Better biocompatibility of nitrogen-doped graphene compared with graphene oxide by reducing cell autophagic flux blockage and cell apoptosis

Nitrogen-doped graphene (C2 N), a novel graphene-based materials, has been proposed as a potential alternative to graphene oxide (GO) in biomedical applications. However, due to the challenges in synthesizing C2 N, reports in the biomedical field are currently rare. Here, we have modified the reported procedure and successfully synthesized C2 N nanoparticles at 120°C, which we refer to as C2 N-120. The toxicity and biocompatibility of GO and C2 N-120 were evaluated using a mouse model injected with GO/C2 N-120 via the tail vein, as well as cell models treated with GO/C2 N-120. In vivo studies revealed that GO/C2 N-120 showed similar distribution patterns after tail vein injection. The liver, spleen, and lung are the major nanoparticle uptake organs of GO and C2 N-120. However, GO deposition in the major nanoparticle uptake organs was more significant than that of C2 N-120. In addition, GO deposition caused structural abnormalities, increased apoptotic cells, and enhanced macrophage infiltration whereas C2 N-120 exhibited fewer adverse effects. In vitro experiments were conducted using different cell lines treated with GO/C2 N-120. Unlike GO which induced mitochondrial damage, oxidative stress, inflammatory response, autophagic flux blockage and cell apoptosis, C2 N-120 showed lower cytotoxicity in cell models. Our data demonstrated that C2 N-120 exhibits higher biocompatibility than GO, both in vivo and in vitro, suggesting its potential for biomedical application in the future.

Fabrication of OVs enriched BiOCl microflowers doped with Fe3+ for effective destruction of two typical contaminants

In this study, a one-step solvothermal method was used to fabricate Fe3+ doped BiOCl microflowers with abundant oxygen vacancies (OVs) in the presence of glacial acetic acid. Various analytical techniques were employed to characterize the structural, morphological, and optical properties of the prepared samples. The presence of OVs was confirmed by low temperature electron paramagnetic resonance (EPR) analysis. The photocatalytic results show that Fe3+ doped BiOCl photocatalysts have higher activity than the bare BiOCl, and 10% Fe3+/BiOCl exhibits the highest photocatalytic performance, the photocatalytic efficiency of this sample is 2.3 and 1.1 times higher than that of the blank BiOCl toward photocatalytic degradation of perfluorooctanoic acid (PFOA) and rhodamine B (RhB), respectively. Furthermore, Fe3+ doped BiOCl demonstrates excellent reusability. Based on the experimental observations, an enhancement mechanism for the photocatalytic activity of Fe3+ doped BiOCl was reasonably elucidated.

Autonomous nanorobots with powerful thrust under dry solid-contact conditions by photothermal shock

Nanorobotic motion on solid substrates is greatly hindered by strong nanofriction, and powerful nanomotors‒the core components for nanorobotic motion‒are still lacking. Optical actuation addresses power and motion control issues simultaneously, while conventional technologies with small thrust usually apply to fluid environments. Here, we demonstrate micronewton-thrust nanomotors that enable the autonomous nanorobots working like conventional robots with precise motion control on dry surfaces by a photothermal-shock technique. We build a pulsed laser-based actuation and trapping platform, termed photothermal-shock tweezers, for general motion control of metallic nanomaterials and assembled nanorobots with nanoscale precision. The thrust-to-weight ratios up to 107 enable nanomotors output forces to interact with external micro/nano-objects. Leveraging machine vision and deep learning technologies, we assemble the nanomotors into autonomous nanorobots with complex structures, and demonstrate multi-degree-of-freedom motion and sophisticated functions. Our photothermal shock-actuation concept fundamentally addresses the nanotribology challenges and expands the nanorobotic horizon from fluids to dry solid surfaces.

2, 2-dimethylthiazolidine hydrochloride protects against experimental contrast-induced acute kidney injury via inhibition of tubular ferroptosis

Contrast-induced acute kidney injury (CI-AKI) has become the third leading cause of AKI acquired in hospital, lacking of effective interventions. In the study, we identified the renal beneficial role of 2, 2-dimethylthiazolidine hydrochloride (DMTD), a safer compound which is readily hydrolyzed to cysteamine, in the rodent model of CI-AKI. Our data showed that administration of DMTD attenuated the impaired renal function and tubular injury induced by the contrast agent. Levels of MDA, 4-hydroxynonenal, ferrous iron and morphological signs showed that contrast agent induced ferroptosis, which could be inhibited in the DMTD group. In vitro, DMTD suppressed ferroptosis induced by ioversol in the cultured tubular cells. Treatment of DMTD upregulated glutathione (GSH) and glutathione peroxidase 4 (GPX4). Moreover, we found that DMTD promoted the ubiquitin-mediated proteasomal degradation of Keap1, and thus increased the activity of nuclear factor erythroid 2-related factor 2 (Nrf2). Mechanistically, increase of the ubiquitylation degradation of Keap1 mediates the upregulated effect of DMTD on Nrf2. Consequently, activated Nrf2/Slc7a11 results in the increase of GSH and GPX4, and therefore leads to the inhibition of ferroptosis. Herein, we imply DMTD as a potential therapeutic agent for the treatment of CI-AKI.

Atrial Fibrillation (AFIB) in the ICU: Incidence, Risk Factors, and Outcomes: The International AFIB-ICU Cohort Study

OBJECTIVES

To assess the incidence, risk factors, and outcomes of atrial fibrillation (AF) in the ICU and to describe current practice in the management of AF.

DESIGN

Multicenter, prospective, inception cohort study.

SETTING

Forty-four ICUs in 12 countries in four geographical regions.

SUBJECTS

Adult, acutely admitted ICU patients without a history of persistent/permanent AF or recent cardiac surgery were enrolled; inception periods were from October 2020 to June 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We included 1,423 ICU patients and analyzed 1,415 (99.4%), among whom 221 patients had 539 episodes of AF. Most (59%) episodes were diagnosed with continuous electrocardiogram monitoring. The incidence of AF was 15.6% (95% CI, 13.8-17.6), of which newly developed AF was 13.3% (11.5-15.1). A history of arterial hypertension, paroxysmal AF, sepsis, or high disease severity at ICU admission was associated with AF. Used interventions to manage AF were fluid bolus 19% (95% CI 16-23), magnesium 16% (13-20), potassium 15% (12-19), amiodarone 51% (47-55), beta-1 selective blockers 34% (30-38), calcium channel blockers 4% (2-6), digoxin 16% (12-19), and direct current cardioversion in 4% (2-6). Patients with AF had more ischemic, thromboembolic (13.6% vs 7.9%), and severe bleeding events (5.9% vs 2.1%), and higher mortality (41.2% vs 25.2%) than those without AF. The adjusted cause-specific hazard ratio for 90-day mortality by AF was 1.38 (95% CI, 0.95-1.99).

