Human Model Research Articles

Characterization of a novel heterozygous variant in the histidyl-tRNA synthetase gene associated with Charcot-Marie-Tooth disease type 2W.

Heterozygous pathogenic variants in the histidyl-tRNA synthetase (HARS) gene are associated with Charcot-Marie-Tooth (CMT) type 2W disease, classified as an axonal peripheral neuropathy. To date, at least 60 variants causing CMT symptoms have been identified in seven different aminoacyl-tRNA synthetases, with eight being found in the catalytic domain of HARS. The genetic data clearly show a causative role of aminoacyl-tRNA synthetases in CMT; however, the cellular mechanisms leading to pathology can vary widely and are unknown in the case of most identified variants. Here we describe a novel HARS variant, c.412T>C; p.Y138H, identified through a CMT gene panel in a patient with peripheral neuropathy. To determine the effect of p.Y138H we employed a humanized HARS yeast model and recombinant protein biochemistry, which identified a deficiency in protein dimerization and a growth defect which shows mild but significant improvement with histidine supplementation. This raises the potential for a clinical trial of histidine.

Human assembloids reveal the consequences of CACNA1G gene variants in the thalamocortical pathway

Abnormalities in thalamocortical crosstalk can lead to neuropsychiatric disorders. Variants in CACNA1G, which encodes the α1G subunit of the thalamus-enriched T-type calcium channel, are associated with absence seizures, intellectual disability, and schizophrenia, but the cellular and circuit consequences of these genetic variants in humans remain unknown. Here, we developed a human assembloid model of the thalamocortical pathway to dissect the contribution of genetic variants in T-type calcium channels. We discovered that the M1531V CACNA1G variant associated with seizures led to changes in T-type currents in thalamic neurons, as well as correlated hyperactivity of thalamic and cortical neurons in assembloids. By contrast, CACNA1G loss, which has been associated with risk of schizophrenia, resulted in abnormal thalamocortical connectivity that was related to both increased spontaneous thalamic activity and aberrant axonal projections. These results illustrate the utility of multi-cellular systems for interrogating human genetic disease risk variants at both cellular and circuit level.

Effects of land use types on the soil physicochemical characteristics of Inyi community, Enugu State, Nigeria: Application of multivariate statistical, and eco-toxicological and human risk model approaches

The constant and increased use of arable lands for cultivation has led to its degradation; hence the impacts of different land-use patterns on the soil physical and chemical properties were investigated. Soil samples (n = 36) were collected from the oil palm plantation (OPP), cashew plantation (CP) and untampered forest (UF), in Inyi community, Enugu State, Nigeria. They were air-dried, sieved, and analyzed for their physicochemical properties. The results revealed that the average soil pH ranged from 5.9 to 8.2. Moisture and carbon contents ranged from 6.3 to 35.4, and 3.5 to 6.7 % respectively. Low CEC values were recorded for all the soil samples. The total mean soil textural fractions decreased as follows: sand > clay > silt. Also, the total mean concentrations of N, P, K, and Mg in the study area decreased in the order: OPP>UF>CP, OPP>UF>CP, UF>OPP>CP, and OPP>UF>CP respectively while the S, NO3-, NO2-, and HCO3- followed the order; OPP>UF>CP, UF>OPP>CP, OPP>CP>UF, and CP>OPP>UF respectively. The soil ecological risk index was < 40 in all sample locations, indicating slight contamination of the study area. Therefore, regular monitoring and soil nutrient management practices should be maintained and encouraged.

On the necessity of accounting for age structure in human malaria transmission modelling

Malaria is one of the most common mosquito-borne diseases widespread in tropical and subtropical regions, causing thousands of deaths every year in the world. In a previous paper, we formulated an age-structured model containing three structural variables: (i) the chronological age of human and mosquito populations, (ii) the time since they are infected, and (iii) humans waning immunity (i.e. the progressive loss of protective antibodies after recovery). In the present paper, we expand the analysis of this age-structured model and focus on the derivation of entomological and epidemiological results commonly used in the literature, following the works of Smith and McKenzie. We generalize their results to the age-structured case. In order to quantify the impact of neglecting structuring variables such as chronological age, we assigned values from the literature to our model parameters. While some parameters values are readily accessible from the literature, at least those about the human population, the parameters concerning mosquitoes are less commonly documented and the values of a number of them (e.g. mosquito survival in the presence or in absence of infection) can be discussed extensively. Our analysis, informed by parameter values from the literature, demonstrates that overlooking those structural variables of human and mosquito populations may result in inaccurate epidemiological predictions and suboptimal control strategies. We highlight the epidemiological implications of these findings and emphasize the necessity of considering age structure in future malaria control programs.

