenously administered T lymphocytes led to an augmented accumulation of T cells in the spleen. The model predicted a linear dependence of T cell dynamics on the dose of adoptively transferred T cells. Discussion: The mathematical model of T cell migration presented here can be integrated into a multi-scale model of the immune system and be used in a preclinical setting for predicting the distribution of genetically modified T lymphocytes in various organs, following adoptive T cell therapies. [ABSTRACT FROM AUTHOR]

With the promise of a potentially single‐dose curative regimen, CAR‐T cell therapies have brought a paradigm shift in the treatment and management of hematological malignancies with 6 approved products in the USA. However, there are no approved CAR‐T cell therapies for solid tumors. Herein, we report the clinical pharmacology profile of AMG 119, the first CAR‐T cell therapy targeting delta‐like ligand 3 (DLL3), in patients with relapsed/refractory (R/R) small cell lung cancer (SCLC). AMG 119 demonstrated robust cellular expansion with long‐lasting cell persistence and a favorable exposure–response relationship. AMG 119 has been demonstrated to be clinically safe and well tolerated at the doses tested, with no dose‐limiting toxicities (DLTs) reported. This is the first publication of the clinical pharmacology profile of a CAR‐T cell therapy in SCLC, with encouraging cellular kinetics data supporting the potential for CAR‐T cell therapy in solid tumor space. [ABSTRACT FROM AUTHOR]

The emerging use of qPCR and dPCR in regulated bioanalysis and absence of regulatory guidance on assay validations for these platforms has resulted in discussions on lack of harmonization on assay design and appropriate acceptance criteria for these assays. Both qPCR and dPCR are extensively used to answer bioanalytical questions for novel modalities such as cell and gene therapies. Following cross-industry conversations on the lack of information and guidelines for these assays, an American Association of Pharmaceutical Scientists working group was formed to address these gaps by bringing together 37 industry experts from 24 organizations to discuss best practices to gain a better understanding in the industry and facilitate filings to health authorities. Herein, this team provides considerations on assay design, development, and validation testing for PCR assays that are used in cell and gene therapies including (1) biodistribution; (2) transgene expression; (3) viral shedding; (4) and persistence or cellular kinetics of cell therapies. [ABSTRACT FROM AUTHOR]

IntroductionIn vivo T cell migration has been of interest to scientists for the past 60 years. T cell kinetics are important in the understanding of the immune response to infectious agents. More recently, adoptive T cell therapies have proven to be a most promising approach to treating a wide range of diseases, including autoimmune and cancer diseases, whereby the characterization of cellular kinetics represents an important step towards the prediction of therapeutic efficacy. MethodsHere, we developed a physiologically-based pharmacokinetic (PBPK) model that describes endogenous T cell homeostasis and the kinetics of exogenously administered T cells in mouse. Parameter calibration was performed using a nonlinear fixed-effects modeling approach based on published data on T cell kinetics and steady-state levels in different tissues of mice. The Partial Rank Correlation Coefficient (PRCC) method was used to perform a global sensitivity assessment. To estimate the impact of kinetic parameters on exogenously administered T cell dynamics, a local sensitivity analysis was conducted. ResultsWe simulated the model to analyze cellular kinetics following various T cell doses and frequencies of CCR7+ T cells in the population of infused lymphocytes. The model predicted the effects of T cell numbers and of population composition of infused T cells on the resultant concentration of T cells in various organs. For example, a higher percentage of CCR7+ T cells among exogenously administered T lymphocytes led to an augmented accumulation of T cells in the spleen. The model predicted a linear dependence of T cell dynamics on the dose of adoptively transferred T cells. DiscussionThe mathematical model of T cell migration presented here can be integrated into a multi-scale model of the immune system and be used in a preclinical setting for predicting the distribution of genetically modified T lymphocytes in various organs, following adoptive T cell therapies.

