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Wang, D.

Publications and source records attributed to Wang, D..

At least 505 records · Page 28Linked to original sources

Brain and Organoid Manifold Alignment (BOMA), a machine learning framework for comparative gene expression analysis across brains and organoids

Organoids have become valuable models for understanding cellular and molecular mechanisms in human development including brains. However, whether developmental gene expression programs are preserved between human organoids and brains, especially in specific cell types, remains unclear. Importantly, there is a lack of effective computational approaches for comparative data analyses between organoids and developing humans. To address this, by considering the public data availability and research significance, we developed a machine learning framework, Brain and Organoid Manifold Alignment (BOMA) for comparative gene expression analysis of brains and organoids, to identify conserved and specific developmental trajectories as well as developmentally expressed genes and functions, especially at cellular resolution. BOMA first performs a global alignment and then uses manifold learning to locally refine the alignment, revealing conserved developmental trajectories between brains and organoids. Using BOMA, we found that human cortical organoids better align with certain brain cortical regions than other non-cortical regions, implying organoid-preserved developmental gene expression programs specific to brain regions. Additionally, our alignment of non-human primate and human brains reveals highly conserved gene expression around birth. Also, we integrated and analyzed developmental scRNA-seq data of human brains and organoids, showing conserved and specific cell trajectories and clusters. Further identification of expressed genes of such clusters and enrichment analyses reveal brain- or organoid-specific developmental functions and pathways. Finally, we experimentally validated important specific expressed genes using immunofluorescence. BOMA is open-source available as a web tool for general community use.

bioinformatics↗

Protective human anti-poxvirus monoclonal antibodies are generated from rare memory B cells isolated by multicolor antigen tetramers

Smallpox, an epidemic disease caused by Orthopoxvirus variola, was eradicated worldwide through immunization. The immunization against smallpox was discontinued in 1980. However, incidences of monkeypox virus infection in humans have occurred sporadically, and there is also great fear that engineered forms of poxvirus could be used as biological weapons. Therefore, monoclonal antibodies against poxvirus are in urgent need for the detection and treatment of poxvirus infection. The vaccinia virus extracellular envelope protein A33 is a potential candidate for subunit vaccine. We used multi-fluorescence-labeled tetrameric A33 antigen to identify rare poxvirus specific memory B cells from PBMC of volunteers with vaccinia virus immunization more than 40 years ago. Despite extremely low frequencies of the poxvirus specific memory B cells, we successfully sorted A33 tetramer-labeled single memory B cells and reconstructed antibodies with single-cell RT-PCR of the B-cell receptor. Among the monoclonal antibodies, one clone H2 exhibited high specificity and affinity with A33. H2 efficiently inhibited viral infection and spread in cells. Passive immunotherapy of H2 in mice protected mice from lethal infection when administered either prophylactically or therapeutically. These results suggest the potential of the anti-A33 human antibody-based detection and therapeutics for poxvirus infection.

immunology↗

From sequence to Boltzmann weighted ensemble of structures with AlphaFold2-RAVE

While AlphaFold2 is rapidly being adopted as a new standard in protein structure predictions, it is limited to single structure prediction. This can be insufficient for the inherently dynamic world of biomolecules. Even with recent modifications towards conformational diversity, AlphaFold2 is devoid of providing thermodynamically ranked conformations. AlphaFold2-RAVE is an efficient protocol using the structural outputs from AlphaFold2 as initializations for AI augmented molecular dynamics. These simulations result in Boltzmann ranked ensembles, which we demonstrate on different proteins.

biophysics↗

Intermittent systemic exposure to lipopolysaccharide-induced inflammation disrupts hippocampal long-term potentiation and impairs cognition in aging male mice

Age-related cognitive decline, a common component of the brain aging process, is associated with significant impairment in daily functioning and quality of life among geriatric adults. While the complexity of mechanisms underlying cognitive aging are still being elucidated, microbial exposure and the multifactorial inflammatory cascades associated with systemic infections is emerging as a potential driver of neurological senescence. The negative cognitive and neurobiological consequences of a single pathogen-associated inflammatory experience, such as that modeled through treatment with lipopolysaccharide (LPS), are well documented. Yet, the brain aging impacts of repeated, intermittent inflammatory challenges are less well studied. To extend the emerging literature assessing the impact of infection burden on cognitive function among normally aging mice, here, we repeatedly exposed adult mice to intermittent LPS challenges during the aging period. Male 10-month-old C57BL6 mice were systemically administered escalating doses of LPS once every two weeks for 2.5 months. We evaluated cognitive consequences using the non-spatial step-through inhibitory avoidance task and both spatial working and reference memory versions of the Morris water maze. We also probed several potential mechanisms, including cortical and hippocampal cytokine/chemokine gene expression as well as hippocampal neuronal function via extracellular field potential recordings. Though there was limited evidence for an ongoing inflammatory state in cortex and hippocampus, we observed impaired learning and memory and a disruption of hippocampal long-term potentiation. These data suggest that a history of intermittent exposure to LPS-induced inflammation is associated with a subtle but significantly accelerated trajectory of cognitive decline. The broader impact of these findings may have important implications for standard of care involving infections in aging individuals or populations at-risk for dementia.

