Intramuscular injection of mesenchymal stem cells augments basal muscle protein synthesis after bouts of resistance exercise in male mice

Skeletal muscle mass is critical for activities of daily living. Resistance training maintains or increases muscle mass, and various strategies maximize the training adaptation. Mesenchymal stem cells (MSCs) are multipotent cells with differential potency in skeletal muscle cells and the capacity to secrete growth factors. However, little is known regarding the effect of intramuscular injection of MSCs on basal muscle protein synthesis and catabolic systems after resistance training. Here, we measured changes in basal muscle protein synthesis, the ubiquitin-proteasome system, and autophagy-lysosome system-related factors after bouts of resistance exercise by intramuscular injection of MSCs. Mice performed three bouts of resistance exercise (each consisting of 50 maximal isometric contractions elicited by electrical stimulation) on the right gastrocnemius muscle every 48 h, and immediately after the first bout, mice were intramuscularly injected with either MSCs (2.0 × 106 cells) labeled with green fluorescence protein (GFP) or vehicle only placebo. Seventy-two hours after the third exercise bout, GFP was detected only in the muscle injected with MSCs with concomitant elevation of muscle protein synthesis. The injection of MSCs also increased protein ubiquitination. These results suggest that the intramuscular injection of MSCs augmented muscle protein turnover at the basal state after consecutive resistance exercise.

Discovery of Clinical Candidate AZD5462, a Selective Oral Allosteric RXFP1 Agonist for Treatment of Heart Failure

Optimization of the highly potent and selective, yet metabolically unstable and poorly soluble hRXFP1 agonist AZ7976 led to the identification of the clinical candidate, AZD5462. Assessment of RXFP1-dependent cell signaling demonstrated that AZD5462 activates a highly similar panel of downstream pathways as relaxin H2 but does not modulate relaxin H2-mediated cAMP second messenger responsiveness. The therapeutic potential of AZD5462 was assessed in a translatable cynomolgus monkey heart failure model. Following 8 weeks of treatment with AZD5462, robust improvements in functional cardiac parameters including LVEF were observed at weeks 9, 13, and 17 without changes in heart rate or mean arterial blood pressure. AZD5462 was well tolerated in both rat and cynomolgus monkey and has successfully completed phase I studies in healthy volunteers. In summary, AZD5462 is a small molecule pharmacological mimetic of relaxin H2 signaling at RXFP1 and holds promise as a potential therapeutic approach to treat heart failure patients.

Identification of Novel Series of Potent and Selective Relaxin Family Peptide Receptor 1 (RXFP1) Agonists

Relaxin H2 is a clinically relevant peptide agonist for relaxin family peptide receptor 1 (RXFP1), but a combination of this hormone's short plasma half-life and the need for injectable delivery limits its therapeutic potential. We sought to overcome these limitations through the development of a potent small molecule (SM) RXFP1 agonist. Although two large SM HTS campaigns failed in identifying suitable hit series, we uncovered novel chemical space starting from the only known SM RXFP1 agonist series, represented by ML290. Following a design-make-test-analyze strategy based on improving early dose to man ranking, we discovered compound 42 (AZ7976), a highly selective RXFP1 agonist with sub-nanomolar potency. We used AZ7976, its 10 000-fold less potent enantiomer 43 and recombinant relaxin H2 to evaluate in vivo pharmacology and demonstrate that AZ7976-mediated heart rate increase in rats was a result of RXFP1 agonism. As a result, AZ7976 was selected as lead for continued optimization.

Inhibition of repulsive guidance molecule-a ameliorates compromised blood-spinal cord barrier integrity associated with neuromyelitis optica in rats

The influx of pathogenic aquaporin-4 antibodies (AQP4-Abs) across the blood-spinal cord barrier (BSCB) is crucial for the development and exacerbation of neuromyelitis optica (NMO). We examined whether prophylactic intravenous administration of anti-repulsive guidance molecule-a antibodies (RGMa-Abs) has disease-modifying effects on BSCB dysfunction using an NMO model elicited by peripheral administration of AQP4-Abs to rats. RGMa-Ab treatment attenuated the acute exacerbation of perivascular astrocytopathy in the spinal cord and clinical symptoms, which were highly correlated with neurofilament light chain levels in both the cerebrospinal fluid (CSF) and serum. Additionally, RGMa-Ab treatment suppressed the expression of proinflammatory cytokines/chemokines and the infiltration of inflammatory cells into the spinal cord. CSF analysis of NMO rats revealed that RGMa-Ab treatment improved the CSF/serum albumin ratio and suppressed AQP4-Abs influx. RGMa inhibition using RGMa-Abs is suggested as a potential therapeutic option for BSCB dysfunction associated with NMO.

Modeling dry eye with an air-liquid interface in corneal epithelium-on-a-chip

Dry eye syndrome (DES) is a complex ocular condition characterized by an unstable tear film and inadequate tear production, leading to tissue damage. Despite its common occurrence, there is currently no comprehensive in vitro model that accurately reproduce the cellular characteristics of DES. Here we modified a corneal epithelium-on-a-chip (CEpOC) model to recapitulate DES by subjecting HCE-T human corneal epithelial cells to an air-liquid (AL) interface stimulus. We then assessed the effects of AL stimulation both in the presence and absence of diclofenac (DCF), non-steroidal anti-inflammatory drug. Transcriptomic analysis revealed distinct gene expression changes in response to AL and AL_DCF, affecting pathways related to development, epithelial structure, inflammation, and extracellular matrix remodeling. Both treatments upregulated PIEZO2, linked to corneal damage signaling, while downregulating OCLN, involved in cell-cell junctions. They increased the expression of inflammatory genes (e.g., IL-6) and reduced mucin production genes (e.g., MUC16), reflecting dry eye characteristics. Metabolomic analysis showed increased secretion of metabolites associated with cell damage and inflammation (e.g., methyl-2-oxovaleric acid, 3-methyl-2-oxobutanoic acid, lauroyl-carnitine) in response to AL and even more with AL_DCF, indicating a shift in cellular metabolism. This study showcases the potential use of AL stimulus within the CEpOC to induce cellular characteristics relevant to DES.

