Agreement and discrepancies in patient-clinician reports of DSM-5-TR section III maladaptive personality traits: A study on a mixed outpatient sample.

The assessment of personality pathology based on dimensional models may improve self-other agreement, but previous research mainly adopted a categorical approach and overlooked the role of the person of the therapist. Our study examined patient-clinician agreement in a mixed sample of Italian outpatients using the Personality Inventory for DSM-5 (PID-5) and the PID-5-Informant Form (PID-5-IRF). Moreover, the role of clinician personality traits on agreement was preliminary explored. Sixty-eight outpatients (51.4% male, M = 30.30, SD = 12.05 years) and their treating clinicians (N = 22; 77.3% female, M = 43.77 ± 8.45 years) entered the study. Patients completed the PID-5, whereas clinicians filled-in the PID-5-Brief Form (PID-5-BF) and the PID-5-IRF for each patient they involved. A multilevel Bayesian analysis showed that rank-order agreement was large for domains (mean r = .60) and moderate for facets (mean r = .44). As regards mean-level agreement, patient ratings on cognitive/perceptual dysregulation, distractibility, eccentricity, and emotional lability were higher than clinician ratings, whereas patients' scores on depressivity were lower than clinicians' ones. Scores on the PID-5-BF detachment positively predicted agreement on anhedonia, anxiousness, depressivity, distractibility, separation insecurity, and suspiciousness, while scores on the PID-5-BF negative affectivity, antagonism, and disinhibition negatively predicted agreement on few specific facets. Current findings suggest that clinician personality traits may contribute to agreement on maladaptive personality traits, but areas of discrepancies remain in case of low observable internal ones. Since patient-clinician agreement is crucially involved in therapeutic alliance, further research on this issue is highly encouraged. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Effects of the COVID-19 pandemic on dentists' workforce confidence and workflow.

BACKGROUND: The COVID-19 pandemic has affected the US economy and workforce, including marked effects on small businesses. Researchers have evaluated workers' views of financial confidence and advancement, but there has been limited focus on the dental industry. METHODS: To extend investigations to dentistry, the authors used published scales and pretested questions to determine workforce confidence and workflow changes among dentists. Data were evaluated using descriptive and bivariate statistics. In the wake of the pandemic, surveys were distributed to the memberships of the American Dental Association and American Association of Orthodontists (n = 656). RESULTS: Dentists' top concern was increased cost of providing treatment (57.4%; 95% CI, 53.5% to 61.3%), associated with widely adopted workflow changes including reduced patient volumes (66.0%; 95% CI, 62.4% to 69.6%) and increased safety protocols and equipment (health screening: 75.5%; 95% CI, 72.2% to 78.8%; KN/N95 respirators: 76.7%; 95% CI, 73.5% to 80.0%). However, most respondents did not expect their personal or practice finances to be negatively affected after the pandemic, as only 18.5% (95% CI, 15.4% to 21.7%) predicted their practice's gross revenue would decrease. CONCLUSIONS: Dentists were optimistic in the wake of vaccinations and lifting restrictions. Most expected their finances and practice performance to remain the same or grow in the short term and expected long-term improvements postpandemic. PRACTICAL IMPLICATIONS: Results suggest that despite shutdowns and workflow changes, dentists have rebounded financially and anticipate future growth.

Ethanol and fatty acids impair lipid homeostasis in an in vitro model of hepatic steatosis.

Excess ethanol consumption and fatty acid intake lead to a cumulative effect on liver steatosis through still unclear mechanisms. This study aimed to characterize the lipid homoeostasis alterations under the exposure of hepatocytes to ethanol alone or combined with fatty acids. FaO hepatoma cells were incubated in the absence (C) or in the presence of 100 mM ethanol (EtOH) or 0.35 mM oleate/palmitate (FFA) alone or in the combination (FFA/EtOH). Content of intra- and extra-cellular triglycerides (TAGs) and of lipid droplets (LDs), expression of lipogenic and lipolytic genes, and oxidative stress-related parameters were evaluated. Exposure to either FFAs or EtOH given separately led to steatosis which was augmented when they were combined. Our results show that FFA/EtOH: (i) increased the LD number, but reduced their size compared to separate treatments; (ii) up-regulated PPARγ and SREBP-1c and down-regulated sirtuin-1 (SIRT1); (iii) impaired FFA oxidation; (iv) did not change lipid secretion and oxidative stress. Our findings indicate that one of the major mechanisms of the metabolic interference between ethanol and fat excess is the impairment of FFA oxidation, in addition to lipogenic pathway stimulation. Interestingly, ethanol combined with FFAs led to a shift from macrovesicular to microvesicular steatosis that represents a more dangerous condition.

