Impaired hemoglobin clearance by sinusoidal endothelium promotes vaso-occlusion and liver injury in sickle cell disease

Sickle cell disease (SCD) is a monogenic disorder that affects 100,000 African-Americans and millions of people worldwide. Intra-erythrocytic polymerization of sickle hemoglobin (HbS) promotes erythrocyte sickling, impaired rheology, ischemia and hemolysis, leading to the development of progressive liver injury in SCD. Liver-resident macrophages and monocytes are known to enable the clearance of HbS; however, the role of liver sinusoidal endothelial cells (LSEC) in HbS clearance and liver injury in SCD remains unknown. Using real-time intravital (in vivo) imaging in mice liver as well as flow cytometric analysis and confocal imaging of primary human LSEC, we show for the first time that liver injury in SCD is associated with accumulation of HbS and iron in the LSEC, leading to senescence of these cells. Hemoglobin uptake by LSEC was mediated by micropinocytosis. Hepatic monocytes were observed to attenuate LSEC senescence by accelerating HbS clearance in the liver of SCD mice; however, this protection was impaired in P-selectin-deficient SCD mice secondary to reduced monocyte recruitment in the liver. These findings are the first to suggest that LSEC contribute to HbS clearance and HbS-induced LSEC senescence promotes progressive liver injury in SCD mice. Our results provide a novel insight into the pathogenesis of hemolysis-induced chronic liver injury in SCD caused by LSEC senescence. Identifying the regulators of LSEC-mediated HbS clearance may lead to new therapies to prevent the progression of liver injury in SCD.

Hemoglobin scavenger receptor CD163 as a potential biomarker of hemolysis induced hepatobiliary injury in sickle cell disease

Sickle cell disease (SCD) associated chronic hemolysis promotes oxidative stress, inflammation and thrombosis leading to organ damage, including liver damage. Hemoglobin scavenger receptor CD163 plays a protective role in SCD by scavenging both hemoglobin-haptoglobin complexes and cell free hemoglobin. A limited number of studies in the past have shown a positive correlation of CD163 expression with poor disease outcomes in patients with SCD. However, the role and regulation of CD163 in SCD related hepatobiliary injury has not been fully elucidated yet. Here, we show that chronic liver injury in SCD patients is associated with elevated levels of hepatic membrane bound CD163. Hemolysis and increase in hepatic heme, hemoglobin and iron levels elevate CD163 expression in the SCD mouse liver. Mechanistically we show that HO-1 positively regulates membrane bound CD163 expression independent of NRF2 signaling in SCD liver. We further demonstrate that of the interaction between CD163 and HO-1 is not dependent on CD163-hemoglobin binding. These findings indicate that CD163 is a potential biomarker of SCD associated hepatobiliary injury. Understanding the role of HO-1 in membrane bound CD163 regulation may help identify novel therapeutic targets for hemolysis induced chronic liver injury.

Sexual dysfunctions in psoriatic patients

Introduction

Psoriasis is one the most common skin diseases associated with a great decrease in the quality of patients' lives.

Methods

We aimed to study sexual dysfunctions in psoriatic patients using the Female Sexual Function Index (FSFI) for women and the International Index of Erectile Function (IIEF) for men via an anonymous online survey. The study included 80 psoriatic patients and 75 controls without dermatoses.

Results

There was a downward trend in the total IIEF score in psoriatic men compared to controls. 58% of male patients and 76% of controls had a normal IIEF score. There was no significant difference in IIEF between patients treated and not with systemic agents. 62% of female patients had a decreased FSFI score, whereas in the control group, the majority of subjects (54%) had a normal FSFI score. There was no significant difference in FSFI score between patients and controls. Female patients treated with systemic antipsoriatic agents had significantly worse lubrication, satisfaction with sexual life, and pain.

Discussion

Our study has shown that the majority of questioned female psoriatic patients had sexual dysfunction according to FSFI, particularly they had worse satisfaction with sexual life and less sexual desire compared to women without psoriasis. The majority of male patients did not have sexual dysfunction according to IIEF, however, they had significantly worse overall satisfaction with sexual life and confidence to keep an erection. Systemic antipsoriatic treatment does not probably influence sexual dysfunctions in men but it does in women although we were not able to assess the severity or resolution of lesions after those treatments. However embarrassing, psoriatic patients should be questioned about their sexual lives by dermatologists, and more studies are needed to explore this matter.

Subcutaneous injection of IHP-102 prevents lung vaso-occlusion in sickle cell disease mice

Not available.