Corneal epithelium models for safety assessment in drug development: Present and future directions

The human corneal epithelial barrier plays a crucial role in drug testing studies, including drug absorption, distribution, metabolism, and excretion (ADME), as well as toxicity testing during the preclinical stages of drug development. However, despite the valuable insights gained from animal and current in vitro models, there remains a significant discrepancy between preclinical drug predictions and actual clinical outcomes. Additionally, there is a growing emphasis on adhering to the 3R principles (refine, reduce, replace) to minimize the use of animals in testing. To tackle these challenges, there is a rising demand for alternative in vitro models that closely mimic the human corneal epithelium. Recently, remarkable advancements have been made in two key areas: microphysiological systems (MPS) or organs-on-chips (OoCs), and stem cell-derived organoids. These cutting-edge platforms integrate four major disciplines: stem cells, microfluidics, bioprinting, and biosensing technologies. This integration holds great promise in developing powerful and biomimetic models of the human cornea.

A case of primary lung cancer requiring differentiation from metastatic cervical cancer

p16 has been used as a surrogate marker for human papillomavirus (HPV)-related tumours. However, it remains unclear whether p16 is also a potential marker for pulmonary tumours. Herein, we report the case of an 80-year-old woman with a history of papillary squamous cell carcinoma of the uterine cervix, presenting with a left pulmonary tumour. A bronchoscopic biopsy revealed squamous cell carcinoma with a papillary pattern, which did not rule out pulmonary metastasis from the cervix. Immunohistochemical staining revealed that the cervical tumour was positive for p16, whereas the pulmonary tumour was negative and was effectively diagnosed as primary pulmonary carcinoma.

Defects in early synaptic formation and neuronal function in Prader-Willi syndrome

Prader-Willi syndrome (PWS), which is a complex epigenetic disorder caused by the deficiency of paternally expressed genes in chromosome 15q11-q13, is associated with several psychiatric dimensions, including autism spectrum disorder. We have previously reported that iPS cells derived from PWS patients exhibited aberrant differentiation and transcriptomic dysregulation in differentiated neural stem cells (NSCs) and neurons. Here, we identified SLITRK1 as a downregulated gene in NSCs differentiated from PWS patient iPS cells by RNA sequencing analysis. Because SLITRK1 is involved in synaptogenesis, we focused on the synaptic formation and function of neurons differentiated from PWS patient iPS cells and NDN or MAGEL2 single gene defect mutant iPS cells. Although βIII tubulin expression levels in all the neurons were comparable to the level of differentiation in the control, pre- and postsynaptic markers were significantly lower in PWS and mutant neurons than in control neurons. PSD-95 puncta along βIII tubulin neurites were also decreased. Membrane potential responses were measured while exposed to high K⁺ stimulation. The neuronal excitabilities in PWS and mutant neurons showed significantly lower intensity than that of control neurons. These functional defects in PWS neurons may reflect phenotypes of neurodevelopmental disorders in PWS.

Openable artificial intestinal tract device integrated with a permeable filter for evaluating drug permeation through cells

Organs-on-chips using cultured cells have been developed and applied for evaluating in vitro biological phenomena. We previously reported an openable artificial intestinal tract system, as an in vitro model of the small intestine, for in vitro drug screening. The intestinal tract device could be transformed using an integrated artificial muscle actuator. An initial flat state was suitable for cell culture, and the transformed tubular structure was used as a fluidic channel for perfusion tests. The previously developed intestinal tract system could be used to evaluate drug absorption by cells through perfusion testing. This study presents an improved artificial intestinal tract system for analysis of drug permeation, in addition to absorption. Permeable filters were integrated into the intestinal tract device. Integration of additional filters into the design of the existing artificial muscle actuator was accomplished by considering device performance and available filter locations. Filter permeability was evaluated by perfusion testing. MDCK-II cells were cultured on the device and visually and electrically evaluated. The openable device, equipped with new functions for further pharmacokinetic analysis, could perform and evaluate drug disposition using cultured cells. We anticipate that the improved, openable organ-on-a-chip device system will contribute to advances in in vitro drug screening technology.

Early Differentiation Signatures in Human Induced Pluripotent Stem Cells Determined by Non-Targeted Metabolomics Analysis

Human induced pluripotent stem cells (hiPSCs) possess immense potential as a valuable source for the generation of a wide variety of human cells, yet monitoring the early cell differentiation towards a specific lineage remains challenging. In this study, we employed a non-targeted metabolomic analysis technique to analyze the extracellular metabolites present in samples as small as one microliter. The hiPSCs were subjected to differentiation by initiating culture under the basal medium E6 in combination with chemical inhibitors that have been previously reported to direct differentiation towards the ectodermal lineage such as Wnt/β-catenin and TGF-β kinase/activin receptor, alone or in combination with bFGF, and the inhibition of glycogen kinase 3 (GSK-3), which is commonly used for the diversion of hiPSCs towards mesodermal lineage. At 0 h and 48 h, 117 metabolites were identified, including biologically relevant metabolites such as lactic acid, pyruvic acid, and amino acids. By determining the expression of the pluripotency marker OCT3/4, we were able to correlate the differentiation status of cells with the shifted metabolites. The group of cells undergoing ectodermal differentiation showed a greater reduction in OCT3/4 expression. Moreover, metabolites such as pyruvic acid and kynurenine showed dramatic change under ectodermal differentiation conditions where pyruvic acid consumption increased 1-2-fold, while kynurenine secretion decreased 2-fold. Further metabolite analysis uncovered a group of metabolites specifically associated with ectodermal lineage, highlighting the potential of our findings to determine the characteristics of hiPSCs during cell differentiation, particularly under ectodermal lineage conditions.

