Adipocyte HSL is required for maintaining circulating vitamin A and RBP4 levels during fasting.

Vitamin A (retinol) is distributed via the blood bound to its specific carrier protein, retinol-binding protein 4 (RBP4). Retinol-loaded RBP4 is secreted into the circulation exclusively from hepatocytes, thereby mobilizing hepatic retinoid stores that represent the major vitamin A reserves in the body. The relevance of extrahepatic retinoid stores for circulating retinol and RBP4 levels that are usually kept within narrow physiological limits is unknown. Here, we show that fasting affects retinoid mobilization in a tissue-specific manner, and that hormone-sensitive lipase (HSL) in adipose tissue is required to maintain serum concentrations of retinol and RBP4 during fasting in mice. We found that extracellular retinol-free apo-RBP4 induces retinol release by adipocytes in an HSL-dependent manner. Consistently, global or adipocyte-specific HSL deficiency leads to an accumulation of retinoids in adipose tissue and a drop of serum retinol and RBP4 during fasting, which affects retinoid-responsive gene expression in eye and kidney and lowers renal retinoid content. These findings establish a novel crosstalk between liver and adipose tissue retinoid stores for the maintenance of systemic vitamin A homeostasis during fasting.

Prospective Study on the Influence of Occupational Hand Protection Products on the Efficacy of Hand Disinfection.

BACKGROUND: To prevent occupational skin diseases, employees are instructed to periodically apply hand protection products as a barrier to protect their hands from water, cleaning agents or other irritants. The aim of this work was to investigate whether bacteria present on the skin at the time of protection product application are enclosed underneath this protective layer, if they can be transferred to other surfaces and if a standard isopropanol-based skin disinfectant can nonetheless reduce the bacterial burden. METHODS: This prospective study was conducted in human volunteers based on the European Standard (EN 1500) to assess the burden of microorganisms before and after the application of various protection product formulations and subsequent hand disinfection. RESULTS: All protection products, with the exception of alcohol-based gels, enclosed bacteria underneath a lipid layer which could be transferred onto other surfaces. Still, the hand disinfectant efficiently reduced the bacteria burden. DISCUSSION: In occupations where proper hand hygiene is vital, alcohol-based gels might be the best option for the protection of the skin barrier as well as for reducing the contamination risk. CONCLUSION: An alcohol-based disinfection agent can dissolve the lipid film of protection products following the standard protocol for hygienic hand disinfection.

Experience report of two living systematic Cochrane reviews on COVID-19.

INTRODUCTION: Up-to-date systematic reviews (SRs) are essential for making evidence-based decisions. During the 2019 coronavirus (COVID-19) pandemic, there was a particular need for up-to-date evidence, making the living systematic review (LSR) approach an appropriate review type. However, this approach poses certain challenges. OBJECTIVE AND OUTLINE: We aim to provide practice insights and report challenges that we faced while conducting two Cochrane LSRs on COVID-19 treatments with (i) convalescent plasma and (ii) systemic corticosteroids. We address our objective with an experience report and share challenges of the following components based on Iannizzi et al. (2022): study design, publication types, intervention/comparator, outcomes, search strategy, review updates and transparent reporting of differences between review updates. RESULTS: Regarding the study design, the plasma LSR included different study designs because RCT data were not available at the beginning of the pandemic, whereas for the corticosteroids LSR, which started several months later, RCT data were already available. The challenges in both LSRs included the publication types (preprints were included with caution) and the intervention/comparator, for instance the unavailability of standard of care for either LSR, or SARS-CoV-2 variants occurrence. Further challenges in both LSRs occurred in the components "outcome sets" (which had to be adjusted) and "literature search". The decision criteria for updating were based on important studies and available resources in both LSRs and policy relevance in the plasma LSR. Transparent reporting of the differences between the various update versions were discussed for both LSRs. DISCUSSION AND CONCLUSION: In summary, there are similarities and differences regarding challenges of review components for both LSRs. It is important to keep in mind that the two LSR examples presented here were conducted in the wake of the COVID-19 pandemic. Therefore, many of the challenges are attributable to the pandemic and are not specific to LSRs, such as constant adjustments of the outcome sets or changes in the database search. Nevertheless, we believe that some of these aspects are helpful for LSR authors and are applicable to other LSRs outside the pandemic context, particularly in areas where new evidence is rapidly emerging.

Systemic corticosteroids for the treatment of COVID-19: Equity-related analyses and update on evidence.