neuroscience↗

A toxin-mediated policing system in Bacillus improves population fitness via penalizing non-cooperating phenotypic cheaters

Microbial cooperation is vulnerable to exploitation by social cheaters. Although the strategies for controlling genotypic cheaters have been well investigated, the mechanism and significance of preventing phenotypic cheating remain largely unknown. Here, we revealed the molecular mechanism and ecological significance of a policing system for punishing phenotypic cheaters in the community of a plant beneficial strain Bacillus velezensis SQR9. Coordinated activation of extracellular matrix (ECM) production and autotoxin bacillunoic acids (BAs) biosynthesis/self-immunity, punished public goods-nonproducing cheaters in strain SQR9s community. Spo0A was identified to be the co-regulator for triggering both ECM production and BAs synthesis/immunity, which activates acetyl-CoA carboxylase (ACC) to produce malonyl-CoA, an essential precursor for BAs biosynthesis, thereby stimulating BAs production and self-immunity. Elimination of phenotypic cheaters by this policing system, significantly enhanced population fitness under different stress conditions and in plant rhizosphere. This study provides insights into our understanding of maintenance and evolution of microbial cooperation.

microbiology↗

The highly conserved stem-loop II motif is important for the lifecycle of astroviruses but dispensable for SARS-CoV-2

The stem-loop II motif (s2m) is an RNA element present in viruses from divergent viral families, including astroviruses and coronaviruses, but its functional significance is unknown. We created deletions or substitutions of the s2m in astrovirus VA1 (VA1), classic human astrovirus 1 (HAstV1) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For VA1, recombinant virus could not be rescued upon partial deletion of the s2m or substitutions of G-C base pairs. Compensatory substitutions that restored the G-C base-pair enabled recovery of VA1. For HAstV1, a partial deletion of the s2m resulted in decreased viral titers compared to wild-type virus, and reduced activity in a replicon system. In contrast, deletion or mutation of the SARS-CoV-2 s2m had no effect on the ability to rescue the virus, growth in vitro, or growth in Syrian hamsters. Our study demonstrates the importance of the s2m is virus-dependent.

microbiology↗

Placental mammal derived microRNAs alter pathways in the endometrial epithelia important for endometrial function.

We tested the hypothesis that a panel of placental mammal-specific miRNAs and their targets play important to establish receptivity to implantation and their dysregulated expression may be a feature in women with early pregnancy loss. Relative expression levels of miR-340-5p, -542-3p, and -671-5p all increased following treatment of Ishikawa cells with progesterone (10 g/ml) for 24 hrs (p < 0.05). RNA sequencing of these P4-treated cells identified co-ordinate changes to 6,367 transcripts of which 1713 were predicted targets of miR-340-5p, 670 of miR-542-3p, and 618 of miR-671-5p. Quantitative proteomic analysis of Ishikawa cells transfected with mimic or inhibitor (48 hrs: n=3 biological replicates) for each of the P4-regulated miRNAs was carried out to identify targets of these miRNAs. Excluding off target effects, mir-340-5p mimic altered 1,369 proteins while inhibition changed expression of 376 proteins (p < 0.05) of which, 72 were common to both treatments. A total of 280 proteins were identified between predicted (mirDB) and confirmed (in vitro) targets. In total, 171 proteins predicted to be targets by mirDB were altered in vitro by treatment with miR-340-5p mimic or inhibitor and were also altered by treatment of endometrial epithelial cells with P4. In vitro targets of miR-542-3p identified 1,378 proteins altered by mimic while inhibition altered 975 a core of 200 proteins were changed by both. 100 protein targets were predicted and only 46 proteins were P4 regulated. miR-671-mimic altered 1,252 proteins with inhibition changing 492 proteins of which 97 were common to both, 95 were miDB predicted targets and 46 were also P4-regulated. All miRNAs were detected in endometrial biopsies taken from patients during the luteal phase of their cycle, irrespective of prior or future pregnancy outcomes Expression of mir-340-5p showed an overall increase in patients who had previously suffered a miscarriage and had a subsequent miscarriage, as compared to those who had infertility or previous miscarriage and subsequently went on to have a life birth outcome. The regulation of these miRNAs and their protein targets regulate the function of transport and secretion, and adhesion of the endometrial epithelia required for successful implantation in humans. Dysfunction of these miRNAs (and therefore the targets they regulate) may contribute to endometrial-derived recurrent pregnancy loss in women.