Triglyceride Mobilization from Lipid Droplets Sustains the Anti-Steatotic Action of Iodothyronines in Cultured Rat Hepatocytes.

Adipose tissue, dietary lipids and de novo lipogenesis are sources of hepatic free fatty acids (FFAs) that are stored in lipid droplets (LDs) as triacylglycerols (TAGs). Destiny of TAGs stored in LDs is determined by LD proteomic equipment. When adipose triglyceride lipase (ATGL) localizes at LD surface the lipid mobilization is stimulated. In this work, an in vitro model of cultured rat hepatocytes mimicking a mild steatosis condition was used to investigate the direct lipid-lowering action of iodothyronines, by focusing, in particular, on LD-associated proteins, FFA oxidation and lipid secretion. Our results demonstrate that in "steatotic" hepatocytes iodothyronines reduced the lipid excess through the recruitment of ATGL on LD surface, and the modulation of the LD-associated proteins Rab18 and TIP47. As an effect of ATGL recruitment, iodothyronines stimulated the lipid mobilization from LDs then followed by the up-regulation of carnitine-palmitoyl-transferase (CPT1) expression and the stimulation of cytochrome-c oxidase (COX) activity that seems to indicate a stimulation of mitochondrial function. The lipid lowering action of iodothyronines did not depend on increased TAG secretion. On the basis of our data, ATGL could be indicated as an early mediator of the lipid-lowering action of iodothyronines able to channel hydrolyzed FFAs toward mitochondrial beta-oxidation rather than secretion.

Altered oxidative stress/antioxidant status in blood of alcoholic subjects is associated with alcoholic liver disease.

BACKGROUND: Oxidative stress is implicated in pathogenesis of alcoholic liver disease (ALD). This study investigated the possible correlation among the erythrocyte indices of oxidative stress, the leukocyte panels of antioxidant proteins (metallothioneins), the serum biochemical parameters and the liver steatosis grade. METHODS: A total of 118 cases including 60 alcoholic subjects and 58 controls were enrolled. All the alcoholic subjects were screened for body mass index (BMI), liver steatosis, and blood chemistry and serology. The level of oxidative stress and oxidative stress-related parameters were measured in the blood and correlated with clinical findings. RESULTS: Alcoholic subjects showed higher BMI, moderate/severe hepatic steatosis, increase in the levels of triglycerides, cholesterol, glucose, γ-glutamyl-transpeptidase (GGT), alanine aminotransferase (ALT), bilirubin, alpha 1 and beta 2 globulins, iron and a decrease in the levels of aspartate aminotransferase (AST) and beta 1 globulin with respect to the reference values. Moreover, alcoholic subjects showed: (i) an increase in Thiobarbituric Acid Reactive Substance (TBARS) content representing a good estimation of global oxidative stress; (ii) a stimulation of the activities of the antioxidant enzymes catalase and SOD; (iii) a modulation of expression of metallothioneins, with a down-regulation of MT-1A and an up-regulation of MT-1E isoforms. CONCLUSIONS: Our data suggest that alcoholism is strongly associated with altered pattern of blood metallothioneins; this parameter combined with the score calculated by an ad hoc implemented algorithm (HePaTest) could offer a non-invasive alternative approach for evaluating alcohol-related damages and could be used in follow-up of alcoholic patients.

Co-exposure to n-TiO2 and Cd2+ results in interactive effects on biomarker responses but not in increased toxicity in the marine bivalve M. galloprovincialis.