BACKGROUND: Systemic corticosteroids are used to treat people with COVID-19 because they counter hyper-inflammation. Existing evidence syntheses suggest a slight benefit on mortality. Nonetheless, size of effect, optimal therapy regimen, and selection of patients who are likely to benefit most are factors that remain to be evaluated. OBJECTIVES: To assess whether and at which doses systemic corticosteroids are effective and safe in the treatment of people with COVID-19, to explore equity-related aspects in subgroup analyses, and to keep up to date with the evolving evidence base using a living systematic review approach. SEARCH METHODS: We searched the Cochrane COVID-19 Study Register (which includes PubMed, Embase, CENTRAL, ClinicalTrials.gov, WHO ICTRP, and medRxiv), Web of Science (Science Citation Index, Emerging Citation Index), and the WHO COVID-19 Global literature on coronavirus disease to identify completed and ongoing studies to 6 January 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that evaluated systemic corticosteroids for people with COVID-19. We included any type or dose of systemic corticosteroids and the following comparisons: systemic corticosteroids plus standard care versus standard care, different types, doses and timings (early versus late) of corticosteroids. We excluded corticosteroids in combination with other active substances versus standard care, topical or inhaled corticosteroids, and corticosteroids for long-COVID treatment. DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methodology. To assess the risk of bias in included studies, we used the Cochrane 'Risk of bias' 2 tool for RCTs. We rated the certainty of the evidence using the GRADE approach for the following outcomes: all-cause mortality up to 30 and 120 days, discharged alive (clinical improvement), new need for invasive mechanical ventilation or death (clinical worsening), serious adverse events, adverse events, hospital-acquired infections, and invasive fungal infections. MAIN RESULTS: We included 16 RCTs in 9549 participants, of whom 8271 (87%) originated from high-income countries. A total of 4532 participants were randomised to corticosteroid arms and the majority received dexamethasone (n = 3766). These studies included participants mostly older than 50 years and male. We also identified 42 ongoing and 23 completed studies lacking published results or relevant information on the study design. Hospitalised individuals with a confirmed or suspected diagnosis of symptomatic COVID-19 Systemic corticosteroids plus standard care versus standard care plus/minus placebo We included 11 RCTs (8019 participants), one of which did not report any of our pre-specified outcomes and thus our analyses included outcome data from 10 studies. Systemic corticosteroids plus standard care compared to standard care probably reduce all-cause mortality (up to 30 days) slightly (risk ratio (RR) 0.90, 95% confidence interval (CI) 0.84 to 0.97; 7898 participants; estimated absolute effect: 274 deaths per 1000 people not receiving systemic corticosteroids compared to 246 deaths per 1000 people receiving the intervention (95% CI 230 to 265 per 1000 people); moderate-certainty evidence). The evidence is very uncertain about the effect on all-cause mortality (up to 120 days) (RR 0.74, 95% CI 0.23 to 2.34; 485 participants). The chance of clinical improvement (discharged alive at day 28) may slightly increase (RR 1.07, 95% CI 1.03 to 1.11; 6786 participants; low-certainty evidence) while the risk of clinical worsening (new need for invasive mechanical ventilation or death) may slightly decrease (RR 0.92, 95% CI 0.84 to 1.01; 5586 participants; low-certainty evidence). For serious adverse events (two RCTs, 678 participants), adverse events (three RCTs, 447 participants), hospital-acquired infections (four RCTs, 598 participants), and invasive fungal infections (one study, 64 participants), we did not perform any analyses beyond the presentation of descriptive statistics due to very low-certainty evidence (high risk of bias, heterogeneous definitions, and underreporting). Different types, dosages or timing of systemic corticosteroids We identified one RCT (86 participants) comparing methylprednisolone to dexamethasone, thus the evidence is very uncertain about the effect of methylprednisolone on all-cause mortality (up to 30 days) (RR 0.51, 95% CI 0.24 to 1.07; 86 participants). None of the other outcomes of interest were reported in this study. We included four RCTs (1383 participants) comparing high-dose dexamethasone (12 mg or higher) to low-dose dexamethasone (6 mg to 8 mg). High-dose dexamethasone compared to low-dose dexamethasone may reduce all-cause mortality (up to 30 days) (RR 0.87, 95% CI 0.73 to 1.04; 1269 participants; low-certainty evidence), but the evidence is very uncertain about the effect of high-dose dexamethasone on all-cause mortality (up to 120 days) (RR 0.93, 95% CI 0.79 to 1.08; 1383 participants) and it may have little or no impact on clinical improvement (discharged alive at 28 days) (RR 0.98, 95% CI 0.89 to 1.09; 200 participants; low-certainty evidence). Studies did not report data on clinical worsening (new need for invasive mechanical ventilation or death). For serious adverse events, adverse events, hospital-acquired infections, and invasive fungal infections, we did not perform analyses beyond the presentation of descriptive statistics due to very low-certainty evidence. We could not identify studies for comparisons of different timing and systemic corticosteroids versus other active substances. Equity-related subgroup analyses We conducted the following subgroup analyses to explore equity-related factors: sex, age (< 70 years; ≥ 70 years), ethnicity (Black, Asian or other versus White versus unknown) and place of residence (high-income versus low- and middle-income countries). Except for age and ethnicity, no evidence for differences could be identified. For all-cause mortality up to 30 days, participants younger than 70 years seemed to benefit from systemic corticosteroids in comparison to those aged 70 years and older. The few participants from a Black, Asian, or other minority ethnic group showed a larger estimated effect than the many White participants. Outpatients with asymptomatic or mild disease There are no studies published in populations with asymptomatic infection or mild disease. AUTHORS' CONCLUSIONS: Systemic corticosteroids probably slightly reduce all-cause mortality up to 30 days in people hospitalised because of symptomatic COVID-19, while the evidence is very uncertain about the effect on all-cause mortality up to 120 days. For younger people (under 70 years of age) there was a potential advantage, as well as for Black, Asian, or people of a minority ethnic group; further subgroup analyses showed no relevant effects. Evidence related to the most effective type, dose, or timing of systemic corticosteroids remains immature. Currently, there is no evidence on asymptomatic or mild disease (non-hospitalised participants). Due to the low to very low certainty of the current evidence, we cannot assess safety adequately to rule out harmful effects of the treatment, therefore there is an urgent need for good-quality safety data. Findings of equity-related subgroup analyses should be interpreted with caution because of their explorative nature, low precision, and missing data. We identified 42 ongoing and 23 completed studies lacking published results or relevant information on the study design, suggesting there may be possible changes of the effect estimates and certainty of the evidence in the future.