5-ALA treatment increases intracellular heme levels and enhances CYP3A4 activity in genome-edited Caco-2 cells

In nonclinical studies, models that can predict the metabolism of drug candidates by cytochrome P450 (CYP), including Cytochrome P450 family 3 subfamily A member 4 (CYP3A4) are helpful. CYP3A4-overexpressing human cells have been used universally to evaluate whether CYP3A4 metabolizes drug-candidate compounds. However, CYP3A4-overexpressing human cell lines are problematic because their activity levels are lower than that of in vivo human CYP3A4. Heme plays a paramount role in CYP activity. The rate-limiting step in heme biosynthesis is the generation of 5-aminolevulinic acid (5-ALA). In this study, we examined whether treatment with 5-ALA to CYP3A4-POR-UGT1A1-CES2 knockin and CES1 knockout (genome-edited) Caco-2 cells enhances CYP3A4 activity. A 7-day 5-ALA treatment increased intracellular heme levels in genome-edited Caco-2 cells without cytotoxicity. Moreover, consistent with the increase in intracellular heme content, 5-ALA treatment increased CYP3A4 activity in genome-edited Caco-2 cells. The results of this research are expected to be applied to pharmacokinetic studies using CYP-overexpressing human cells containing CYP3A4.

Generation of Caco-2 cells with predictable metabolism by CYP3A4, UGT1A1 and CES using the PITCh system

Caco-2 cells are widely used as an in vitro intestinal model. However, the expression levels of the drug-metabolizing enzymes CYP3A4 and UGT1A1 are lower in these cells than in intestinal cells. Furthermore, the majority of prodrugs in use today are ester-containing, and carboxylesterase (CES) 1 and CES2 are among the enzymes that process the prodrugs into drugs. In the human small intestine, CES1 is hardly expressed while CES2 is highly expressed, but the CES expression pattern in Caco-2 cells is the opposite. In this study, we generated CYP3A4-POR-UGT1A1-CES2 knock-in (KI) and CES1 knock-out (KO) Caco-2 (genome-edited Caco-2) cells using a PITCh system. Genome-edited Caco-2 cells were shown to express functional CYP3A4, POR, UGT1A1 and CES2 while the expression of the CES1 protein was completely knocked out. We performed transport assays using temocapril. The Papp value of temocapril in genome-edited Caco-2 cells was higher than that in WT Caco-2 cells. Interestingly, the amount of temocaprilat on the apical side in genome-edited Caco-2 cells was lower than that in WT Caco-2 cells. These results suggest that genome-edited Caco-2 cells are more suitable than WT Caco-2 cells as a model for predicting intestinal drug absorption and metabolism.

Developing a Novel Method for the Analysis of Spinal Cord-Penile Neurotransmission Mechanisms

Sexual dysfunction can be caused by impaired neurotransmission from the peripheral to the central nervous system. Therefore, it is important to evaluate the input of sensory information from the peripheral genital area and investigate the control mechanisms in the spinal cord to clarify the pathological basis of sensory abnormalities in the genital area. However, an in vivo evaluation system for the spinal cord-penile neurotransmission mechanism has not yet been developed. Here, urethane-anesthetized rats were used to evaluate neuronal firing induced by innocuous or nociceptive stimulation of the penis using extracellular recording or patch-clamp techniques in the lumbosacral spinal dorsal horn and electrophysiological evaluation in the peripheral pelvic nerves. As a result, innocuous and nociceptive stimuli-evoked neuronal firing was successfully recorded in the deep and superficial spinal dorsal horns, respectively. The innocuous stimuli-evoked nerve firing was also recorded in the pelvic nerve. These firings were suppressed by lidocaine. To the best of our knowledge, this is the first report of a successful quantitative evaluation of penile stimuli-evoked neuronal firing. This method is not only useful for analyzing the pathological basis of spinal cord-penile neurotransmission in sexual dysfunction but also provides a useful evaluation system in the search for new treatments.

Inhibition of Liquid-Liquid Phase Separation for Breaking the Solubility Barrier of Amorphous Solid Dispersions to Improve Oral Absorption of Naftopidil

Amorphous solid dispersion (ASD) is one of the most promising technologies for improving the oral absorption of poorly soluble compounds. In this study, naftopidil (NFT) ASDs were prepared using vinylpyrrolidone-vinyl acetate copolymer (PVPVA), hydroxypropyl methylcellulose acetate succinate (HPMCAS), and poly(methacrylic acid-co-methyl methacrylate) L100-55 (Eudragit) to improve the dissolution and oral absorption behaviors of NFT. During the dissolution process of ASD, liquid-liquid phase separation (LLPS) may occur when certain requirements are met for providing a maximum quasi-stable concentration achievable by amorphization. The occurrence of LLPS was confirmed in the presence of PVPVA and HPMCAS; however, Eudragit inhibited LLPS owing to its molecular interaction with NFT. Although the dissolution behavior of the Eudragit ASD was found to be markedly poorer than that of other ASDs, it offered the best oral absorption in rats. The findings of the current study highlight the possibility for improving the oral absorption of poorly soluble drugs by this ASD, which should be eliminated from candidate formulations based on the conventional in vitro tests.

Alleviative effects of glutamate against chemotherapeutic agent-induced intestinal mucositis

5-Fluorouracil (5-FU) is one of the most widely used chemotherapeutic agents; however, it often causes intestinal mucositis with severe diarrhea. An efficient treatment strategy to reduce this side effect is lacking. Glutamate (Glu), a nonessential amino acid, is the most important energy source in the small intestine and has been shown to maintain intestinal morphology, barrier function, and antioxidative capacity. However, the effects of Glu on intestinal mucositis induced by chemotherapeutic agents have not been explored. This study aimed to demonstrate the alleviative effects of Glu on 5-FU-induced intestinal mucositis. Mucositis was induced in C57B/6N mice by intraperitoneal injection of 5-FU (50 mg/kg) for 6 days and assessed by histological and physiological analyses. Glu (500 or 1000 mg/kg) was orally administered as a pretreatment twice daily for 7 days before the initial treatment of 5-FU. Cellular proliferation and apoptosis were assessed using Ki-67 immunostaining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively. Furthermore, fluorescein isothiocyanate-dextran infiltration was assessed to measure intestinal permeability. In vitro experiments using rat intestinal epithelial cells (IEC-6 cells) were performed to clarify the effect of Glu on 5-FU-induced barrier dysfunction. Glu alleviated 5-FU-induced intestinal mucositis by reducing villi shortening, enhancing cell proliferation, and suppressing apoptosis. It also alleviated the 5-FU-induced increased intestinal permeability. In vitro studies revealed significantly increased trans-epithelial electrical resistance (TEER) in Glu-pretreated IEC-6 cells compared to that in 5-FU-treated and control cells. In conclusion, the findings of this study provide evidence for the potential of Glu to protect against 5-FU-induced intestinal mucositis in patients with cancer.