cell biology↗

HIV-linked gut dysbiosis associates with cytokine production capacity in viral-suppressed people living with HIV

People living with HIV (PLHIV) are exposed to chronic immune dysregulation, even when virus replication is suppressed by antiretroviral therapy (ART). Given the emerging role of the gut microbiome in immunity, we hypothesized that the gut microbiome may be related to the cytokine production capacity of PLHIV. To test this hypothesis, we collected metagenomic data from 143 ART-treated PLHIV and assessed the ex vivo production capacity of eight different cytokines (IL-1{beta}, IL-6, IL-1Ra, IL-10, IL17, IL22, TNF and IFN-{gamma}) in response to different stimuli. We also characterized CD4+ T cell-counts, HIV reservoir and other clinical parameters. Compared to 190 age- and sex-matched controls and a second independent control cohort, PLHIV showed microbial dysbiosis that was correlated with viral reservoir levels, cytokine production capacity and sexual behavior. Notably, we identified two genetically different P. copri strains that were enriched in either PLHIV or healthy controls. The control-enriched strain was negatively associated with IL-10, IL-6 and TNF production, independent of age, sex and sexual behavior, and positively associated with CD4+ T cell-level, whereas the PLHIV-enriched strain showed no associations. Our findings suggest that modulating the gut microbiome may be a strategy to modulate immune response in PLHIV. Novel PointsO_LIWe identified compositional and functional changes in the gut microbiome of PLHIV that were strongly related to sexual behavior. C_LIO_LIHIV-associated bacterial changes are negatively associated with HIV reservoir. The relative abundance of Firmicutes bacterium CAG 95 and Prevotella sp CAG 5226 both show a negative association with CD4+ T cell-associated HIV-1 DNA. C_LIO_LIPrevotella copri and Bacteroides vulgatus show association with PBMC production capacity of IL-1{beta} and IL-10 that is independent of age, sex, BMI and sexual behavior. C_LIO_LIWe observed two genetically different P. copri strains that are enriched in PLHIV and healthy individuals, respectively. C_LIO_LIThe control-related P. copri strain specifically shows a negative association with IL-10, IL-6 and TNF production and a positive association with CD4+ T cell-level. This suggests it plays a potential protective role in chronic inflammation, which may be related to enrichment of a specific epitope peptide. C_LI

microbiology↗

Mycn regulates intestinal development through ribosomal biogenesis in a zebrafish model of Feingold syndrome 1

Feingold syndrome type 1, caused by loss-of-function of MYCN, is characterized by varied phenotypes including esophageal and duodenal atresia. However, no adequate model exists for studying the syndromes pathological or molecular mechanisms, nor is there a treatment strategy. Here, we developed a zebrafish Feingold syndrome type 1 model with nonfunctional mycn, which had severe intestinal atresia. Single-cell RNA-seq identified a subcluster of intestinal cells was highly sensitive to Mycn, and impaired cell proliferation decreased the overall number of intestinal cells in the mycn mutant fish. Bulk RNA-seq and metabolomic analysis showed that expression of ribosomal genes was downregulated and amino acid metabolism was abnormal. Ribosomal profiling analysis showed decreases in free 40S, 60S, and 80S ribosome particles, which led to impaired translation in the mutant. Further, both L-leucine and Rheb, which can elevate translation via TOR pathway, rescued the intestinal phenotype of mycn mutant. In summary, by this zebrafish Feingold syndrome type 1 model, we found that disturbance of ribosomal biogenesis and blockage of protein synthesis during development are primary causes of the intestinal defect in Feingold syndrome type 1. Importantly, our work suggests that leucine supplementation may be a feasible and easy treatment option for this disease.

developmental biology↗

Structural and biochemical mechanism for increased infectivity and immune evasion of Omicron BA.1 and BA.2 variants and their mouse origins

