Gene Co-Expression Networks Offer New Perspectives on Sepsis Pathophysiology.

Sepsis is among the most common causes of death in intensive care units. Septic shock is a type of circulatory shock that shows signs and symptoms that are similar to non-septic shock. Despite the impact of shock on patients and the economic burden, knowledge of the pathophysiology of septic shock is scarce. In this context, weighted gene co-expression network analysis can help to elucidate the molecular mechanisms of this condition. The gene expression dataset used in this study was downloaded from the Gene Expression Omnibus, which contains 80 patients with septic shock, 33 patients with non-septic shock, and 15 healthy controls. Our novel analysis revealed five gene modules specific for patients with septic shock and three specific gene modules for patients with non-septic shock. Interestingly, genes related to septic shock were mainly involved in the immune system and endothelial cells, while genes related to non-septic shock were primarily associated with endothelial cells. Together, the results revealed the specificity of the genes related to the immune system in septic shock. The novel approach developed here showed its potential to identify critical pathways for the occurrence and progression of these conditions while offering new treatment strategies and effective therapies.

Dyslipidemia and Inflammation as Hallmarks of Oxidative Stress in COVID-19: A Follow-Up Study.

Recent works have demonstrated a significant reduction in cholesterol levels and increased oxidative stress in patients with coronavirus disease 2019 (COVID-19). The cause of this alteration is not well known. This study aimed to comprehensively evaluate their possible association during the evolution of COVID-19. This is an observational prospective study. The primary endpoint was to analyze the association between lipid peroxidation, lipid, and inflammatory profiles in COVID-19 patients. A multivariate regression analysis was employed. The secondary endpoint included the long-term follow-up of lipid profiles. COVID-19 patients presented significantly lower values in their lipid profile (total, low, and high-density lipoprotein cholesterol) with greater oxidative stress and inflammatory response compared to the healthy controls. Lipid peroxidation was the unique oxidative parameter with a significant association with the total cholesterol (OR: 0.982; 95% CI: 0.969-0.996; p = 0.012), IL1-RA (OR: 0.999; 95% CI: 0.998-0.999; p = 0.021) IL-6 (OR: 1.062; 95% CI: 1.017-1.110; p = 0.007), IL-7 (OR: 0.653; 95% CI: 0.433-0.986; p = 0.042) and IL-17 (OR: 1.098; 95% CI: 1.010-1.193; p = 0.028). Lipid abnormalities recovered after the initial insult during long-term follow-up (IQR 514 days); however, those with high LPO levels at hospital admission had, during long-term follow-up, an atherogenic lipid profile. Our study suggests that oxidative stress in COVID-19 is associated with derangements of the lipid profile and inflammation. Survivors experienced a recovery in their lipid profiles during long-term follow-up, but those with stronger oxidative responses had an atherogenic lipid profile.

PCR-based diagnosis of respiratory virus in postsurgical septic patients: A preliminary study before SARS-CoV-2 pandemic.

Respiratory viruses are part of the normal microbiota of the respiratory tract, which sometimes cause infection with/without respiratory insufficiency and the need for hospital or ICU admission. The aim of this study is to determine the prevalence of respiratory viruses in nontransplanted postoperative septic patients as well as lymphocyte count influence in their presence and its relationship to mortality. 223 nontransplanted postsurgical septic patients were recruited on the Intensive Care Unit (ICU) at Hospital Clínico Universitario de Valladolid prior to the SARS-COV-2 pandemic. Patients were split into 2 groups according to the presence/absence of respiratory viruses. Multivariate logistic regression analysis was used to identify independent factors related to positive respiratory virus PCR test. Respiratory viruses were isolated in 28.7% of patients. 28-day mortality was not significantly different between virus-positive and virus-negative groups. Logistic regression analysis revealed that lymphocyte count ≤ 928/µl is independently associated with a positive PCR result [OR 3.76, 95% CI (1.71-8.26), P = .001] adjusted by platelet count over 128,500/µL [OR 4.27, 95% CI (1.92-9.50) P < .001] and the presence of hypertension [OR 2.69, 95% CI (1.13-6.36) P = .025] as confounding variables. Respiratory viruses' detection by using PCR in respiratory samples of nontransplanted postoperative septic patients is frequent. These preliminary results revealed that the presence of lymphopenia on sepsis diagnosis is independently associated to a positive virus result, which is not related to a higher 28-day mortality.

CEACAM7 polymorphisms predict genetic predisposition to mortality in post-surgical septic shock patients.