Mesenchymal Stem Cells Promote IL-6 Secretion and Suppress the Gene Expression of Proinflammatory Cytokines in Contractile C2C12 Myotubes

Sarcopenia is not only a major cause of disability but also a risk factor for obesity and diabetes in elderly persons. Exercise is an effective method for improving the sarcopenic condition by inducing the secretion of interleukin (IL)-6, which has the capacities to both promote muscle hypertrophy and regulate lipid metabolism and glucose homeostasis, by skeletal muscle. We previously showed that mesenchymal stem cells (MSCs) promote IL-6 secretion by lipopolysaccharide-stimulated C2C12 mouse skeletal muscle myotubes via paracrine mechanisms. Therefore, in this study, we investigated the effect of paracrine actions of MSCs on IL-6 and proinflammatory cytokine expression in contractile C2C12 myotubes by applying electrical stimulation. IL-6 secretion by C2C12 myotubes was increased by electrical stimulation, and a more significant increase in IL-6 secretion was observed in electrically stimulated C2C12 myotubes cultured in conditioned medium from MSCs. The activation of nuclear factor-κB in C2C12 myotubes was also promoted by the combination of conditioned medium from MSCs and electrical stimulation. Moreover, the increases in tumor necrosis factor-α and IL-1β mRNA expression in C2C12 myotubes induced by electrical stimulation were suppressed by culture in conditioned medium from MSCs. The present findings suggest that MSCs transplantation or injection of their extracellular vesicles improve the therapeutic effect of exercise against sarcopenia without exacerbating inflammation.

Generation of HepG2 Cells with High Expression of Multiple Drug-Metabolizing Enzymes for Drug Discovery Research Using a PITCh System

HepG2 cells are an inexpensive hepatocyte model that can be used for repeated experiments, but HepG2 cells do not express major cytochrome P450s (CYPs) and UDP glucuronosyltransferase family 1 member A1 (UGT1A1). In this study, we established CYP3A4–POR–UGT1A1–CYP1A2–CYP2C19–CYP2C9–CYP2D6 (CYPs–UGT1A1) knock-in (KI)-HepG2 cells using a PITCh system to evaluate whether they could be a new hepatocyte model for pharmaceutical studies. To evaluate whether CYPs–UGT1A1 KI-HepG2 cells express and function with CYPs and UGT1A1, gene expression levels of CYPs and UGT1A1 were analyzed by using real-time PCR, and metabolites of CYPs or UGT1A1 substrates were quantified by HPLC. The expression levels of CYPs and UGT1A1 in the CYPs–UGT1A1 KI-HepG2 cells were comparable to those in primary human hepatocytes (PHHs) cultured for 48 h. The CYPs and UGT1A1 activity levels in the CYPs–UGT1A1 KI-HepG2 cells were much higher than those in the wild-type (WT)-HepG2 cells. These results suggest that the CYPs–UGT1A1 KI-HepG2 cells expressed functional CYPs and UGT1A1. We also confirmed that the CYPs–UGT1A1 KI-HepG2 cells were more sensitive to drug-induced liver toxicity than the WT-HepG2 cells. CYPs–UGT1A1 KI-HepG2 cells could be used to predict drug metabolism and drug-induced liver toxicity, and they promise to be a helpful new hepatocyte model for drug discovery research.

Involvement of Histamine H3 Receptor Agonism in Premature Ejaculation Found by Studies in Rats

Several of the drugs currently available for the treatment of premature ejaculation (PE) (e.g., local anesthetics or antidepressants) are associated with numerous safety concerns and exhibit weak efficacy. To date, no therapeutics for PE have been approved in the United States, highlighting the need to develop novel agents with sufficient efficacy and fewer side effects. In this study, we focused on the histamine H₃ receptor (H₃R) as a potential target for the treatment of PE and evaluated the effects of imetit (an H₃R/H₄R agonist), ciproxifan (an H₃R antagonist), and JNJ-7777120 (an H₄R antagonist) in vivo. Our in vivo electrophysiological experiments revealed that imetit reduced mechanical stimuli-evoked neuronal firing in anesthetized rats. This effect was inhibited by ciproxifan but not by JNJ-7777120. Subsequently, we evaluated the effect of imetit using a copulatory behavior test to assess ejaculation latency (EL) in rats. Imetit prolonged EL, although this effect was inhibited by ciproxifan. These findings indicate that H₃R stimulation suppresses mechanical stimuli-evoked neuronal firing in the spinal-penile neurotransmission system, thereby resulting in prolonged EL. To our knowledge, this is the first report to describe the relationship between H₃R and PE. Thus, H₃R agonists may represent a novel treatment option for PE.

Efficacy, safety, and optimal timing of single-trocar video-assisted flexible thoracoscopic debridement under local anesthesia for complicated parapneumonic empyema

OBJECTIVE

Thoracoscopic debridement under local anesthesia is a useful approach for complicated parapneumonic effusion or empyema (CPE) and is a less invasive procedure than video-assisted thoracoscopic surgery under general anesthesia. There are various methods of thoracoscopic debridement under local anesthesia, although the optimal timing of treatment is unknown. The objective of this study was to verify the efficacy and safety of our video-assisted flexible thoracoscopic debridement (VAFTS-D) procedure under local anesthesia, and to investigate the clinical features associated with the success of VAFTS-D.

METHODS

The study included 71 consecutive patients with CPE who underwent VAFTS-D. The primary outcome was success of VAFTS-D. We retrospectively analyzed the efficacy and safety of VAFTS-D from the clinical data obtained from hospital medical records, and used univariate logistic analyses to identify potential predictors of the outcome.

RESULTS

VAFTS-D was considered successful in 62 of 71 patients (87.3%). Two of the remaining nine patients died and the other seven patients required subsequent operation under general anesthesia. Complications due to VAFTS-D occurred in six patients (8.5%). Duration of empyema < 10 days (P = 0.024) and negative bacterial culture in pleural effusion (P = 0.029) were independently associated with the success of VAFTS-D by univariate logistic regression analysis.