The increasing production of nanoparticles (NPs) will lead to their release into the aquatic environment, where they could modify the bioavailability/bioconcentration and consequent biological impact of other contaminants. Interactive effects of n-TiO2, one of the most widespread NP type, and Cd(2+), a common heavy metal pollutant, have been described in freshwater species, whereas no information is available in marine organisms. In this work, the effects of co-exposure to n-TiO2 and Cd(2+) were investigated in the marine bivalve Mytilus galloprovincialis. Experimental conditions (100 µg/L, 96 h), were chosen in order to induce early but measurable stress responses (biomarkers) without toxicity. Several biomarkers, from molecular to tissue level, were measured in hemolymph and digestive gland; the effects on embryo development were also evaluated. In hemolymph, Cd(2+) abolished the increase in immune parameters induced by n-TiO2 (NO production and lysozyme activity). In the digestive gland, distinct interactive effects of n-TiO2 and Cd(2+) were observed on different lysosomal biomarkers (lysosomal membrane stability, lipid accumulation and lysosome/cytoplasm volume ratio) and transcription of the immune genes lysozyme and toll-like receptor (TLR). However, n-TiO2 did not affect specific metal-induced responses (metallothionein induction) and tissue metal accumulation. Cd(2+) alone, but not in combination with n-TiO2, affected embryo development. The interactive effects observed on different biomarkers were not apparently due to differences in bioavailability/bioaccumulation of Cd(2+) in the presence of n-TiO2 agglomerates; these effects may result from interactions of either contaminant with both common and distinct targets/mechanisms of action at different levels of biological organization. Overall, the results indicate that co-exposure to n-TiO2 and Cd(2+) did not result in increased adverse effects in M. galloprovincialis. These data underline the need for further knowledge on the potential interactions of NPs with existing contaminants in marine organisms.

3,5-diiodo-L-thyronine modifies the lipid droplet composition in a model of hepatosteatosis.

BACKGROUND/AIMS: Fatty acids are the main energy stores and the major membrane components of the cells. In the hepatocyte, fatty acids are esterified to triacylglycerols (TAGs) and stored in lipid droplets (LDs). The lipid lowering action of 3,5-diiodo-L-thyronine (T2) on an in vitro model of hepatosteatosis was investigated in terms of fatty acid and protein content of LDs, lipid oxidation and secretion. METHODS: FaO cells were exposed to oleate/palmitate, then treated with T2. RESULTS: T2 reduced number and size of LDs, and modified their acyl composition by decreasing the content of saturated (SFA) vs monounsaturated (MUFA) fatty acids thus reversing the SFA/MUFA ratio. The expression of the LD-associated proteins adipose differentiation-related protein (ADRP), oxidative tissue-enriched PAT protein (OXPAT), and adipose triglyceride lipase (ATGL) was increased in 'steatotic' cells and further up-regulated by T2. Moreover, T2 stimulated the mitochondrial oxidation by up-regulating carnitine-palmitoyl-transferase (CPT1), uncoupling protein 2 (UCP2) and very long-chain acyl-coenzyme A dehydrogenase (VLCAD). CONCLUSIONS: T2 leads to mobilization of TAGs from LDs and stimulates mitochondrial oxidative metabolism of fatty acids, in particular of SFAs, and thus enriches of MUFAs the LDs. This action may protect the hepatocyte from excess of SFAs that are more toxic than MUFAs.

Effects of binge ethanol on lipid homeostasis and oxidative stress in a rat model of nonalcoholic fatty liver disease.

Excess fat accumulation renders the liver more vulnerable to ethanol, but it is still unclear how alcohol enhances lipid dysmetabolism and oxidative stress in a pre-existing steatosis condition. The effects produced by binge ethanol consumption in the liver of male Wistar rats fed a standard (Ctrl) or a high-fat diet HFD were compared. The liver status was checked through tissue histology and standard serum parameters. Alteration of hepatic lipid homeostasis and consequent oxidative unbalance were assessed by quantifying the mRNA expression of the lipid-regulated peroxisome proliferator-activated receptors (PPARs), of the cytochromes CYP2E1 and CYP4A1, and of some antioxidant molecules such as the metallothionein isoforms MT1 and MT2 and the enzymes catalase and superoxide dismutase. The number of adipose differentiation-related protein (ADRP)-positive lipid droplets (LDs) was evaluated by immunohistochemical staining. As a response to the double insult of diet and ethanol the rat liver showed: (1) a larger increase in fat accumulation within ADRP-positive LDs; (2) stimulation of lipid oxidation in the attempt to limit excess fat accumulation; (3) induction of antioxidant proteins (MT2, in particular) to protect the liver from the ethanol-induced overproduction of oxygen radicals. The data indicate an increased susceptibility of fatty liver to ethanol and suggest that the synergistic effect of diet and ethanol on lipid dysmetabolism might be mediated, at least in part, by PPARs and cytochromes CYP4A1 and CYP2E1.

In vivo effects of n-TiO2 on digestive gland and immune function of the marine bivalve Mytilus galloprovincialis.