Acute retinol mobilization by retinol-binding protein 4 in mouse liver induces fibroblast growth factor 21 expression.

Hepatocytes secrete retinol-binding protein 4 (RBP4) into circulation, thereby mobilizing vitamin A from the liver to provide retinol for extrahepatic tissues. Obesity and insulin resistance are associated with elevated RBP4 levels in the blood. However, in a previous study, we observed that chronically increased RBP4 by forced Rbp4 expression in the liver does not impair glucose homeostasis in mice. Here, we investigated the effects of an acute mobilization of hepatic vitamin A stores by hepatic overexpression of RBP4 in mice. We show that hepatic retinol mobilization decreases body fat content and enhances fat turnover. Mechanistically, we found that acute retinol mobilization increases hepatic expression and serum levels of fibroblast growth factor 21 (FGF21), which is regulated by retinol mobilization and retinoic acid in primary hepatocytes. Moreover, we provide evidence that the insulin-sensitizing effect of FGF21 is associated with organ-specific adaptations in retinoid homeostasis. Taken together, our findings identify a novel crosstalk between retinoid homeostasis and FGF21 in mice with acute RBP4-mediated retinol mobilization from the liver.

KIAA1363-A Multifunctional Enzyme in Xenobiotic Detoxification and Lipid Ester Hydrolysis.

KIAA1363, annotated as neutral cholesterol ester hydrolase 1 (NCEH1), is a member of the arylacetamide deacetylase (AADAC) protein family. The name-giving enzyme, AADAC, is known to hydrolyze amide and ester bonds of a number of xenobiotic substances, as well as clinical drugs and of endogenous lipid substrates such as diglycerides, respectively. Similarly, KIAA1363, annotated as the first AADAC-like protein, exhibits enzymatic activities for a diverse substrate range including the xenobiotic insecticide chlorpyrifos oxon and endogenous substrates, acetyl monoalkylglycerol ether, cholesterol ester, and retinyl ester. Two independent knockout mouse models have been generated and characterized. However, apart from reduced acetyl monoalkylglycerol ether and cholesterol ester hydrolase activity in specific tissues and cell types, no gross-phenotype has been reported. This raises the question of its physiological role and whether it functions as drug detoxifying enzyme and/or as hydrolase/lipase of endogenous substrates. This review delineates the current knowledge about the structure, function and of the physiological role of KIAA1363, as evident from the phenotypical changes inflicted by pharmacological inhibition or by silencing as well as knockout of KIAA1363 gene expression in cells, as well as mouse models, respectively.

ATGL-dependent white adipose tissue lipolysis controls hepatocyte PPARα activity.

In hepatocytes, peroxisome proliferator-activated receptor α (PPARα) orchestrates a genomic and metabolic response required for homeostasis during fasting. This includes the biosynthesis of ketone bodies and of fibroblast growth factor 21 (FGF21). Here we show that in the absence of adipose triglyceride lipase (ATGL) in adipocytes, ketone body and FGF21 production is impaired upon fasting. Liver gene expression analysis highlights a set of fasting-induced genes sensitive to both ATGL deletion in adipocytes and PPARα deletion in hepatocytes. Adipose tissue lipolysis induced by activation of the ß3-adrenergic receptor also triggers such PPARα-dependent responses not only in the liver but also in brown adipose tissue (BAT). Intact PPARα activity in hepatocytes is required for the cross-talk between adipose tissues and the liver during fat mobilization.