CONCLUSION

VAFTS-D might be an acceptable first-line procedure in patients with suspected CPE. VAFTS-D should be performed as early as possible for a successful outcome, and to obtain useful information on the pleural cavity.

Intramuscular injection of mesenchymal stem cells activates anabolic and catabolic systems in mouse skeletal muscle

Skeletal muscle mass is critical for good quality of life. Mesenchymal stem cells (MSCs) are multipotent stem cells distributed across various tissues. They are characterized by the capacity to secrete growth factors and differentiate into skeletal muscle cells. These capabilities suggest that MSCs might be beneficial for muscle growth. Nevertheless, little is known regarding the effects on muscle protein anabolic and catabolic systems of intramuscular injection of MSCs into skeletal muscle. Therefore, in the present study, we measured changes in mechanistic target of rapamycin complex 1 (mTORC1) signaling, the ubiquitin–proteasome system, and autophagy-lysosome system-related factors after a single intramuscular injection of MSCs with green fluorescence protein (GFP) into mouse muscles. The intramuscularly-injected MSCs were retained in the gastrocnemius muscle for 7 days after the injection, indicated by detection of GFP and expression of platelet-derived growth factor receptor-alpha. The injection of MSCs increased the expression of satellite cell-related genes, activated mTORC1 signaling and muscle protein synthesis, and increased protein ubiquitination and autophagosome formation (indicated by the expression of microtubule-associated protein 1 light chain 3-II). These results suggest that the intramuscular injection of MSCs activated muscle anabolic and catabolic systems and accelerated muscle protein turnover.

Generation of Caco-2 cells stably expressing CYP3A4·POR·UGT1A1 and CYP3A4·POR·UGT1A1*6 using a PITCh system

The small intestine plays a critical role in the absorption and metabolism of orally administered drugs. Therefore, a model capable of evaluating drug absorption and metabolism in the small intestine would be useful for drug discovery. Patients with genotype UGT1A1*6 (exon 1, 211G > A) treated with the antineoplastic drug SN-38 have been reported to exhibit decreased glucuronide conjugation and increased incidence of intestinal toxicity and its severe side effects, including severe diarrhea. To ensure the safety of drugs, we must develop a drug metabolism and toxicity evaluation model which considers UGT1A1*6. In this study, we generated CYP3A4·POR·UGT1A1 KI- and CYP3A4·POR·UGT1A1*6 KI-Caco-2 cells for pharmaceutical research using a PITCh system. The CYP3A4·POR·UGT1A1 KI-Caco-2 cells were shown to express functional CYP3A4 and UGT1A1. The CYP3A4·POR·UGT1A1*6 KI-Caco-2 cells were sensitive to SN-38-induced intestinal toxicity. We thus succeeded in generating CYP3A4·POR·UGT1A1 KI- and CYP3A4·POR·UGT1A1*6 KI-Caco-2 cells, which can be used in pharmaceutical research. We also developed an intestinal epithelial cell model of patients with UGT1A1*6 and showed that it was useful as a tool for drug discovery.

Association between lowering heart rate during IMPELLA support and favorable short-term outcome in patients with cardiogenic shock

Background

Impella has been increasingly used in patients with cardiogenic shock (CGS). Target values for clinical indices for appropriate management of Impella have not yet been established.

Purpose

We aimed to elucidate the association between heat rate (HR) during Impella treatment in patients with CGS and clinical outcomes.

Methods and results

We retrospectively evaluated 62 patients (68±14 years; male 77%) with CGS receiving temporary circulatory support with the Impella between February 1, 2019, and February 31, 2021. The primary end point was 30-day mortality. Clinical characteristics, laboratory and hemodynamic markers at implantation of Impella (baseline), 12, 24 hr after implantation, and removal of Impella were assessed. There were 28 patients with concomitant use of extracorporeal membrane oxygenation (ECMO). Treatment periods using Impella were 8±6 days. After excluding 11 patients who died during Impella support, the relationship between clinical indicators at each time points and 30-day mortality was evaluated. There were 22 patients (43%) with 30-day mortality. Factors associated with 30-day mortality were: female, ECMO, higher 24-hr lactate level, lower 24-hr cardiac power output, and higher HR at removal. Lower HR of ≤81 bpm at removal was found to most accurately predict lower 30-day mortality (Figure 1). Higher increases in dose of beta-blockers during Impella support and lower absolute doses of norepinephrine at removal were correlated with decreases in HR during Impella support.

Conclusions

In patients with CGS treated with Impella, lower HR at removal was associated with lower incidence of 30-day mortality. Lowering HR during Impella treatment was recognized as a simple indicator for favorable clinical outcomes in patients with CGS. It was suggested that chronotropic interventions during Impella treatment may be novel therapeutic options in patients with CGS.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Coincidence of Thyroid Transcription Factor-1 Positive Thymoma and Pulmonary Adenocarcinoma

Thyroid transcription factor-1 (TTF-1) has been widely used as a marker of primary lung cancer. However, there have been few reports on TTF-1 expression in thymomas. We here report the case of an asymptomatic 63-year-old man who presented with a right upper lung nodule and cystic mid-mediastinal tumor. The right upper lobe of the lung and the mediastinal tumor were resected. Histological examination of the operative specimen revealed TTF-1-positive type B2 thymoma and invasive pulmonary adenocarcinoma. Although rare, thymoma should be included in the different diagnosis of TTF-1-positive tumors.

Cardiac hemangioma producing pericardial effusion detected on thoracoscopic pericardial fenestration

A 76-year-old woman presented with dyspnea. Computed tomography showed massive pericardial effusion, so percutaneous catheter drainage was performed. The usual causes of exudate were ruled out, and no diagnosis was reached. Thoracoscopic pericardial fenestration was performed for the purpose of pericardial biopsy and to create a passage allowing longer-term drainage. We observed the pericardial cavity after removing effusion, and incidentally revealed a tumor measuring 2 cm in diameter located between the left atrial appendage and left pulmonary artery. Surgical resection of the tumor attached to the left atrial appendage was performed. The pathological diagnosis was hemangioma.