The Omicron BA.2 variant has become a dominant infective strain worldwide. Receptor binding studies reveal that the Omicron BA.2 spike trimer have 11-fold and 2-fold higher potency to human ACE2 than the spike trimer from the wildtype (WT) and Omicron BA.1 strains. The structure of the BA.2 spike trimer complexed with human ACE2 reveals that all three receptor-binding domains (RBDs) in the spike trimer are in open conformation, ready for ACE2 binding, thus providing a basis for the increased infectivity of the BA.2 strain. JMB2002, a therapeutic antibody that was shown to have efficient inhibition of Omicron BA.1, also shows potent neutralization activities against Omicron BA.2. In addition, both BA.1 and BA.2 spike trimers are able to bind to mouse ACE2 with high potency. In contrast, the WT spike trimer binds well to cat ACE2 but not to mouse ACE2. The structures of both BA.1 and BA.2 spike trimer bound to mouse ACE2 reveal the basis for their high affinity interactions. Together, these results suggest a possible evolution pathway for Omicron BA.1 and BA.2 variants from human-cat-mouse-human circle, which could have important implications in establishing an effective strategy in combating viral infection.

biophysics↗

Expanding adult tubular microvessels on stiff substrates with endothelial cells and pericytes from the same tissue

Microvessels are essential for tissue engineering and regeneration. In current methods, endothelial cells are usually cultured in commercially available media and form a monolayer of cell sheets on stiff substrates and a tubular structure when cultured with soft hydrogels. To mimic the microvessels in vivo, researchers usually coculture the endothelial cells and pericytes from different adult tissues or derived from pluripotent stem cells in a three-dimensional hydrogel. However, there is a challenge for these models to reflect tissue-specific characteristics due to the vascular heterogeneity throughout the body. Here, we established a culture model for expanding adult tubular microvessels on stiff substrates with endothelial cells and pericytes derived from the same tissue. We isolated microvessels from adult rat subcutaneous soft connective tissue and cultured them on regular plastic dishes. We performed a series of screenings and formulated a custom-made medium (Medium-X), containing mainly antioxidants and three small molecules, Chir99021, A83-01, and Y27632. Medium-X significantly promoted adult microvessel growth while maintaining their characteristic tubular morphology up to 8 weeks in vitro, contrary to the monolayer of endothelial cell sheets in the commercially available medium EGM2MV. Transcriptomic analysis showed that Medium-X maintained the tubular morphology of microvessels by promoting angiogenesis and vascular remodeling while suppressing oxidation and lipid metabolic pathways. The model presented in this study can be applied to other organs for expanding organ-specific microvessels for tissue engineering and vascular regeneration.

bioengineering↗

Selective IL13Rα2-Targeted Functionality of IL13-Ligand CARs is Enhanced by Inclusion of 4-1BB Co-Stimulation

ABSTRACTChimeric antigen receptor (CAR) T cell immunotherapy is emerging as a powerful strategy for cancer therapy; however, an important safety consideration is the potential for off-tumor recognition of normal tissue. This is particularly important as ligand-based CARs are optimized for clinical translation. Our group has developed and clinically translated an IL13(E12Y) ligand- based CAR targeting the cancer antigen IL13R2 for treatment of glioblastoma (GBM). There remains limited understanding of how IL13-ligand CAR design impacts the activity and selectivity for the intended tumor-associated target IL13R2 versus the more ubiquitous unintended target IL13R1. In this study, we functionally compared IL13(E12Y)-CARs incorporating different intracellular signaling domains, including first-generation CD3{zeta}- containing CARs (IL13{zeta}), second-generation 4-1BB- (CD137) or CD28-containing CARs (IL13- BB{zeta} or IL13-28{zeta}), and third-generation CARs containing both 4-1BB and CD28 (IL13-28BB{zeta}). In vitro co-culture assays at high tumor burden establish that 2nd generation IL13-BB{zeta} or IL13- 28{zeta} outperform first-generation IL13{zeta} and 3rd generation IL13-28BB{zeta} CAR designs, with IL13- BB{zeta} providing superior CAR proliferation and in vivo anti-tumor potency in human xenograft mouse models. IL13-28{zeta} displayed a lower threshold for antigen recognition, resulting in higher off-target IL13R1 reactivity both in vitro and in vivo. Syngeneic mouse models of GBM also demonstrate safety and anti-tumor potency of murine IL13-BB{zeta} CAR T cells delivered systemically after lymphodepletion. These findings support the use of IL13-BB{zeta} CARs for greater selective recognition of IL13R2 over IL13R1, higher proliferative potential, and superior anti-tumor responsiveness. This study exemplifies the potential of modulating factors outside the antigen targeting domain of a CAR to improve selective tumor recognition..