We carried out a retrospective exploratory study on 173 patients who underwent major surgery and developed septic shock after surgery. Our findings suggest that CEACAM7 rs1001578, rs10409040, and rs889365 polymorphisms could influence septic shock-related death in individuals who underwent major surgery.

Effect of environmental stressors on the mRNA expression of ecdysone cascade genes in Chironomus riparius.

Chemical compounds produced by humans are continuously reaching the environment. In this work, we characterised the expression patterns of important endocrine-related genes involved in the ecdysone pathway in the fourth larval instar of the model species Chironomus riparius after exposure to three chemicals: ethinyl oestradiol (EE), nonylphenol (NP) and bis(tributyltin) oxide (TBTO). We used real-time PCR to analyse the gene expression levels of ecdysone receptor (EcR) and ultraspiracle (usp), two genes that encode the dimerising partners of the functional ecdysone receptor; the orphan receptor ERR (oestrogen-related receptor), with an unknown function in invertebrates; and E74, an early response gene induced by ecdysteroids. We estimated the bioaccumulation potential, bioavailability and physicochemical properties of these chemicals, together with a number of other exogenous agents known to interfere with the hormonal system. We also provide a review of previous transcriptional studies showing the effect of all these chemicals on ecdysone cascade genes. This analysis provides useful data for future ecotoxicological studies involving invertebrate species. CAPSULE: Changes in transcriptional activities of EcR, E74, usp and ERR genes after exposure to endocrine-disrupting chemicals would be useful as molecular bioindicators of endocrine disruption in Chironomus riparius.

Can the Cytokine Profile According to ABO Blood Groups Be Related to Worse Outcome in COVID-19 Patients? Yes, They Can.

Severe status of coronavirus disease 2019 (COVID-19) is extremely associated to cytokine release. Moreover, it has been suggested that blood group is also associated with the prevalence and severity of this disease. However, the relationship between the cytokine profile and blood group remains unclear in COVID-19 patients. In this sense, we prospectively recruited 108 COVID-19 patients between March and April 2020 and divided according to ABO blood group. For the analysis of 45 cytokines, plasma samples were collected in the time of admission to hospital ward or intensive care unit and at the sixth day after hospital admission. The results show that there was a risk of more than two times lower of mechanical ventilation or death in patients with blood group O (log rank: p = 0.042). At first time, all statistically significant cytokine levels, except from hepatocyte growth factor, were higher in O blood group patients meanwhile the second time showed a significant drop, between 20% and 40%. In contrast, A/B/AB group presented a maintenance of cytokine levels during time. Hepatocyte growth factor showed a significant association with intubation or mortality risk in non-O blood group patients (OR: 4.229, 95% CI (2.064-8.665), p < 0.001) and also was the only one bad prognosis biomarker in O blood group patients (OR: 8.852, 95% CI (1.540-50.878), p = 0.015). Therefore, higher cytokine levels in O blood group are associated with a better outcome than A/B/AB group in COVID-19 patients.

Lipid peroxidation as a hallmark of severity in COVID-19 patients.

BACKGROUND: Oxidative stress may be a key player in COVID-19 pathogenesis due to its significant role in response to infections. A defective redox balance has been related to viral pathogenesis developing a massive induction of cell death provoked by oxidative stress. The aim of this study is to perform a complete oxidative stress profile evaluation regarding antioxidant enzymes, total antioxidant capacity and oxidative cell damage in order to characterize its role in diagnosis and severity of this disease. METHODS: Blood samples were obtained from 108 COVID-19 patients and 28 controls and metabolites representative of oxidative stress were assessed. The association between lipid peroxidation and 28-day intubation/death risk was evaluated by multivariable regression analysis. Probability of intubation/death to day-28 was analyzed by using Kaplan-Meier curves and tested with the log-rank test. RESULTS: Antioxidant enzymes (Superoxide dismutase (SOD) and Catalase) and oxidative cell damage (Carbonyl and Lipid peroxidation (LPO)) levels were significantly higher in COVID-19 patients while total antioxidant capacity (ABTS and FRAP) levels were lower in these patients. The comparison of oxidative stress molecules' levels across COVID-19 severity revealed that only LPO was statistically different between mild and intubated/death COVID-19 patients. COX multivariate regression analysis identified LPO levels over the OOP (LPO>1948.17 µM) as an independent risk factor for 28-day intubation/death in COVID-19 patients [OR: 2.57; 95% CI: 1.10-5.99; p = 0.029]. Furthermore, Kaplan-Meier curve analysis revealed that COVID-19 patients showing LPO levels above 1948.17 µM were intubated or died 8.4 days earlier on average (mean survival time 15.4 vs 23.8 days) when assessing 28-day intubation/death risk (p < 0.001). CONCLUSION: These findings deepen our knowledge of oxidative stress status in SARS-CoV-2 infection, supporting its important role in COVID-19. In fact, higher lipid peroxidation levels are independently associated to a higher risk of intubation or death at 28 days in COVID-19 patients.