Due to the increasing production of nanoparticles (NPs) and their potential release in the aquatic environment, evaluation of their biological impact on aquatic organisms represents a major concern. Suspension feeding invertebrates, in particular bivalve mollusks, may play a role in NP biotransformation and transfer through food webs and may represent a significant target for NP toxicity. In this work, the in vivo effects of titanium dioxide (n-TiO2), one of the most widespread NPs in use, were investigated in the bivalve Mytilus galloprovincialis, largely utilised as a sentinel for marine contamination. Mussels were exposed for 96h to different concentrations of n-TiO2 suspensions (1, 10 and 100µgL(-1)) and multiple responses were evaluated in the digestive gland and immune cells, the haemocytes. In the digestive gland, n-TiO2 affected lysosomal and oxidative stress biomarkers and decreased transcription of antioxidant and immune-related genes. In the haemocytes, n-TiO2 decreased lysosomal membrane stability-LMS and phagocytosis, increased oxyradical production and transcription of antimicrobial peptides; moreover, pre-apoptotic processes were observed. The effects of n-TiO2 on digestive gland and haemocytes were distinct, also depending on the endpoint and on nominal NP concentrations, with many significant responses elicited by the lowest concentrations tested. The results show that n-TiO2, at concentrations close to predicted environmental levels, significantly affected different functional and molecular parameters of mussel digestive gland and immune cells. In particular, the observed changes in immune parameters that represent significant biomarkers of exposure at the organism level suggest that exposure to n-TiO2 may pose a serious risk to mussel health.

Direct effects of Bisphenol A on lipid homeostasis in rat hepatoma cells.

Bisphenol A (BPA), used in the manufacture of polycarbonate plastic and epoxy resin, is one of the most abundant endocrine disruptors in the environment, considered as a xenoestrogen. BPA has recently become of additional public health concern because of increasing evidence of deleterious effects on metabolism. Dietary intake seems the most important route for BPA exposure, followed by rapid biotransformation in the gut and liver and elimination in the urine. Although hepatocytes can represent a significant target for this compound, little is known on the direct effects and mechanisms of action of BPA on lipid homeostasis at the cellular level. In this work, the effects of BPA (0.3-3-30-300 ng mL(-1), 24 h) were investigated in rat FaO hepatoma, a well differentiated liver cell line. At both 30 and 300 ng mL(-1), BPA significantly increased intracellular triglyceride (TAG) content and lipid accumulation in lipid droplets (LDs), without affecting cell viability. The effects of BPA were associated with decreased mRNA levels of the transcription factors Peroxisome Proliferator-Activated Receptor (PPAR) isoforms α and ßδ, as well as of their downstream genes acyl-CoA oxidase (AOX) and carnitine palmitoyl transferase (CPT1) involved in lipid oxidation. No increase in transcription of lipogenic genes was observed. BPA also decreased mRNA levels of ApolipoproteinB (apoB) and the extracellular TAG content, indicating alterations in lipid secretion. FaO cells did not express Estrogen Receptor α (ERα and showed a very low expression of ERß compared to rat liver. All the effects of BPA were prevented by cell pretreatment with Wortmannin, indicating the involvement of phosphatidyl inositol-3 kinase activation. The results demonstrate a direct action of BPA on lipid homeostasis in FaO cells through interference with lipid oxidation and secretion, and add further information on the cellular pathways that can be perturbed by this compound.

Effects of sublethal, environmentally relevant concentrations of hexavalent chromium in the gills of Mytilus galloprovincialis.

Hexavalent chromium Cr(VI) is an important contaminant released from both domestic and industrial effluents, and represents the predominant chemical form of the metal in aquatic ecosystems. In the marine bivalve Mytilus galloprovincialis exposure to non-toxic, environmentally relevant concentrations of Cr(VI) was shown to modulate functional parameters and gene expression in both the digestive gland and hemocytes. In this work, the effects of exposure to Cr(VI) (0.1-1-10 µg L(-1) animal(-1) for 96 h) in mussel gills were investigated. Gill morphology and immunolocalization of GSH-transferase (GST), of components involved in cholinergic (AChE and ChAT), adrenergic (TH) and serotoninergic (5-HT(3) receptor) systems, regulating gill motility, were evaluated. Total glutathione content, activities of GSH-related enzymes (glutathione reductase - GSR, GST), of catalase, and of key glycolytic enzymes (phosphofructokinase - PFK and pyruvate kinase - PK) were determined. Moreover, mRNA expression of selected Mytilus genes (GST-π, metallothionein isoforms MT10 and MT20, HSP70 and 5-HT receptor) was assessed by RT-q-PCR. Cr(VI) exposure induced progressive changes in gill morphology and in immunoreactivity to components involved in neurotransmission that were particularly evident at the highest concentration tested, and associated with large metal accumulation. Cr(VI) increased the activities of GST and GSR, and total glutathione content to a different extent at different metal concentrations, this suggesting Cr(VI) detoxication/reduction at the site of metal entry. Cr(VI) exposure also increased the activity of glycolytic enzymes, indicating modulation of carbohydrate metabolism. Significant changes in transcription of different genes were observed. In particular, the mRNA level for the 5-HTR was increased, whereas both decreases and increases were observed for GST-π, MT10, MT20 and HSP70 mRNAs, showing sex- and concentration-related differences. The results demonstrate that Cr(VI) significantly affected functional and molecular parameters in mussel gills, and indicate that this tissue represents the major target of exposure to environmentally relevant concentrations of the metal.

