Metabolic Engineering of Candida tropicalis for the De Novo Synthesis of ß-Ionone.

ß-ionone, a norisoprenoid, is a natural aromatic compound derived from plants, which displays various biological activities including anticancer, antioxidant and deworming properties. Due to its large biomass and strong environmental tolerance, the nonconventional oleaginous yeast Candida tropicalis was selected to efficiently synthesize ß-ionone. We initially investigated the capacity of the cytoplasm and subcellular compartments to synthesize ß-ionone independently. Subsequently, through adaptive screening of enzymes, functional identification of subcellular localization signal peptides and subcellular compartment combination strategies, a titer of 152.4 mg/L of ß-ionone was achieved. Finally, directed evolution of rate-limiting enzyme and overexpression of key enzymes were performed to enhance ß-ionone production. The resulting titer was 400.5 mg/L in shake flasks and 730 mg/L in a bioreactor. This study demonstrates the first de novo synthesis of ß-ionone in C. tropicalis, providing a novel cellular chassis for terpenoid fragrances with considerable industrial potential.

Transitioning weathered oil fields towards new energy: A review on utilizing hydrogenotrophic methanogens for petroleum hydrocarbons remediation.

The weathering process can cause the volatilization of light components in crude oil, leading to the accumulation of total petroleum hydrocarbons (TPH) in weathered oil field soils. These TPH compounds are relatively resistant to biodegradation, posing a significant environmental hazard by contributing to soil degradation. TPH represents a complex mixture of petroleum-based hydrocarbons classified as persistent organic pollutants in soil and groundwater. The release of TPH pollutants into the environment poses serious threats to ecosystems and human health. Currently, various methods are available for TPH-contaminated soil remediation, with bioremediation technology recognized as an environmentally friendly and cost-effective approach. While converting TPH to CO2 is a common remediation method, the complex structures and diverse types of petroleum hydrocarbons (PHs) involved can result in excessive CO2 generation, potentially exacerbating the greenhouse effect. Alternatively, transforming TPH into energy forms like methane through bioremediation, followed by collection and reuse, can reduce greenhouse gas emissions and energy consumption. This process relies on the synergistic interaction between Methanogens archaea and syntrophic bacteria, forming a consortium known as the oil-degrading bacterial consortium. Methanogens produce methane through anaerobic digestion (AD), with hydrogenotrophic methanogens (HTMs) utilizing H2 as an electron donor, playing a crucial role in biomethane production. Candidatus Methanoliparia (Ca. Methanoliparia) was found in the petroleum archaeal community of weathered Oil field in northeast China. Ca. Methanoliparia has demonstrated its independent ability to decompose and produce new energy (biomethane) without symbiosis, contribute to transitioning weathered oil fields towards new energy. Therefore, this review focuses on the principles, mechanisms, and developmental pathways of HTMs during new energy production in the degradation of PHs. It also discusses strategies to enhance TPH degradation and recovery methods.

Trinitarian Design of Gradient Artificial Interphase Enables Colossal Granular Li Deposits for Stable Li-Metal Batteries.

The cycling lifespan of Li-metal batteries is compromised by the unstable solid electrolyte interphase (SEI) and the continuous Li dendrites, restricting their practical implementations. Given these challenges, establishing an artificial SEI holds promise. Herein, a trinitarian gradient interphase is innovatively designed through composite coatings of magnesium fluoride (MgF2), N-hexadecyltrimethylammonium chloride (CTAC), and polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) on Li-metal anode (LMA). Specifically, the MgF2/CTAC/PVDF-HFP SEI spontaneously forms a lithium fluoride (LiF)-rich PVDF-HFP-based SEI, along with lithium-magnesium (Li-Mg) alloy substrate as lithiophilic electronic conductor and positively charged CTAC during plating. Noticeably, the Li-Mg alloy homogenizes the distribution of electric field and reduce the internal resistance, while the electronically insulated LiF/PVDF-HFP composite SEI offers fast ion-conducting and mechanical flexibility, accommodating the volumetric expansion and ensuring stable Li-ion flux. Additionally, CTAC at the dendritic tip is pivotal for mitigating dendrites through its electrostatic shield mechanism. Innovatively, this trinitarian synergistic mechanism, which facilitates colossal granular Li deposits, constructs a dendrite-free LMA, leading to stable cycling performances in practical Li||LFP, popular Li||NCM811, and promising Li||S full cells. This work demonstrates the design of multifunctional composite SEI for comprehensive Li protection, thereby inspiring further advancements in artificial SEI engineering for alkali-metal batteries.