ABSTRACT Brachybacterium species have been identified in various ecological niches and belong to the family Dermabacteriaceae within the phylum Actinobacteria. In this study, we isolated a novel Brachybacterium equifaecis JHP9 strain from horse feces and compared its kinetic, biochemical, and genomic features with those of other Brachybacterium strains. Moreover, comparative genomic analysis using publicly available Brachybacterium genomes was performed to determine the properties involved in their ecological adaptation and metabolic potential. Novel species delineation was determined phylogenetically through 16S rRNA gene similarity (up to 97.9%), average nucleotide identity (79.5–82.5%), average amino acid identity (66.7–75.8%), and in silico DNA-DNA hybridization (23.7–27.9) using closely related strains. This study also presents the first report of the kinetic properties of Brachybacterium species. Most of the Brachybacterium strains displayed high oxygen (K m(app) =1.6–24.2 µM) and glucose (K m(app) =0.73–1.22 µM) affinities, which may manifest niche adaptations. Various carbohydrate metabolisms under aerobic and anaerobic conditions, antibiotic resistance, mobile genetic elements, carbohydrate-active enzymes, lactic acid production, and the clustered regularly interspaced short palindromic repeats-Cas and bacteriophage exclusion systems were observed in the genotypic and/or phenotypic properties of Brachybacterium species, suggesting their genome flexibility, defense mechanisms, and adaptability. Our study contributes to the knowledge of the kinetic, physiological, and genomic properties of Brachybacterium species, including the novel JHP9 strain, which advocates for their tolerant and thriving nature in various environments, leading to their ecological adaptation. IMPORTANCE Basic physiological and genomic properties of most of the Brachybacterium isolates have been studied; however, the ability of this bacterium to adapt to diverse environments, which may demonstrate its role in niche differentiation, is to be identified yet. Therefore, here, we explored cellular kinetics, metabolic diversity, and ecological adaptation/defensive properties of the novel Brachybacterium strain through physiological and comparative genomic analysis. In addition, we presented the first report examining Brachybacterium kinetics, indicating that all strains of Brachybacterium, including the novel one, have high oxygen and glucose affinity. Furthermore, the comparative genomic analysis also revealed that the novel bacterium contains versatile genomic properties, which provide the novel bacterium with significant competitive advantages. Thus, in-depth genotypic and phenotypic analysis with kinetic properties at the species level of this genus is beneficial in clarifying its differential characteristics, conferring the ability to inhabit diverse ecological niches.

The RELIANCE study has demonstrated the activity and safety of relmacabtagene autoleucel (relma-cel) (JW Therapeutics [Shanghai] Co, Ltd, Shanghai, China), a CD19-targeted chimeric antigen receptor T-cell product, in patients with heavily pre-treated relapsed/refractory large B-cell lymphoma (r/r LBCL). This study aimed to report the updated 2-year data of the RELIANCE study. The RELIANCE study (NCT04089215) was an open-label, multi-center, randomized, phase 1/2 registrational clinical trial conducted at 10 clinical sites in China. Adult patients with heavily pre-treated r/r LBCL were enrolled and received lymphodepletion chemotherapy followed by infusion of 100 × 106 or 150 × 106 relma-cel. The primary endpoint was objective response rate (ORR) at 3 months, as assessed by investigators. Secondary endpoints were duration of response (DoR), progression-free survival (PFS), overall survival (OS) and safety profiles. From November 2017 to January 2022, a total of 68 patients were enrolled, and 59 patients received relma-cel infusion. As of March 29, 2022, a total of 59 patients had a median follow-up of 17.9 months (range, 0.3–25.6). ORR was 77.59% (95% confidence interval [CI], 64.73–87.49) and complete response rate was 53.45% (95% CI, 39.87–66.66). Median DoR was 20.3 months (95% CI, 4.86–not reached [NR]) and median PFS was 7.0 months (95% CI, 4.76–24.15). Median OS was NR and 1-year and 2-year OS rates were 75.0% and 69.3%, respectively. Three (5.1%) patients experienced grade ≥3 cytokine release syndrome and two (3.4%) patients had grade ≥3 neurotoxicity. The updated data of the RELIANCE study demonstrate durable response with and manageable safety profile of relma-cel in patients with heavily pre-treated r/r LBCL. [ABSTRACT FROM AUTHOR]

A vast evolution of drug modalities has occurred over the last several decades. Novel modalities such as cell and gene therapies have proven to be efficacious for numerous clinical indications–primarily in rare disease and immune oncology. Because of this success, drug developers are heavily investing in these novel modalities. Given the complexity of these therapeutics, a variety of bioanalytical techniques are employed to fully characterize the pharmacokinetics of these therapies in clinical studies. Industry trends indicate that quantitative PCR (qPCR) and multiparameter flow cytometry are both valuable in determining the pharmacokinetics, i.e. cellular kinetics, of cell therapies. This manuscript will evaluate the pros and cons of both techniques and highlight regulatory guidance on assays for measuring cellular kinetics. Moreover, common considerations when developing these assays will be addressed. [ABSTRACT FROM AUTHOR]

Keywords: CAR-T cell therapies; cellular kinetics; exposure-response models; fixed and body-weight-based dosing EN CAR-T cell therapies cellular kinetics exposure-response models fixed and body-weight-based dosing 1130 1135 6 10/06/22 20221001 NES 221001 Historically, body-size-based dosing has been utilized for many anticancer drugs. For example, the CK curves of lisocabtagene maraleucel overlapped across 50, 100, and 150 million cells dose levels, and no dose-exposure or dose-efficacy relationships were identified.16 BW was not identified as a significant covariate.16 Although there was a positive trend for the E-R between CAR-T cell growth and tumor response, FDA evaluation (lisocabtagene maraleucel BLA 125714 Clinical Pharmacology Review document) suggested it should not be interpreted as causally connected between dose and response, given the observed flat dose-exposure-response relationship. At a dose of 0.5 × 10 SP 6 sp CAR-T cells/kg, the C SB max sb and AUC SB 0-28d sb of brexucabtagene autoleucel were approximately 60% of that in subjects treated at a dose of 2 × 10 SP 6 sp CAR-T cells/kg, exhibiting a potential underexposure. A Consideration of Fixed Dosing Versus Body Size-Based Dosing Strategies for Chimeric Antigen Receptor T-Cell Therapies. [Extracted from the article]