CONCLUSIONS

In ICU patients, AF occurred in one of six and was associated with different conditions. AF was associated with worse outcomes while not statistically significantly associated with 90-day mortality in the adjusted analyses. We observed variations in the diagnostic and management strategies for AF.

Corrigendum: DDX5 and DDX17-multifaceted proteins in the regulation of tumorigenesis and tumor progression

[This corrects the article DOI: 10.3389/fonc.2022.943032.].

Knowledge mapping of exosomes in metabolic diseases: a bibliometric analysis (2007-2022)

Background

Research on exosomes in metabolic diseases has been gaining attention, but a comprehensive and objective report on the current state of research is lacking. This study aimed to conduct a bibliometric analysis of publications on "exosomes in metabolic diseases" to analyze the current status and trends of research using visualization methods.

Methods

The web of science core collection was searched for publications on exosomes in metabolic diseases from 2007 to 2022. Three software packages, VOSviewer, CiteSpace, and R package "bibliometrix" were used for the bibliometric analysis.

Results

A total of 532 papers were analyzed, authored by 29,705 researchers from 46 countries/regions and 923 institutions, published in 310 academic journals. The number of publications related to exosomes in metabolic diseases is gradually increasing. China and the United States were the most productive countries, while Ciber Centro de Investigacion Biomedica en Red was the most active institution. The International Journal of Molecular Sciences published the most relevant studies, and Plos One received the most citations. Khalyfa, Abdelnaby published the most papers and Thery, C was the most cited. The ten most co-cited references were considered as the knowledge base. After analysis, the most common keywords were microRNAs, biomarkers, insulin resistance, expression, and obesity. Applying basic research related on exosomes in metabolic diseases to clinical diagnosis and treatment is a research hotspot and trend.

Conclusion

This study provides a comprehensive summary of research trends and developments in exosomes in metabolic diseases through bibliometrics. The information points out the research frontiers and hot directions in recent years and will provide a reference for researchers in this field.

Phosphoenolpyruvate induces endothelial dysfunction and cell senescence through stimulation of metabolic reprogramming

Endothelial dysfunction is a key early link in the pathogenesis of atherosclerosis, and the accumulation of senescent vascular endothelial cells causes endothelial dysfunction. Phosphoenolpyruvate (PEP), which is a high-energy glycolytic intermediate, protects against ischemia-reperfusion injury in isolated rat lung, heart, and liver tissue by quickly providing ATP. However, it was reported that serum PEP concentrations are 13-fold higher in healthy elderly compare to the young. Unlike that of other cell types, the energy required for the physiological function of endothelial cells is mainly derived from glycolysis. Recently, it is unclear whether circulating accumulation of PEP affects endothelial cell function. In this study, we found for the first time that 50-250 μM of PEP significantly promoted THP-1 monocyte adhesion to human umbilical vein endothelial cells (HUVECs) through increased expression of vascular endothelial adhesion factor 1 (VCAM1) and intercellular adhesion factor 1 (ICAM1) in HUVECs. Meanwhile, 50-250 μM of PEP decreased the expression of endothelial nitric oxide synthase (eNOS) and cellular level of nitric oxide (NO) in HUVECs. Moreover, PEP increased levels of ROS, enhanced the numbers of SA-β-Gal-positive cells and upregulated the expression of cell cycle inhibitors such as p21, p16 and the phosphorylation level of p53 on Ser15, and the expression of proinflammatory factors including TNF-α, IL-1β, IL-6, IL-8, IL-18 and MCP-1 in HUVECs. Furthermore, PEP increased both oxygen consumption rate (OCR) and glycolysis rate, and was accompanied by reduced NAD⁺/NADH ratios and enhanced phosphorylation levels of AMPKα (Thr172), p38 MAPK (T180/Y182) and NF-κB p65 (Ser536) in HUVECs. Notably, PEP had no significant effect on hepG2 cells. In conclusion, these results demonstrated that PEP induced dysfunction and senescence in vascular endothelial cells through stimulation of metabolic reprogramming.

Apigenin alleviates oxidative stress-induced myocardial injury by regulating SIRT1 signaling pathway

Apigenin is a natural flavonoid which is widely found in vegetables and fruits. However, the mechanism of apigenin in oxidative stress-induced myocardial injury has not been fully elucidated. We established an isoproterenol (Iso)-induced myocardial injury mouse model and a hypoxia/reoxygenation (H/R)-induced H9c2 cell injury model, followed by pretreatment with apigenin to explore its protective effects. Apigenin can significantly alleviate isoproterenol-induced oxidative stress, cell apoptosis and myocardial remodeling in vivo. Apigenin pretreatment can also significantly improve cardiomyocyte morphology, decrease H/R induced oxidative stress, and attenuate cell apoptosis and inflammation in vitro. Further mechanism study revealed that apigenin treatment reversed isoprenaline and H/R-induced decrease of Sirtuin1 (SIRT1). Molecular docking results proved that apigenin can form hydrogen bond with 230 Glu, a key site of SIRT1 activation, indicating that apigenin is an agonist of SIRT1. Moreover, SIRT1 knockdown by siRNA significantly reversed the protective effect of apigenin in H/R-induced myocardial injury. In conclusion, apigenin protects cardiomyocyte function from oxidative stress-induced myocardial injury by modulating SIRT1 signaling pathway, which provides a new potential therapeutic natural compound for the clinical treatment of cardiovascular diseases.

Boosted photocatalytic performance of OVs-rich BiVO4 hollow microsphere self-assembled with the assistance of SDBS

In this study, monoclinic phase bismuth vanadate (BiOV₄) photocatalyst with unique hollow microsphere morphology was successfully prepared by a hydrothermal method in the existence of sodium dodecyl benzene sulfonate (SDBS). The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron (SEM) and X-ray photoelectron spectrometer (XPS) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). Experimental results show that SDBS definitely changes the microstructure of BiVO₄, which is allocated to the template role of SDBS in the preparation process. Moreover, the hydrothermal treatment time is also of crucial importance in affecting the structure and morphology of the photocatalysts, and the optimal hydrothermal treatment time for the formation of hollow microsphere is 24 h. Furthermore, the feasible growth mechanism for hollow microsphere was elaborated. Enriched oxygen vacancies (OVs) are introduced into BiOV₄ prepared with SDBS, largely elevating the separation efficiency of photo-generated charges. Under visible light irradiation, the photocatalytic activities of BiOV₄ for destruction of rhodamine (RhB) were evaluated. The photocatalytic degradation rate constant of RhB on the 3SBVO is 2.23 times of that on the blank BiOV₄ as the mass ratio of SDBS/BiOV₄ is 3 %. Photocatalytic degradation mechanism of BiVO₄ toward detoxification of organic pollutants was presented.