Glucose regulation of adipose tissue browning by CBP/p300- and HDAC3-mediated reversible acetylation of CREBZF.

Glucose is required for generating heat during cold-induced nonshivering thermogenesis in adipose tissue, but the regulatory mechanism is largely unknown. CREBZF has emerged as a critical mechanism for metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD). We investigated the roles of CREBZF in the control of thermogenesis and energy metabolism. Glucose induces CREBZF in human white adipose tissue (WAT) and inguinal WAT (iWAT) in mice. Lys208 acetylation modulated by transacetylase CREB-binding protein/p300 and deacetylase HDAC3 is required for glucose-induced reduction of proteasomal degradation and augmentation of protein stability of CREBZF. Glucose induces rectal temperature and thermogenesis in white adipose of control mice, which is further potentiated in adipose-specific CREBZF knockout (CREBZF FKO) mice. During cold exposure, CREBZF FKO mice display enhanced thermogenic gene expression, browning of iWAT, and adaptive thermogenesis. CREBZF associates with PGC-1α to repress thermogenic gene expression. Expression levels of CREBZF are negatively correlated with UCP1 in human adipose tissues and increased in WAT of obese ob/ob mice, which may underscore the potential role of CREBZF in the development of compromised thermogenic capability under hyperglycemic conditions. Our results reveal an important mechanism of glucose sensing and thermogenic inactivation through reversible acetylation.

ChemR23 signaling ameliorates brain injury via inhibiting NLRP3 inflammasome-mediated neuronal pyroptosis in ischemic stroke.

BACKGROUND: Inflammatory response has been recognized as a pivotal pathophysiological process during cerebral ischemia. ChemR23 signaling is involved in the pathophysiology of various inflammatory diseases. Nevertheless, the role of ChemR23 signaling in ischemic stroke remains largely unknown. METHODS: Permanent ischemic stroke mouse model was accomplished by middle cerebral artery occlusion (MCAO). Resolvin E1 (RvE1) or chemerin-9 (C-9), the agonists of ChemR23, were administered by intracerebroventricular (i.c.v) injection before MCAO induction. Then, analysis of neurobehavioral deficits and brain sampling were done at Day 1 after MCAO. The brain samples were further analyzed by histological staining, immunofluorescence, RNA sequencing, ELISA, transmission electron microscope, and western blots. Furthermore, oxygen-glucose deprivation (OGD) was employed in SH-SY5Y to mimic MCAO in vitro, and ChemR23 signaling pathway was further studied by overexpression of ChemR23 or administration of related agonists or antagonists. Analysis of cell death and related pathway markers were performed. RESULTS: ChemR23 expression was upregulated following MCAO. Under in vitro and in vivo ischemic conditions, ChemR23 deficiency or inhibition contributed to excessive NLRP3-mediated maturation and release of IL-1ß and IL-18, as well as enhanced cleavage of GSDMD-N and neuronal pyroptosis. These influences ultimately aggravated brain injury and neuronal damage. On the other hand, ChemR23 activation by RvE1 or C-9 mitigated the above pathophysiological abnormalities in vivo and in vitro, and overexpression of ChemR23 in SH-SY5Y cells also rescued OGD-induced neuronal pyroptosis. Blockade of NLRP3 mimics the protective effects of ChemR23 activation in vitro. CONCLUSION: Our data indicated that ChemR23 modulates NLRP3 inflammasome-mediated neuronal pyroptosis in ischemic stroke. Activation of ChemR23 may serve as a promising potential target for neuroprotection in cerebral ischemia.

Macrophage CREBZF Orchestrates Inflammatory Response to Potentiate Insulin Resistance and Type 2 Diabetes.