Chimeric antigen receptor (CAR)-T cell therapies reprogram T cells to engage and eliminate cancer cells. Patients’ T cells are transduced in vitro using lentiviral or retroviral vectors containing a CAR transgene. Following infusion, CAR-T cells expand in vivo and may persist in the peripheral blood and bone marrow for years. Therefore, monitoring in vivo copies of the CAR transgene requires highly sensitive, validated analytical methods. Herein, we describe the validation of a qPCR assay to detect tisagenlecleucel transgene in patient samples. The limit of detection and lower limit of quantitation were 3.1 and 10 copies/200 ng genomic DNA, respectively, equivalent to ∼50 copies/μg genomic DNA and in alignment with US Food and Drug Administration guidance on bioanalytical method validation. The assay allowed quantitation of the tisagenlecleucel transgene over a wide dynamic range with a high degree of linearity, that is, 101–106 copies/200 ng genomic DNA (R2 ≥ 0.9988). Coefficients of variation of measured transgene copies ranged from 0.2% to 12.8%. A droplet digital PCR assay was performed as a method of validation and showed a strong correlation with the qPCR assay (R2 = 0.9980, p < 0.0001). This qPCR assay is being utilized to monitor tisagenlecleucel expansion and persistence in clinical trials.

Abstract Background Despite numerous chimeric antigen receptor T‐cell (CAR‐T) trials conducted in China, no CAR‐T has been registered in the country. Furthermore, China law and regulations restrict the export of patient material for CAR‐T manufacture abroad. Relma‐cel (JWCAR029), an anti‐CD19 product produced with a commercial‐ready process in China, was evaluated in the first prospective, single‐arm, multicenter, pivotal study of CAR‐T therapy conducted under Chinese IND to support an NMPA‐accepted BLA submission in relapsed/refractory (r/r) LBCL (NCT04089215). Methods Patients were randomized to receive either 100 × 106 (low dose, n = 27) or 150 × 106 (high dose, n = 32) CAR+ T‐cells as a single infusion following lymphodepleting chemotherapy (fludarabine 25 mg/m2 and cyclophosphamide 250 mg/m2 daily × 3), and then, monitored for efficacy and safety outcomes and pharmacokinetics. The primary endpoint was ORR at 3 months, as assessed by the investigators. Secondary endpoints included DOR, PFS, OS, and adverse event frequency/severity and cell expansion kinetics. Results As of the data cutoff on 17 June 2020, 68 patients were enrolled, and 59 were treated. Among the 58 efficacy‐evaluable patients, the primary endpoint of 3 month ORR was 60.3% (95% CI, 46.6–73.0), excluding the null hypothesis rate of 20%. Any grade and severe grade CRS occurred in 47.5% and 5.1%, respectively, and any grade and severe grade neurotoxicity events occurred in 20.3% and 5.1%. Conclusions Relma‐cel met the primary endpoint analysis and demonstrated a high rate of durable responses and low rate of CAR‐T‐associated toxicities in patients with r/r LBCL in a multicenter trial supporting regulatory submission in China.

BackgroundThe use of T cells expressing chimeric antigen receptor (CAR T) engineered to target CD19 constitutes breakthrough treatment for relapsed or refractory B cell non-Hodgkin lymphoma (R/R B-NHL). Despite improved outcomes, high relapse rate remains a challenge to overcome. Here, we report the clinical results and the pharmacokinetics of bispecific CD19/22 CAR T in patients with R/R B-NHL.MethodsWe performed a prospective, single-arm study of bispecific CD19/22 CAR T cells in R/R B-NHL. We analyzed the safety and efficacy and investigated the kinetic profiles of the CAR T cells. CAR transgene levels were measured using quantitative polymerase chain reaction, and correlation analyses of pharmacodynamic markers and product characteristics, disease conditions, clinical efficacy and adverse events were performed.ResultsFrom August 2017 to September 2020, a total of 32 patients with CD19/22 CAR T administration were analyzed. The overall response rate was 79.3%, and the complete response rate was 34.5%. The progression-free survival (PFS) and overall survival (OS) rates at 12 months were 40.0% and 63.3%, respectively. Among patients who had a CR at 3 months, the PFS and OS rates at 12 months were 66.7% and 100%, respectively. Severe cytokine release syndrome (sCRS) (grade 3 and higher) occurred in nine patients (28.1%). Grade 3 or higher neurologic events occurred in four patients (12.5%). One patient died from irreversible severe CRS-associated acute kidney injury. Long-term CAR T cells persistence correlated with clinical efficacy (133 days vs 22 days, P = 0.004). Patients treated with more than three prior therapies and presenting extranodal organ involvement had lower maximal concentration (Cmax) values than other patients. Responders had higher Cmax and area under the curve values than non-responders. Tumour burden and Cmax were potentially associated with the severity of CRS.ConclusionsThis study demonstrates the safety and potential clinical efficacy of bispecific CD19/22 CAR T cells in patients with R/R B-NHL and highlights the importance of measuring kinetic parameters in PB to predict efficacy and safety in clinical applications of CAR T cell therapy.Clinical Trial Registrationhttps://www.clinicaltrials.gov/ct2/show/NCT03196830, identifier NCT03196830.