Immunomodulation by different types of N-oxides in the hemocytes of the marine bivalve Mytilus galloprovincialis.

The potential toxicity of engineered nanoparticles (NPs) for humans and the environment represents an emerging issue. Since the aquatic environment represents the ultimate sink for NP deposition, the development of suitable assays is needed to evaluate the potential impact of NPs on aquatic biota. The immune system is a sensitive target for NPs, and conservation of innate immunity represents an useful basis for studying common biological responses to NPs. Suspension-feeding invertebrates, such as bivalves, are particularly at risk to NP exposure, since they have extremely developed systems for uptake of nano and microscale particles integral to intracellular digestion and cellular immunity. Evaluation of the effects of NPs on functional parameters of bivalve immunocytes, the hemocytes, may help understanding the major toxic mechanisms and modes of actions that could be relevant for different NP types in aquatic organisms.In this work, a battery of assays was applied to the hemocytes of the marine bivalve Mytilus galloprovincialis to compare the in vitro effects of different n-oxides (n-TiO(2), n-SiO(2), n-ZnO, n-CeO(2)) chosen on the basis of their commercial and environmental relevance. Physico-chemical characterization of both primary particles and NP suspensions in artificial sea water-ASW was performed. Hemocyte lysosomal and mitochondrial parameters, oxyradical and nitric oxide production, phagocytic activity, as well as NP uptake, were evaluated. The results show that different n-oxides rapidly elicited differential responses hemocytes in relation to their chemical properties, concentration, behavior in sea water, and interactions with subcellular compartments. These represent the most extensive data so far available on the effects of NPs in the cells of aquatic organisms. The results indicate that Mytilus hemocytes can be utilized as a suitable model for screening the potential effects of NPs in the cells of aquatic invertebrates, and may provide a basis for future experimental work for designing environmentally safer nanomaterials.

Bivalve molluscs as a unique target group for nanoparticle toxicity.

Due to the continuous development and production of manufactured nanomaterials or nanoparticles (NPs), their uptake and effects in the aquatic biota represent a major concern. Estuarine and coastal environments are expected to represent the ultimate sink for NPs, where their chemical behavior (aggregation/agglomeration) and consequent fate may be critical in determining the biological impact. Bivalve mollusks are abundant from freshwater to marine ecosystems, where they are widely utilized in biomonitoring of environmental perturbations. As suspension-feeders, they have highly developed processes for cellular internalization of nano- and micro-scale particles (endo- and phagocytosis), integral to key physiological functions such as intra-cellular digestion and cellular immunity. Here we will summarise available information on the effects of different types of NPs in different bivalve species, in particular Mytilus spp. Data on the effects and modes of action of different NPs on mussel hemocytes in vitro demonstrate that cell-mediated immunity represents a significant target for NPs. Moreover, in vivo exposure to NPs indicates that, due to the physiological mechanisms involved in the feeding process, NP agglomerates/aggregates taken up by the gills are directed to the digestive gland, where intra-cellular uptake of nanosized materials induces lysosomal perturbations and oxidative stress. Overall, bivalves represent a particularly suitable model for investigating the effects and mechanisms of action underlying the potential toxicity of NPs in marine invertebrates.

3,5-Diiodo-L-thyronine modulates the expression of genes of lipid metabolism in a rat model of fatty liver.