Chronic adipose tissue inflammation accompanied by macrophage accumulation and activation is implicated in the pathogenesis of insulin resistance and type 2 diabetes in humans. The transcriptional coregulator CREBZF is a key factor in hepatic metabolism, yet its role in modulating adipose tissue inflammation and type 2 diabetes remains elusive. The present study demonstrates that overnutrition-induced CREBZF links adipose tissue macrophage (ATM) proinflammatory activation to insulin resistance. CREBZF deficiency in macrophages, not in neutrophils, attenuates macrophage infiltration in adipose, proinflammatory activation, and hyperglycemia in diet-induced insulin-resistant mice. The coculture assays show that macrophage CREBZF deficiency improves insulin sensitivity in primary adipocytes and adipose tissue. Mechanistically, CREBZF competitively inhibits the binding of IκBα to p65, resulting in enhanced NF-κB activity. In addition, bromocriptine is identified as a small molecule inhibitor of CREBZF in macrophages, which suppresses the proinflammatory phenotype and improves metabolic dysfunction. Furthermore, CREBZF is highly expressed in ATM of obese humans and mice, which is positively correlated with proinflammatory genes and insulin resistance in humans. This study identifies a previously unknown role of CREBZF coupling ATM activation to systemic insulin resistance and type 2 diabetes.

RIPK1 plays a crucial role in maintaining regulatory T-Cell homeostasis by inhibiting both RIPK3- and FADD-mediated cell death.

Regulatory T (Treg) cells play an essential role in maintaining immune balance across various physiological and pathological conditions. However, the mechanisms underlying Treg homeostasis remain incompletely understood. Here, we report that RIPK1 is crucial for Treg cell survival and homeostasis. We generated mice with Treg cell-specific ablation of Ripk1 and found that these mice developed fatal systemic autoimmunity due to a dramatic reduction in the Treg cell compartment caused by excessive cell death. Unlike conventional T cells, Treg cells with Ripk1 deficiency were only partially rescued from cell death by blocking FADD-dependent apoptosis. However, simultaneous removal of both Fadd and Ripk3 completely restored the homeostasis of Ripk1-deficient Treg cells by blocking two cell death pathways. Thus, our study highlights the critical role of RIPK1 in regulating Treg cell homeostasis by controlling both apoptosis and necroptosis, thereby providing novel insights into the mechanisms of Treg cell homeostasis.

ABIN1 (Q478) is Required to Prevent Hematopoietic Deficiencies through Regulating Type I IFNs Expression.

A20-binding inhibitor of NF-κB activation (ABIN1) is a polyubiquitin-binding protein that regulates cell death and immune responses. Although Abin1 is located on chromosome 5q in the region commonly deleted in patients with 5q minus syndrome, the most distinct of the myelodysplastic syndromes (MDSs), the precise role of ABIN1 in MDSs remains unknown. In this study, mice with a mutation disrupting the polyubiquitin-binding site (Abin1Q478H/Q478H ) is generated. These mice develop MDS-like diseases characterized by anemia, thrombocytopenia, and megakaryocyte dysplasia. Extramedullary hematopoiesis and bone marrow failure are also observed in Abin1Q478H/Q478H mice. Although Abin1Q478H/Q478H cells are sensitive to RIPK1 kinase-RIPK3-MLKL-dependent necroptosis, only anemia and splenomegaly are alleviated by RIPK3 deficiency but not by MLKL deficiency or the RIPK1 kinase-dead mutation. This indicates that the necroptosis-independent function of RIPK3 is critical for anemia development in Abin1Q478H/Q478H mice. Notably, Abin1Q478H/Q478H mice exhibit higher levels of type I interferon (IFN-I) expression in bone marrow cells compared towild-type mice. Consistently, blocking type I IFN signaling through the co-deletion of Ifnar1 greatly ameliorated anemia, thrombocytopenia, and splenomegaly in Abin1Q478H/Q478H mice. Together, these results demonstrates that ABIN1(Q478) prevents the development of hematopoietic deficiencies by regulating type I IFN expression.

MLKL deficiency alleviates neuroinflammation and motor deficits in the α-synuclein transgenic mouse model of Parkinson's disease.

Parkinson's disease (PD), one of the most devastating neurodegenerative brain disorders, is characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN) and deposits of α-synuclein aggregates. Currently, pharmacological interventions for PD remain inadequate. The cell necroptosis executor protein MLKL (Mixed-lineage kinase domain-like) is involved in various diseases, including inflammatory bowel disease and neurodegenerative diseases; however, its precise role in PD remains unclear. Here, we investigated the neuroprotective role of MLKL inhibition or ablation against primary neuronal cells and human iPSC-derived midbrain organoids induced by toxic α-Synuclein preformed fibrils (PFFs). Using a mouse model (Tg-Mlkl-/-) generated by crossbreeding the SNCA A53T synuclein transgenic mice with MLKL knockout (KO)mice, we assessed the impact of MLKL deficiency on the progression of Parkinsonian traits. Our findings demonstrate that Tg-Mlkl-/- mice exhibited a significant improvement in motor symptoms and reduced phosphorylated α-synuclein expression compared to the classic A53T transgenic mice. Furthermore, MLKL deficiency alleviated tyrosine hydroxylase (TH)-positive neuron loss and attenuated neuroinflammation by inhibiting the activation of microglia and astrocytes. Single-cell RNA-seq (scRNA-seq) analysis of the SN of Tg-Mlkl-/- mice revealed a unique cell type-specific transcriptome profile, including downregulated prostaglandin D synthase (PTGDS) expression, indicating reduced microglial cells and dampened neuron death. Thus, MLKL represents a critical therapeutic target for reducing neuroinflammation and preventing motor deficits in PD.