Lung microvascular occlusion by platelet-rich neutrophil-platelet aggregates promotes cigarette smoke-induced severe flu

Cigarette smoking is associated with a higher risk of ICU admissions among patients with flu. However, the etiological mechanism by which cigarette smoke (CS) exacerbates flu remains poorly understood. Here, we show that a mild dose of influenza A virus promotes a severe lung injury in mice preexposed to CS but not room air for 4 weeks. Real-time intravital (in vivo) lung imaging revealed that the development of acute severe respiratory dysfunction in CS- and flu-exposed mice was associated with the accumulation of platelet-rich neutrophil-platelet aggregates (NPAs) in the lung microcirculation within 2 days following flu infection. These platelet-rich NPAs formed in situ and grew larger over time to occlude the lung microvasculature, leading to the development of pulmonary ischemia followed by the infiltration of NPAs and vascular leakage into the alveolar air space. These findings suggest, for the first time to our knowledge, that an acute onset of platelet-driven thrombo-inflammatory response in the lung contributes to the development of CS-induced severe flu.

Dry eye syndrome symptoms in patients with psoriasis

BACKGROUND

Psoriasis is one of the most common dermatoses associated with a variety of comorbidities. There have been some reports on its possible association with ocular disorders however dry eye syndrome (DES) in such patients has been poorly investigated.

OBJECTIVES

To investigate the frequency of DES symptoms in psoriatic patients, also regarding psoriasis severity in PASI, manifestation and therapy.

METHODS

40 patients with psoriasis and 40 volunteers without dermatoses were enrolled in the study. They completed Ocular Surface Disease Index (OSDI) questionnaire and were objectively examined by IDRA® device to perform automatic interferometry, automatic meibography of lower eyelid glands, non-invasive break-up time (NIBUT), blink quality and tear meniscus height.

RESULTS

Patients with psoriasis had statistically significantly thicker lipid layer (p = 0.0042 left eye, p = 0.0313 right eye) and greater loss of Meibomian glands compared to controls (p = 0.0128 left eye, p = 0.048 right eye). The patients had lower, although insignificantly, eye blink quality and tear meniscus height than the control group, as well as shorter NIBUT and higher score in OSDI. After the division of patients into two groups-with or without nails involvement/psoriatic arthritis/systemic treatment- we did not observe any significant differences between the groups. PASI did not correlate with any DES parameter.

CONCLUSIONS

This is the first study of DES symptoms with an objective IDRA® analyzer. We managed to observe that patients with psoriasis have thicker lipid layer and higher Meibomian glands' loss in lower eyelids. Based on all assessed objective and subjective parameters psoriatics do not seem to have an increased risk of DES. The presence of psoriatic arthritis or nail involvement does not seem to be a predisposing factor for DES development. PASI probably cannot be a prognostic factor for any of the DES-associated parameters. Nevertheless, DES in psoriasis requires further research on bigger samples to establish reliable recommendations.

Liver-to-lung microembolic NETs promote gasdermin D-dependent inflammatory lung injury in sickle cell disease

Acute lung injury, referred to as the acute chest syndrome, is a major cause of morbidity and mortality in patients with sickle cell disease (SCD), which often occurs in the setting of a vaso-occlusive painful crisis. P-selectin antibody therapy reduces hospitalization of patients with SCD by ∼50%, suggesting that an unknown P-selectin-independent mechanism promotes remaining vaso-occlusive events. In patients with SCD, intraerythrocytic polymerization of mutant hemoglobin promotes ischemia-reperfusion injury and hemolysis, which leads to the development of sterile inflammation. Using intravital microscopy in transgenic, humanized mice with SCD and in vitro studies with blood from patients with SCD, we reveal for the first time that the sterile inflammatory milieu in SCD promotes caspase-4/11-dependent activation of neutrophil-gasdermin D (GSDMD), which triggers P-selectin-independent shedding of neutrophil extracellular traps (NETs) in the liver. Remarkably, these NETs travel intravascularly from liver to lung, where they promote neutrophil-platelet aggregation and the development of acute lung injury. This study introduces a novel paradigm that liver-to-lung embolic translocation of NETs promotes pulmonary vascular vaso-occlusion and identifies a new GSDMD-mediated, P-selectin-independent mechanism of lung injury in SCD.

Recent Advances in the Treatment of Insulin Resistance Targeting Molecular and Metabolic Pathways: Fighting a Losing Battle?

Diabetes Mellitus (DM) is amongst the most notable causes of years of life lost worldwide and its prevalence increases perpetually. The disease is characterized as multisystemic dysfunctions attributed to hyperglycemia resulting directly from insulin resistance (IR), inadequate insulin secretion, or enormous glucagon secretion. Insulin is a highly anabolic peptide hormone that regulates blood glucose levels by hastening cellular glucose uptake as well as controlling carbohydrate, protein, and lipid metabolism. In the course of Type 2 Diabetes Mellitus (T2DM), which accounts for nearly 90% of all cases of diabetes, the insulin response is inadequate, and this condition is defined as Insulin Resistance. IR sequela include, but are not limited to, hyperglycemia, cardiovascular system impairment, chronic inflammation, disbalance in oxidative stress status, and metabolic syndrome occurrence. Despite the substantial progress in understanding the molecular and metabolic pathways accounting for injurious effects of IR towards multiple body organs, IR still is recognized as a ferocious enigma. The number of widely available therapeutic approaches is growing, however, the demand for precise, safe, and effective therapy is also increasing. A literature search was carried out using the MEDLINE/PubMed, Google Scholar, SCOPUS and Clinical Trials Registry databases with a combination of keywords and MeSH terms, and papers published from February 2021 to March 2022 were selected as recently published papers. This review paper aims to provide critical, concise, but comprehensive insights into the advances in the treatment of IR that were achieved in the last months.