Background: The use of T cells expressing chimeric antigen receptor (CAR T) engineered to target CD19 constitutes breakthrough treatment for relapsed or refractory B cell non-Hodgkin lymphoma (R/R B-NHL). Despite improved outcomes, high relapse rate remains a challenge to overcome. Here, we report the clinical results and the pharmacokinetics of bispecific CD19/22 CAR T in patients with R/R B-NHL. Methods: We performed a prospective, single-arm study of bispecific CD19/22 CAR T cells in R/R B-NHL. We analyzed the safety and efficacy and investigated the kinetic profiles of the CAR T cells. CAR transgene levels were measured using quantitative polymerase chain reaction, and correlation analyses of pharmacodynamic markers and product characteristics, disease conditions, clinical efficacy and adverse events were performed. Results: From August 2017 to September 2020, a total of 32 patients with CD19/22 CAR T administration were analyzed. The overall response rate was 79.3%, and the complete response rate was 34.5%. The progression-free survival (PFS) and overall survival (OS) rates at 12 months were 40.0% and 63.3%, respectively. Among patients who had a CR at 3 months, the PFS and OS rates at 12 months were 66.7% and 100%, respectively. Severe cytokine release syndrome (sCRS) (grade 3 and higher) occurred in nine patients (28.1%). Grade 3 or higher neurologic events occurred in four patients (12.5%). One patient died from irreversible severe CRS-associated acute kidney injury. Long-term CAR T cells persistence correlated with clinical efficacy (133 days vs 22 days, P = 0.004). Patients treated with more than three prior therapies and presenting extranodal organ involvement had lower maximal concentration (Cmax) values than other patients. Responders had higher Cmax and area under the curve values than non-responders. Tumour burden and Cmax were potentially associated with the severity of CRS. Conclusions: This study demonstrates the safety and potential clinical efficacy of bispecific CD19/22 CAR T cells in patients with R/R B-NHL and highlights the importance of measuring kinetic parameters in PB to predict efficacy and safety in clinical applications of CAR T cell therapy. Clinical Trial Registration: https://www.clinicaltrials.gov/ct2/show/NCT03196830 , identifier NCT03196830. [ABSTRACT FROM AUTHOR]

Characterizing in vivo cellular kinetics and biodistribution of chimeric antigen receptor T (CAR-T) cells is critical for toxicity assessment, nonclinical and clinical efficacy studies. To date, the standardized assay to characterize CAR-T cell distribution, expansion, contraction, and persistence profiles is not readily available. To overcome this limitation and increase comparability among studies, we have established a universal protocol for analysis. We established a duplexing ddPCR protocol for the CAR-T transgene and reference gene to normalize the genomic DNA input prepared from mouse blood and tissues. The high-throughput gDNA extraction method enabled highly reproducible gDNA extraction while eliminating labor-intensive steps. The investigational CAR-T cells were intravenously injected into immunodeficient mice bearing human colorectal cancer xenografts. The blood and tissue samples were collected to measure the cellular kinetics by ddPCR and flow cytometry. The standard curves were linear throughout the calibration range with acceptable intra- and inter-day precision and accuracy. The gDNA recovery study performed by spiking in the exo-gene plasmid DNA or CAR-T cells revealed that the recovery ranged from 60 to 100% in blood and tissue homogenates. The use of both units of copy/μg gDNA and copy/μL blood met the current regulatory requirement and allowed for a systematic understanding of CAR-T cell expansion and a direct comparison with the flow cytometry data. A standardized ddPCR assay, including automated gDNA extraction procedures, has been established for evaluating cellular kinetics and biodistribution in CAR-T cell therapies. [ABSTRACT FROM AUTHOR]