Inhaled corticosteroids for the treatment of COVID-19.

BACKGROUND: Inhaled corticosteroids are well established for the long-term treatment of inflammatory respiratory diseases such as asthma or chronic obstructive pulmonary disease. They have been investigated for the treatment of coronavirus disease 2019 (COVID-19). The anti-inflammatory action of inhaled corticosteroids might have the potential to reduce the risk of severe illness resulting from hyperinflammation in COVID-19. OBJECTIVES: To assess whether inhaled corticosteroids are effective and safe in the treatment of COVID-19; and to maintain the currency of the evidence, using a living systematic review approach. SEARCH METHODS: We searched the Cochrane COVID-19 Study Register (which includes CENTRAL, PubMed, Embase, ClinicalTrials.gov, WHO ICTRP, and medRxiv), Web of Science (Science Citation Index, Emerging Citation Index), and the WHO COVID-19 Global literature on coronavirus disease to identify completed and ongoing studies to 7 October 2021. SELECTION CRITERIA: We included randomised controlled trials (RCTs) evaluating inhaled corticosteroids for COVID-19, irrespective of disease severity, age, sex, or ethnicity. We included the following interventions: any type or dose of inhaled corticosteroids. We included the following comparison: inhaled corticosteroids plus standard care versus standard care (with or without placebo). We excluded studies examining nasal or topical steroids. DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methodology. For risk of bias assessment, we used the Cochrane RoB 2 tool. We rated the certainty of evidence using the GRADE approach for the outcomes of mortality, admission to hospital or death, symptom resolution, time to symptom resolution, serious adverse events, adverse events, and infections. MAIN RESULTS: Inhaled corticosteroids plus standard care versus standard care (with/without placebo) - People with a confirmed diagnosis of moderate-to-severe COVID-19 We found no studies that included people with a confirmed diagnosis of moderate-to-severe COVID-19. - People with a confirmed diagnosis of asymptomatic SARS-CoV-2 infection or mild COVID-19 We included three RCTs allocating 3607 participants, of whom 2490 had confirmed mild COVID-19. We analysed a subset of the total number of participants recruited to the studies (2171, 52% female) as some trials had a platform design where not all participants were allocated to treatment groups simultaneously. The included studies were community-based, recruiting people who were able to use inhaler devices to deliver steroids and relied on remote assessment and self-reporting of outcomes. Most people were older than 50 years and had co-morbidities such as hypertension, lung disease, or diabetes. The studies were conducted in high-income countries prior to wide-scale vaccination programmes. A total of 1057 participants were analysed in the inhaled corticosteroid arm (budesonide: 860 participants; ciclesonide: 197 participants), and 1075 participants in the control arm. No studies included people with asymptomatic SARS-CoV-2 infection. With respect to the following outcomes, inhaled corticosteroids compared to standard care: - may result in little to no difference in all-cause mortality (at up to day 30) (risk ratio (RR) 0.61, 95% confidence interval (CI) 0.22 to 1.67; 2132 participants; low-certainty evidence). In absolute terms, this means that for every nine deaths per 1000 people not receiving inhaled corticosteroids, there were six deaths per 1000 people who did receive the intervention (95% CI 2 to 16 per 1000 people); - probably reduces admission to hospital or death (at up to 30 days) (RR 0.72, 95% CI 0.51 to 0.99; 2025 participants; moderate-certainty evidence); - probably increases resolution of all initial symptoms at day 14 (RR 1.19, 95% CI 1.09 to 1.30; 1986 participants; moderate-certainty evidence); - may reduce the duration to symptom resolution (at up to day 30) (by -4.00 days, 95% CI -6.22 to -1.78 less than control group rate of 12 days; 139 participants; low-certainty evidence); - the evidence is very uncertain about the effect on serious adverse events (during study period) (RR 0.51, 95% CI 0.09 to 2.76; 1586 participants; very low-certainty evidence); - may result in little to no difference in adverse events (at up to day 30) (RR 0.78, 95% CI 0.47 to 1.31; 400 participants; low-certainty evidence); - may result in little to no difference in infections (during study period) (RR 0.88, 95% CI 0.30 to 2.58; 400 participants; low-certainty evidence). As studies did not report outcomes for subgroups (e.g. age, ethnicity, sex), we did not perform subgroup analyses. AUTHORS' CONCLUSIONS: In people with confirmed COVID-19 and mild symptoms who are able to use inhaler devices, we found moderate-certainty evidence that inhaled corticosteroids probably reduce the combined endpoint of admission to hospital or death and increase the resolution of all initial symptoms at day 14. Low-certainty evidence suggests that corticosteroids make little to no difference in all-cause mortality up to day 30 and may decrease the duration to symptom resolution. We do not know whether inhaled corticosteroids increase or decrease serious adverse events due to heterogeneity in the way they were reported across the studies. There is low-certainty evidence that inhaled corticosteroids may decrease infections. The evidence we identified came from studies in high-income settings using budesonide and ciclesonide prior to vaccination roll-outs. We identified a lack of evidence concerning quality of life assessments, serious adverse events, and people with asymptomatic infection or with moderate-to-severe COVID-19. The 10 ongoing and four completed, unpublished RCTs that we identified in trial registries address similar settings and research questions as in the current body of evidence. We expect to incorporate the findings of these studies in future versions of this review. We monitor newly published results of RCTs on inhaled corticosteroids on a weekly basis and will update the review when the evidence or our certainty in the evidence changes.