Indigo enhances wound healing activity of Caco-2 cells via activation of the aryl hydrocarbon receptor

Indigo Naturalis, also known as Qing Dai (QD) is a compound obtained from Indigofera tinctoria, Isatis tinctoria, and Polygonum tinctoria and is known to ameliorate refractory ulcerative colitis (UC) by an unknown mechanism. QD maintains both homeostasis and the integrity of colon epithelia in mice that have experimentally induced colitis. The primary component of QD, indigo, comprises 42.4% of the compound. Indigo efficiently suppresses rectal bleeding and reduces the erosion of the colon epithelium, whereas it does not reduce weight loss or increase survival in a certain condition. Indigo is a ligand of the aryl hydrocarbon receptor (AhR), which is involved in the anti-colitis activity of QD. Here we investigate the effects of indigo on wound (erosion) closure in colon epithelial cells. Oral administration of indigo induced expression of Cytochrome P450 1A1 (Cyp1a1) in the colon but not in the liver, suggesting that indigo stimulates AhR from the luminal side of the colon. The erosion-closure activity tested in the scratch assays using Caco-2 cells was accelerated by addition of QD and indigo to the culture medium. QD and indigo also induced nuclear localization of AhR and expression of CYP1A1 in the Caco-2 cells. Acceleration of scratch wound closure was abolished by addition of the AhR-antagonist CH223191. Cell proliferation and actin polymerization were also shown to contribute to erosion closure. The results suggest that indigo exerts its erosion-healing effects by increasing proliferation and migration of colon epithelial cells via activation of AhR in intestinal epithelia.

Characterization of P-Glycoprotein Inhibitors for Evaluating the Effect of P-Glycoprotein on the Intestinal Absorption of Drugs

For developing oral drugs, it is necessary to predict the oral absorption of new chemical entities accurately. However, it is difficult because of the involvement of efflux transporters, including P-glycoprotein (P-gp), in their absorption process. In this study, we conducted a comparative analysis on the inhibitory activities of seven P-gp inhibitors (cyclosporin A, GF120918, LY335979, XR9576, WK-X-34, VX-710, and OC144-093) to evaluate the effect of P-gp on drug absorption. GF120918, LY335979, and XR9576 significantly decreased the basal-to-apical transport of paclitaxel, a P-gp substrate, across Caco-2 cell monolayers. GF120918 also inhibited the basal-to-apical transport of mitoxantrone, a breast cancer resistance protein (BCRP) substrate, in Caco-2 cells, whereas LY335979 hardly affected the mitoxantrone transport. In addition, the absorption rate of paclitaxel after oral administration in wild-type mice was significantly increased by pretreatment with LY335979, and it was similar to that in mdr1a/1b knockout mice. Moreover, the absorption rate of topotecan, a BCRP substrate, in wild-type mice pretreated with LY335979 was similar to that in mdr1a/1b knockout mice but significantly lower than that in bcrp knockout mice. These results indicate that LY335979 has a selective inhibitory activity for P-gp, and would be useful for evaluating the contribution of P-gp to drug absorption.

Disappearance of Gastric Hyperplastic Polyps after the Discontinuation of Proton Pump Inhibitor in a Patient with Liver Cirrhosis

Here, we report on a rare case of gastric hyperplastic polyps which disappeared after the discontinuation of proton pump inhibitor (PPI). The patient was an 83-year-old woman with liver cirrhosis and portal hypertension, along with gastroesophageal reflux disease treated by PPI. An initial upper gastrointestinal endoscopy showed unique polypoid lesions in the greater curvature of the stomach. Biopsy specimens of the lesions were diagnosed as hyperplastic polyps and she was followed. One year later, a second endoscopy showed that the lesions had increased in number and size, and an endoscopic mucosal resection (EMR) was performed for the main polyps. The resected specimens indicated a proliferation of foveolar epithelium cells with an increase of capillary ectasia and parietal cell hyperplasia, which was thought to be induced by hypergastrinemia from the PPI. Three months after the EMR, she was admitted because of bleeding from the remaining polyps along with an increase in new polyps. After conservative treatment, PPI was stopped and rebamipide was used. One year and 6 months later, an endoscopy showed the complete disappearance of all gastric polyps.

Relevance of Liquid-Liquid Phase Separation of Supersaturated Solution in Oral Absorption of Albendazole from Amorphous Solid Dispersions

Amorphous solid dispersion (ASD) is one of the most promising formulation technologies for improving the oral absorption of poorly soluble drugs, where the maintenance of supersaturation plays a key role in enhancing the absorption process. However, quantitative prediction of oral absorption from ASDs is still difficult. Supersaturated solutions can cause liquid-liquid phase separation through the spinodal decomposition mechanism, which must be adequately comprehended to understand the oral absorption of drugs quantitatively. In this study, albendazole (ALZ) was formulated into ASDs using three types of polymers, poly(methacrylic acid-co-methyl methacrylate) (Eudragit) L100, Vinylpyrrolidone-vinyl acetate copolymer (PVPVA), and hydroxypropyl methylcellulose acetate succinate (HPMCAS). The oral absorption of ALZ in rats administered as ASD suspensions was not explained by dissolution study but was predicted using liquid-liquid phase separation concentration, which suggested that the absorption of ALZ was solubility-limited. The oral administration study in dogs performed using solid capsules demonstrated the low efficacy of ASDs because the absorption was likely to be limited by dissolution rate, which indicated the importance of designing the final dosage form of the ASDs.

Magnetization of mesenchymal stem cells using magnetic liposomes enhances their retention and immunomodulatory efficacy in mouse inflamed skeletal muscle

Sarcopenia, an age-related reduction in skeletal muscle mass and strength, is mainly caused by chronic inflammation. Because mesenchymal stem cells (MSCs) have the capacity to both promote myogenic cell differentiation and suppress inflammation, they are a promising candidate for sarcopenia treatment. In this study, to achieve the long-term retention of MSCs in skeletal muscle, we prepared magnetized MSCs using magnetic anionic liposome/atelocollagen complexes that we had previously developed, and evaluated their retention efficiency and immunomodulatory effects in mouse inflamed skeletal muscle. Mouse MSCs were efficiently magnetized by incubation with magnetic anionic liposome/atelocollagen complexes for 30 min under a magnetic field. The magnetized MSCs differentiated normally into osteoblasts and adipocytes. Additionally, non-magnetized MSCs and magnetized MSCs increased IL-6 and inducible nitric oxide synthase mRNA expression and decreased TNF-α and IL-1β mRNA expression in C2C12 mouse skeletal muscle myotubes through paracrine effects. Moreover, magnetized MSCs were significantly retained in cell culture plates and mouse skeletal muscle after their local injection in the presence of a magnetic field. Furthermore, magnetized MSCs significantly increased IL-6 and IL-10 mRNA expression and decreased TNF-α and IL-1β mRNA expression in inflamed skeletal muscle. These results suggest that magnetized MSCs may be useful for effective sarcopenia treatment.