Development and empirical verification of non-uniformly layout semiconductor liquid cooling garment model based on CFD simulation

Personal cooling garments (PCGs) are important to help human body regulate its own thermal comfort under high temperature environments. This study focuses on the thermal comfort of personal cooling garment in high temperature environments, which is of great significance in the context of current climate warming and frequent extreme high temperature events. Traditional research on cooling garment mainly focuses on improving its cooling performance, but ignores how to improve human thermal comfort by optimizing cooling equipment and garment parameters. This study developed a semiconductor liquid cooling garment (SLCG) that can adjust and help the human body achieve optimal thermal comfort under different environmental conditions. Through computational fluid dynamics (CFD) simulation, this study established a human body model wearing SLCG to analyze the effects of parameters such as external ambient temperature, flow rate, and inlet water temperature on thermal comfort. Different from traditional research, this study proposed a heat exchange network design with non-uniformity layout, this layout accounted for the variations in heat dissipation across different regions of the human body, enabling targeted optimization of the cooling effect. The results show that among the five different pipe spacings, the spacing of 2–3.5 cm can most effectively improve human thermal comfort. Specifically, in an environment of 34 °C, the parameter combination of inlet water temperature of 24 °C and flow rate of 26 kg/h was selected; at 36 °C, the inlet water temperature was 22 °C and the flow rate was 40 kg/h; at 38 °C, the inlet water temperature was 20 °C and the flow rate was 54 kg/h. The accuracy of the newly developed numerical model was evaluated through a series of experiments. Validation efforts involved comparing the model’s numerical results with experimental outcomes derived from human trials. The error between the simulated and experimental temperatures at each inlet and outlet was confined to within 0.2 °C. The error of cooling power is within 8 %, which proves the accuracy of the numerical model and the rationality of SLCG optimal parameters. This study not only proposed a new SLCG design idea, filling the research gap on thermal comfort optimization in the field of cooling garment, but also provided a theoretical basis and practical reference for the future design of cooling garment in different high temperature environments.

Facial pore refining by targeting dermal and epidermal functions: Assessment across age and gender.

Conspicuous facial pores are benign but represent a cosmetic concern for men and women. Recent works described dermal and epidermal impairments as clinical causes of enlarged pores. Morphological modifications of skin at the site of pores were associated with collagen density loss, possible alteration of extracellular matrix and abnormal differentiation of keratinocytes. A composition containing mannose-6-phosphate (Active Complex) was designed to address these different aspects of pore enlargement. Invitro and exvivo evaluations were conducted in different models mimicking disturbance of dermal and epidermal functions. The pore refining activity of Active Complex was assessed in two clinical trials studying a Caucasian women cohort and an Asian men cohort. At the dermal level, Active Complex upregulated collagen I and decorin synthesis, and genes encoding collagens I, III, V, VII, XVII; suggesting its ability to favor collagen fiber organization and anchorage. The downregulation of matrix metalloprotease, involved in extracellular matrix degradation, reinforced the protective effect of Active Complex in the dermis. Active Complex down modulated differentiation markers in keratinocytes as well as genes involved in cell renewal. Study of reconstructed human epidermis modeling keratinocyte hyperproliferation revealed that Active Complex mitigated two markers of this state: number of nuclei in the stratum corneum and involucrin expression. Clinical trials confirmed the pore refining activity of Active Complex on men and women of different ages and ethnicities; -24% total skin pore area after 56 days of application on women, and -30.2% on men after 7 days. This work demonstrates the interest to target dermal and epidermal modifications described in conspicuous pore area, especially dermis fiber organization, to address this cosmetic concern.

The Role of Natural Background Radiation in Maintaining Genomic Stability in the CGL1 Human Hybrid Model System.