KIAA1363 affects retinyl ester turnover in cultured murine and human hepatic stellate cells.

Large quantities of vitamin A are stored as retinyl esters (REs) in specialized liver cells, the hepatic stellate cells (HSCs). To date, the enzymes controlling RE degradation in HSCs are poorly understood. In this study, we identified KIAA1363 (also annotated as arylacetamide deacetylase 1 or neutral cholesterol ester hydrolase 1) as a novel RE hydrolase. We show that KIAA1363 is expressed in the liver, mainly in HSCs, and exhibits RE hydrolase activity at neutral pH. Accordingly, addition of the KIAA1363-specific inhibitor JW480 largely reduced RE hydrolase activity in lysates of cultured murine and human HSCs. Furthermore, cell fractionation experiments and confocal microscopy studies showed that KIAA1363 localizes to the endoplasmic reticulum. We demonstrate that overexpression of KIAA1363 in cells led to lower cellular RE content after a retinol loading period. Conversely, pharmacological inhibition or shRNA-mediated silencing of KIAA1363 expression in cultured murine and human HSCs attenuated RE degradation. Together, our data suggest that KIAA1363 affects vitamin A metabolism of HSCs by hydrolyzing REs at the endoplasmic reticulum, thereby counteracting retinol esterification and RE storage in lipid droplets.

Systemic corticosteroids for the treatment of COVID-19.