Predictive Modeling of Poor Outcome in Severe COVID-19: A Single-Center Observational Study Based on Clinical, Cytokine and Laboratory Profiles.

Pneumonia is the main cause of hospital admission in COVID-19 patients. We aimed to perform an extensive characterization of clinical, laboratory, and cytokine profiles in order to identify poor outcomes in COVID-19 patients. METHODS: A prospective and consecutive study involving 108 COVID-19 patients was conducted between March and April 2020 at Hospital Clínico Universitario de Valladolid (Spain). Plasma samples from each patient were collected after emergency room admission. Forty-five serum cytokines were measured in duplicate, and clinical data were analyzed using SPPS version 25.0. RESULTS: A multivariate predictive model showed high hepatocyte growth factor (HGF) plasma levels as the only cytokine related to intubation or death risk at hospital admission (OR = 7.38, 95%CI-(1.28-42.4), p = 0.025). There were no comorbidities included in the model except for the ABO blood group, in which the O blood group was associated with a 14-fold lower risk of a poor outcome. Other clinical variables were also included in the predictive model. The predictive model was internally validated by the receiver operating characteristic (ROC) curve with an area under the curve (AUC) of 0.94, a sensitivity of 91.7% and a specificity of 95%. The use of a bootstrapping method confirmed these results. CONCLUSIONS: A simple, robust, and quick predictive model, based on the ABO blood group, four common laboratory values, and one specific cytokine (HGF), could be used in order to predict poor outcomes in COVID-19 patients.

Evaluation of Cytokines as Robust Diagnostic Biomarkers for COVID-19 Detection.

Antigen tests or polymerase chain reaction (PCR) amplification are currently COVID-19 diagnostic tools. However, developing complementary diagnosis tools is mandatory. Thus, we performed a plasma cytokine array in COVID-19 patients to identify novel diagnostic biomarkers. A discovery-validation study in two independent prospective cohorts was performed. The discovery cohort included 136 COVID-19 and non-COVID-19 patients recruited consecutively from 24 March to 11 April 2020. Forty-five cytokines' quantification by the MAGPIX system (Luminex Corp., Austin, TX, USA) was performed in plasma samples. The validation cohort included 117 patients recruited consecutively from 15 to 25 April 2020 for validating results by ELISA. COVID-19 patients showed different levels of multiple cytokines compared to non-COVID-19 patients. A single chemokine, IP-10, accurately identified COVID-19 patients who required hospital admission (AUC: 0.962; 95%CI (0.933-0.992); p < 0.001)). The results were validated in an independent cohort by multivariable analysis (OR: 25.573; 95%CI (8.127-80.469); p < 0.001) and AUROC (AUC: 0.900; 95%CI (0.846-0.954); p < 0.001). Moreover, showing IP-10 plasma levels over 173.35 pg/mL identified COVID-19 with higher sensitivity (86.20%) than the first SARS-CoV-2 PCR. Our discover-validation study identified IP-10 as a robust biomarker in clinical practice for COVID-19 diagnosis at hospital. Therefore, IP-10 could be used as a complementary tool in clinical practice, especially in emergency departments.

Genetic Susceptibility to Acute Kidney Injury.

Acute kidney injury (AKI) is a widely held concern related to a substantial burden of morbidity, mortality and expenditure in the healthcare system. AKI is not a simple illness but a complex conglomeration of syndromes that often occurs as part of other syndromes in its wide clinical spectrum of the disease. Genetic factors have been suggested as potentially responsible for its susceptibility and severity. As there is no current cure nor an effective treatment other than generally accepted supportive measures and renal replacement therapy, updated knowledge of the genetic implications may serve as a strategic tactic to counteract its dire consequences. Further understanding of the genetics that predispose AKI may shed light on novel approaches for the prevention and treatment of this condition. This review attempts to address the role of key genes in the appearance and development of AKI, providing not only a comprehensive update of the intertwined process involved but also identifying specific markers that could serve as precise targets for further AKI therapies.

