Elevated cholesterol in ATAD3 mutants is a compensatory mechanism that leads to membrane cholesterol aggregation.

Aberrant cholesterol metabolism causes neurological disease and neurodegeneration, and mitochondria have been linked to perturbed cholesterol homeostasis via the study of pathological mutations in the ATAD3 gene cluster. However, whether the cholesterol changes were compensatory or contributory to the disorder was unclear, and the effects on cell membranes and the wider cell were also unknown. Using patient-derived cells, we show that cholesterol perturbation is a conserved feature of pathological ATAD3 variants that is accompanied by an expanded lysosome population containing membrane whorls characteristic of lysosomal storage diseases. Lysosomes are also more numerous in Drosophila neural progenitor cells expressing mutant Atad3, which exhibit abundant membrane-bound cholesterol aggregates, many of which co-localize with lysosomes. By subjecting the Drosophila Atad3 mutant to nutrient restriction and cholesterol supplementation, we show that the mutant displays heightened cholesterol dependence. Collectively, these findings suggest that elevated cholesterol enhances tolerance to pathological ATAD3 variants; however, this comes at the cost of inducing cholesterol aggregation in membranes, which lysosomal clearance only partly mitigates.

Janus kinase 2 inhibition by pacritinib as potential therapeutic target for liver fibrosis.

BACKGROUND AND AIMS: Janus kinase 2 (JAK2) signaling is increased in human and experimental liver fibrosis with portal hypertension. JAK2 inhibitors, such as pacritinib, are already in advanced clinical development for other indications and might also be effective in liver fibrosis. Here, we investigated the antifibrotic role of the JAK2 inhibitor pacritinib on activated hepatic stellate cells (HSCs) in vitro and in two animal models of liver fibrosis in vivo . APPROACH AND RESULTS: Transcriptome analyses of JAK2 in human livers and other targets of pacritinib have been shown to correlate with profibrotic factors. Although transcription of JAK2 correlated significantly with type I collagen expression and other profibrotic genes, no correlation was observed for interleukin-1 receptor-associated kinase and colony-stimulating factor 1 receptor. Pacritinib decreased gene expression of fibrosis markers in mouse primary and human-derived HSCs in vitro . Moreover, pacritinib decreased the proliferation, contraction, and migration of HSCs. C 57 BL/6J mice received ethanol in drinking water (16%) or Western diet in combination with carbon tetrachloride intoxication for 7 weeks to induce alcoholic or nonalcoholic fatty liver disease. Pacritinib significantly reduced liver fibrosis assessed by gene expression and Sirius red staining, as well as HSC activation assessed by alpha-smooth muscle actin immunostaining in fibrotic mice. Furthermore, pacritinib decreased the gene expression of hepatic steatosis markers in experimental alcoholic liver disease. Additionally, pacritinib protected against liver injury as assessed by aminotransferase levels. CONCLUSIONS: This study demonstrates that the JAK2 inhibitor pacritinib may be promising for the treatment of alcoholic and nonalcoholic liver fibrosis and may be therefore relevant for human pathology.

Zonal expression of StARD1 and oxidative stress in alcoholic-related liver disease.

Alcoholic-related liver disease (ALD) is one of the leading causes of chronic liver disease and morbidity. Unfortunately, the pathogenesis of ALD is still incompletely understood. StARD1 has emerged as a key player in other etiologies of chronic liver disease, and alcohol-induced liver injury exhibits zonal distribution. Here, we report that StARD1 is predominantly expressed in perivenous (PV) zone of liver sections from mice-fed chronic and acute-on-chronic ALD models compared to periportal (PP) area and is observed as early as 10 days of alcohol feeding. Ethanol and chemical hypoxia induced the expression of StARD1 in isolated primary mouse hepatocytes. The zonal-dependent expression of StARD1 resulted in the accumulation of cholesterol in mitochondria and increased lipid peroxidation in PV hepatocytes compared to PP hepatocytes, effects that were abrogated in PV hepatocytes upon hepatocyte-specific Stard1 KO mice. Transmission electron microscopy indicated differential glycogen and lipid droplets content between PP and PV areas, and alcohol feeding decreased glycogen content in both areas while increased lipid droplets content preferentially in PV zone. Moreover, transmission electron microscopy revealed that mitochondria from PV zone exhibited reduced length with respect to PP area, and alcohol feeding increased mitochondrial number, particularly, in PV zone. Extracellular flux analysis indicated lower maximal respiration and spared respiratory capacity in control PV hepatocytes that were reversed upon alcohol feeding. These findings reveal a differential morphology and functional activity of mitochondria between PP and PV hepatocytes following alcohol feeding and that StARD1 may play a key role in the zonal-dependent liver injury characteristic of ALD.