Transport Characteristics of 5-Aminosalicylic Acid Derivatives Conjugated with Amino Acids via Human H+-Coupled Oligopeptide Transporter PEPT1

5-Aminosalicylic acid (5-ASA) is used as first line therapy for symptom remission and maintenance of inflammatory bowel disease (IBD). Because 5-ASA is well absorbed from the small intestine when orally administered, several 5-ASA formulations for selective delivery to the colon have been developed and used in clinical practice. However, its delivery efficiency to local inflamed colonic sites remains low. Intestinal H⁺-coupled oligopeptide transporter 1 (PEPT1) expression in the colon is low, whereas its expression is induced in the colon under chronic inflammation conditions, such as IBD. Therefore, we considered that PEPT1 would be a target transporter to improve 5-ASA delivery efficiency to local colonic lesions. We evaluated the transport characteristics of dipeptide-like 5-ASA derivatives, which were coupling glycine (Gly), lysine, glutamic acid (Glu), valine (Val) and tyrosine to amino or carboxyl group of 5-ASA, in Caco-2 cells. [³H]Glycylsarcosine (Gly-Sar) uptake into Caco-2 cells was inhibited by all 5-ASA derivatives. In addition, 5-ASA derivatives (Gly-ASA, Glu-ASA and Val-ASA), which were coupled by glycine, glutamic acid and valine to amino group of 5-ASA, were taken up in a pH- and concentration-dependent manner and their uptake was inhibited by excess Gly-Sar. Two-electrode voltage-clamp experiment using human PEPT1 expressing Xenopus oocytes showed that Gly-ASA, Glu-ASA and Val-ASA induced marked currents at pH 6.0. Taken together, these results showed that these 5-ASA derivatives are transportable substrates for PEPT1.

Relationship between left atrial strain and left atrial bipolar voltage in patients undergoing catheter ablation for atrial fibrillation

Background

Low-voltage zone (LVZ) in the left atrium (LA) seems to represent fibrosis. LA longitudinal strain assessed by speckle tracking method is known to correlate with the extent of fibrosis in patients with mitral valve disease.

Purpose

We sought to identify the relationship between LA longitudinal strain and LA bipolar voltage in patients with atrial fibrillation (AF). We tested the hypothesis that LA strain can predict LA bipolar voltage.

Methods

A total of 96 consecutive patients undergoing initial AF ablation were analyzed. All patients underwent transthoracic echocardiography including 2D speckle tracking measurement on the day before ablation during sinus rhythm (SR group, N=54) or during AF (AF group, N=42). LA longitudinal strain was measured at basal, mid, and roof level of septal, lateral, anterior, and inferior wall in apical 4- and 2-chamber view. Global longitudinal strain (GLS) was defined as an average value of the 12 segments. LA voltage map was created using EnSite system, and global mean voltage was defined as a mean of bipolar voltage of the whole LA excluding pulmonary veins and left atrial appendage. LVZ was defined as less than 1.0 mV.

Results

There was a significantly positive correlation between GLS and global mean voltage (r=0.708, p&lt;0.001). Multivariate regression analysis showed that GLS and age were independent predictors of global mean voltage. There was a significant negative correlation between global mean voltage and LVZ areas.

Conclusions

There was a strong correlation between LA longitudinal strain and LA mean voltage. GLS can independently predict LA mean voltage, subsequently LVZ areas in patients with AF.

Funding Acknowledgement

Type of funding source: None

Prognostic implications of late gadolinium enhancement for re-worsening left ventricular ejection fraction in patients with dilated cardiomyopathy: a longitudinal study of left ventricular function

Background

Re-worsening left ventricular ejection fraction (LVEF) after initial recovery occurs in some patients with dilated cardiomyopathy (DCM). However, prevalence and predictors of re-worsening LVEF in longitudinal follow-up are unclear. Late gadolinium enhancement of cardiovascular magnetic resonance (LGE-CMR) can evaluate the damage of myocardial tissue.

Purpose

This study sought to evaluate the clinical parameters including LGE-CMR to predict re-worsening LVEF in patients with recent-onset DCM.

Methods

We included patients with recent-onset DCM who had an LVEF &lt;45% and underwent LGE-CMR at diagnosis. We performed yearly echocardiographc follow-up [median 6 [4–8.3] years]. Initial LVEF recovery defined as patients increased in &gt;5% LVEF from baseline and had an LVEF≥45% after medical therapy. Patients were divided into three groups: (1) Improved: defined as those with sustained LVEF ≥45% after initial LVEF recovery; (2) Re-worse: those with decreased &gt;5% and had an LVEF &lt;45% after initial LVEF recovery. and (3) Not-improved: those with no initial LVEF recovery during follow-up. To evaluate the prognostic factors for Re-worsening LVEF after initial LVEF recovery, multivariate logistic regression analysis performed between the Improved group and the Re-worse group. Cardiac events defined as hospitalization due to heart failure and sudden death.

Results

Of 138 patents, 82 patients (59%) were the Improved group, 42 patients (30%) were the Re-worse group, and 14 (10%) were the Not-improved group. Loess curves of long-term LVEF trajectories showed that LVEF in the Re-worse group increased first 2 years and declined slowly thereafter (Fig. 1A). Re-worsening LVEF occurred 4.5±2.2 years after initial LVEF recovery. Multivariate logistic regression analysis demonstrated that LGE area at baseline (Odds ratio: 1.09, 95% confidence interval (CI) 1.02–1.18, p=0.014) and Log brain natriuretic peptide (BNP) at initial LVEF recovery (Odds ratio: 1.53, 95% confidence interval (CI) 1.01–2.31, p=0.042) were independent predictors for Re-worsening LVEF. Kaplan Meier analysis demonstrated that the risk of cardiac events in the Re-worse group was significantly higher (hazard ratio: 3.93, 95% CI 1.49–10.36, p=0.006) than in the Improved group and lower risk than in the Not-improved group (hazard ratio: 0.28, 95% CI 0.12–0.62, p=0.002) (Fig. 1B).