BACKGROUND: Systemic corticosteroids are used to treat people with COVID-19 because they counter hyper-inflammation. Existing evidence syntheses suggest a slight benefit on mortality. So far, systemic corticosteroids are one of the few treatment options for COVID-19. Nonetheless, size of effect, certainty of the evidence, optimal therapy regimen, and selection of patients who are likely to benefit most are factors that remain to be evaluated. OBJECTIVES: To assess whether systemic corticosteroids are effective and safe in the treatment of people with COVID-19, and to keep up to date with the evolving evidence base using a living systematic review approach. SEARCH METHODS: We searched the Cochrane COVID-19 Study Register (which includes PubMed, Embase, CENTRAL, ClinicalTrials.gov, WHO ICTRP, and medRxiv), Web of Science (Science Citation Index, Emerging Citation Index), and the WHO COVID-19 Global literature on coronavirus disease to identify completed and ongoing studies to 16 April 2021. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that evaluated systemic corticosteroids for people with COVID-19, irrespective of disease severity, participant age, gender or ethnicity.  We included any type or dose of systemic corticosteroids. We included the following comparisons: systemic corticosteroids plus standard care versus standard care (plus/minus placebo), dose comparisons, timing comparisons (early versus late), different types of corticosteroids and systemic corticosteroids versus other active substances.  We excluded studies that included populations with other coronavirus diseases (severe acute respiratory syndrome or Middle East respiratory syndrome), corticosteroids in combination with other active substances versus standard care, topical or inhaled corticosteroids, and corticosteroids for long-COVID treatment. DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methodology. To assess the risk of bias in included studies, we used the Cochrane 'Risk of bias' 2 tool for RCTs. We rated the certainty of evidence using the GRADE approach for the following outcomes: all-cause mortality, ventilator-free days, new need for invasive mechanical ventilation, quality of life, serious adverse events, adverse events, and hospital-acquired infections. MAIN RESULTS: We included 11 RCTs in 8075 participants, of whom 7041 (87%) originated from high-income countries. A total of 3072 participants were randomised to corticosteroid arms and the majority received dexamethasone (n = 2322). We also identified 42 ongoing studies and 16 studies reported as being completed or terminated in a study registry, but without results yet.  Hospitalised individuals with a confirmed or suspected diagnosis of symptomatic COVID-19 Systemic corticosteroids plus standard care versus standard care plus/minus placebo  We included 10 RCTs (7989 participants), one of which did not report any of our pre-specified outcomes and thus our analysis included outcome data from nine studies.  All-cause mortality (at longest follow-up available): systemic corticosteroids plus standard care probably reduce all-cause mortality slightly in people with COVID-19 compared to standard care alone (median 28 days: risk difference of 30 in 1000 participants fewer than the control group rate of 275 in 1000 participants; risk ratio (RR) 0.89, 95% confidence interval (CI) 0.80 to 1.00; 9 RCTs, 7930 participants; moderate-certainty evidence).  Ventilator-free days: corticosteroids may increase ventilator-free days (MD 2.6 days more than control group rate of 4 days, 95% CI 0.67 to 4.53; 1 RCT, 299 participants; low-certainty evidence). Ventilator-free days have inherent limitations as a composite endpoint and should be interpreted with caution.  New need for invasive ventilation: the evidence is of very low certainty. Because of high risk of bias arising from deaths that occurred before ventilation we are uncertain about the size and direction of the effects. Consequently, we did not perform analysis beyond the presentation of descriptive statistics.  Quality of life/neurological outcome: no data were available. Serious adverse events: we included data on two RCTs (678 participants) that evaluated systemic corticosteroids compared to standard care (plus/minus placebo); for adverse events and hospital-acquired infections, we included data on five RCTs (660 participants). Because of high risk of bias, heterogeneous definitions, and underreporting we are uncertain about the size and direction of the effects. Consequently, we did not perform analysis beyond the presentation of descriptive statistics (very low-certainty evidence).    Different types, dosages or timing of systemic corticosteroids  We identified one study that compared methylprednisolone with dexamethasone. The evidence for mortality and new need for invasive mechanical ventilation is very low certainty due to the small number of participants (n = 86). No data were available for the other outcomes. We did not identify comparisons of different dosages or timing. Outpatients with asymptomatic or mild disease Currently, there are no studies published in populations with asymptomatic infection or mild disease. AUTHORS' CONCLUSIONS: Moderate-certainty evidence shows that systemic corticosteroids probably slightly reduce all-cause mortality in people hospitalised because of symptomatic COVID-19. Low-certainty evidence suggests that there may also be a reduction in ventilator-free days. Since we are unable to  adjust for the impact of early death on subsequent endpoints, the findings for ventilation outcomes and harms have limited applicability to inform treatment decisions. Currently, there is no evidence for asymptomatic or mild disease (non-hospitalised participants).  There is an urgent need for good-quality evidence for specific subgroups of disease severity, for which we propose level of respiratory support at randomisation. This applies to the comparison or subgroups of different types and doses of corticosteroids, too. Outcomes apart from mortality should be measured and analysed appropriately taking into account confounding through death if applicable.  We identified 42 ongoing and 16 completed but not published RCTs in trials registries suggesting possible changes of effect estimates and certainty of the evidence in the future. Most ongoing studies target people who need respiratory support at baseline. With the living approach of this review, we will continue to update our search and include eligible trials and published data.

Advanced lipodystrophy reverses fatty liver in mice lacking adipocyte hormone-sensitive lipase.

Modulation of adipocyte lipolysis represents an attractive approach to treat metabolic diseases. Lipolysis mainly depends on two enzymes: adipose triglyceride lipase and hormone-sensitive lipase (HSL). Here, we investigated the short- and long-term impact of adipocyte HSL on energy homeostasis using adipocyte-specific HSL knockout (AHKO) mice. AHKO mice fed high-fat-diet (HFD) progressively developed lipodystrophy accompanied by excessive hepatic lipid accumulation. The increased hepatic triglyceride deposition was due to induced de novo lipogenesis driven by increased fatty acid release from adipose tissue during refeeding related to defective insulin signaling in adipose tissue. Remarkably, the fatty liver of HFD-fed AHKO mice reversed with advanced age. The reversal of fatty liver coincided with a pronounced lipodystrophic phenotype leading to blunted lipolytic activity in adipose tissue. Overall, we demonstrate that impaired adipocyte HSL-mediated lipolysis affects systemic energy homeostasis in AHKO mice, whereby with older age, these mice reverse their fatty liver despite advanced lipodystrophy.

Lysosomal acid lipase is the major acid retinyl ester hydrolase in cultured human hepatic stellate cells but not essential for retinyl ester degradation.