Triggering endogenous Z-RNA sensing for anti-tumor therapy through ZBP1-dependent necroptosis.

ZBP1 senses viral Z-RNAs to induce necroptotic cell death to restrain viral infection. ZBP1 is also thought to recognize host cell-derived Z-RNAs to regulate organ development and tissue inflammation in mice. However, it remains unknown how the host-derived Z-RNAs are formed and how these endogenous Z-RNAs are sensed by ZBP1. Here, we report that oxidative stress strongly induces host cell endogenous Z-RNAs, and the Z-RNAs then localize to stress granules for direct sensing by ZBP1 to trigger necroptosis. Oxidative stress triggers dramatically increase Z-RNA levels in tumor cells, and the Z-RNAs then directly trigger tumor cell necroptosis through ZBP1. Localization of the induced Z-RNAs to stress granules is essential for ZBP1 sensing. Oxidative stress-induced Z-RNAs significantly promote tumor chemotherapy via ZBP1-driven necroptosis. Thus, our study identifies oxidative stress as a critical trigger for Z-RNA formation and demonstrates how Z-RNAs are directly sensed by ZBP1 to trigger anti-tumor necroptotic cell death.

Excessive apoptosis of Rip1-deficient T cells leads to premature aging.

In mammals, the most remarkable T cell variations with aging are the shrinking of the naïve T cell pool and the enlargement of the memory T cell pool, which are partially caused by thymic involution. However, the mechanism underlying the relationship between T-cell changes and aging remains unclear. In this study, we find that T-cell-specific Rip1 KO mice show similar age-related T cell changes and exhibit signs of accelerated aging-like phenotypes, including inflammation, multiple age-related diseases, and a shorter lifespan. Mechanistically, Rip1-deficient T cells undergo excessive apoptosis and promote chronic inflammation. Consistent with this, blocking apoptosis by co-deletion of Fadd in Rip1-deficient T cells significantly rescues lymphopenia, the imbalance between naïve and memory T cells, and aging-like phenotypes, and prolongs life span in T-cell-specific Rip1 KO mice. These results suggest that the reduction and hyperactivation of T cells can have a significant impact on organismal health and lifespan, underscoring the importance of maintaining T cell homeostasis for healthy aging and prevention or treatment of age-related diseases.

Vemurafenib inhibits necroptosis in normal and pathological conditions as a RIPK1 antagonist.

Necroptosis, a programmed cell death with necrotic-like morphology, has been recognized as an important driver in various inflammatory diseases. Inhibition of necroptosis has shown potential promise in the therapy of multiple human diseases. However, very few necroptosis inhibitors are available for clinical use as yet. Here, we identified an FDA-approved anti-cancer drug, Vemurafenib, as a potent inhibitor of necroptosis. Through direct binding, Vemurafenib blocked the kinase activity of receptor-interacting protein kinases 1 (RIPK1), impeded the downstream signaling and necrosome complex assembly, and inhibited necroptosis. Compared with Necrostain-1, Vemurafenib stabilized RIPK1 in an inactive DLG-out conformation by occupying a distinct allosteric hydrophobic pocket. Furthermore, pretreatment with Vemurafenib provided strong protection against necroptosis-associated diseases in vivo. Altogether, our results demonstrate that Vemurafenib is an effective RIPK1 antagonist and provide rationale and preclinical evidence for the potential application of approved drug in necroptosis-related diseases.

A Visual Color Response Test Paper for the Detection of Hydrogen Sulfide Gas in the Air.