Natural background ionizing radiation is present on the earth's surface; however, the biological role of this chronic low-dose-rate exposure remains unknown. The Researching the Effects of the Presence and Absence of Ionizing Radiation (REPAIR) project is examining the impacts of sub-natural background radiation exposure through experiments conducted 2 km underground in SNOLAB. The rock overburden combined with experiment-specific shielding provides a background radiation dose rate 30 times lower than on the surface. We hypothesize that natural background radiation is essential for life and maintains genomic stability and that prolonged exposure to sub-background environments will be detrimental to biological systems. To evaluate this, human hybrid CGL1 cells were continuously cultured in SNOLAB and our surface control laboratory for 16 weeks. Cells were assayed every 4 weeks for growth rate, alkaline phosphatase (ALP) activity (a marker of cellular transformation in the CGL1 system), and the expression of genes related to DNA damage and cell cycle regulation. A subset of cells was also exposed to a challenge radiation dose (0.1 to 8 Gy of X rays) and assayed for clonogenic survival and DNA double-strand break induction to examine if prolonged sub-background exposure alters the cellular response to high-dose irradiation. At each 4-week time point, sub-background radiation exposure did not significantly alter cell growth rates, survival, DNA damage, or gene expression. However, cells cultured in SNOLAB showed significantly higher ALP activity, a marker of carcinogenesis in these cells, which increased with longer exposure to the sub-background environment, indicative of neoplastic progression. Overall, these data suggest that sub-background radiation exposure does not impact growth, survival, or DNA damage in CGL1 cells but may lead to increased rates of neoplastic transformation, highlighting a potentially important role for natural background radiation in maintaining normal cellular function and genomic stability.

Cytotoxic Impacts of Seven Alternative Bisphenols on Human In Vitro Cellular Models

Bisphenols, common in plastics, coatings, and resins, are under scrutiny for potential endocrine disruption. Despite banning Bisphenol A (BPA), its perceived safer alternatives may still pose health risks, urging thorough studies on their toxicity mechanisms. This study aimed to investigate the cellular toxicity of the top seven most commonly used BPs, bisphenol S (BPS), bisphenol F (BPF), bisphenol AF (BPAF), bisphenol P (BPP), bisphenol AP (BPAP), bisphenol B (BPB), bisphenol E (BPE) in eight different relevant human in vitro cell models: liver (HepaRG), intestinal (CaCo-2), breast (T47D), brain (HMC-3), lungs (MRC-5), kidney (HEK293), endothelial (HMEC-1), and skin (HEK-001) cell lines. BPE manifested the highest cytotoxicity in CaCo-2 cells, presenting an EC50 value of roughly 0.2 μM (95% confidence interval). In contrast, HEK293 and HepaRG cells demonstrated significant resilience to BPS (EC50 >1000 μM). BPAF, BPP, and BPAP had consistently low EC50 values across cell lines (6-27.9 μM, 0.6-134.7 μM, and 3.6-178.8 μM), indicating elevated toxicity. After 24 hours, all bisphenols adhered to nominal concentrations except BPAF, BPP, and BPS. BPP's concentration notably decreased (30.82 ± 5.53% of nominal value). The results reveal diverse effects of bisphenol analogs on different cell types. These findings emphasize the considerable cytotoxic potential of specific bisphenol analogs across various human cell models, underlining the necessity for a re-evaluation of their safety and regulatory standards.

Multi-gene duplication removal in an engineered human cellular MECP2 duplication syndrome model with an IRAK1-MECP2 duplication

Recent progress in genome editing technologies has catalyzed the generation of sophisticated cell models, however; the precise modeling of copy number variation (CNV) diseases remains a significant challenge, despite their substantial prevalence in the human population. To overcome this barrier, we have explored the utility of HAP1 cells for the accurate modeling of disease genomes with large structural variants. As an example, this study details the strategy to generate a novel cell line that serves as a model for the neurological disorder, MECP2 Duplication Syndrome (MDS), featuring the critical duplication of both the MECP2 and IRAK1 genes. This model faithfully recapitulates MDS genomic rearrangement, allowing for the mechanistic study of gene overexpression and the development of therapeutic interventions. Employing a single-guide RNA (sgRNA) CRISPR-Cas9 strategy, we successfully excised the duplicated genomic segment, notably halving both MECP2 and IRAK1 expression levels. The evidence establishes our model as a crucial tool for research into MDS. Furthermore, the outlined workflow is readily adaptable to model other CNV disorders and subsequently test genomic and pharmacological interventions.