Beneficial effect of ursodeoxycholic acid in patients with acyl-CoA oxidase 2 (ACOX2) deficiency-associated hypertransaminasemia.

BACKGROUND AND AIMS: A variant (p.Arg225Trp) of peroxisomal acyl-CoA oxidase 2 (ACOX2), involved in bile acid (BA) side-chain shortening, has been associated with unexplained persistent hypertransaminasemia and accumulation of C27-BAs, mainly 3α,7α,12α-trihydroxy-5ß-cholestanoic acid (THCA). We aimed to investigate the prevalence of ACOX2 deficiency-associated hypertransaminasemia (ADAH), its response to ursodeoxycholic acid (UDCA), elucidate its pathophysiological mechanism and identify other inborn errors that could cause this alteration. METHODS AND RESULTS: Among 33 patients with unexplained hypertransaminasemia from 11 hospitals and 13 of their relatives, seven individuals with abnormally high C27-BA levels (>50% of total BAs) were identified by high-performance liquid chromatography-mass spectrometry. The p.Arg225Trp variant was found in homozygosity (exon amplification/sequencing) in two patients and three family members. Two additional nonrelated patients were heterozygous carriers of different alleles: c.673C>T (p.Arg225Trp) and c.456_459del (p.Thr154fs). In patients with ADAH, impaired liver expression of ACOX2, but not ACOX3, was found (immunohistochemistry). Treatment with UDCA normalized aminotransferase levels. Incubation of HuH-7 hepatoma cells with THCA, which was efficiently taken up, but not through BA transporters, increased reactive oxygen species production (flow cytometry), endoplasmic reticulum stress biomarkers (GRP78, CHOP, and XBP1-S/XBP1-U ratio), and BAXα expression (reverse transcription followed by quantitative polymerase chain reaction and immunoblot), whereas cell viability was decreased (tetrazolium salt-based cell viability test). THCA-induced cell toxicity was higher than that of major C24-BAs and was not prevented by UDCA. Fourteen predicted ACOX2 variants were generated (site-directed mutagenesis) and expressed in HuH-7 cells. Functional tests to determine their ability to metabolize THCA identified six with the potential to cause ADAH. CONCLUSIONS: Dysfunctional ACOX2 has been found in several patients with unexplained hypertransaminasemia. This condition can be accurately identified by a noninvasive diagnostic strategy based on plasma BA profiling and ACOX2 sequencing. Moreover, UDCA treatment can efficiently attenuate liver damage in these patients.

Tcf20 deficiency is associated with increased liver fibrogenesis and alterations in mitochondrial metabolism in mice and humans.

BACKGROUND & AIMS: Transcription co-activator factor 20 (TCF20) is a regulator of transcription factors involved in extracellular matrix remodelling. In addition, TCF20 genomic variants in humans have been associated with impaired intellectual disability. Therefore, we hypothesized that TCF20 has several functions beyond those described in neurogenesis, including the regulation of fibrogenesis. METHODS: Tcf20 knock-out (Tcf20-/- ) and Tcf20 heterozygous mice were generated by homologous recombination. TCF20 gene genotyping and expression was assessed in patients with pathogenic variants in the TCF20 gene. Neural development was investigated by immufluorescense. Mitochondrial metabolic activity was evaluated with the Seahorse analyser. The proteome analysis was carried out by gas chromatography mass-spectrometry. RESULTS: Characterization of Tcf20-/- newborn mice showed impaired neural development and death after birth. In contrast, heterozygous mice were viable but showed higher CCl4 -induced liver fibrosis and a differential expression of genes involved in extracellular matrix homeostasis compared to wild-type mice, along with abnormal behavioural patterns compatible with autism-like phenotypes. Tcf20-/- embryonic livers and mouse embryonic fibroblast (MEF) cells revealed differential expression of structural proteins involved in the mitochondrial oxidative phosphorylation chain, increased rates of mitochondrial metabolic activity and alterations in metabolites of the citric acid cycle. These results parallel to those found in patients with TCF20 pathogenic variants, including alterations of the fibrosis scores (ELF and APRI) and the elevation of succinate concentration in plasma. CONCLUSIONS: We demonstrated a new role of Tcf20 in fibrogenesis and mitochondria metabolism in mice and showed the association of TCF20 deficiency with fibrosis and metabolic biomarkers in humans.