Delphinidin induces autophagic flux blockage and apoptosis by inhibiting both multidrug resistance gene 1 and DEAD-box helicase 17 expressions in liver cancer cells

OBJECTIVES

To investigate the function and regulatory mechanisms of delphinidin in the treatment of hepatocellular carcinoma.

METHODS

HepG2 and HuH-7 cells were treated with different concentrations of delphinidin. Cell viability was analysed by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The cell autophagy and autophagic flux were analysed by LC3b-green fluorescent protein (GFP)-Adv and LC3b-GFP-monomeric red fluorescent protein-Adv transfected HepG2 and HuH-7 cells, respectively. Cell apoptosis was analysed by Hoechst33342 staining, terminal deoxynucleotidyl transferase dUTP nick end labeling staining and DNA laddering. Cell autophagy, apoptosis and survival related protein expressions were detected by Western blotting.

KEY FINDINGS

After treatment with different concentrations of delphinidin, the cell survival rate was significantly decreased. Delphinidin could block the autophagic flux, resulting in a significant increase in autophagosomes, and led to an increase in cell apoptosis. The combined application of delphinidin and cisplatin could promote the antitumour effect and reduce the dose of cisplatin in tumour cells. Further mechanism studies reveal that delphinidin could inhibit the multidrug resistance gene 1 (MDR1) and the tumour-promoting transcription cofactor DEAD-box helicase 17 (DDX17) expression in tumour cells. Overexpression of DDX17 could reverse delphinidin's antitumor function in tumour cells.

CONCLUSIONS

Delphinidin has a strong anti-tumour effect by inducing tumour cell autophagic flux blockage and apoptosis by inhibiting of both MDR1 and DDX17 expression.

Aging and aging-related diseases: from molecular mechanisms to interventions and treatments

Aging is a gradual and irreversible pathophysiological process. It presents with declines in tissue and cell functions and significant increases in the risks of various aging-related diseases, including neurodegenerative diseases, cardiovascular diseases, metabolic diseases, musculoskeletal diseases, and immune system diseases. Although the development of modern medicine has promoted human health and greatly extended life expectancy, with the aging of society, a variety of chronic diseases have gradually become the most important causes of disability and death in elderly individuals. Current research on aging focuses on elucidating how various endogenous and exogenous stresses (such as genomic instability, telomere dysfunction, epigenetic alterations, loss of proteostasis, compromise of autophagy, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, deregulated nutrient sensing) participate in the regulation of aging. Furthermore, thorough research on the pathogenesis of aging to identify interventions that promote health and longevity (such as caloric restriction, microbiota transplantation, and nutritional intervention) and clinical treatment methods for aging-related diseases (depletion of senescent cells, stem cell therapy, antioxidative and anti-inflammatory treatments, and hormone replacement therapy) could decrease the incidence and development of aging-related diseases and in turn promote healthy aging and longevity.

DDX5 and DDX17—multifaceted proteins in the regulation of tumorigenesis and tumor progression

DEAD-box (DDX)5 and DDX17, which belong to the DEAD-box RNA helicase family, are nuclear and cytoplasmic shuttle proteins. These proteins are expressed in most tissues and cells and participate in the regulation of normal physiological functions; their abnormal expression is closely related to tumorigenesis and tumor progression. DDX5/DDX17 participate in almost all processes of RNA metabolism, such as the alternative splicing of mRNA, biogenesis of microRNAs (miRNAs) and ribosomes, degradation of mRNA, interaction with long noncoding RNAs (lncRNAs) and coregulation of transcriptional activity. Moreover, different posttranslational modifications, such as phosphorylation, acetylation, ubiquitination, and sumoylation, endow DDX5/DDX17 with different functions in tumorigenesis and tumor progression. Indeed, DDX5 and DDX17 also interact with multiple key tumor-promoting molecules and participate in tumorigenesis and tumor progression signaling pathways. When DDX5/DDX17 expression or their posttranslational modification is dysregulated, the normal cellular signaling network collapses, leading to many pathological states, including tumorigenesis and tumor development. This review mainly discusses the molecular structure features and biological functions of DDX5/DDX17 and their effects on tumorigenesis and tumor progression, as well as their potential clinical application for tumor treatment.

[Association of skin lesion severity with clinical features of psoriatic arthritis]

Objective: To investigate the relationship between psoriasis severity and clinical features in psoriatic arthritis (PsA). Methods: Patients were recruited from the Chinese REgistry of Psoriatic ARthritis (CREPAR) between December 2018 and June 2021, and data were collected including the baseline demographic characteristics, various clinical manifestations (including arthritis, nail disease, comorbidities), laboratory tests[including erythrocyte sedimentation rate(ESR), C-reactive protein (CRP)], health assessment questionnaire (HAQ). Body surface area (BSA) and psoriasis area and severity index (PASI) were selected for the tools of assessment of cutaneous psoriasis. Patients were divided to two groups, including the severe psoriasis group (BSA>10%) and the non-severe psoriasis group (BSA≤10%). Disease assessment included ankylosing spondylitis disease activity score (ASDAS), disease activity score 28 (DAS28) and disease activity in psoriatic arthritis (DAPSA). Results: 1 074 eligible patients with PsA were recruited, and 106 (9.9%) had severe psoriasis. Compared with non-severe psoriasis group, the severe psoriasis group had more peripheral joint involvement (including patients with ever or current peripheral arthritis, 94.3% vs. 85.6%), more polyarticular joint involvement (including patients with current peripheral arthritis, 74.0% vs. 58.2%), more axial joint involvement (51.4% vs. 39.9%), more nail disease (72.6% vs. 61.4%), more frequency of smoking (20.2% vs. 18.7%), and higher proportion of hypertension (23.4% vs. 14.4%). In addition, the severe psoriasis group had higher level of ESR [33(10, 70) mm/1h vs. 20(9, 38) mm/1h] and CRP [18.6(5.0, 60.8) mg/L vs. 7.0(2.4, 18.1) mg/L], higher values of DAS28-ESR (4.5±1.7 vs. 3.7±1.5), DAS28-CRP (4.2±1.5 vs. 3.4±1.4), ASDAS-ESR (3.5±1.4 vs. 2.6±1.2), and ASDAS-CRP(3.4±1.6 vs. 2.5±1.2), higher scores of HAQ [0.6(0.1, 1.0) vs. 0.3(0.0, 0.8)]. Conclusion: Patients with PsA with severe psoriasis bore a heavier disease burden. Therefore, clinicians were supposed to pay more attention to them. In addition to skin lesions, they should also focus on examination of other clinical manifestations, such as joints and nails.