Elucidation of DPP-4 involvement in systemic distribution and renal reabsorption of linagliptin by PBPK modeling with a cluster Gauss-Newton method.

The dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin (LNG) exhibits target-mediated drug disposition (TMDD) in clinical settings, characterized by saturable binding to plasma soluble DPP-4 (sDPP-4) and tissue transmembrane DPP-4 (tDPP-4). Previous studies have indicated that saturable renal reabsorption of LNG contributes to its nonlinear urinary excretion observed in humans and wild-type mice, but not in Dpp-4 knockout mice. To elucidate the mechanisms underlying these complex phenomena, including DPP-4-related renal reabsorption of LNG, we employed physiologically-based pharmacokinetic (PBPK) modeling combined with a cluster Gauss-Newton method (CGNM). The CGNM facilitated the exploration of parameters in rat and human PBPK models for LNG and the determination of parameter identifiability. Through PBPK-CGNM analysis using reported autoradiography data ([14C]-LNG) in wild-type and Dpp-4-deficient rats, DPP-4-specific distributions of LNG in various tissues were clearly differentiated from nonspecific parts. By fitting to human plasma concentrations and urinary and fecal excretions of LNG after intravenous and oral administrations, multiple unknown PBPK parameters were simultaneously estimated by the CGNM. Notably, the amount of tDPP-4 and the reabsorption clearance for LNG-DPP-4 complexes were identifiable, indicating their critical role in explaining the complex nonlinear pharmacokinetics of LNG. Compared with previous PBPK analyses, the CGNM allowed us to incorporate greater model complexity (e.g., consideration of tDPP-4 expressions and invitro binding kinetics), ultimately resulting in a more accurate reproduction of LNG's TMDD. In conclusion, by considering LNG as a high-affinity probe for DPP-4, comprehensive PBPK-CGNM analyses suggested a dynamic whole-body distribution of DPP-4, including its involvement in the renal reabsorption of LNG.

Interpreting the Projected Frontal Area in Front Crawl: Determining the Projected Frontal Area of Each Body Segment.

This study aimed to provide evidence for the interpretation of the projected frontal area (PFA) during front crawl. To achieve this goal, we developed a method for calculating the PFA of each body segment using digital human technology and compared the pressure drag under two calculation conditions: a combination of the PFA with and without accounting for the horizontal velocity of each body segment. Twelve competitive male swimmers performed a 15-meter front crawl at 1.20 m·s-1. The three-dimensional positions of the reflective markers attached to the swimmer's body were recorded using an underwater motion-capture system. Based on the body shape of each swimmer obtained from the photogenic body scanner, individual digital human body models were created with the color of the model's vertices divided into eight body segments. The time series of the volumetric swimming motion was reconstructed using inverse kinematics. The PFA of each body segment was then calculated by the automatic processing of a series of parallel frontal images. The pressure drag index, defined as the value excluding the drag coefficient while simultaneously considering the PFA and the horizontal velocity, was calculated under two conditions: the static condition (accounting for only the PFA of each body segment) and the dynamic condition (accounting for the PFA and horizontal velocity of each body segment). Notably, the pressure drag index was higher under the static condition than under the dynamic condition for the humerus, ulna, and hand segments (p < 0.001). The results obtained using our methodology indicate that the PFA of the upper limb segments overestimates their contribution to pressure drag during front crawl under the static condition.

Sevoflurane Activates PI3K/AKT Signaling Pathway by Upregulating GDF11 Expression to Attenuate Ischemia/Reperfusion Injury in Cardiomyocytes.