MITOCHONDRIAL CHOLESTEROL AND CANCER.

Cholesterol is a crucial component of membrane bilayers that determines their physical and functional properties. Cells largely satisfy their need for cholesterol through the novo synthesis from acetyl-CoA and this demand is particularly critical for cancer cells to sustain dysregulated cell proliferation. However, the association between serum or tissue cholesterol levels and cancer development is not well established as epidemiologic data do not consistently support this link. While most preclinical studies focused on the role of total celular cholesterol, the specific contribution of the mitochondrial cholesterol pool to alterations in cancer cell biology has been less explored. Although low compared to other bilayers, the mitochondrial cholesterol content plays an important physiological function in the synthesis of steroid hormones in steroidogenic tissues or bile acids in the liver and controls mitochondrial function. In addition, mitochondrial cholesterol metabolism generates oxysterols, which in turn, regulate multiple pathways, including cholesterol and lipid metabolism as well as cell proliferation. In the present review, we summarize the regulation of mitochondrial cholesterol, including its role in mitochondrial routine performance, cell death and chemotherapy resistance, highlighting its potential contribution to cancer. Of particular relevance is hepatocellular carcinoma, whose incidence in Western countries had tripled in the past decades due to the obesity and type II diabetes epidemic. A better understanding of the role of mitochondrial cholesterol in cancer development may open up novel opportunities for cancer therapy.

Splicing Factor SLU7 Prevents Oxidative Stress-Mediated Hepatocyte Nuclear Factor 4α Degradation, Preserving Hepatic Differentiation and Protecting From Liver Damage.

BACKGROUND AND AIMS: Hepatocellular dedifferentiation is emerging as an important determinant in liver disease progression. Preservation of mature hepatocyte identity relies on a set of key genes, predominantly the transcription factor hepatocyte nuclear factor 4α (HNF4α) but also splicing factors like SLU7. How these factors interact and become dysregulated and the impact of their impairment in driving liver disease are not fully understood. APPROACH AND RESULTS: Expression of SLU7 and that of the adult and oncofetal isoforms of HNF4α, driven by its promoter 1 (P1) and P2, respectively, was studied in diseased human and mouse livers. Hepatic function and damage response were analyzed in wild-type and Slu7-haploinsufficient/heterozygous (Slu7+/- ) mice undergoing chronic (CCl4 ) and acute (acetaminophen) injury. SLU7 expression was restored in CCl4 -injured mice using SLU7-expressing adeno-associated viruses (AAV-SLU7). The hepatocellular SLU7 interactome was characterized by mass spectrometry. Reduced SLU7 expression in human and mouse diseased livers correlated with a switch in HNF4α P1 to P2 usage. This response was reproduced in Slu7+/- mice, which displayed increased sensitivity to chronic and acute liver injury, enhanced oxidative stress, and marked impairment of hepatic functions. AAV-SLU7 infection prevented liver injury and hepatocellular dedifferentiation. Mechanistically we demonstrate a unique role for SLU7 in the preservation of HNF4α1 protein stability through its capacity to protect the liver against oxidative stress. SLU7 is herein identified as a key component of the stress granule proteome, an essential part of the cell's antioxidant machinery. CONCLUSIONS: Our results place SLU7 at the highest level of hepatocellular identity control, identifying SLU7 as a link between stress-protective mechanisms and liver differentiation. These findings emphasize the importance of the preservation of hepatic functions in the protection from liver injury.

Gender-based differences in perceptions about sexual violence, equality and drug­facilitated sexual assaults in nightlife contexts. / Diferencias de género en percepciones sobre violencia sexual, igualdad y agresiones sexuales facilitadas por drogas en ocio nocturno.