Enhanced photocatalytic performance of ZnO/AgCl composites prepared by high-energy mechanical ball milling

ZnO/AgCl composites prepared by high-energy ball milling showed excellent photocatalytic activity for RhB degradation and 1,4-DHP dehydrogenation under visible-light irradiation.

Bone marrow macrophage-derived exosomal miR-143-5p contributes to insulin resistance in hepatocytes by repressing MKP5

OBJECTIVE

In this study, we aim to explore the role of bone marrow macrophage-derived exosomes in hepatic insulin resistance, investigate the substance in exosomes that regulates hepatic insulin signalling pathways, reveal the specific molecular mechanisms involved in hepatic insulin resistance and further explore the role of exosomes in type 2 diabetes.

MATERIALS AND METHODS

High-fat diet (HFD)-fed mice were used as obesity-induced hepatic insulin resistance model, exosomes were isolated from BMMs which were extracted from HFD-fed mice by ultracentrifugation. Exosomes were analysed the spectral changes of microRNA expression using a microRNA array. The activation of the insulin signalling pathway and the level of glycogenesis were examined in hepatocytes after transfected with miR-143-5p mimics. Luciferase assay and western blot were used to assess the target of miR-143-5p.

RESULTS

BMMs from HFD-fed mice were polarized towards M1, and miR-143-5p was significantly upregulated in exosomes of BMMs from HFD-fed mice. Overexpression of miR-143-5p in Hep1-6 cells led to decreased phosphorylation of AKT and GSK and glycogen synthesis. Dual-luciferase reporter assay and western blot demonstrated that mitogen-activated protein kinase phosphatase-5 (Mkp5, also known as Dusp10) was the target gene of miR-143-5p. Moreover, the overexpression of MKP5 could rescue the insulin resistance induced by transfection miR-143-5p mimics in Hep1-6.

CONCLUSION

Bone marrow macrophage-derived exosomal miR-143-5p induces insulin resistance in hepatocytes through repressing MKP5.

miR-23a/b-3p promotes hepatic lipid accumulation by regulating Srebp-1c and Fas

miR-23a-3p and miR-23b-3p are members of the miR-23~27~24-2 superfamily. The role of miR-23a/b-3p in regulating hepatic lipid accumulation is still unknown. Here, we found that increased miR-23a-3p and miR-23b-3p levels were accompanied by an increase in the protein levels of the sterol regulatory element-binding protein-1 (SREBP-1) and fatty acid synthase (FAS) in the steatotic livers of mice fed a high-fat diet and leptin receptor-deficient type 2 diabetic mice (db/db). Importantly, overexpression of miR-23a/b-3p in Hep1-6 cells elevated the intracellular triglyceride level and upregulated the expression of Srebp-1c and Fas. Taken together, these results suggested that miR-23a/b-3p enhanced mRNA stability by binding the 5'-UTR of Srebp-1c and Fas mRNA, thereby promoting triglyceride accumulation in hepatocytes.

WO3/Ag2CO3 Mixed Photocatalyst with Enhanced Photocatalytic Activity for Organic Dye Degradation

The development of an efficient photocatalyst with superior activity under visible light has been regarded as a significant strategy for pollutant degradation and environmental remediation. Herein, a series of WO₃/Ag₂CO₃ mixed photocatalysts with different proportions were prepared by a simple mixing method and characterized by XRD, SEM, TEM, XPS, and DRS techniques. The photocatalytic performance of the WO₃/Ag₂CO₃ mixed photocatalyst was investigated by the degradation of rhodamine B (RhB) under visible light irradiation (λ > 400 nm). The photocatalytic efficiency of the mixed WO₃/Ag₂CO₃ photocatalyst was rapidly increased with the proportion of Ag₂CO₃ up to 5%. The degradation percentage of RhB by WO₃/Ag₂CO₃-5% reached 99.7% within 8 min. The pseudo-first-order reaction rate constant of WO₃/Ag₂CO₃-5% (0.9591 min^-1) was 118- and 14-fold higher than those of WO₃ (0.0081 min^-1) and Ag₂CO₃ (0.0663 min^-1). The catalytic activities of the mixed photocatalysts are not only higher than those of the WO₃ and Ag₂CO₃ but also higher than that of the WO₃/Ag₂CO₃ composite prepared by the precipitation method. The activity enhancement may be because of the easier separation of photogenerated electron-hole pairs. The photocatalytic mechanism was investigated by free radical capture performance and fluorescence measurement. It was found that light-induced holes (h⁺) was the major active species and superoxide radicals (·O₂ ^-) also played a certain role in photocatalytic degradation of RhB.

Protein Phosphatase 4 Promotes Hepatocyte Lipoapoptosis by Regulating RAC1/MLK3/JNK Pathway

Lipotoxicity-induced apoptosis, also referred to as lipoapoptosis, is one of the important initial factors promoting the progression from hepatosteatosis to nonalcoholic steatohepatitis (NASH). Saturated free fatty acids (SFAs), which are increased significantly in NASH, are directly hepatotoxic which induce hepatocyte lipoapoptosis. Previously, we reported that protein phosphatase 4 (PP4) was a novel regulator of hepatic insulin resistance and lipid metabolism, but its role in hepatic lipoapoptosis remains unexplored. In this study, we found out that PP4 was upregulated in the livers of western diet-fed-induced NASH mice and SFA-treated murine primary hepatocytes and HepG2 cells. In addition, we found for the first time that suppression of PP4 decreased SFA-induced JNK activation and expression of key modulators of hepatocyte lipoapoptosis including p53-upregulated modulator of apoptosis (PUMA) and Bcl-2-interacting mediator (Bim) and reduced hepatocyte lipoapoptosis level as well both in vitro and in vivo. Further study revealed that PP4 induced JNK activation and lipoapoptosis-related protein expression by regulating the RAC1/MLK3 pathway instead of the PERK/CHOP pathway. The effects of palmitate-treated and PP4-induced lipoapoptosis pathway activation were largely abolished by RAC1 inhibition. Moreover, we identified that PP4 interacted with RAC1 and regulated GTPase activity of RAC1. In conclusion, these results demonstrated that PP4 was a novel regulator of hepatocyte lipoapoptosis and mediated hepatocyte lipoapoptosis by regulating the RAC1/MLK3/JNK signaling pathway. Our finding provided new insights into the mechanisms of this process.