Background: Despite numerous chimeric antigen receptor T‐cell (CAR‐T) trials conducted in China, no CAR‐T has been registered in the country. Furthermore, China law and regulations restrict the export of patient material for CAR‐T manufacture abroad. Relma‐cel (JWCAR029), an anti‐CD19 product produced with a commercial‐ready process in China, was evaluated in the first prospective, single‐arm, multicenter, pivotal study of CAR‐T therapy conducted under Chinese IND to support an NMPA‐accepted BLA submission in relapsed/refractory (r/r) LBCL (NCT04089215). Methods: Patients were randomized to receive either 100 × 106 (low dose, n = 27) or 150 × 106 (high dose, n = 32) CAR+ T‐cells as a single infusion following lymphodepleting chemotherapy (fludarabine 25 mg/m2 and cyclophosphamide 250 mg/m2 daily × 3), and then, monitored for efficacy and safety outcomes and pharmacokinetics. The primary endpoint was ORR at 3 months, as assessed by the investigators. Secondary endpoints included DOR, PFS, OS, and adverse event frequency/severity and cell expansion kinetics. Results: As of the data cutoff on 17 June 2020, 68 patients were enrolled, and 59 were treated. Among the 58 efficacy‐evaluable patients, the primary endpoint of 3 month ORR was 60.3% (95% CI, 46.6–73.0), excluding the null hypothesis rate of 20%. Any grade and severe grade CRS occurred in 47.5% and 5.1%, respectively, and any grade and severe grade neurotoxicity events occurred in 20.3% and 5.1%. Conclusions: Relma‐cel met the primary endpoint analysis and demonstrated a high rate of durable responses and low rate of CAR‐T‐associated toxicities in patients with r/r LBCL in a multicenter trial supporting regulatory submission in China. [ABSTRACT FROM AUTHOR]

Chimeric antigen receptors (CARs) are synthetic fusion proteins that can reprogram immune cells to target specific antigens. CAR-expressing T cells have emerged as an effective treatment method for hematological cancers; despite this success, the mechanisms and structural properties that govern CAR responses are not fully understood. Here, we provide a simple assay to assess cellular avidity using a standard flow cytometer. This assay measures the interaction kinetics of CAR-expressing T cells and targets antigen-expressing target cells. By co-culturing stably transfected CAR Jurkat cells with target positive and negative cells for short periods of time in a varying effector-target gradient, we were able to observe the formation of CAR-target cell doublets, providing a readout of actively bound cells. When using the optimized protocol reported here, we observed unique cellular binding curves that varied between CAR constructs with differing antigen binding domains. The cellular binding kinetics of unique CARs remained consistent, were dependent on specific target antigen expression, and required active biological signaling. While existing literature is not clear at this time whether higher or lower CAR cell binding is beneficial to CAR therapeutic activity, the application of this simplified protocol for assessing CAR binding could lead to a better understanding of the proximal signaling events that regulate CAR functionality. Key features • Determines CAR receptor cellular interaction kinetics using a Jurkat cell model. • Can be used for a wide variety of CAR target antigens, including both hematological and solid tumor targets. • Experiments can be performed in under two hours with no staining using a standard flow cytometer. • Requires stable CAR Jurkat cells and target cells with stable fluorescent marker expression for optimal results., Competing Interests: Competing interestsThere are no conflicts of interest or competing interests., (©Copyright : © 2024 The Authors; This is an open access article under the CC BY license.)

Chimeric antigen receptor (CAR) cells are genetically engineered immune cells that specifically target tumor-associated antigens and have revolutionized cancer treatment, particularly in hematological malignancies, with ongoing investigations into their potential applications in solid tumors. This review provides a comprehensive overview of the current status and challenges in drug metabolism and pharmacokinetics (DMPK) for CAR cell therapy, specifically emphasizing on quantitative modeling and simulation (M&S). Furthermore, the recent advances in quantitative model analysis have been reviewed, ranging from clinical data characterization to mechanism-based modeling that connects in vitro and in vivo nonclinical and clinical study data. Additionally, the future perspectives and areas for improvement in CAR cell therapy translation have been reviewed. This includes using formulation quality considerations, characterization of appropriate animal models, refinement of in vitro models for bottom-up approaches, and enhancement of quantitative bioanalytical methodology. Addressing these challenges within a DMPK framework is pivotal in facilitating the translation of CAR cell therapy, ultimately enhancing the patients' lives through efficient CAR cell therapies., Competing Interests: Declaration of competing interest AG, YM, MN, SI, and SY are employees of Takeda Pharmaceutical Company Limited., (Copyright © 2024 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.)