Sexual violence, including drug-facilitated sexual assaults, is a serious issue that is becoming increasingly common in leisure nightlife contexts. This study provides information about the attitudes and perceptions of Spanish youths towards sexual violence within that setting. The participants were recruited by a snowball sampling scheme. A bivariate analysis was performed to identify possible sociodemographic and nightlife recreational habit factors related to gender. The statistical significance of the differences between the studied variables was assessed using the chi-squared and Fisher's exact tests. Women perceived a low level of personal security, as well as the existence of social perceptions penalizing female more than male drug use, and blaming women for the sexual violence they suffer. Women also recognised less explicit violent behaviours as violence significantly more than men did. Men were more willing to have sexual intercourse with someone unable to express consent because of drugs. In addition, they believed more strongly that sexual assaults take place because of the victim's use of alcohol or other drugs. In a leisure nightlife context, women are prone to perceive a lack of social support for themselves and the feeling of impunity for the perpetrators. Furthermore, numerous misconceptions surround drug-facilitated sexual assaults, with the majority of respondents believing that assaults happen after the surreptitious administration of substances to the victim by an unknown assailant. Moreover, the involvement of alcohol was underestimated. Our findings are useful for designing prevention efforts, demystifying the drug-facilitated sexual assaults and enhancing social support for victims.

La violencia sexual, incluyendo las agresiones sexuales facilitadas por drogas, es un serio problema cada vez más común en los contextos de ocio nocturno. Este trabajo estudia las actitudes y percepciones de la juventud española en torno a la violencia sexual en dicho ámbito. Los participantes se reclutaron mediante muestreo en bola de nieve. Se realizó un análisis bivariado para identificar posibles factores sociodemográficos y de ocio nocturno relacionados con género. La significación estadística de las diferencias entre estas variables se evaluó mediante las pruebas de chi-cuadrado y exacta de Fisher. Las mujeres percibieron un menor nivel de seguridad personal, así como la existencia de percepciones sociales que penalizan en mayor medida el consumo de drogas femenino que el masculino, y que culpabilizan a las mujeres por la violencia que sufren. Además, ellos mostraron mayor disposición a mantener relaciones sexuales con personas incapaces de otorgar su consentimiento debido a los efectos de las drogas. Los hombres creen en mayor medida que las agresiones sexuales ocurren debido al uso de alcohol u otras drogas por parte de las víctimas. En el contexto de ocio nocturno, las mujeres son propensas a percibir la existencia de una falta de apoyo social hacia ellas, así como un sentimiento de impunidad social hacia los agresores. Además, existen numerosas concepciones erróneas en torno a las agresiones sexuales facilitadas por drogas. La mayoría cree que las agresiones ocurren tras la administración encubierta de sustancias a la víctima por parte de un agresor desconocido. Además, se subestimó la participación del alcohol. Nuestros hallazgos son útiles para diseñar esfuerzos preventivos bien dirigidos, desmitificar el fenómeno de las agresiones sexuales facilitadas por drogas y mejorar el apoyo social a las víctimas.

Sphingomyelin synthase 1 mediates hepatocyte pyroptosis to trigger non-alcoholic steatohepatitis.

OBJECTIVE: Lipotoxic hepatocyte injury is a primary event in non-alcoholic steatohepatitis (NASH), but the mechanisms of lipotoxicity are not fully defined. Sphingolipids and free cholesterol (FC) mediate hepatocyte injury, but their link in NASH has not been explored. We examined the role of free cholesterol and sphingomyelin synthases (SMSs) that generate sphingomyelin (SM) and diacylglycerol (DAG) in hepatocyte pyroptosis, a specific form of programmed cell death associated with inflammasome activation, and NASH. DESIGN: Wild-type C57BL/6J mice were fed a high fat and high cholesterol diet (HFHCD) to induce NASH. Hepatic SMS1 and SMS2 expressions were examined in various mouse models including HFHCD-fed mice and patients with NASH. Pyroptosis was estimated by the generation of the gasdermin-D N-terminal fragment. NASH susceptibility and pyroptosis were examined following knockdown of SMS1, protein kinase Cδ (PKCδ), or the NLR family CARD domain-containing protein 4 (NLRC4). RESULTS: HFHCD increased the hepatic levels of SM and DAG while decreasing the level of phosphatidylcholine. Hepatic expression of Sms1 but not Sms2 was higher in mouse models and patients with NASH. FC in hepatocytes induced Sms1 expression, and Sms1 knockdown prevented HFHCD-induced NASH. DAG produced by SMS1 activated PKCδ and NLRC4 inflammasome to induce hepatocyte pyroptosis. Depletion of Nlrc4 prevented hepatocyte pyroptosis and the development of NASH. Conditioned media from pyroptotic hepatocytes activated the NOD-like receptor family pyrin domain containing 3 inflammasome (NLRP3) in Kupffer cells, but Nlrp3 knockout mice were not protected against HFHCD-induced hepatocyte pyroptosis. CONCLUSION: SMS1 mediates hepatocyte pyroptosis through a novel DAG-PKCδ-NLRC4 axis and holds promise as a therapeutic target for NASH.