Hydrogen sulfide (H2S) is widely found in oil and natural gas wells and industrial wastewater tanks. Owing to its high toxicity, the monitoring and detection of H2S in the air is essential. However, recent techniques for the quantitative detection of H2S gas suffer from limitations such as high cost, complicated operation, and insufficient sensitivity, preventing their practical application in industry. Thus, we have developed a portable test paper for real-time and inexpensive monitoring of H2S gas by color changes. The test paper had a significantly low H2S detection limit of 200 ppb, which is considered safe for humans. Moreover, the color of the test paper did not change noticeably when exposed to CO2, N2, O2, and air environments, indicating that the test paper is selective for H2S gas and can be stored for a long time. In addition, we fitted a color difference linear model between the color difference values (ΔE) and the concentrations of H2S gas. The establishment of the linear model substantiates that the test paper can provide accurate intensity information when detecting H2S gas leakage.

High-Strength Double-Network Conductive Hydrogels Based on Polyvinyl Alcohol and Polymerizable Deep Eutectic Solvent.

Conductive hydrogels feature the flexibility of soft materials plus conductive properties providing functionality for effectively sticking to the epidermis and detecting human activity signals. Their stable electrical conductivity also effectively avoids the problem of uneven distribution of solid conductive fillers inside traditional conductive hydrogels. However, the simultaneous integration of high mechanical strength, stretchability, and transparency through a simple and green fabrication method remains a great challenge. Herein, a polymerizable deep eutectic solvent (PDES) composed of choline chloride and acrylic acid was added to a biocompatible PVA matrix. The double-network hydrogels were then simply prepared by thermal polymerization and one freeze-thaw method. The introduction of the PDES significantly improved the tensile properties (1.1 MPa), ionic conductivity (2.1 S/m), and optical transparency (90%) of the PVA hydrogels. When the gel sensor was fixed to human skin, real-time monitoring of a variety of human activities could be implemented with accuracy and durability. Such a simple preparation method performed by combining a deep eutectic solvent with traditional hydrogels offers a new avenue to construct multifunctional conductive hydrogel sensors with excellent performance.

Non-invasive detection and differentiation of apoptotic and necroptotic cell death in vitro.

Cell death plays an important role in the development of multicellular organisms and the maintenance of adult homeostasis. However, traditional methods of cell death detection can damage cells and tissues. Here, we report the use of near-infrared (NIR) spectroscopy for non-invasively distinguishing between cell death types. We found a difference between normal, apoptotic, and necroptotic mouse dermal fibroblast cells in the wavelength range of 1100-1700 nm. In particular, the differences in scattering of NIR light between cells at different states are enough to be distinguished. This feature was exploited by measuring the attenuation coefficient (δµ), which specifies the ease at which light can pass through a substance. The results showed that δµ can be used to distinguish between different types of cell death. Therefore, this study proposes a new, non-invasive, and fast method to differentiate cell death types without the additional fluorescent labeling.

Proline hydroxylation of CREB-regulated transcriptional coactivator 2 controls hepatic glucose metabolism.

Prolyl hydroxylase domain (PHD) enzymes change HIF activity according to oxygen signal; whether it is regulated by other physiological conditions remains largely unknown. Here, we report that PHD3 is induced by fasting and regulates hepatic gluconeogenesis through interaction and hydroxylation of CRTC2. Pro129 and Pro615 hydroxylation of CRTC2 following PHD3 activation is necessary for its association with cAMP-response element binding protein (CREB) and nuclear translocation, and enhanced binding to promoters of gluconeogenic genes by fasting or forskolin. CRTC2 hydroxylation-stimulated gluconeogenic gene expression is independent of SIK-mediated phosphorylation of CRTC2. Liver-specific knockout of PHD3 (PHD3 LKO) or prolyl hydroxylase-deficient knockin mice (PHD3 KI) show attenuated fasting gluconeogenic genes, glycemia, and hepatic capacity to produce glucose during fasting or fed with high-fat, high-sucrose diet. Importantly, Pro615 hydroxylation of CRTC2 by PHD3 is increased in livers of fasted mice, diet-induced insulin resistance or genetically obese ob/ob mice, and humans with diabetes. These findings increase our understanding of molecular mechanisms linking protein hydroxylation to gluconeogenesis and may offer therapeutic potential for treating excessive gluconeogenesis, hyperglycemia, and type 2 diabetes.

Lipopolysaccharide and Glycolipoprotein Coordinately Triggered Necroptosis Contributes to the Pathogenesis of Leptospira Infection in Mice.