Vitamin A is stored as retinyl esters (REs) in lipid droplets of hepatic stellate cells (HSCs). To date, two different pathways are known to facilitate the breakdown of REs: (i) Hydrolysis of REs by neutral lipases, and (ii) whole lipid droplet degradation in autolysosomes by acid hydrolysis. In this study, we evaluated the contribution of neutral and acid RE hydrolases to the breakdown of REs in human HSCs. (R)-Bromoenol lactone (R-BEL), inhibitor of adipose triglyceride lipase (ATGL) and patatin-like phospholipase domain-containing 3 (PNPLA3), the hormone-sensitive lipase (HSL) inhibitor 76-0079, as well as the serine-hydrolase inhibitor Orlistat reduced neutral RE hydrolase activity of LX-2 cell-lysates between 20 and 50%. Interestingly, in pulse-chase experiments, R-BEL, 76-0079, as well as Orlistat exerted little to no effect on cellular RE breakdown of LX-2 cells as well as primary human HSCs. In contrast, Lalistat2, a specific lysosomal acid lipase (LAL) inhibitor, virtually blunted acid in vitro RE hydrolase activity of LX-2 cells. Accordingly, HSCs isolated from LAL-deficient mice showed RE accumulation and were virtually devoid of acidic RE hydrolase activity. In pulse-chase experiments however, LAL-deficient HSCs, similar to LX-2 cells and primary human HSCs, were not defective in degrading REs. In summary, results demonstrate that ATGL, PNPLA3, and HSL contribute to neutral RE hydrolysis of human HSCs. LAL is the major acid RE hydrolase in HSCs. Yet, LAL is not limiting for RE degradation under serum-starvation. Together, results suggest that RE breakdown of HSCs is facilitated by (a) so far unknown, non-Orlistat inhibitable RE-hydrolase(s).

Comparative transcriptomics reveals candidate carotenoid color genes in an East African cichlid fish.

BACKGROUND: Carotenoids contribute significantly to animal body coloration, including the spectacular color pattern diversity among fishes. Fish, as other animals, derive carotenoids from their diet. Following uptake, transport and metabolic conversion, carotenoids allocated to body coloration are deposited in the chromatophore cells of the integument. The genes involved in these processes are largely unknown. Using RNA-Sequencing, we tested for differential gene expression between carotenoid-colored and white skin regions of a cichlid fish, Tropheus duboisi "Maswa", to identify genes associated with carotenoid-based integumentary coloration. To control for positional gene expression differences that were independent of the presence/absence of carotenoid coloration, we conducted the same analyses in a closely related population, in which both body regions are white. RESULTS: A larger number of genes (n = 50) showed higher expression in the yellow compared to the white skin tissue than vice versa (n = 9). Of particular interest was the elevated expression level of bco2a in the white skin samples, as the enzyme encoded by this gene catalyzes the cleavage of carotenoids into colorless derivatives. The set of genes with higher expression levels in the yellow region included genes involved in xanthophore formation (e.g., pax7 and sox10), intracellular pigment mobilization (e.g., tubb, vim, kif5b), as well as uptake (e.g., scarb1) and storage (e.g., plin6) of carotenoids, and metabolic conversion of lipids and retinoids (e.g., dgat2, pnpla2, akr1b1, dhrs). Triglyceride concentrations were similar in the yellow and white skin regions. Extracts of integumentary carotenoids contained zeaxanthin, lutein and beta-cryptoxanthin as well as unidentified carotenoid structures. CONCLUSION: Our results suggest a role of carotenoid cleavage by Bco2 in fish integumentary coloration, analogous to previous findings in birds. The elevated expression of genes in carotenoid-rich skin regions with functions in retinol and lipid metabolism supports hypotheses concerning analogies and shared mechanisms between these metabolic pathways. Overlaps in the sets of differentially expressed genes (including dgat2, bscl2, faxdc2 and retsatl) between the present study and previous, comparable studies in other fish species provide useful hints to potential carotenoid color candidate genes.

Hepatocyte-specific deletion of lysosomal acid lipase leads to cholesteryl ester but not triglyceride or retinyl ester accumulation.

Lysosomal acid lipase (LAL) hydrolyzes cholesteryl ester (CE) and retinyl ester (RE) and triglyceride (TG). Mice globally lacking LAL accumulate CE most prominently in the liver. The severity of the CE accumulation phenotype progresses with age and is accompanied by hepatomegaly and hepatic cholesterol crystal deposition. In contrast, hepatic TG accumulation is much less pronounced in these mice, and hepatic RE levels are even decreased. To dissect the functional role of LAL for neutral lipid ester mobilization in the liver, we generated mice specifically lacking LAL in hepatocytes (hep-LAL-ko). On a standard chow diet, hep-LAL-ko mice exhibited increased hepatic CE accumulation but unaltered TG and RE levels. Feeding the hep-LAL-ko mice a vitamin A excess/high-fat diet (VitA/HFD) further increased hepatic cholesterol levels, but hepatic TG and RE levels in these mice were lower than in control mice. Performing in vitro activity assays with lysosome-enriched fractions from livers of mice globally lacking LAL, we detected residual acid hydrolytic activities against TG and RE. Interestingly, this non-LAL acid TG hydrolytic activity was elevated in lysosome-enriched fractions from livers of hep-LAL-ko mice upon VitA/HFD feeding. In conclusion, the neutral lipid ester phenotype in livers from hep-LAL-ko mice indicates that LAL is limiting for CE turnover, but not for TG and RE turnovers. Furthermore, in vitro hydrolase activity assays revealed the existence of non-LAL acid hydrolytic activities for TG and RE. The corresponding acid lipase(s) catalyzing these reactions remains to be identified.