GDF11 restricts aberrant lipogenesis and changes in mitochondrial structure and function in human hepatocellular carcinoma cells.

Growth differentiation factor 11 (GDF11) has been characterized as a key regulator of differentiation in cells that retain stemness features. Recently, it has been reported that GDF11 exerts tumor-suppressive properties in hepatocellular carcinoma cells, decreasing clonogenicity, proliferation, spheroid formation, and cellular function, all associated with a decrement in stemness features, resulting in mesenchymal to epithelial transition and loss of aggressiveness. The aim of the present work was to investigate the mechanism associated with the tumor-suppressive properties displayed by GDF11 in liver cancer cells. Hepatocellular carcinoma-derived cell lines were exposed to GDF11 (50 ng/ml), RNA-seq analysis in Huh7 cell line revealed that GDF11 exerted profound transcriptomic impact, which involved regulation of cholesterol metabolic process, steroid metabolic process as well as key signaling pathways, resembling endoplasmic reticulum-related functions. Cholesterol and triglycerides determination in Huh7 and Hep3B cells treated with GDF11 exhibited a significant decrement in the content of these lipids. The mTOR signaling pathway was downregulated, and this was associated with a reduction in key proteins involved in the mevalonate pathway. In addition, real-time metabolism assessed by Seahorse technology showed abridged glycolysis as well as glycolytic capacity, closely related to an impaired oxygen consumption rate and decrement in adenosine triphosphate production. Finally, transmission electron microscopy revealed mitochondrial abnormalities, such as cristae disarrangement, consistent with metabolic changes. Results provide evidence that GDF11 impairs cancer cell metabolism targeting lipid homeostasis, glycolysis, and mitochondria function and morphology.

STARD1 promotes NASH-driven HCC by sustaining the generation of bile acids through the alternative mitochondrial pathway.

BACKGROUND & AIMS: Besides their physiological role in bile formation and fat digestion, bile acids (BAs) synthesised from cholesterol in hepatocytes act as signalling molecules that modulate hepatocellular carcinoma (HCC). Trafficking of cholesterol to mitochondria through steroidogenic acute regulatory protein 1 (STARD1) is the rate-limiting step in the alternative pathway of BA generation, the physiological relevance of which is not well understood. Moreover, the specific contribution of the STARD1-dependent BA synthesis pathway to HCC has not been previously explored. METHODS: STARD1 expression was analyzed in a cohort of human non-alcoholic steatohepatitis (NASH)-derived HCC specimens. Experimental NASH-driven HCC models included MUP-uPA mice fed a high-fat high-cholesterol (HFHC) diet and diethylnitrosamine (DEN) treatment in wild-type (WT) mice fed a HFHC diet. Molecular species of BAs and oxysterols were analyzed by mass spectrometry. Effects of NASH-derived BA profiles were investigated in tumour-initiated stem-like cells (TICs) and primary mouse hepatocytes (PMHs). RESULTS: Patients with NASH-associated HCC exhibited increased hepatic expression of STARD1 and an enhanced BA pool. Using NASH-driven HCC models, STARD1 overexpression in WT mice increased liver tumour multiplicity, whereas hepatocyte-specific STARD1 deletion (Stard1ΔHep) in WT or MUP-uPA mice reduced tumour burden. These findings mirrored the levels of unconjugated primary BAs, ß-muricholic acid and cholic acid, and their tauroconjugates in STARD1-overexpressing and Stard1ΔHep mice. Incubation of TICs or PMHs with a mix of BAs mimicking this profile stimulated expression of genes involved in pluripotency, stemness and inflammation. CONCLUSIONS: The study reveals a previously unrecognised role of STARD1 in HCC pathogenesis, wherein it promotes the synthesis of primary BAs through the mitochondrial pathway, the products of which act in TICs to stimulate self-renewal, stemness and inflammation. LAY SUMMARY: Effective therapy for hepatocellular carcinoma (HCC) is limited because of our incomplete understanding of its pathogenesis. The contribution of the alternative pathway of bile acid (BA) synthesis to HCC development is unknown. We uncover a key role for steroidogenic acute regulatory protein 1 (STARD1) in non-alcoholic steatohepatitis-driven HCC, wherein it stimulates the generation of BAs in the mitochondrial acidic pathway, the products of which stimulate hepatocyte pluripotency and self-renewal, as well as inflammation.