Recent reports demonstrated that 3,5-diiodo-l-thyronine (T(2)) was able to prevent lipid accumulation in the liver of rats fed a high-fat diet (HFD). In this study, we investigated how the rat liver responds to HFD and T(2) treatment by assessing the transcription profiles of some genes involved in the pathways of lipid metabolism: oxidation, storage and secretion. The mRNA levels of the peroxisome proliferator-activated receptors (PPARα, PPARγ and PPARδ), and of their target enzymes acyl-CoA oxidase and stearoyl-CoA desaturase were evaluated by real-time RT-PCR. Moreover, the expression of the adipose triglyceride lipase involved in lipid mobilisation, of the main PAT proteins acting in lipid droplet (LD) turnover, and of apoprotein B (apo B), the major protein component of very low-density lipoproteins (VLDLs) were analysed. Overall, our data demonstrated that T(2) administration to HFD rats counteracts most of the hepatic transcriptional changes that occurred in response to the excess exogenous fat. In particular, our results suggest that T(2) may prevent the pathways leading to lipid storage in LDs, promote the processes of lipid mobilisation from LDs and secretion as VLDL, in addition to the stimulation of pathways of lipid oxidation. In conclusion, our findings might give an insight into the mechanisms underlying the anti-steatotic ability of T(2) and help to define the potential therapeutic role of T(2) for preventing or treating liver steatosis.

The organophosphate Chlorpyrifos interferes with the responses to 17ß-estradiol in the digestive gland of the marine mussel Mytilus galloprovincialis.

BACKGROUND: Many pesticides have been shown to act as endocrine disrupters. Although the potencies of currently used pesticides as hormone agonists/antagonists are low compared with those of natural ligands, their ability to act via multiple mechanisms might enhance the biological effect. The organophosphate Chlorpyrifos (CHP) has been shown to be weakly estrogenic and cause adverse neurodevelopmental effects in mammals. However, no information is available on the endocrine effects of CHP in aquatic organisms. In the digestive gland of the bivalve Mytilus galloprovincialis, a target tissue of both estrogens and pesticides, the possible effects of CHP on the responses to the natural estrogen 17ß-estradiol (E(2)) were investigated. METHODOLOGY/PRINCIPAL FINDINGS: Mussels were exposed to CHP (4.5 mg/l, 72 hrs) and subsequently injected with E(2) (6.75 ng/g dw). Responses were evaluated in CHP, E(2) and CHP/E(2) treatment groups at 24 h p.i. by a biomarker/transcriptomic approach. CHP and E(2) induced additive, synergistic, and antagonistic effects on lysosomal biomarkers (lysosomal membrane stability, lysosome/cytoplasm volume ratio, lipofuscin and neutral lipid accumulation). Additive and synergistic effects were also observed on the expression of estrogen-responsive genes (GSTπ, catalase, 5-HTR) evaluated by RT-Q-PCR. The use of a 1.7K cDNA Mytilus microarray showed that CHP, E(2) and CHP/E(2), induced 81, 44, and 65 Differentially Expressed Genes (DEGs), respectively. 24 genes were exclusively shared between CHP and CHP/E(2), only 2 genes between E(2) and CHP/E(2). Moreover, 36 genes were uniquely modulated by CHP/E(2). Gene ontology annotation was used to elucidate the putative mechanisms involved in the responses elicited by different treatments. CONCLUSIONS: The results show complex interactions between CHP and E(2) in the digestive gland, indicating that the combination of certain pesticides and hormones may give rise to unexpected effects at the molecular/cellular level. Overall, these data demonstrate that CHP can interfere with the mussel responses to natural estrogens.

Non-receptor-mediated actions are responsible for the lipid-lowering effects of iodothyronines in FaO rat hepatoma cells.

Iodothyronines influence lipid metabolism and energy homeostasis. Previous studies demonstrated that 3,5-l-diiodothyronine (T(2)), as well as 3,3',5-L-triiodothyronine (T(3)), was able to both prevent and reverse hepatic steatosis in rats fed a high-fat diet, and this effect depends on a direct action of iodothyronines on the hepatocyte. However, the involvement of thyroid hormone receptors (TRs) in mediating the lipid-lowering effect of iodothyronines was not elucidated. In this study, we investigated the ability of T(2) and T(3) to reduce the lipid overloading using the rat hepatoma FaO cells defective for functional TRs. The absence of constitutive mRNA expression of both TRα1 and TRß1 in FaO cells was verified by RT-qPCR. To mimic the fatty liver condition, FaO cells were treated with a fatty acid mixture and then exposed to pharmacological doses of T(2) or T(3) for 24 h. Lipid accumulation, mRNA expression of the peroxisome proliferator-activated receptors (PPAR-α, -γ, -δ) the acyl-CoA oxidase (AOX), and the stearoyl CoA desaturase (SCD1), as well as fuel-stimulated O(2) consumption in intact cells, were evaluated. Lipid accumulation was associated with an increase in triacylglycerol content, PPARγ mRNA expression, and a decrease in PPARδ and SCD1 mRNA expression. The addition of T(2) or T(3) to lipid-overloaded cells resulted in i) reduction in lipid content; ii) downregulation of PPARα, PPARγ, and AOX expression; iii) increase in PPARδ expression; and iv) stimulation of mitochondrial uncoupling. These data demonstrate, for the first time, that in the hepatocyte, the lipid-lowering actions of both T(2) and T(3) are not mediated by TRs.