Myocardial ischemia/reperfusion (I/R) injury stands as a primary contributor to ischemic heart disease. Sevoflurane (SEVO), a commonly used inhalation anesthetic, has been shown to exert a direct protective effect on ischemic heart injury. However, the specific mechanism by which it exerts the protective effect remains unclear. This study was designed to investigate the role of SEVO in myocardial I/R injury and its potential molecular mechanisms. Blood samples were collected from patients with acute myocardial infarction (AMI) (n = 20) and healthy volunteers (n = 20). The human cardiomyocytes AC16 models of I/R injury were induced by hypoxia/reoxygenation. The mRNA expression levels of growth differentiation factor 11 (GDF11) in the cells and blood were determined by reverse transcription quantitative real-time PCR (RT-qPCR). The cell proliferation was detected by Cell Counting Kit-8 (CCK-8). Enzyme-Linked Immunosorbent Assay (ELISA) was utilized to detect the levels of inflammatory factors interleukin (IL)-8, IL-1β and IL-6 in the cells. And biochemical assay kits were applied for the measurement of the activity of lactate dehydrogenase (LDH) and superoxide dismutase (SOD) as well as the malondialdehyde (MDA) level in the cells. Moreover, western blot was employed to evaluate the levels of the p-serine-threonine protein kinase (AKT), AKT, and phosphatidylinositol 3-kinase (PI3K), protein expression in the cells. The GDF11 expression was decreased in the blood of AMI patients and cardiomyocytes induced by I/R (p < 0.01). Besides, 1% SEVO was presented to promote cardiomyocyte proliferation, inhibit apoptosis, oxidative stress and inflammation, and activate the PI3K/AKT signaling pathway through up-regulation of GDF11 expression (p < 0.01). SEVO promotes proliferation and inhibits inflammatory response, apoptosis, and oxidative stress of I/R-treated cardiomyocytes by elevating GDF11 expression, thereby reducing myocardial I/R injury. Notably, the mechanism underlying the alleviation of the I/R injury may involve the activation of PI3K/AKT signaling pathway.

Urine-Derived Stem Cells Display Homing, Incorporation, and Repair in Human Organoid and Mouse Models of AKI

Urine-Derived Stem Cells Display Homing, Incorporation, and Repair in Human Organoid and Mouse Models of AKI

Prevention of postpartum methamphetamine use with micronized progesterone trial (PROMPT): A pilot randomized controlled trial protocol

While most pregnant individuals with methamphetamine use disorder (MUD) achieve abstinence, the postpartum period remains a vulnerable time for return to methamphetamine use (MU). Promising data from human and animal models, including three randomized controlled trials, suggest that micronized progesterone may prevent postpartum return to cocaine and nicotine use by reducing cravings. The primary objective of this study is to assess feasibility of enrollment and randomization of postpartum individuals with MUD to micronized progesterone to prevent return to MU. The secondary objectives are to evaluate safety, establish a preliminary estimate of efficacy, and characterize the association between allopregnanolone levels and methamphetamine cravings. This is a pilot double-blind placebo randomized controlled trial. We plan to enroll 40 postpartum individuals with MUD over 24-months. Individuals, stratified by opioid use disorder (OUD), are randomized 1:1-400mg oral micronized progesterone daily or placebo and attend weekly study sessions for 12 weeks. Feasibility is measured by achieving 80% of enrollment goal. Safety is evaluated by side effect frequency, mental health status changes, lactation and medical complications. Efficacy is assessed by comparing proportion of participants with return to MU and time to return to MU based on self-report or urine testing between treatment and control groups. Salivary allopregnanolone levels and methamphetamine cravings are compared between the groups. Study results will provide a first critical step towards potential intervention for prevention of return to MU among postpartum individuals. Completion of this trial will set the stage for a large-scale efficacy trial.

666P MyoScreen™ infantile and late-onset Pompe human skeletal muscle disease models for drug discovery and development of next-generation gene therapies

666P MyoScreen™ infantile and late-onset Pompe human skeletal muscle disease models for drug discovery and development of next-generation gene therapies

Unveiling a critical role of IL-7 in Celiac Disease - Insights from a novel human autoimmune organoid model

Unveiling a critical role of IL-7 in Celiac Disease - Insights from a novel human autoimmune organoid model

Unraveling Axonal Transcriptional Landscapes: Insights from iPSC-Derived Cortical Neurons and Implications for Motor Neuron Degeneration.