Advanced preclinical models for evaluation of drug-induced liver injury - consensus statement by the European Drug-Induced Liver Injury Network [PRO-EURO-DILI-NET].

Drug-induced liver injury (DILI) is a major cause of acute liver failure (ALF) and one of the leading indications for liver transplantation in Western societies. Given the wide use of both prescribed and over the counter drugs, DILI has become a major health issue for which there is a pressing need to find novel and effective therapies. Although significant progress has been made in understanding the molecular mechanisms underlying DILI, our incomplete knowledge of its pathogenesis and inability to predict DILI is largely due to both discordance between human and animal DILI in preclinical drug development and a lack of models that faithfully recapitulate complex pathophysiological features of human DILI. This is exemplified by the hepatotoxicity of acetaminophen (APAP) overdose, a major cause of ALF because of its extensive worldwide use as an analgesic. Despite intensive efforts utilising current animal and in vitro models, the mechanisms involved in the hepatotoxicity of APAP are still not fully understood. In this expert Consensus Statement, which is endorsed by the European Drug-Induced Liver Injury Network, we aim to facilitate and outline clinically impactful discoveries by detailing the requirements for more realistic human-based systems to assess hepatotoxicity and guide future drug safety testing. We present novel insights and discuss major players in APAP pathophysiology, and describe emerging in vitro and in vivo pre-clinical models, as well as advanced imaging and in silico technologies, which may improve prediction of clinical outcomes of DILI.

Comparison between computed tomography and silicone-casting methods to determine gunshot cavities in ballistic soap.

Current methods used in terminal ballistics to determine the volume of temporary cavities created by projectiles in soft tissue simulants (such as ballistic soap) usually involve silicone-casting to obtain the cavity moulds. However, these methods have important drawbacks including their little sensitivity and precision, besides the fact that they are destructive. Imaging techniques such as computed tomography (CT) might not only overcome those limitations but also offer useful tools for digitally reporting the scientific results. This work accomplished the 3D digital reconstruction of the cavities created by different projectiles in ballistic soap blocks. This way, the total volume of the cavities, the projectile penetration depths, and other measurements were determined, rendering better capabilities when compared to the current silicone method. All these features were achieved through the CT analysis and 3D Slicer imaging software. In addition, it is worth mentioning that the method can preserve the evidence by digitally obtaining, signing, and storing the infographic videos displaying the 3D-reconstructed cavities. Graphical abstract.

Introducing ATR-FTIR Spectroscopy through Analysis of Acetaminophen Drugs: Practical Lessons for Interdisciplinary and Progressive Learning for Undergraduate Students.

Infrared (IR) spectroscopy is a vibrational spectroscopic technique useful in chemical, pharmaceutical, and forensic sciences. It is essential to identify chemicals for reasons spanning from scientific research and academic practices to quality control in companies. However, in some university degrees, graduate students do not get the proficiency to optimize the experimental parameters to obtain the best IR spectra; to correlate the IR spectral bands with the molecular vibrations (chemical elucidation); to have some criteria for any substance identification (especially relevant in quality control to recognize counterfeit); and to apply chemometrics for comparing, visualizing, and classifying the IR spectra. This work presents an experimental laboratory practice for an introductory teaching of the IR instrumental conditions in the identification of substances based on visual spectra comparison and statistical analysis and matching. Then, the selected IR conditions are applied to different commercial drugs, in the solid state or in solution, mostly composed of acetaminophen. Finally, the students apply chemometrics analysis to the IR data. This practice was designed for the training in a chemistry subject for undergraduate students of the chemistry, pharmacy, or forensics degrees, among others related to science, medical, food, or technological sciences.