Cardiac Aging: From Basic Research to Therapeutics

With research progress on longevity, we have gradually recognized that cardiac aging causes changes in heart structure and function, including progressive myocardial remodeling, left ventricular hypertrophy, and decreases in systolic and diastolic function. Elucidating the regulatory mechanisms of cardiac aging is a great challenge for biologists and physicians worldwide. In this review, we discuss several key molecular mechanisms of cardiac aging and possible prevention and treatment methods developed in recent years. Insights into the process and mechanism of cardiac aging are necessary to protect against age-related diseases, extend lifespan, and reduce the increasing burden of cardiovascular disease in elderly individuals. We believe that research on cardiac aging is entering a new era of unique significance for the progress of clinical medicine and social welfare.

LncRNA NEAT1 promotes cardiac hypertrophy through microRNA-19a-3p/SMYD2 axis

OBJECTIVE

The role of NEAT1 in cancers has been demonstrated. But the role of NEAT1 in cardiac hypertrophy still remains unknown. This study aimed to elucidate the specific function of long non-coding RNA (lncRNA) NEAT1 in cardiac hypertrophy and its underlying mechanism.

PATIENTS AND METHODS

In this study, the in vivo and in vitro cardiac hypertrophy models were constructed by transverse aortic coarctation (TAC) procedure in rats and phenylephrine (PE) induction in primary cardiomyocytes, respectively. The expression levels of NEAT1, microRNA-19a-3p, SMYD2, and cardiac hypertrophic markers were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Cardiac hypertrophy was evaluated as calculating the surface area of hypertrophic cardiomyocyte by fluorescein isothiocyanate (FITC)-Phalloidin staining. Luciferase Reporter Gene Assay was conducted to detect the binding of NEAT1, SMYD2, and microRNA-19a-3p.

RESULTS

The results showed that NEAT1 and SMYD2 were highly expressed in myocardium of rats with cardiac hypertrophy and PE-induced primary cardiomyocytes, whereas microRNA-19a-3p was lowly expressed. Besides, NEAT1 overexpression markedly upregulated levels of the cardiac hypertrophic markers. Moreover, FITC-Phalloidin staining also revealed hypertrophic cardiomyocytes overexpressing NEAT1. On the contrary, microRNA-19a-3p overexpression reduced the cardiomyocyte surface area and downregulated the levels of the cardiac hypertrophic markers. As luciferase reporter gene assay demonstrated, NEAT1 and SMYD2 could bind to microRNA-19a-3p. Finally, the gain-of-function experiments were designed to verify whether NEAT1 exerted its functions in cardiac hypertrophy by modulating SMYD2 and microRNA-19a-3p. Furthermore, both microRNA-19a-3p overexpression or SMYD2 knockdown could inhibit and reduce the cardiomyocyte surface area, and downregulate the levels of the cardiac hypertrophic markers.

CONCLUSIONS

In summary, NEAT1 promotes the occurrence and progression of cardiac hypertrophy by upregulating SMYD2 by binding to microRNA-19a-3p.

Excellent visible light responsive photocatalytic behavior of N-doped TiO2 toward decontamination of organic pollutants

In this work, N-doped TiO₂ (N-TiO₂) with ample and tunable OVs was successfully synthesized, deriving from facile hydrothermal method and baked in the NH₃ atmosphere. N-doping boosts the amount of surface hydroxyl and superoxide (O₂^-) of TiO₂, demonstrated by XPS and nitroblue tetrazolium (NBT)-O₂^- quantitative reaction. Rich and tunable OVs were confirmed by low temperature electron spin resonance (ESR) results, demonstrating that doping of N into TiO₂ can definitely construct higher OVs than the reference TiO₂. Surface photovoltage spectrum (SPS) test, fluorescence experiments and electrochemical measurements all display that N-TiO₂ photocatalysts with OVs have a higher severance efficiency of photogenerated e-/h⁺ pairs than the pristine TiO₂. Photocatalytic evaluation results exhibit that N-TiO₂ photocatalysts demonstrate better performance than the reference TiO₂ toward decontamination of rhodamine B and tetracycline. TiO₂ treated in ammonia atmosphere for 1 h shows the highest photocatalytic property. The visible light responsive catalytic behavior of TiO₂ treated in ammonia atmosphere for 1 h is much higher than that of commercial TiO₂ (P25) and the pristine TiO₂, separately. The ameliorated visible light behavior of N-TiO₂ photocatalysts is attributable to rich oxygen vacancies produced through introducing N into TiO₂ and the boosted severance of photoactivated e-/h⁺.

Naringin Attenuates High Fat Diet Induced Non-alcoholic Fatty Liver Disease and Gut Bacterial Dysbiosis in Mice

The incidence of non-alcoholic fatty liver disease (NAFLD) is rising annually, and emerging evidence suggests that the gut bacteria plays a causal role in NAFLD. Naringin, a natural flavanone enriched in citrus fruits, is reported to reduce hepatic lipid accumulation, but to date, no investigations have examined whether the benefits of naringin are associated with the gut bacteria. Thus, we investigated whether the antilipidemic effects of naringin are related to modulating the gut bacteria and metabolic functions. In this study, C57BL/6J mice were fed a high-fat diet (HFD) for 8 weeks, then fed an HFD with or without naringin administration for another 8 weeks. Naringin intervention reduced the body weight gain, liver lipid accumulation, and lipogenesis and attenuated plasma biochemical parameters in HFD-fed mice. Gut bacteria analysis showed that naringin altered the community compositional structure of the gut bacteria characterized by increased benefits and fewer harmful bacteria. Additionally, Spearman’s correlation analysis showed that at the genus level, Allobaculum, Alloprevotella, Butyricicoccus, Lachnospiraceae_NK4A136_group, Parasutterella and uncultured_bacterium_f_Muribaculaceae were negatively correlated and Campylobacter, Coriobacteriaceae_UCG-002, Faecalibaculum and Fusobacterium were positively correlated with serum lipid levels. These results strongly suggest that naringin may be used as a potential agent to prevent gut dysbiosis and alleviate NAFLD.

MicroRNA-494-3p alleviates inflammatory response in sepsis by targeting TLR6

OBJECTIVE

To clarify whether microRNA-494-3p could exert an anti-inflammation effect by suppressing the expression of toll-like receptor 6 (TLR6), thus inhibiting the development of sepsis.