Neuronal function and pathology are deeply influenced by the distinct molecular profiles of the axon and soma. Traditional studies have often overlooked these differences due to the technical challenges of compartment specific analysis. In this study, we employ a robust RNA-sequencing (RNA-seq) approach, using microfluidic devices, to generate high-quality axonal transcriptomes from iPSC-derived cortical neurons (CNs). We achieve high specificity of axonal fractions, ensuring sample purity without contamination. Comparative analysis revealed a unique and specific transcriptional landscape in axonal compartments, characterized by diverse transcript types, including protein-coding mRNAs, RNAs encoding ribosomal proteins (RPs), mitochondrial-encoded RNAs, and long non-coding RNAs (lncRNAs). Previous works have reported the existence of transcription factors (TFs) in the axon. Here, we detect a set of TFs specific to the axon and indicative of their active participation in transcriptional regulation. To investigate transcripts and pathways essential for central motor neuron (MN) degeneration and maintenance we analyzed KIF1C-knockout (KO) CNs, modeling hereditary spastic paraplegia (HSP), a disorder associated with prominent length-dependent degeneration of central MN axons. We found that several key factors crucial for survival and health were absent in KIF1C-KO axons, highlighting a possible role of these also in other neurodegenerative diseases. Taken together, this study underscores the utility of microfluidic devices in studying compartment-specific transcriptomics in human neuronal models and reveals complex molecular dynamics of axonal biology. The impact of KIF1C on the axonal transcriptome not only deepens our understanding of MN diseases but also presents a promising avenue for exploration of compartment specific disease mechanisms.

Identification of distinct stool metabolites in women with endometriosis for non-invasive diagnosis and potential for microbiota-based therapies.

Endometriosis, a poorly studied gynecological condition, is characterized by the presence of ectopic endometrial lesions resulting in pelvic pain, inflammation, and infertility. These associated symptoms contribute to a significant burden, often exacerbated by delayed diagnosis. Current diagnostic methods involve invasive procedures, and existing treatments provide no cure. Microbiome-metabolome signatures in stool samples from individuals with and without endometriosis were determined using unbiased metabolomics and 16S bacteria sequencing. Functional studies for selected microbiota-derived metabolites were conducted invitro using patient-derived cells and invivo by employing murine and human xenograft pre-clinical disease models. We discovered a unique bacteria-derived metabolite signature intricately linked to endometriosis. The altered fecal metabolite profile exhibits a strong correlation with that observed in inflammatory bowel disease (IBD), revealing intriguing connections between these two conditions. Notably, we validated 4-hydroxyindole, a gut-bacteria-derived metabolite that is lower in stool samples of endometriosis. Extensive invivo studies found that 4-hydroxyindole suppressed the initiation and progression of endometriosis-associated inflammation and hyperalgesia in heterologous mouse and in pre-clinical models of the disease. Our findings are the first to provide a distinct stool metabolite signature in women with endometriosis, which could serve as stool-based non-invasive diagnostics. Further, the gut-microbiota-derived 4-hydroxyindole poses as a therapeutic candidate for ameliorating endometriosis. This work was funded by the NIH/NICHD grants (R01HD102680, R01HD104813) and a Research Scholar Grant from the American Cancer Society to R.K.

In vitro human cell-based models: What can they do and what are their limitations?

In vitro human cell-based models: What can they do and what are their limitations?

The Role of Microbiome and Probiotics in Chemo-Radiotherapy-Induced Diarrhea: A Narrative Review of the Current Evidence.

In this article, we review the most recent research on probiotics effects on diarrhea in both human and animal models of the condition along with the therapeutic potential of these compounds based on their findings. Nearly 50%-80% of cancer patients experience chemotherapy-induced diarrhea (CID), serious gastrointestinal toxicity of chemotherapeutic and radiation regimens that leads to prolonged hospitalizations, cardiovascular problems, electrolyte imbalances, disruptions in cancer treatment, poor cancer prognosis, and death. CID is typically categorized as osmotic diarrhea. The depletion of colonic crypts and villi by radiotherapy and chemotherapy agents interferes with the absorptive function of the intestine, thereby decreasing the absorption of chloride and releasing water into the intestinal lumen. Probiotic supplements have been found to be able to reverse the intestinal damage caused by chemo-radiation therapy by promoting the growth of crypt and villi and reducing inflammatory pathways. In addition, they support the modulation of immunological and angiogenesis responses in the gut as well as the metabolism of certain digestive enzymes by altering the gut microbiota. Beyond the benefits of probiotics, additional clinical research is required to clarify the most effective strain combinations and dosages for preventing chemotherapy and radiotherapy diarrhea.