Endoplasmic Reticulum Stress-Induced Upregulation of STARD1 Promotes Acetaminophen-Induced Acute Liver Failure.

BACKGROUND & AIMS: Acetaminophen (APAP) overdose is a major cause of acute liver failure (ALF). Mitochondrial SH3BP5 (also called SAB) and phosphorylation of c-Jun N-terminal kinase (JNK) mediate the hepatotoxic effects of APAP. We investigated the involvement of steroidogenic acute regulatory protein (STARD1), a mitochondrial cholesterol transporter, in this process and sensitization by valproic acid (VPA), which depletes glutathione and stimulates steroidogenesis. METHODS: Nonfasted C57BL/6J mice (control) and mice with liver-specific deletion of STARD1 (Stard1ΔHep), SAB (SabΔHep), or JNK1 and JNK2 (Jnk1+2ΔHep) were given VPA with or without APAP. Liver tissues were collected and analyzed by histology and immunohistochemistry and for APAP metabolism, endoplasmic reticulum (ER) stress, and mitochondrial function. Adult human hepatocytes were transplanted into Fah-/-/Rag2-/-/Il2rg-/-/NOD (FRGN) mice to create mice with humanized livers. RESULTS: Administration of VPA before administration of APAP increased the severity of liver damage in control mice. The combination of VPA and APAP increased expression of CYP2E1, formation of NAPQI-protein adducts, and depletion of glutathione from liver tissues of control mice, resulting in ER stress and the upregulation of STARD1. Livers from control mice given VPA and APAP accumulated cholesterol in the mitochondria and had sustained mitochondrial depletion of glutathione and mitochondrial dysfunction. Inhibition of ER stress, by administration of tauroursodeoxycholic acid to control mice, prevented upregulation of STARD1 in liver and protected the mice from hepatoxicity following administration of VPA and APAP. Administration of N-acetylcysteine to control mice prevented VPA- and APAP-induced ER stress and liver injury. Stard1ΔHep mice were resistant to induction of ALF by VPA and APAP, despite increased mitochondrial levels of glutathione and phosphorylated JNK; we made similar observations in fasted Stard1ΔHep mice given APAP alone. SabΔHep mice or Jnk1+2ΔHep mice did not develop ALF following administration of VPA and APAP. The ability of VPA to increase the severity of APAP-induced liver damage was observed in FRGN mice with humanized liver. CONCLUSIONS: In studies of mice, we found that upregulation of STARD1 following ER stress mediates APAP hepatoxicity via SH3BP5 and phosphorylation of JNK1 and JNK2.

Zinc mitigates renal ischemia-reperfusion injury in rats by modulating oxidative stress, endoplasmic reticulum stress, and autophagy.

Oxidative stress is a major factor involved in the pathogenesis of renal ischemia/reperfusion (I/R). Exogenous zinc (Zn) was suggested as a potent antioxidant; however, the mechanism by which it strengthens the organ resistance against the effects of reactive oxygen species (ROS) is not yet investigated. The present study aims to determine whether acute zinc chloride (ZnCl2 ) administration could attenuate endoplasmic reticulum (ER) stress, autophagy, and inflammation after renal I/R. Rats were subjected to either sham operation (Sham group, n = 6), or 1 hr of bilateral ischemia followed by 2 hr of reperfusion (I/R groups, n = 6), or they received ZnCl2 orally 24 hr and 30 min before ischemia (ZnCl2 group, n = 6). Rats were subjected to 1 hr of bilateral renal ischemia followed by 2 hr of reperfusion (I/R group, n = 6). Our results showed that ZnCl2 enhances renal function and reduces cytolysis (p < 0,05). In addition, it increased significantly the activities of antioxidant enzymes (SOD, CAT, and GPX) and the level of GSH in comparison to I/R (p < 0,05). Interestingly, ZnCl2 treatment resulted in significant decreased ER stress, as reflected by GRP78, ATF-6,p-eIF-2α, XPB-1, and CHOP downregulaion. Rats undergoing ZnCl2 treatment demonstrated a low expression of autophagy parameters (Beclin-1 and LAMP-2), which was correlated with low induction of apoptosis (caspase-9, caspase-3, and p-JNK), and reduction of inflammation (IL-1ß, IL-6, and MCP-1) (p < 0,05). In conclusion, we demonstrated the potential effect of Zn supplementation to modulate ER pathway and autophagic process after I/R.