Conclusion

Re-worsening LVEF occurred in 30% of patients in patients with recent-onset DCM. LGE area and BNP at initial LVEF recovery were independently associated with re-worsening LVEF after initial LVEF recovery.

Figure 1

Funding Acknowledgement

Type of funding source: None

Prognostic differences between atrial functional mitral regurgitation and ventricular functional mitral regurgitation

Introduction

Atrial functional mitral regurgitation (A-FMR) has been under-recognized until recently as a cause of FMR, and the prognostic difference between A-FMR and ventricular FMR (V-FMR) has not been fully elucidated. As there has been different mechanisms of FMR suggested in A-FMR and V-FMR, we hypothesized that prognosis and prognostic predictors of A-FMR may differ from those of V-FMR.

Purpose

To investigate the prognosis and prognostic predictors of A-FMR in comparison with V-FMR.

Methods

Among 1312 consecutive patients with grade 3+ (moderate to severe) or 4+ (severe) MR, 378 consecutive FMR patients were identified by excluding patients with degenerative MR, previous cardiac surgery, or concomitant aortic valve disease and/or mitral stenosis. FMR with ejection fraction (EF) &lt;40% or FMR due to regional wall motion abnormalities with leaflet tethering were classified as V-FMR (N=288), and FMR due to left atrial (LA) and/or annular dilatation with preserved or mid-range EF (≥40%) were classified as A-FMR (N=90). All-cause death and heart failure hospitalization were analyzed as cardiovascular (CV) events in this study. Surgical or percutaneous mitral valve intervention without CV events was handled as not reaching an endpoint and these cases were censored.

Results

A-FMR were significantly older (76 [69–82] vs. 70 [58–77] years), higher rates of female (64 vs. 35%) and atrial fibrillation (88 vs. 42%), and lower B-type natriuretic peptide (BNP) values (169 [101–318] vs. 447 [213–952] pg/ml) compared to V-FMR (all P&lt;0.05). On echocardiography, LV end-diastolic and end-systolic dimensions (52 [48–57] vs. 64 [58–72] mm, 34 [31–37] vs. 55 [48–64] mm), respectively) were smaller, and EF (55 [50–60] vs. 28 [19–35] %) and LA volume (99 [73–137] vs. 73 [57–91] ml/m2) were larger in A-FMR (all P&lt;0.05). Effective regurgitant orifice area (32 [26–40] vs. 31 [24–45] mm2) and regurgitant volume (50±15 vs. 52±16 ml) were similar (both n.s.). During a median follow up of 1407 days, 206 (54%) patients developed CV events. Kaplan-Meier analysis revealed that V-FMR had a significantly higher rates of CV events compared to A-FMR (Figure) with adjusted hazard ratio (HR) of 1.762 [1.168–2.660], P=0.007 after adjusted for variables including age, sex, New York Heart Association functional class, previous heart failure hospitalization, estimated glomerular filtration rate (eGFR) and BNP. Further, stepwise multivariate analysis showed that independent prognostic predictors of A-FMR were LA volume and eGFR, while those for V-FMR were LA volume, age, and LV end-systolic dimension.

Conclusions

A-FMR had relatively better prognosis compared to V-FMR, and there were different prognostic predictors between A-FMR and V-FMR. Our results suggest that different treatment strategies need to be considered between A-FMR and V-FMR.

The Kaplan-Meier life table

Funding Acknowledgement

Type of funding source: None

Prediction of negative food effect induced by bile micelle binding on oral absorption of hydrophilic cationic drugs

The purpose of the present study was to quantitatively predict the negative food effect induced by bile micelle binding on the oral absorption of hydrophilic cationic drugs. The intrinsic membrane permeability and bile micelle unbound fraction of 12 model drugs (7 tertiary amines, 3 quaternary ammoniums, and 2 neutral drugs) were calculated from the experimental Caco-2 permeability data (P_app) under fasted and fed conditions. From these input data, the fraction of a dose absorbed (Fa) was predicted using the gastrointestinal unified theoretical framework, a mechanism-based oral absorption model. The predicted Fa ratio (fed/fasted) was then compared with the in vivo fed/fasted area under the plasma concentration-time curve ratio (AUCr). The AUCr values of tertiary amines and neutral drugs were appropriately predicted (absolute average fold error (AAFE) = 1.19), whereas those of quaternary ammoniums were markedly underestimated (AAFE = 4.70). The P_app ratio (fed/fasted) predicted AUCr less quantitatively (AAFE = 1.30 for tertiary amines and neutral drugs). The results of the present study would lead to a better understanding of negative food effect on oral drug absorption.

Bottom-Up Physiologically Based Oral Absorption Modeling of Free Weak Base Drugs

In this study, we systematically evaluated "bottom-up" physiologically based oral absorption modeling, focusing on free weak base drugs. The gastrointestinal unified theoretical framework (the GUT framework) was employed as a simple and transparent model. The oral absorption of poorly soluble free weak base drugs is affected by gastric pH. Alternation of bulk and solid surface pH by dissolving drug substances was considered in the model. Simple physicochemical properties such as pKa, the intrinsic solubility, and the bile micelle partition coefficient were used as input parameters. The fraction of a dose absorbed (Fa) in vivo was obtained by reanalyzing the pharmacokinetic data in the literature (15 drugs, a total of 85 Fa data). The AUC ratio with/without a gastric acid-reducing agent (AUCr) was collected from the literature (22 data). When gastric dissolution was neglected, Fa was underestimated (absolute average fold error (AAFE) = 1.85, average fold error (AFE) = 0.64). By considering gastric dissolution, predictability was improved (AAFE = 1.40, AFE = 1.04). AUCr was also appropriately predicted (AAFE = 1.54, AFE = 1.04). The Fa values of several drugs were slightly overestimated (less than 1.7-fold), probably due to neglecting particle growth in the small intestine. This modeling strategy will be of great importance for drug discovery and development.