Endothelial Dysfunction and Neutrophil Degranulation as Central Events in Sepsis Physiopathology.

Sepsis is a major health problem worldwide. It is a time-dependent disease, with a high rate of morbidity and mortality. In this sense, an early diagnosis is essential to reduce these rates. The progressive increase of both the incidence and prevalence of sepsis has translated into a significant socioeconomic burden for health systems. Currently, it is the leading cause of noncoronary mortality worldwide and represents one of the most prevalent pathologies both in hospital emergency services and in intensive care units. In this article, we review the role of both endothelial dysfunction and neutrophil dysregulation in the physiopathology of this disease. The lack of a key symptom in sepsis makes it difficult to obtain a quick and accurate diagnosis of this condition. Thus, it is essential to have fast and reliable diagnostic tools. In this sense, the use of biomarkers can be a very important alternative when it comes to achieving these goals. Both new biomarkers and treatments related to endothelial dysfunction and neutrophil dysregulation deserve to be further investigated in order to open new venues for the diagnosis, treatment and prognosis of sepsis.

HGF, IL-1α, and IL-27 Are Robust Biomarkers in Early Severity Stratification of COVID-19 Patients.

Pneumonia is the leading cause of hospital admission and mortality in coronavirus disease 2019 (COVID-19). We aimed to identify the cytokines responsible for lung damage and mortality. We prospectively recruited 108 COVID-19 patients between March and April 2020 and divided them into four groups according to the severity of respiratory symptoms. Twenty-eight healthy volunteers were used for normalization of the results. Multiple cytokines showed statistically significant differences between mild and critical patients. High HGF levels were associated with the critical group (OR = 3.51; p < 0.001; 95%CI = 1.95-6.33). Moreover, high IL-1α (OR = 1.36; p = 0.01; 95%CI = 1.07-1.73) and low IL-27 (OR = 0.58; p < 0.005; 95%CI = 0.39-0.85) greatly increased the risk of ending up in the severe group. This model was especially sensitive in order to predict critical status (AUC = 0.794; specificity = 69.74%; sensitivity = 81.25%). Furthermore, high levels of HGF and IL-1α showed significant results in the survival analysis (p = 0.033 and p = 0.011, respectively). HGF, IL-1α, and IL 27 at hospital admission were strongly associated with severe/critical COVID-19 patients and therefore are excellent predictors of bad prognosis. HGF and IL-1α were also mortality biomarkers.

Cytokine and interleukin profile in patients with headache and COVID-19: A pilot, CASE-control, study on 104 patients.

BACKGROUND: The presence of headache during the acute phase of COVID-19 could be associated with the innate response and the cytokine release. We aim to compare the cytokine and interleukin profile in hospitalized COVID-19 patients at the moment of admission with and without headache during the course of the disease. METHODS: An observational analytic study with a case control design was performed. Hospitalized patients from a tertiary hospital with confirmed COVID-19 disease were included. Patients were classified into the headache or the control group depending on whether they presented headache not better accounted for by another headache disorder other than acute headache attributed to systemic viral infection. Several demographic and clinical variables were studies in both groups. We determined the plasmatic levels of 45 different cytokines and interleukins from the first hospitalization plasma extraction in both groups. RESULTS: One hundred and four patients were included in the study, aged 67.4 (12.8), 43.3% female. Among them, 29 (27.9%) had headache. Patients with headache were younger (61.8 vs. 69.5 years, p = 0.005) and had higher frequency of fever (96.6 vs. 78.7%, p = 0.036) and anosmia (48.3% vs. 22.7%, p = 0.016). In the comparison of the crude median values of cytokines, many cytokines were different between both groups. In the comparison of the central and dispersion parameters between the two groups, GROa, IL-10, IL1RA, IL-21, IL-22 remained statistically significant. After adjusting the values for age, sex, baseline situation and COVID-19 severity, IL-10 remained statistically significant (3.3 vs. 2.2 ng/dL, p = 0.042), with a trend towards significance in IL-23 (11.9 vs. 8.6 ng/dL, p = 0.082) and PIGF1 (1621.8 vs. 110.6 ng/dL, p = 0.071). CONCLUSIONS: The higher levels of IL-10 -an anti-inflammatory cytokine- found in our sample in patients with headache may be explained as a counteract of cytokine release, reflecting a more intense immune response in these patients.

Distinguishing septic shock from non-septic shock in postsurgical patients using gene expression.