Selective Monitoring of Oxyanion Mixtures by a Flow System with Raman Detection.

Raman spectroscopy is a selective detection system scarcely applied for the flow analysis of solutions with the aim of detecting several compounds at once without a previous separation step. This work explores the potential of a portable Raman system in a flow system for the selective detection of a mixture of seven oxyanions (carbonate, sulphate, nitrate, phosphate, chlorate, perchlorate, and thiosulphate). The specific bands of these compounds (symmetric stretching Raman active vibrations of carbonate at 1068 cm−1, nitrate at 1049 cm−1, thiosulphate at 998 cm−1, phosphate at 989 cm−1, sulphate at 982 cm−1, perchlorate at 935 cm−1, and chlorate at 932 cm−1) enabled their simultaneous detection in mixtures. Although the oxyanions’ limit of detection (LOD) was rather poor (in the millimolar range), this extremely simple system is very useful for the single-measurement detection of most of the oxyanions in mixtures, without requiring a previous separation step. In addition, quantitative determination of the desired oxyanion can be performed by means of the corresponding calibration line. These are important advantages for controlling in-line processes in industries like those manufacturing fertilizers, pharmaceuticals, chemicals, or food, among others.

Measuring the Human Ultra-Weak Photon Emission Distribution Using an Electron-Multiplying, Charge-Coupled Device as a Sensor.

Ultra-weak photon emission (UPE) is the spontaneous emission from living systems mainly attributed to oxidation reactions, in which reactive oxygen species (ROS) may play a major role. Given the capability of the next-generation electron-multiplying CCD (EMCCD) sensors and the easy use of liquid crystal tunable filters (LCTF), the aim of this work was to explore the potential of a simple UPE spectrometer to measure the UPE from a human hand. Thus, an easy setup was configured based on a dark box for inserting the subject's hand prior to LCTF as a monochromator and an EMCCD sensor working in the full vertical binning mode (FVB) as a spectra detector. Under controlled conditions, both dark signals and left hand UPE were acquired by registering the UPE intensity at different selected wavelengths (400, 450, 500, 550, 600, 650, and 700 nm) during a period of 10 min each. Then, spurious signals were filtered out by ignoring the pixels whose values were clearly outside of the Gaussian distribution, and the dark signal was subtracted from the subject hand signal. The stepped spectrum with a peak of approximately 880 photons at 500 nm had a shape that agreed somewhat with previous reports, and agrees with previous UPE research that reported UPE from 420 to 570 nm, or 260 to 800 nm, with a range from 1 to 1000 photons s-1 cm-2. Obtaining the spectral distribution instead of the total intensity of the UPE represents a step forward in this field, as it may provide extra information about a subject's personal states and relationship with ROS. A new generation of CCD sensors with lower dark signals, and spectrographs with a more uniform spectral transmittance, will open up new possibilities for configuring measuring systems in portable formats.

Study of the adhesion of explosive residues to the finger and transfer to clothing and luggage.

It is important to understand the extent of transfer of explosive particles to different surfaces in order to better evaluate potential cross-contamination by explosives in crowded security controls such as those at airports. This work investigated the transfer of nine explosive residues (ANFO, dynamite, black powder, TNT, HMTD, PETN, NH4NO3, KNO3, NaClO3) through fingerprints from one surface to another. First, the extent of adhesion of explosive residues from different surfaces to the bare finger, nitrile and latex gloves was studied. Then, the transfer of explosive residues from one surface to another through fingerprints was investigated. Cotton fabric (hereinafter referred to as cotton) as clothing material and polycarbonate plastic (hereinafter referred to as polycarbonate) as luggage material were chosen for the experiments. These surfaces containing explosive particles were imaged using a reflex camera before and after the particles were transferred. Afterwards the images were processed in MATLAB where pixels corresponding to explosive residues were quantified. Results demonstrated that transfer of explosive residues frequently occurred with certain differences among materials. Generally, the amount of explosive particles adhered to the finger decreased in the following order: skin>latex>nitrile, while the transfer of particles from the finger to another surface was the opposite. The adhesion of explosive residues from polycarbonate to the finger was found to be better compared to cotton, while the amount of particles transferred to cotton was higher.