Aims/hypothesis: In vitro and rodent studies suggest that pioglitazone, a thiazolidinedione, can promote adipogenesis in adipose tissue (AT); however, there is a lack of in vivo studies in humans to support these findings. The objectives of this randomised, placebo-controlled, parallel-arm trial were to test if pioglitazone stimulates in vivo adipogenesis in the subcutaneous adipose tissue depots and if these measures were related to metabolic health outcomes in women with obesity. Methods: Forty-one healthy women with obesity (20 black; 21 white; 29 ± 6 years; BMI 32.0 ± 1.7 kg/m2; 44.0 ± 3.6% body fat) were randomised to consume 30 mg/day of pioglitazone (n = 21) or placebo (n = 20) for 16 weeks. SAS v9.4 was used to generate the block randomisation code sequence (stored in password-protected files) with a 1:1 allocation ratio. The participants and study staff involved in assessing and analysing data outcomes were blinded to the group assignments. The trial was conducted at Pennington Biomedical Research Center and ended in 2016. At baseline and post-intervention, subcutaneous abdominal (scABD) and femoral (scFEM) AT biopsies were collected, and in vivo cellular kinetics (primary endpoint of the trial) were assessed by an 8 week labelling protocol of deuterium (2H) into the DNA of adipose cells. Body composition was measured by dual-energy x-ray absorptiometry (DXA), scABD and visceral AT (VAT) by MRI, ectopic fat by 1H-MRS, and insulin sensitivity by an OGTT. Results: After the 16 week intervention, there was a significant decrease in visceral fat (VAT:total abdominal AT [as a %]; p = 0.002) and an increase in the Matsuda index (i.e. improved insulin sensitivity; p = 0.04) in the pioglitazone group relative to the placebo group. A significant increase in the formation of new adipocytes was observed in the scFEM (Δ = 3.3 ± 1.6%; p = 0.04) but not the scABD depot (Δ = 2.0 ± 2.1%; p = 0.32) in the pioglitazone group relative to the placebo group. No serious adverse events were reported. Conclusions/interpretation: Pioglitazone may elicit distinct differences in in vivo adipogenesis in subcutaneous adipose depots in women with obesity, with increased rates in the protective scFEM. Trial registrationClinicalTrials.govNCT01748994 Funding This study was funded by R01DK090607, P30DK072476, and R03DK112006 from the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health. U54 GM104940 from the National Institute of General Medical Sciences of the National Institutes of Health. The Robert C. and Veronica Atkins Foundation. [ABSTRACT FROM AUTHOR]

Submicron emulsions (SEs) is an advanced formulation that possesses good biocompatibility, high loading of hydrophobic drugs, and good stability through autoclave sterilization. To enhance tumor targeting and tumor cell uptake, SEs could be modified with positive charge and targeting moieties. In the present study, three formulations were prepared: Docetaxel-loaded SEs (DocSEs), cationic DocSEs (DocCSEs), and low density lipoprotein receptor (LDLR) targeted peptide-RLT (CEKLKEAF RLTRKRGLK LA) modified DocCSEs (RLT-DocCSEs). The optimized RLT-DocCSEs showed a particle size 182.2 ± 10 nm, a zeta potential 39.62 ± 2.41 mV, and a loading efficiency of Docetaxel (Doc) 98%. RLT-DocCSEs demonstrated sustained release in 96 h and was stable for two months at 4 °C. Compared to DocSEs and DocCSEs, RLT-DocCSEs caused significantly more PC-3 cell inhibition and cell apoptosis. RLT-DocCSEs also showed more cellular uptake and slower cellular elimination than that of DocSEs and DocCSEs. The present study indicated RLT-DocCSEs could be a potential formulation for injection of anti-cancer therapeutics with increased tumor targeting and anti-tumor efficacy. [ABSTRACT FROM AUTHOR]

Background: Organ regeneration in mammals is hypothesized to require a functional pool of stem or progenitor cells, but the role of these cells in lung regeneration is unknown. Methods: Based on the fact that postnatal regeneration of alveolar tissue has been attributed to alveolar epithelial cells, we established a hemorrhagic shock and Lipopolysaccharide (LPS) lung injury model. Using this model, we analyzed the cellular kinetics of lung alveolar epithelial cells. Results: The results showed that alveolar epithelium type 2 cells (AEC2s) are damage resistant during acute lung injury, they might be the main cells involved in lung injury and repair. Then we observed the relationship between the expression of HGF, c-Met following ALI in rat lung and proliferation of AEC2s. The proliferation of AEC2s was inhibited when isolated primary AEC2s were co-cultured with c-Met inhibitor SU11274. Furthermore, the numbers of AEC2s was significantly decreased when ALI rats were administrated with SU11274 in vivo. It provided further evidence that the HGF/c-Met signaling plays a vital role in ALI-induced AEC2s proliferation. Conclusions: AEC2s are damage resistant during acute lung injury and the HGF/c-Met signaling pathway is of vital importance in the proliferation of AEC2s after ALI. [ABSTRACT FROM AUTHOR]

Acute pancreatitis remains a disease of uncertain pathogenesis and no established specific therapy. Previously, we found a predominant increase and active proliferation of macrophages in the inflamed tissues of a rat duct-ligation pancreatitis model. To analyze the origin and possible role of these macrophages, we investigated their in situ cellular kinetics in a rat model of duct-ligation pancreatitis using a recently established method of multicolor immunostaining for macrophage markers and for proliferating cells with ethynyl deoxyuridine. To detect monocyte-derived macrophages, green fluorescent protein-transgenic (GFP) leukocytes were transferred to monocyte-depleted recipients. In the inflamed pancreas, infiltrating macrophages were mainly two phenotypes, CD68CD163 round cells and CD68CD163 large polygonal cells, both of which showed active proliferation. In the interlobular area, the proportions of CD68CD163 and CD68CD163 cells increased over time. Most expressed the M2-macrophage markers CD206 and arginase 1. In contrast, in the interacinar area, CD68 cells did not upregulate CD163 and CD206, but ~30 % of them expressed the M1 marker nitric oxide synthase 2 on day 4. GFP-recruited cells were primarily CD68CD163 monocytes on day 1 and showed phenotypic changes similar to those of the monocyte non-depleted groups. In conclusion, infiltrating macrophages mostly formed two distinct subpopulations in different areas: monocyte-derived macrophages with the M2 phenotype in the interlobular area or non-M2 phenotype in the interacinar area. Involvement of resident macrophages might be minor in this model. These results are the first demonstration of an upregulated M2 phenotype in rat inflammatory monocytes, which may promote tissue repair. [ABSTRACT FROM AUTHOR]