Pleiotropic effects of hexavalent chromium (CrVI) in Mytilus galloprovincialis digestive gland.

Hexavalent Chromium Cr(VI) is an important contaminant considered as a model oxidative toxicant released from both domestic and industrial effluents, and represents the predominant chemical form of the metal in aquatic ecosystems. On the other hand, in mammals the reduced form Cr(III) is considered an essential microelement, involved in regulation of lipid and carbohydrate metabolism; moreover, recent evidence suggests that Cr may have endocrine effects. In this work, the effects of Cr(VI) were investigated in the digestive gland of the marine bivalve Mytilus galloprovincialis. Mussels were exposed to 0.1-1-10-100 µg Cr(VI) L(-1) animal(-1) for 96 h. At 100 µg L(-1), a large increase in total Cr tissue content was observed; in these conditions, the lysosomal membranes were completely destabilized, whereas other lysosomal biomarkers (neutral lipids-NL and lipofuscin-LF), as well as different enzyme activities and gene expression were unaffected, this indicating severe stress conditions in the tissue. On the other hand, at lower concentrations, changes in other histochemical, biochemical and molecular endpoints were observed. In particular, at both 1 and 10 µg L(-1), lysosomal destabilization was associated with significant NL and LF accumulation; however, no changes in catalase and GSH transferase (GST) activities were observed. At the same concentrations, GSSG reductase (GSR) activity was significantly increased, this probably reflecting the recycling of GSSG produced in the GSH-mediated intracellular reduction of Cr(VI). Increased activities of the key glycolytic enzymes PFK (phosphofructokinase) and PK (pyruvate kinase) were also observed, indicating that Cr(VI) could affect carbohydrate metabolism. Cr(VI) induced downregulation or no effects on the expression of metallothioneins MT10 and MT20, except for an increase in MT20 transcription in males. Moreover, significant up-regulation of the Mytilus estrogen receptor MeER2 and serotonin receptor (5-HTR) were observed in both sexes. The results demonstrate that exposure to Cr(VI) in the low ppb range did not result in strong toxicity or oxidative stress conditions in mussel digestive gland. On the other hand, our data support the hypothesis that low concentrations of the metal can exert pleiotropic effects on mussel physiology, from modulation of lipid and carbohydrate metabolism, to effects on the expression of estrogen-responsive genes.

Direct effects of iodothyronines on excess fat storage in rat hepatocytes.

BACKGROUND & AIMS: Previous studies have demonstrated that 3,5-L-diiodothyronine (T(2)) is able to prevent lipid accumulation in the liver of rats fed a high-fat diet. Whether this effect is due to a direct action of T(2) on the liver has not been elucidated. In this study, we investigated the ability of T(2) to reduce the excess lipids in isolated hepatocytes treated with fatty acids (FFAs). The effects of T(2) were compared with those elicited by 3,3',5-L-triiodothyronine (T(3)). METHODS: To mimic the fatty liver condition, primary cultures of rat hepatocytes were overloaded with lipids, by exposure to FFAs ("fatty hepatocytes"), and then treated with T(2) or T(3). Lipid content, morphometry of lipid droplets (LDs), and expression of the adipocyte differentiation-related protein (ADRP) and the peroxisome proliferator-activated receptors (PPAR-α, -γ, -δ) were evaluated. Activities of the lipolytic enzyme acyl CoA oxidase-AOX and the antioxidant enzymes superoxide dismutase-SOD and catalase-CAT were also determined. RESULTS: FFA-induced lipid accumulation was associated with an increase in both number/size of LDs and expression of ADRP, PPAR-γ, and PPAR-δ/ß mRNAs, as well as in the activities of AOX, SOD, and CAT. The addition of T(2) or T(3) to "fatty hepatocytes" resulted in a reduction in: (i) lipid content and LD diameter; (ii) PPAR-γ and PPAR-δ expression; (iii) activities of AOX and antioxidant enzymes. CONCLUSIONS: These data demonstrate, for the first time, a direct action of both T(2) and T(3) in reducing the excess fat in cultured hepatocytes.