immunology↗

PPML-Omics: a Privacy-Preserving federated Machine Learning system protects patients' privacy from omic data

Modern machine learning models towards various tasks with omic data analysis give rise to threats of privacy leakage of patients involved in those datasets. Despite the advances in different privacy technologies, existing methods tend to introduce too much computational cost (e.g. cryptographic methods) or noise (e.g. differential privacy), which hampers either model usefulness or accuracy in protecting privacy in biological data. Here, we proposed a secure and privacy-preserving machine learning method (PPML-Omics) by designing a decentralized version of the differential private federated learning algorithm. We applied PPML-Omics to analyze data from three sequencing technologies, and addressed the privacy concern in three major tasks of omic data, namely cancer classification with bulk RNA-seq, clustering with single-cell RNA-seq, and the integration of spatial gene expression and tumour morphology with spatial transcriptomics, under three representative deep learning models. We also examined privacy breaches in depth through privacy attack experiments and demonstrated that PPML-Omics could protect patients privacy. In each of these applications, PPML-Omics was able to outperform methods of comparison under the same level of privacy guarantee, demonstrating the versatility of the method in simultaneously balancing the privacy-preserving capability and utility in practical omic data analysis. Furthermore, we gave the theoretical proof of the privacy-preserving capability of PPML-Omics, suggesting the first mathematically guaranteed method with robust and generalizable empirical performance in protecting patients privacy in omic data.

bioinformatics↗

Influence of residual microbial nucleic acid in instruments for hip joint arthroplasty on false-positive results of metagenomic sequencing

The purpose of this study was to analyze the effect of residual microbial nucleic acid in instruments for hip joint arthroplasty on false-positive sequencing results. Samples were taken from 3 different acetabular reamer for hip arthroplasty in 7 different hospitals. The whole process was strictly aseptic, metagenomic next-generation sequencing (mNGS) was performed according to standard operating procedures. The sterility of instruments was confirmed by culture method. The sequencing results of specimens from different hospitals were compared to analyze the difference of background bacteria. Bioinformatics analysis and visualization were presented through R language. A total of 26 samples were processed by mNGS, including 24 instrument swab samples, 1 blank swab control, and 1 blank water control. 254,314,707 reads were sequenced in all samples. The results showed that 1.13% of Clean Reads can be matched to pathogenic microorganism genomes, of which bacterial sequences account for 87.48%, fungal sequences account for 11.18%, parasite sequences account for 1.26%, and virus sequences account for 0.06%. The results of PCA (Principal Component Analysis) demonstrated that the distribution of bacteria on the surface of instruments was significantly different between medical institutions. Through the Venn diagram, it was found that 465 species of bacteria in all region hospitals, Liaocheng Peoples Hospital had a maximum of 340 species of bacteria, followed by Guanxian County Peoples Hospital with 169 species. The clustering heat map illustrated that the distribution of bacterial groups in three different instrument samples in the same hospital was basically the same, and the bacterial genera varied significantly among hospitals. The residual microbial nucleic acid fragments are mainly bacterial DNA and represent differences in different medical institutions, The establishment of independent background bacterial libraries in different medical institutions can effectively improve the accuracy of mNGS diagnosis and help to exclude background microorganisms interference.

genomics↗

Prevalence of Bourbon and Heartland viruses in field collected ticks at an environmental field station in St. Louis County, Missouri, USA

Heartland and Bourbon viruses are pathogenic tick-borne viruses putatively transmitted by Amblyomma americanum, an abundant tick species in Missouri. To assess the prevalence of these viruses in ticks, we collected 2778 ticks from 8 sampling sites at Tyson Research Center, an environmental field station within St. Louis County and close to the City of St. Louis, from May - July in 2019 and 2021. Ticks were pooled according to life stage and sex, grouped by year and sampling site to create 355 pools and screened by RT-qPCR for Bourbon and Heartland viruses. Overall, 14 (3.9%) and 27 (7.6%) of the pools were positive for Bourbon virus and Heartland virus respectively. In 2019, 11 and 23 pools were positive for Bourbon and Heartland viruses respectively. These positives pools were of males, females and nymphs. In 2021, there were 4 virus positive pools out of which 3 were positive for both viruses and were comprised of females and nymphs. Five out of the 8 sampling sites were positive for at least one virus. This included a site that was positive for both viruses in both years. Detection of these viruses in an area close to a relatively large metropolis presents a greater public health threat than previously thought.