Leptospirosis is a recurring but neglected zoonotic disease caused by pathogenic Leptospira. The explicit underlying mechanism of necroptosis and its role in Leptospira infection have not yet been elucidated. Here we reported that leptospiral pathogen-associated molecular patterns, lipopolysaccharide, and glycolipoprotein activate the necroptotic RIPK1-RIPK3-MLKL cascade through the TLR4 signaling pathway in mouse macrophages. Using the murine acute leptospirosis model, we reveal that abolition of necroptosis exhibited significantly improved outcomes in acute phases, with enhanced eradication of Leptospira from liver, mild clinical symptoms, and decreased cytokine production. RIPK3 was also found to exert a necroptosis-independent function in CXCL1 production and neutrophil recruitment, with the consequence of improved Leptospira control. These findings improve our understanding of the mechanism of Leptospira-macrophage interactions, indicating potential therapeutic values by targeting necroptosis signaling pathways.

Single-cell and spatially resolved transcriptomics for liver biology.

Single-cell transcriptomics enables the identification of rare cell types and the inference of state transitions, whereas spatially resolved transcriptomics allows the quantification of cells and genes in the context of tissues. The recent progress in these new technologies is improving our understanding of the cell landscape and its roles in diseases. Here, we review key biological insights into liver homeostasis, development, regeneration, chronic liver disease, and cancer obtained from single-cell and spatially resolved transcriptomics. We highlight recent progress in the liver cell atlas that characterizes the comprehensive cellular composition; diversity and function; the spatial architecture such as liver zonation, cell communication, and proximity; the cell identity conversion and cell-specific alterations that are associated with liver pathology; and new therapeutic targets. We further discuss outstanding challenges, advanced experimental technologies, and computational methods that help to address these challenges.

Reversible Facet Reconstruction of CdSe/CdS Core/Shell Nanocrystals by Facet-Ligand Pairing.

Synthesis of colloidal semiconductor nanocrystals with defined facet structures is challenging, though such nanocrystals are essential for fully realizing their size-dependent optical and optoelectronic properties. Here, for the mostly developed colloidal wurtzite CdSe/CdS core/shell nanocrystals, facet reconstruction is investigated under typical synthetic conditions, excluding nucleation, growth, and interparticle ripening. Within the reaction time window, two reproducible sets of facets─each with a specific group of low-index facets─can be reversibly reconstructed by switching the ligand system, indicating thermodynamic stability of each set. With a unique <0001> axis, atomic structures of the low-index facets of wurtzite nanocrystals are diverse. Experimental and theoretical studies reveal that each facet in a given set is paired with a common ligand in the solution, namely, either fatty amine and/or cadmium alkanoate. The robust bonding modes of ligands are found to be strongly facet-dependent and often unconventional, instead of following Green's classification. Results suggest that facet-controlled nanocrystals can be synthesized by optimal facet-ligand pairing either in synthesis or after-synthesis reconstruction, implying semiconductor nanocrystal formation with size-dependent properties down to an atomic level.

Intrahepatic osteopontin signaling by CREBZF defines a checkpoint for steatosis-to-NASH progression.

BACKGROUND AND AIMS: NASH has emerged as a leading cause of chronic liver disease. However, the mechanisms that govern NASH fibrosis remain largely unknown. CREBZF is a CREB/ATF bZIP transcription factor that causes hepatic steatosis and metabolic defects in obesity. APPROACH AND RESULTS: Here, we show that CREBZF is a key mechanism of liver fibrosis checkpoint that promotes hepatocyte injury and exacerbates diet-induced NASH in mice. CREBZF deficiency attenuated liver injury, fibrosis, and inflammation in diet-induced mouse models of NASH. CREBZF increases HSC activation and fibrosis in a hepatocyte-autonomous manner by stimulating an extracellular matrix protein osteopontin, a key regulator of fibrosis. The inhibition of miR-6964-3p mediates CREBZF-induced production and secretion of osteopontin in hepatocytes. Adeno-associated virus -mediated rescue of osteopontin restored HSC activation, liver fibrosis, and NASH progression in CREBZF-deficient mice. Importantly, expression levels of CREBZF are increased in livers of diet-induced NASH mouse models and humans with NASH. CONCLUSIONS: Osteopontin signaling by CREBZF represents a previously unrecognized intrahepatic mechanism that triggers liver fibrosis and contributes to the severity of NASH.