OBJECTIVES: To obtain a gene expression signature to distinguish between septic shock and non-septic shock in postoperative patients, since patients with both conditions show similar signs and symptoms. METHODS: Differentially expressed genes were selected by microarray analysis in the discovery cohort. These genes were evaluated by quantitative real time polymerase chain reactions in the validation cohort to determine their reliability and predictive capacity by receiver operating characteristic curve analysis. RESULTS: Differentially expressed genes selected were IGHG1, IL1R2, LCN2, LTF, MMP8, and OLFM4. The multivariate regression model for gene expression presented an area under the curve value of 0.922. These genes were able to discern between both shock conditions better than other biomarkers used for diagnosis of these conditions, such as procalcitonin (0.589), C-reactive protein (0.705), or neutrophils (0.605). CONCLUSIONS: Gene expression patterns provided a robust tool to distinguish septic shock from non-septic shock postsurgical patients and shows the potential to provide an immediate and specific treatment, avoiding the unnecessary use of broad-spectrum antibiotics and the development of antimicrobial resistance, secondary infections and increase health care costs.

IFNL3 rs12980275 Polymorphism Predicts Septic Shock-Related Death in Patients Undergoing Major Surgery: A Retrospective Study.

Interferon lambda 3 (IFNL3, previously called IL-28B) is a cytokine with effects against viral and bacterial pathogens. We aimed to analyze the IFNL3 rs12980275 SNP in patients who underwent major surgery, in order to establish its relationship with susceptibility to septic shock and septic shock-related death in these patients. We performed a case-control study on 376 patients to establish the association between IFNL3 rs12980275 SNP and the susceptibility to develop septic shock. Besides, we performed a longitudinal study among 172 septic shock patients using survival analysis with one censoring point of 28-days mortality. The IFNL3 rs12980275 polymorphism was genotyped by Agena Bioscience's MassARRAY platform. IFNL3 rs12980275 polymorphism was not associated with higher susceptibility to infection and septic shock development. Regarding survival analysis, the Kaplan-Meier analysis showed that patients with IFNL3 rs12980275 AA genotype had higher survival than patients with GG genotype (p = 0.003). The Cox regression analysis adjusted by the most relevant clinical and epidemiological characteristics showed that the GG genotype (recessive model) and the presence of the G allele (additive model) were associated with higher risk of death [adjusted hazard ratio (aHR) = 2.15, p = 0.034; aHR = 1.50, p = 0.030, respectively]. In conclusion, IFNL3 rs12980275 polymorphism was associated with septic shock-related death in patients who underwent major surgery. The A allele was linked to protection, and the G allele was associated with an increased risk of death. This is a first preliminary study that suggests for the first time a role of IFNL3 polymorphisms in the prognosis of septic shock.

Gene Expression Patterns Distinguish Mortality Risk in Patients with Postsurgical Shock.

Nowadays, mortality rates in intensive care units are the highest of all hospital units. However, there is not a reliable prognostic system to predict the likelihood of death in patients with postsurgical shock. Thus, the aim of the present work is to obtain a gene expression signature to distinguish the low and high risk of death in postsurgical shock patients. In this sense, mRNA levels were evaluated by microarray on a discovery cohort to select the most differentially expressed genes between surviving and non-surviving groups 30 days after the operation. Selected genes were evaluated by quantitative real-time polymerase chain reaction (qPCR) in a validation cohort to validate the reliability of data. A receiver-operating characteristic analysis with the area under the curve was performed to quantify the sensitivity and specificity for gene expression levels, which were compared with predictions by established risk scales, such as acute physiology and chronic health evaluation (APACHE) and sequential organ failure assessment (SOFA). IL1R2, CD177, RETN, and OLFM4 genes were upregulated in the non-surviving group of the discovery cohort, and their predictive power was confirmed in the validation cohort. This work offers new biomarkers based on transcriptional patterns to classify the postsurgical shock patients according to low and high risk of death. The results present more accuracy than other mortality risk scores.

Effects at molecular level of multi-walled carbon nanotubes (MWCNT) in Chironomus riparius (DIPTERA) aquatic larvae.