Effects of vibrio challenge on digestive gland biomarkers and antioxidant gene expression in Mytilus galloprovincialis.

In bivalve molluscs, responses to bacterial infection have been largely characterized in terms of both functional responses and gene expression in the immune cells, the hemocytes. The effects of bacterial challenge at the tissue level, where bacterial infection may cause stressful conditions, have not been so far specifically investigated. Biomarkers are widely utilised to evaluate the health status of bivalves, from the molecular to the organism level, in response to both natural and anthropogenic stressors. In this work, the effects of in vivo challenge with heat-killed vibrio species, Vibrio splendidus LGP32 and Vibrio anguillarum (ATCC19264), on different biomarkers in the digestive gland of the marine bivalve Mytilus galloprovincialis were investigated. Mussels were injected with either vibrio and tissues sampled at 3, 6 and 24 h post injection (p.i.). Lysosomal biomarkers, such as lysosomal membrane stability (LMS) and lipofuscin accumulation, as well as specific activities of antioxidant enzymes (catalase and glutathione transferase-GST) were evaluated. Moreover, the expression of antioxidant molecules (catalase, GST-pi and metallothioneins MT10 and MT20) was determined by quantitative RT-PCR. Both V. splendidus and V. anguillarum significantly affected all parameters measured, to a different extent and at different times p.i. Interestingly, whereas both vibrios induced lysosomal membrane destabilisation and increases in the activities of antioxidant enzymes, distinct responses were observed in terms of lysosomal lipofuscin accumulation and expression of antioxidant molecules. In particular, V. splendidus induced a general increase in the transcription of antioxidant genes, indicating that Mytilus digestive gland can mount an efficient antioxidant response towards this vibrio species. On the other hand, a general down-regulation or no effect was observed with V. anguillarum. The lack of this response was reflected in stronger oxidative stress conditions in the digestive gland of mussels challenged with V. anguillarum, as indicated by higher levels of lysosomal lipofuscin observed at longer times p.i. Overall, these data indicate that lysosomal and oxidative stress biomarkers could be usefully applied in order to monitor early changes in the health status of bivalves induced by bacteria. Moreover, the results support the hypothesis that host responses to bacteria may be taken into account when interpreting biomarker data in ecotoxicological studies.

PAT protein mRNA expression in primary rat hepatocytes: Effects of exposure to fatty acids.

Excess energy is stored as neutral lipids in lipid droplets (LDs) whose surface is coated by PAT proteins, each playing a distinct cellular function. The adipocyte differentiation-related protein (ADRP) and tail-interacting protein (TIP47) are expressed almost ubiquitously, whereas the oxidative tissue-enriched PAT protein (OXPAT) is expressed in specific tissues, such as the liver. In rat liver, only ADRP expression has been documented. This study was aimed at identifying OXPAT and TIP47 transcripts in rat hepatocytes, and investigating how their expression is modulated by excess lipids, using fat-enriched hepatocytes to mimic different degrees of steatosis. Primary rat hepatocytes were exposed to fatty acids (FFAs) for 12, 24 and 36 h. Lipid accumulation was estimated by spectrophotometric quantification of triacylglycerol. Expression of PAT proteins as well as of PPARgamma was evaluated by real-time RT-PCR. Hepatocytes exposed to FFAs showed progressive lipid accumulation. The increase in lipid content was associated with the induction of PAT protein expression. At 12 h, OXPAT and TIP47 mRNA expression was up-regulated. At longer times, the level of OXPAT transcripts remained high, whereas that of TIP47 slowly declined. Conversely, ADRP expression showed a time-dependent increase with exposure to FFAs. This study demonstrates, for the first time, the presence of OXPAT and TIP47 transcripts in rat hepatocytes, as well as their up-regulation with lipid accumulation. The distinct time courses observed for the three PAT proteins during FFA exposure might reflect the different roles played by each protein in lipid metabolism in the hepatocyte. Up-regulation of TIP47 and OXPAT might represent an early response to excess lipids, while, in correspondence with a lipid overload, up-regulation of ADRP could address lipids towards storage.