microbiology↗

Live-cell RNA imaging with metabolically incorporated fluorescent nucleosides

Fluorescence imaging is a powerful method for probing macromolecular dynamics in biological systems, however approaches for cellular RNA imaging are limited to the investigation of individual RNA constructs or bulk RNA labeling methods compatible primarily with fixed samples. Here, we develop a platform for fluorescence imaging of bulk RNA dynamics in living cells. We show that fluorescent bicyclic and tricyclic cytidine analogues can be metabolically incorporated into cellular RNA by overexpression of uridine-cytidine kinase 2 (UCK2). In particular, metabolic feeding with the tricyclic cytidine-derived nucleoside tC combined with quantitative confocal imaging enables the investigation of RNA synthesis, degradation, and trafficking at single-cell resolution. We apply our imaging modality to study RNA metabolism and localization during the oxidative stress response and find that bulk RNA turnover is greatly accelerated upon NaAsO2 treatment. Further, we identify cytoplasmic RNA granules containing RNA transcripts generated during oxidative stress that are distinct from canonical stress granules and P-bodies and co-localize with the RNA helicase DDX6. Taken together, our work provides a powerful approach for live-cell RNA imaging and reveals how cells reshape RNA transcriptome dynamics in response to oxidative stress.

biochemistry↗

Associations between locus coeruleus MRI contrast and physiological responses to acute stress in younger and older adults

Acute stress activates the brains locus coeruleus (LC)-noradrenaline system. Recent studies indicate that a magnetic resonance imaging (MRI)-based measure of LC structure is associated with better cognitive outcomes in later life. Yet despite the LCs documented role in promoting physiological arousal during acute stress, no studies have examined whether MRI-assessed LC structure is related to arousal responses to acute stress. In this study, 102 younger and 51 older adults completed an acute stress induction task while we assessed multiple measures of physiological arousal (heart rate, breathing rate, systolic and diastolic blood pressure, sympathetic tone, and heart rate variability, HRV). We used turbo spin echo MRI scans to quantify LC MRI contrast as a measure of LC structure. We applied univariate and multivariate approaches to assess how LC MRI contrast was associated with arousal at rest and during acute stress reactivity and recovery. In older participants, having higher caudal LC MRI contrast was associated with greater stress-related increases in systolic blood pressure and decreases in HRV, as well as lower HRV during recovery from acute stress. These results suggest that having higher caudal LC MRI contrast in older adulthood is associated with more pronounced physiological responses to acute stress. Further work is needed to confirm these patterns in larger samples of older adults.

neuroscience↗

Effect of GDF15 on acetaminophen (APAP)-induced liver injury in mice

Acetaminophen (APAP)-induced liver injury (AILI) has been recognized as a pivotal contributor to drug-induced liver failure in western countries, but its molecular mechanism remains poorly understood. After data mining using the Gene Expression Omnibus (GEO) database, we found that the gene expression of growth differentiation factor 15 (GDF15) increased significantly after APAP-induced hepatotoxicity in mouse liver. However, the precise role of GDF15 in AILI has yet to be clarified. To deal with this question, we first examined the temporal gene expression pattern of GDF15 after APAP treatment. Next, overexpression of hepatic GDF15 using adeno-associated virus serotype 8 (AAV8) was employed to investigate the role of GDF15 in AILI. In addition, therapeutic administration of recombinant human GDF15 (rhGDF15) was conducted to probe its curative effect after APAP overdose. We observed that protein expression of GDF15 was significantly increased after APAP overdose. However, there were no significant differences in AILI-related outcomes after overexpression or supplementation of GDF15. The contents of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), morphological feature of liver, the level of reduced form of glutathione (GSH), the activation of c-Jun-N-terminal kinase (JNK), the expression of genes relevant to oxidative stress and cell proliferation were not remarkably changed between AAV8-GFP and AAV8-Gdf15 groups. Although the liver injury was not improved by rhGDF15 administration, the gene expression levels of glutamate-cysteine ligase modifier subunit (Gclm) and glutamate-cysteine ligase catalytic subunit (Gclc) which function downstream of Nrf2 signaling pathway were significantly increased. Altogether, despite a noticeable elevated expression after APAP overdose, GDF15 overexpression or supplementation exerted no significant ameliorative effect on AILI. Further mechanism and consequence of Gclm and Gclc elevation by GDF15 remains to be elucidated.

pharmacology and toxicology↗