Nowadays, due to the physical, chemical, electrical, thermal and mechanical properties of carbon nanotubes (CNT), its have been currently incorporated into biomedical products and they are employed in drug delivery drug administration, biosensor design, microbial treatments, consumer products, and new products containing CNT are expected in the future. CNT are hydrophobic and have a tendency to accumulate in sediments if they are released into aquatic ecosystems. Vertebrate studies have revealed concerns about the toxicity of carbon nanotubes, but there is very limited data on the toxic effects in aquatic invertebrate species. The aim of the present study is to determine the effects of MWCNT in Chironomus riparius at the molecular level, understanding its mode of action and analyzing the suitability of this species to monitor and assess risk of nanomaterials in aquatic ecosystems. To evaluate possible toxic effects caused by carbon nanotube environmental dispersion with regard to aquatic compartment, we study the mRNA levels of several related genes with DNA repairing mechanisms, cell stress response, cell apoptosis and cytoskeleton by Real-Time PCR and proposed a freshwater invertebrate C. riparius, which is a reference organism in aquatic toxicology. The obtained results show a transcriptional alteration of some genes included in this study, indicating that different cell processes are affected and providing one the first evidences in the mechanisms of action of MWCNT in invertebrates. Moreover, this data reinforces the need for further studies to assess the environmental risk of nanomaterial to prevent future damage to aquatic ecosystems.

Bisphenol A (BPA) modulates the expression of endocrine and stress response genes in the freshwater snail Physa acuta.

Bisphenol A (BPA), a known endocrine disrupting chemical (EDC) that can mimic the action of oestrogens by interacting with hormone receptors, is potentially able to influence reproductive functions in vertebrates and invertebrates. The freshwater pulmonate Physa acuta is a sensitive organism to xenobiotics appropriate for aquatic toxicity testing in environmental studies. This study was conducted to explore the effects of BPA on the Gastropoda endocrine system. The effects following a range of exposure times (5-96h) to BPA in P. acuta were evaluated at the molecular level by analysing changes in the transcriptional activity of the endocrine-related genes oestrogen receptor (ER), oestrogen-related receptor (ERR), and retinoid X receptor (RXR), as well as in genes involved in the stress response, such as hsp70 and hsp90. Real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis showed that BPA induced a significant increase in the mRNA levels of ER, ERR, and RXR, suggesting that these receptors could be involved in similar pathways or regulation events in the endocrine disruptor activity of this chemical at the molecular level in Gastropoda. Additionally, the hsp70 expression was upregulated after 5 and 72h of BPA exposures, but hsp90 was only upregulated after 5h of BPA exposure. Finally, we assessed the glutathione-S-transferase (GST) activity after BPA treatment and found that it was affected after 48h. In conclusion, these data provide, for the first time, evidences of molecular effects produced by BPA in the endocrine system of Gastropoda, supporting the potential of ER, ERR and RXR as biomarkers to analyse putative EDCs in ecotoxicological studies. Moreover, our results suggest that P. acuta is an appropriate sentinel organism to evaluate the effect of EDCs in the freshwater environment.

Response of detoxification system genes on Chironomus riparius aquatic larvae after antibacterial agent triclosan exposures.

Triclosan (TCS) is an antimicrobial agent used in a range of personal care and consumer products and is commonly detected in aquatic ecosystems. In the present study, the effects of TCS at the molecular level on the detoxification system of Chironomus riparius aquatic larvae, a test organism widely used for the assessment of aquatic toxicology, were evaluated. The obtained results show that this xenobiotic was able to induce significant changes in transcripts from different cytochrome P450s and glutathione s-transferases genes, involved in phase I and phase II of detoxification system, respectively. In contrast, TCS did not affect the glutathione S-transferase enzyme activity nor the expression pattern of multidrug resistance-associated protein 1, which belongs to phase III of detoxification system. These results provide information about the effects of TCS on the detoxification mechanism of C. riparius and offers different biomarker genes that could be useful in ecotoxicological studies, risk assessment and bioremediation.

Endocrine-related genes are altered by antibacterial agent triclosan in Chironomus riparius aquatic larvae.

Triclosan (TCS) is an antibacterial agent widely used in personal care and consumer products and commonly detected in aquatic ecosystems. In the present study, the effects of TCS on endocrine-related genes of Chironomus riparius aquatic larvae, a reference organism in aquatic toxicology, were evaluated. Twenty-four-hour in vivo exposures at 10µg/L, 100µg/L, and 1000µg/L TCS revealed that this xenobiotic was able to alter the transcriptional activity of ecdysone receptor gene (EcR), the ultraspiracle gene (usp), the estrogen-related receptor gene (ERR), and the E74 early ecdysone-inducible gene, as measured by real-time RT-PCR. Moreover, the hsp70 gene, a heat shock protein gene, was upregulated after exposure to TCS. The results of the present work provide the first evidence of the potential disruptive effects of TCS in endocrine-related genes suggesting a mode of action that mimics ecdysteroid hormones in insects.