PATIENTS AND METHODS

Plasma levels of microRNA-494-3p and TLR6 in sepsis patients and healthy controls were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Diagnostic potential of microRNA-494-3p in sepsis was evaluated by receiver operating characteristic (ROC) curve. In vitro macrophage inflammation model was established by lipopolysaccharides (LPS) induction in RAW264.7 cells. Expression levels of microRNA-494-3p, TLR6 and tumor necrosis factor-α (TNF-α) in LPS-induced RAW264.7 cells were observed. After transfection of microRNA-494-3p mimics in LPS-induced RAW264.7 cells, mRNA and protein levels of TNF-α were determined by qRT-PCR and Western blot, respectively. Meanwhile, cytoplasmic and nuclear fractions of nuclear factor-kappa B (NF-κB) p65 were respectively extracted for evaluating nuclear translocation of NF-κB p65 by Western blot analysis. Dual-luciferase reporter gene assay was performed to verify the binding between microRNA-494-3p and TLR6. Finally, rescue experiments were carried out to elucidate whether microRNA-494-3p attenuated sepsis-induced inflammation through degrading TLR6.

RESULTS

Plasma level of microRNA-494-3p in sepsis patients was markedly lower than healthy controls, while plasma level of TLR6 was conversely higher in sepsis patients. With the prolongation of LPS induction in RAW264.7 cells, expression levels of TLR6 and TNF-α gradually increased, whereas microRNA-494-3p expression decreased. Transfection of microRNA-494-3p mimics in RAW264.7 cells reduced TNF-α level, and inhibited nuclear translocation of NF-κB p65. TLR6 was found to be a target gene of microRNA-494-3p, and its expression was markedly downregulated by microRNA-494-3p overexpression. Finally, we proved that the inhibitory effects of microRNA-494-3p on TNF-α level and nuclear translocation of NF-κB p65 were reversed by TLR6.

CONCLUSIONS

High expression of microRNA-494-3p attenuated sepsis-induced inflammatory response by degrading TLR6.

Influences of up-regulation of miR-126 on septic inflammation and prognosis through AKT/Rac1 signaling pathway

OBJECTIVE

To explore the influences of the up-regulation of micro ribonucleic acid (miR)-126 on septic inflammation and prognosis through the AKT/Rac1 signaling pathway.

MATERIALS AND METHODS

Human pulmonary microvascular endothelial cells (HMVECs) were cultured and transfected with miR-126 mimics. The HMVECs in the logarithmic growth phase in different groups were incubated with thrombin. The transmembrane resistivity of HMVECs was detected as the permeability via Electric Cell-substrate Impedance Sensing (ECIS) system. The endothelial cell space was observed via immunofluorescence. The mouse model of sepsis was then established and the serum was extracted to detect interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The survival curve was plotted based on the death time. The Statistical Product and Service Solutions (SPSS) 22.0 was used for statistical analysis, and p<0.05 suggested that the difference was statistically significant.

RESULTS

Thrombin could significantly increase the permeability of HMVECs, while the overexpression of miR-126 markedly inhibited the increased permeability. The overexpression of miR-126 also reduced the endothelial cell space induced by thrombin. In addition, the serum IL-6 and TNF-α levels of sepsis mice in miR-126 overexpression group were significantly decreased compared to those in the control group. Moreover, the death rate of mice exogenously expressing miR-126 was lower than that in the control group.

CONCLUSIONS

The up-regulation of miR-126 inhibited the septic inflammation and improved the prognosis of sepsis mice through the AKT/Rac1 signaling pathway.

GPR120 facilitates cholesterol efflux in macrophages through activation of AMPK signaling pathway

Cholesterol efflux from macrophages is the initial step of reverse cholesterol transport, an important process for high-density lipoprotein-mediated atheroprotection. G protein-coupled receptor (GPR) 120, which functions as long-chain fatty acid receptor, is well known for its anti-inflammatory and insulin-sensitizing function in macrophages. However, the role of GPR120 on macrophage foam cell formation, the hallmark of atherosclerotic plaques, has not been verified. In this study, we found for the first time that stimulation of GPR120 by its agonist GW9508 elevated the expression of ATP-binding cassette transporters (ABC) A1 and ABCG1 in THP-1 macrophage-derived foam cells and Raw264.7 macrophages, and promoted ABCA1- and ABCG1-mediated cholesterol efflux and reduced cellular cholesteryl ester (CE) content as well. In addition, GPR120 activation was accompanied with the stimulation of AMPK pathway in macrophages; however, the effect of GPR120 on macrophage cholesterol efflux was largely abolished by AMPK inhibition. Moreover, the AMPK activity and the expression of ABCA1 and ABCG1 were markedly abrogated by knockdown of GPR120, or application of phospholipase C (PLC) inhibitor, calcium chelator, or CaMKK inhibitor. Because only free cholesterol can be effluxed from macrophages, we found that activation of AMPK could lead to increase both neutral CEs hydrolysis by upregulation of neutral cholesterol ester hydrolase expression and acid CEs hydrolysis by activation of ULK1. In conclusion, these results demonstrated that GPR120 facilitated ABCA1- and ABCG1-mediated cholesterol efflux through activation of PLC/Ca²⁺ /CaMKK/AMPK signaling pathway, which induced CE hydrolysis and elevated the expression of ABCA1 and ABCG1 in macrophages.

Decreased Hospital Length of Stay With Early Administration of Oseltamivir in Patients Hospitalized With Influenza

Objective

To evaluate the effects of timely oseltamivir administration in patients hospitalized with seasonal influenza.

Patients and Methods

We performed a single-center retrospective cohort study for hospitalized patients who tested positive for influenza between December 1, 2010, and July 1, 2014. We compared outcomes for patients who received antivirals within 48 hours of symptoms to those of patients who either received oseltamivir after 48 hours or never received oseltamivir. Hospital length of stay (LOS) and 90-day mortality were compared using Cox regression models. Antiviral administration was analyzed as a time-varying covariate.

Results

During the study period, 433 patients were hospitalized with laboratory-confirmed influenza. Of these patients, 146 (33.7%) received oseltamivir within 48 hours of symptoms, 202 (46.7%) received oseltamivir after 48 hours of symptoms, and 85 (19.6%) did not receive antivirals. Baseline characteristics were similar among these patient groups. Receiving oseltamivir within 48 hours was associated with shorter hospital LOS (5.9 days vs 7.2 days; P=.03) but no significant difference in 90-day mortality (13.7% vs 11.5%; P=.51). In a Cox regression analysis, patients who received antivirals within 48 hours had a 50% higher chance of being discharged (hazard ratio, 1.50; 95% CI, 1.14-1.98) on any given day during hospital stay.