We investigated the effects of long- and short-term treatment with pioglitazone (Pio) and/or alogliptin (Alo) on β-cells in diabetic db/db mice. Six-week-old male db/db mice received Pio (25 mg/kg, oral) and/or Alo (30 mg/kg, oral) for 4 weeks and for 2 days. Blood glucose levels were decreased after 4-week intervention, but not after 2-day intervention. Pio increased adiponectin levels, and Alo decreased glucagon levels and increased active GlP-1 levels. Insulin sensitivity was restored by Pio. After 4-week treatment, β-cell mass was increased (over 2-fold increase) and expression levels of various β-cell-related factors were restored. Expression levels of IRS-2 and various downstream factors were up-regulated by Pio and Alo after 2-day and 4-week intervention. In addition, mRNA and protein levels of IRS-2 and various downstream factors were up-regulated in MIN6 cells after 24-h exposure to Pio and exendin-4. These results suggest that Pio and Alo additively up-regulate IRS-2 expression independently of the alteration of glycemic control. Taken together, combination of Pio and Alo exerts protective effects on β-cells in diabetic db/db mice, at least in part, through the augmentation of IRS-2 expression. [ABSTRACT FROM AUTHOR]

The aim was to compare the protective effects of pioglitazone (PIO) and/or liraglutide (LIRA) on β-cells with the progression of diabetes. Male db/db mice were treated with PIO and/or LIRA for 2 weeks in an early and advanced stage. In an early stage insulin biosynthesis and secretion were markedly increased by PIO and LIRA which was not observed in an advanced stage. In concomitant with such phenomena, expression levels of various β-cell-related factors were up-regulated by PIO and LIRA only in an early stage. Furthermore, β-cell mass was also increased by the treatment only in an early stage. Although there was no difference in apoptosis ratio between the two stages, β-cell proliferation was augmented by the treatment only in an early stage. In conclusion, protective effects of pioglitazone and/or liraglutide on β-cells were more powerful in an early stage of diabetes compared to an advanced stage. [ABSTRACT FROM AUTHOR]

A growing body of evidence suggests that studying cell biology in classical two-dimensional formats, such as cell culture plasticware, results in misleading, non-physiological findings. This paper describes the optimization of a microsphere-based system permitting 3D cell culture incorporating physiological extracellular matrix components. Bio-electrospraying, the most advanced method currently available, is used to produce microspheres containing THP-1 cells as a model cell line. The bio-electrospraying para­meters of nozzle size, polymer flow rate, and voltage are systematically investigated in order to allow stable production of size-controlled microspheres containing extracellular matrix material and human cells. The effect of bio-electrospraying parameters, alginate type and cell concentration on cell viability are investigated using trypan blue and propidium iodide staining. Bio-electrospraying has no effect on cell viability nor the ability of cells to proliferate. Cell viability is similarly minimally affected by encapsulation in all types of alginate tested (MVM, MVG, chemical and food-grade). Cell density of 5 × 106 cells mL−1 within microspheres is the optimum for cell survival and proliferation. The stable generation of microspheres incorporating cells and extracellular matrix for use in a 3D cell culture will benefit study of many diverse diseases and permit investigation of cellular biology within a 3D matrix. [ABSTRACT FROM AUTHOR]

Purpose: To examine the effects of change in weight bearing on the growth plate metabolism, a simulated animal model of weightlessness was introduced and the chondrocytes' cellular kinetics was evaluated. Materials and Methods: Unloading condition on the hind-limb of Sprague-Dawley rats was created by fixing a tail and lifting the hind-limb. Six rats aged 6 weeks old were assigned to each group of unloading, reloading, and control groups of unloading or reloading. Unloading was maintained for three weeks, and then reloading was applied for another one week thereafter. Histomorphometry for the assessment of vertical length of the growth plate, 5-bromo-2'-deoxyuridin immunohistochemistry for cellular kinetics, and biotin nick end labeling transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay for chondrocytes apoptosis in the growth plate were performed. Results: The vertical length of the growth plate and the proliferative potential of chondrocytes were decreased in the unloading group compared to those of control groups. Inter-group differences were more significant in the proliferative and hypertrophic zones. Reloading increased the length of growth plate and proliferative potential of chondrocytes. However, apoptotic changes in the growth plate were not affected by the alterations of weight bearing. Conclusion: Alterations in the weight bearing induced changes in the chondrocytic proliferative potential of the growth plate, however, had no effects on the apoptosis. This may explain why non-weight bearing in various clinical situations hampers normal longitudinal bone growth. Further studies on the factors for reversibility of chondrocytic proliferation upon variable mechanical stresses are needed. [ABSTRACT FROM AUTHOR]