Illumination with blue light reactivates respiratory activity of mitochondria inhibited by nitric oxide, but not by glycerol trinitrate.

Nitric oxide (NO) is known to inhibit mitochondrial respiration reversibly. This study aimed at clarifying whether low level illumination at specific wavelengths recovers mitochondrial respiration inhibited by NO and glycerol-trinitrate (GTN), a clinically used NO mimetic. NO fully inhibited respiration of liver mitochondria at concentrations occurring under septic shock. The respiration was completely restored by illumination at the wavelength of 430nm while longer wavelengths were less effective. GTN inhibited mitochondrial respiration though the efficiency of GTN was lower compared to NO concentrations observed in sepsis models. However, GTN inhibition was absolutely insensitive to illumination regardless of wavelength used. Our data show that visible light of short wavelengths efficiently facilitates the recovery of mitochondria inhibited by NO-gas at the levels generated under septic conditions. The inhibition of mitochondrial respiration by GTN is not sensitive to visible light, suggesting an inhibition mechanism other that NO mediation.

Collagen binding protein Mip enables Legionella pneumophila to transmigrate through a barrier of NCI-H292 lung epithelial cells and extracellular matrix.

Guinea pigs are highly susceptible to Legionella pneumophila infection and therefore have been the preferred animal model for studies of legionellosis. In this study guinea pig infections revealed that the Legionella virulence factor Mip (macrophage infectivity potentiator) contributes to the bacterial dissemination within the lung tissue and the spread of Legionella to the spleen. Histopathology of infected animals, binding assays with components of the extracellular matrix (ECM), bacterial transmigration experiments across an artificial lung epithelium barrier, inhibitor studies and ECM degradation assays were used to elucidate the underlying mechanism of the in vivo observation. The Mip protein, which belongs to the enzyme family of FK506-binding proteins (FKBP), was shown to bind to the ECM protein collagen (type I, II, III, IV, V, VI). Transwell assays with L. pneumophila and recombinant Escherichia coli HB101 strains revealed that Mip enables these bacteria to transmigrate across a barrier of NCI-H292 lung epithelial cells and ECM (NCI-H292/ECM barrier). Mip-specific monoclonal antibodies and the immunosuppressants rapamycin and FK506, which inhibit the peptidyl prolyl cis/trans isomerase (PPIase) activity of Mip, were able to inhibit this transmigration. By using protease inhibitors we found that the penetration of the NCI-H292/ECM barrier additionally requires a serine protease activity. Degradation assays with (35)S-labelled ECM proteins supported the finding of a concerted action of Mip and a serine protease. The described synergism between the activity of the collagen binding Mip protein and the serine protease activity represents an entirely new mechanism for bacterial penetration of the lung epithelial barrier and has implications for other prokaryotic and eukaryotic pathogens.

Function and mechanism of action of Dictyostelium Nramp1 (Slc11a1) in bacterial infection.

Dictyostelium amoebae are professional phagocytes, which ingest bacteria as the principal source of food. We have cloned the Dictyostelium homologue of human natural resistance-associated membrane protein 1 (Nramp1) [solute carrier family 11 member 1 (Slc11a1)], an endo-lysosomal membrane protein that confers on macrophages resistance to infection by a variety of intracellular bacteria and protozoa. The Dictyostelium Nramp1 gene encodes a protein of 53 kDa with 11 putative transmembrane domains. The Nramp1 gene is transcribed during the growth-phase and downregulated to barely detectable levels upon starvation. To gain insights into their intracellular localization, we fused Nramp1 or the vatB subunit of the V-H(+)ATPase with green fluorescent protein and expressed in cells. Green fluorescent protein-vatB was inserted in membranes of all acidic compartments and the contractile vacuole network and decorated macropinosomes and phagosomes. Green fluorescent protein-Nramp1 decorated macropinosomes and phagosomes, in addition to intracellular vesicular compartments positive for endosomal SNARE protein Vti1 or vacuolin, a marker of the exocytic pathway. Nramp1 disruption generated mutants that were more permissive hosts than wild-type cells for intracellular growth of Legionella pneumophila and Micobacterium avium. Nramp1 overexpression protected cells from L. pneumophila infection. Evidence is provided that Nramp1 transports metal cations out of the phagolysosome in an ATP-dependent process and that L. pneumophila and M. avium use different mechanisms to neutralize Nramp1 activity.