Conclusion

In patients hospitalized with laboratory-confirmed influenza, timely administration of oseltamivir was associated with shorter hospital LOS.

Dexrazoxane ameliorates doxorubicin-induced cardiotoxicity by inhibiting both apoptosis and necroptosis in cardiomyocytes

Doxorubicin, as a first line chemotherapeutic agent, its usage is limited owing to cardiotoxicity. Necroptosis is a new form of programmed cell death, and recent investigations indicated that necroptosis is vitally involved in serious cardiac pathological conditions. Dexrazoxane is the only cardiac protective drug approved by FDA for anthracycline. We aimed to explore whether and how dexrazoxane regulates doxorubicin-induced cardiomyocyte necroptosis. First, doxorubicin could cause heart failure and reduce cardiomyocyte viability by promoting cell apoptosis and necroptosis in vivo and in vitro. Second, necroptosis plays an important role in doxorubicin induced cardiomyocyte injury, which could be inhibited by Nec-1. Third, dexrazoxane increased cell viability and protect heart function by decreasing both cardiomyocyte apoptosis and necroptosis after doxorubicin treatment. Forth, dexrazoxane attenuated doxorubicin-induced inflammation and necroptosis by the inhibition of p38MAPK/NF-κB pathways. These results indicated that dexrazoxane ameliorates cardiotoxicity and protects heart function by attenuating both apoptosis and necroptosis in doxorubicin induced cardiomyocyte injury.

Inhibition of Poly(ADP-Ribose) Polymerase Increased Lipid Accumulation Through SREBP1 Modulation

Background/Aims: Excess energy intake leads to metabolic dysfunction, accompanied by oxidative stress and poly(ADP-ribose) polymerase (PARP) activation. Methods: To determine the role of PARP activation in the incidence of metabolic dysfunction, PJ34, the PARP inhibitor, was administered to the oleic acid-treated hepatoma cells and high-fat diet-fed mice. The expression of genes was detected by quantitative real-time PCR and western blotting. Lipid droplets in the cells and tissues were stained with Oil Red O. Results: PJ34 treatment aggravated oleic acid-induced lipid accumulation in hepatoma cells and induced SREBP1 expression by modulating the modification of transcription factor specificity protein 1 (Sp1). The high-fat diet-mice exhibited hyperglycemia, insulin resistance and lipid accumulation after 3 months of feeding. Although the serum level of lipid was not altered after PJ34 treatment, the expression level of lipogenic gene was up-regulated and the lipid accumulation was increased in the liver tissues of high-fat diet + PJ34-treated mice. In the high-fat diet + PJ34-treated mice, the insulin sensitivity was slightly changed and the levels of blood glucose and serum insulin were decreased compared with the mice fed with a high-fat diet alone. Conclusion: Taken together, PARP inhibition up-regulated the expression level of lipogenic gene and significantly induced lipid accumulation in the liver, which might worsen lipid metabolism disorders. These data will guide future research into the application of PARP inhibitors in the management of metabolic diseases.

miR‑338‑3p mediates gluconeogenesis via targeting of PP4R1 in hepatocytes

Hyperglycaemia is a characteristic of type 2 diabetes. In hepatocytes, impaired insulin sensitivity leads to increased gluconeogenesis and decreased glycogenesis. MicroRNA (miR)‑338‑3p is associated with tumour necrosis factor (TNF)‑α‑induced suppression of hepatic glycogenesis via regulation of protein phosphatase 4 regulatory subunit 1 (PP4R1). However, the effect of miR‑338‑3p on gluconeogenesis in hepatocytes remains unknown. In a previous study, it was demonstrated that miR‑338‑3p is downregulated in the livers of mice and in mouse HEPA1‑6 hepatocytes following treatment with TNF‑α. In the present study, the effect of miR‑338‑3p on TNF‑α‑induced gluconeogenesis in hepatocytes was investigated. The levels of phosphorylated‑FOXO1/FOXO1, phosphoenolpyruvate carboxykinase (PEPCK), peroxisome proliferator‑activated receptor γ coactivator (PGC‑1α) and glucose‑6‑phosphatase (G6Pase) were measured by western blotting. The mRNA levels of PEPCK, PGC‑1α and G6Pase were determined by quantitative polymerase chain reaction. Pyruvate tolerance testing was used to determine the gluconeogenesis of mouse livers. The results demonstrated that treatment with TNF‑α resulted in increased levels of gluconeogenesis in the livers of mice and decreased miR‑338‑3p expression levels in HEPA1‑6 cells. Overexpression of miR‑338‑3p reversed TNF‑α‑induced glucose production via enhancement of phosphorylated forkhead box O1 levels and downregulation of the expression levels of genes associated with gluconeogenesis, including peroxisome proliferator‑activated receptor γ coactivator‑1α, phosphoenolpyruvate carboxykinase and glucose‑6‑phosphatase. However, inhibition of miR‑338‑3p expression was revealed to enhance gluconeogenesis in the livers of mice and in HEPA1‑6 cells. Furthermore, downregulation of PP4R1 was revealed to attenuate the effect on glucose production following treatment with miR‑338‑3p inhibitors. In conclusion, the results of the present study revealed that miR‑338‑3p may be involved in TNF‑α‑mediated gluconeogenesis via targeting of PP4R1 in hepatocytes.

miR-291b-3p mediated ROS-induced endothelial cell dysfunction by targeting HUR

Endothelial dysfunction is an early marker of atherosclerosis. Previous studies have indicated that microRNA (miR)-291b-3p regulates the metabolism of lipids and glucose in the liver via targeting adenosine monophosphate-activated kinase α1 and transcription factor p65. The present study investigated whether miR-291b-3p mediated H₂O₂-mediated endothelial dysfunction. The level of apoptosis of EOMA mouse endothelial cells was analyzed by terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling staining. The mRNA levels of miR-291b-3p, intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) were determined by quantitative polymerase chain reaction. The level of phosphorylated extracellular signal-regulated kinase, and levels of B-cell lymphoma 2 (Bcl-2)-associated X protein and Bcl-2 protein were detected by western blot analysis. The treatment of H₂O₂ induced the apoptosis and increased the mRNA levels of miR-291b-3p, ICAM-1 and VCAM-1 in EOMA cells. It was also demonstrated that the overexpression of miR-291b-3p promoted EOMA cell apoptosis and dysfunction. In contrast, the downregulation of miR-291b-3p rescued the effect of H₂O₂ on EOMA cell dysfunction. In addition, Hu antigen R (HuR) was identified as a target gene of miR-291b-3p in EOMA cells. The overexpression of HuR reversed the endothelial dysfunction induced by miR-291b-3p mimics. The present study provides novel insight into the critical role of miR-291b-3p on the endothelial dysfunction induced by H₂O₂. miR-291b-3p may mediate H₂O₂-induced endothelial dysfunction via targeting HuR.