Neuroblastoma is known for its peculiar cellular kinetics, which has provoked some controversy regarding surgical treatment. Highly sensitive exploration systems using reverse transcription polymerase chain reaction (RT-PCR) methods have been developed to detect neuroblastoma cells. In our series of 49 patients with advanced neuroblastoma, circulating tumor cells (CTC) were detected by this system in 55.6% of the stage 4 patients who were examined, suggesting that the primary lesion may release tumor cells into the peripheral blood. The Kaplan-Meier survival rate was significantly lower among the patients with CTC or chemotherapy-insensitive bone marrow micrometastasis, compared with those without detectable micrometastasis (33.8 vs. 87.5%, P < 0.05). In contrast, a stage 3 patient with MYCN amplification exhibited drastic local relapse without systemic dissemination of the disease. Two patients were positive for CTC without an identifiable primary site. These observations indicate that the local growth of the primary tumor and tumor cell dissemination may be regulated by different molecular mechanisms in neuroblastomas. MYCN amplification seemed to be more closely associated with localized tumor growth but was minimally correlated with CTC positivity. High-risk neuroblastoma may include two separate subgroups characterized by different cellular kinetics: a local risk cohort and a systemic risk cohort. Surgical strategies for neuroblastoma should be determined with taking this cellular kinetics into consideration. [ABSTRACT FROM AUTHOR]

Abstract: A new class of anti-retrovirals, cyclotriazadisulfonamide (CADA) and its derivatives, specifically down-regulate CD4, the main receptor of HIV, and prevent HIV infection in vitro. In this work, several CADA derivatives, chemically labeled with a fluorescent dansyl group, were evaluated for their biological features and cellular uptake kinetics. We identified a derivative KKD-016 with antiviral and CD4 down-modulating capabilities similar to those of the parental compound CADA. By using flow cytometry, we demonstrated that the dose-dependent cellular uptake of this derivative correlated with CD4 down-modulation. The uptake and activity of the dansyl-labeled compounds were not dependent on the level of expression of CD4 at the cell surface. Removal of the CADA compounds from the cell culture medium resulted in their release from the cells followed by a complete restoration of CD4 expression. The inability of several fluorescent CADA derivatives to down-modulate CD4 was not associated with their lower cellular uptake and was not reversed by facilitating their cell penetration by a surfactant. These results prove the successful integration of the dansyl fluorophore into the chemical structure of a CD4 down-modulating anti-HIV compound, and show the feasibility of tracking a receptor and its down-modulator simultaneously. These fluorescent CADA analogs with reversible CD4 down-regulating potency can now be applied in further studies on receptor modulation, and in the exploration of their potentials as preventive and therapeutic anti-HIV drugs. [Copyright &y& Elsevier]

Imatinib and AMN107 are protein tyrosine kinase inhibitors which reduce KIT autophosphorylation with similar potency. This report describes the cellular uptake of these compounds in two human gastrointestinal stromal tumor (GIST)-derived cell lines (GIST882 and GIST GDG1), which both express constitutively activated KIT. In GIST882 and GIST GDG1 cell lines, HPLC analysis revealed AMN107 intracellular concentrations to be 7- and 10-fold greater than those of imatinib. These data indicate either increased cellular uptake or decreased cellular efflux of AMN107 when compared to imatinib in GIST cell lines. The finding suggests that AMN107 might be less susceptible to transport-driven imatinib resistance. The stable and increased exposure of GIST cells to a highly active AMN107 agent could be important in the treatment of imatinib-resistant GIST patients in whom resistance has developed as a result of changes in cellular transport mechanisms for which AMN107 is not a substrate. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

In recent studies, riddelliine, a pyrrolizidine alkaloid, was found to increase rates of replication and apoptosis and induce hemangiosarcoma in the liver of rats and mice. To analyze DNA replication and apoptosis data taken from the same animals, we have developed a predictive mathematical model for describing BrdU labeling and apoptotic processes. The model allows the incorporation of simple diurnal patterns in cellular kinetics and is applied to data on hepatocytes and endothelial cells taken from riddelliine exposed rats. Predictions from the model were used with multivariable nonlinear regression techniques to estimate replication and apoptotic rate constants for both cell types and all treatment groups. Hypothesis tests were used with the predicted rates to separate the competing effects of riddelliine on replication and apoptosis of hepatocytes and endothelial cells as well as compare replication rates between cell types. That estimated replication rates were found to be significantly higher for endothelial cells supports the supposition of induction of hemangiosarcoma by riddelliine in the liver. [ABSTRACT FROM AUTHOR]