Long Noncoding RNA lncSHGL Recruits hnRNPA1 to Suppress Hepatic Gluconeogenesis and Lipogenesis

Mammalian genomes encode a huge number of long noncoding RNAs (lncRNAs) with unknown functions. This study determined the role and mechanism of a new lncRNA, lncRNA suppressor of hepatic gluconeogenesis and lipogenesis (lncSHGL), in regulating hepatic glucose/lipid metabolism. In the livers of obese mice and patients with nonalcoholic fatty liver disease, the expression levels of mouse lncSHGL and its human homologous lncRNA B4GALT1-AS1 were reduced. Hepatic lncSHGL restoration improved hyperglycemia, insulin resistance, and steatosis in obese diabetic mice, whereas hepatic lncSHGL inhibition promoted fasting hyperglycemia and lipid deposition in normal mice. lncSHGL overexpression increased Akt phosphorylation and repressed gluconeogenic and lipogenic gene expression in obese mouse livers, whereas lncSHGL inhibition exerted the opposite effects in normal mouse livers. Mechanistically, lncSHGL recruited heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) to enhance the translation efficiency of CALM mRNAs to increase calmodulin (CaM) protein level without affecting their transcription, leading to the activation of the phosphatidyl inositol 3-kinase (PI3K)/Akt pathway and repression of the mTOR/SREBP-1C pathway independent of insulin and calcium in hepatocytes. Hepatic hnRNPA1 overexpression also activated the CaM/Akt pathway and repressed the mTOR/SREBP-1C pathway to ameliorate hyperglycemia and steatosis in obese mice. In conclusion, lncSHGL is a novel insulin-independent suppressor of hepatic gluconeogenesis and lipogenesis. Activating the lncSHGL/hnRNPA1 axis represents a potential strategy for the treatment of type 2 diabetes and steatosis.

Piperlongumine induces apoptosis and autophagy in leukemic cells through targeting the PI3K/Akt/mTOR and p38 signaling pathways

Piperlongumine is an alkaloid compound extracted from Piper longum L. It is a chemical substance with various pharmacological effects and medicinal value, including anti-tumor, lipid metabolism regulatory, antiplatelet aggregation and analgesic properties. The present study aimed to understand whether piperlongumine induces the apoptosis and autophagy of leukemic cells, and to identify the mechanism involved. Cell viability and autophagy were detected using MTT, phenazine methyl sulfate and trypan blue exclusion assays. The apoptosis rate was calculated using flow cytometry. The protein expression levels of microtubule-associated protein 1A/1B-light chain 3, Akt and mechanistic target of rapamycin (mTOR) were measured using western blotting. The cell growth of leukemic cells was completely inhibited following treatment with piperlongumine, and marked apoptosis was also induced. Dead cells as a result of autophagy were stained using immunofluorescence and observed under a light microscope. Phosphoinositide 3-kinase (PI3K)/Akt/mTOR signaling was suppressed by treatment with piperlongumine, while p38 signaling and caspase-3 activity were induced by treatment with piperlongumine. It was concluded that piperlongumine induces apoptosis and autophagy in leukemic cells through targeting the PI3K/Akt/mTOR and p38 signaling pathways.

Reduced miR-200b and miR-200c expression contributes to abnormal hepatic lipid accumulation by stimulating JUN expression and activating the transcription of srebp1

Previous studies indicated that miR-200s participated in IL-6-induced hepatic insulin resistance. However, the role of miR-200s in hepatic lipid accumulation has not been elucidated. Here we found that miR-200b and miR-200c were reduced in the steatotic livers of mice fed a high-fat diet (HFD) and patients with nonalcoholic fatty liver disease. This down-regulation was accompanied by an increase in the expression of lipogenic proteins such as sterol regulatory element-binding protein 1 (SREBP1) and fatty acid synthase (FAS). The suppression of miR-200b and miR-200c in Hep1-6 and NCTC1469 hepatocytes enhanced intracellular triglyceride levels, which were associated with increased SREBP-1 and FAS protein levels. In contrast, the over-expression of miR-200b and miR-200c suppressed lipid accumulation and reduced the expression of SREBP1 and FAS in Hep1-6 and NCTC1469 cells transfected with miR-200b or miR-200c mimics. Importantly, the up-regulation of miR-200b and miR-200c could reverse oleic acid/palmitic acid-induced lipid accumulation in hepatocytes. A luciferase reporter assay identified that miR-200b and miR-200c could directly bind the 3′UTR of jun. JUN activated the transcription of srebp1 to increase lipid accumulation. The data also demonstrated that increased miR-200b and miR-200c expression might be associated with sitagliptin-reduced hepatic lipid accumulation in mice fed a HFD. These findings suggest, for the first time, that reduced miR-200b and miR-200c expression contributes to abnormal hepatic lipid accumulation by stimulating JUN expression and activating the transcription of srebp1.

MiR-19a mediates gluconeogenesis by targeting PTEN in hepatocytes

As a member of miR-17-92 miRNA clusters, miR‑19a has been considered to regulate hepatic glycogenesis by mediating the PI3K/AKT signaling pathway. However, whether miR‑19a serves an important role in gluconeogenesis in hepatocytes remains unknown. In the present study, the impact of miR‑19a on gluconeogenesis in HEP1‑6 cells and its mechanisms of action were investigated. It was observed that overexpression of miR‑19a led to decreased glucose production, accompanied by increased activation of the AKT/FOXO1 signaling pathway and downregulated expression of gluconeogenesis‑associated genes, including peroxisome proliferator‑activated receptor γ coactivator 1α, phosphoenolpyruvate carboxykinase and glucose 6‑phosphatase in the HEP1‑6 cells transfected with the miR‑19a mimic. In contrast, suppression of miR‑19a impaired the activation of the AKT/FOXO1 signaling pathway and increased the expression of gluconeogenesis‑associated genes, accompanied by an elevated glucose production. Additionally, phosphatase and tensin homolog (PTEN) was identified as a target of miR‑19a and participated in the miR‑19a‑mediated gluconeogenesis in hepatocytes. These findings provide mechanistic insight into the effects of miR‑19a on the regulation of the AKT/FOXO1 signaling pathway and the expression of gluconeogenesis‑associated genes. MiR‑19a may mediate gluconeogenesis in hepatocytes by downregulating PTEN expression.