Intravital imaging reveals inflammation as a dominant pathophysiology of age-related hepatovascular changes

Aging is the most significant risk factor for the majority of chronic diseases, including liver disease. The cellular, molecular, and pathophysiological mechanisms that promote age-induced hepatovascular changes are unknown due to our inability to visualize changes in liver pathophysiology in live mice over time. We performed quantitative liver intravital microscopy (qLIM) in live C57BL/6J mice to investigate the impact of aging on the hepatovascular system over a 24-mo period. qLIM revealed that age-related hepatic alterations include reduced liver sinusoidal blood flow, increased sinusoidal vessel diameter, and loss of small hepatic vessels. The ductular cell structure deteriorates with age, along with altered expression of hepatic junctional proteins. Furthermore, qLIM imaging revealed increased inflammation in the aged liver, which was linked to increased expression of proinflammatory macrophages, hepatic neutrophils, liver sinusoidal endothelial cells, senescent cells, and procoagulants. Finally, we detected elevated NF-κB pathway activity in aged livers. Overall, these findings emphasize the importance of inflammation in age-related hepatic vasculo-epithelial alterations and highlight the utility of qLIM in studying age-related effects in organ pathophysiology.

Assessment of Life Quality, Stress and Physical Activity Among Patients with Psoriasis

Introduction

Psoriasis is a chronic, autoimmune, inflammatory skin disease affecting 2–4% of the general population, which nowadays is even perceived as a systemic illness. The nature of this dermatosis may negatively influence patients’ general condition, life expectancy, and quality of life, which highlights the severity of the problem and the need to perform further investigation. We aimed to assess quality of life, stress severity, and physical activity of patients with psoriasis in relation to demographic and clinical data and comparison to the control group without dermatoses.

Methods

A set of surveys was conducted in 56 patients with psoriasis hospitalized at the Department of Dermatology, Medical University of Bialystok. Questionnaires used involved the Dermatology Life Quality Index, WHO Quality of Life questionnaire, International Questionnaire of Physical Activity, and a self-invented stress survey. Obtained data were compared to a sex- and age-matched control group without dermatoses. Statistical analysis was performed using GraphPad Prism.

Results

Patients with psoriasis were found to be significantly less satisfied with their health and had lower scores in WHO social, environmental, and psychological domains, comparing to controls. Patients reported higher stress severity and lower satisfaction with sex life and physical appearance than controls. Patients with psoriasis also tended to perform less intensive physical activity than controls.

Conclusions

This study highlights the perception of psoriasis as not only affecting skin but also having a multifactorial impact on psychological and internal condition. Described lifestyle abnormalities can be easily evaluated with validated questionnaires, which could be introduced to patients in order to raise their awareness of comorbidities and mobilize them to modify incorrect lifestyle habits. Screening for other disorders and introduction of a holistic approach to every patient could be beneficial because the improvement of patients’ life quality is one of the most important issues.

Intravital Imaging of Hepatic Blood Biliary Barrier in Live Mice

Understanding the kinetics and spatiotemporal interactions of living cells within the tissue environment requires real-time imaging. The introduction of two-photon microscopy has substantially boosted the power of live intravital imaging, making it possible to obtain information of individual cells in near-physiologic conditions within intact tissues nondestructively. Intravital imaging of the liver has proved useful in understanding its 3D structure, function, and dynamic cellular interactions. Recently we have shown that integrity of the blood-bile barrier in different physiologic and pathophysiologic conditions can be imaged in real time using intravital microscopy. Here we discuss the real-time intravital imaging method to visualize blood-bile barrier integrity in the murine liver. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Live imaging in the mouse liver Support Protocol: Monitoring vital signs of the mouse during live liver imaging Basic Protocol 2: Visualizing blood and bile transport using intravital microscopy.

Live Imaging of the Lung

Live imaging is critical to determining the dynamics and spatial interactions of cells within the tissue environment. In the lung, this has proven to be difficult due to the motion brought about by ventilation and cardiac contractions. A previous version of this Current Protocols in Cytometry article reported protocols for imaging ex vivo live lung slices and the intact mouse lung. Here, we update those protocols by adding new methodologies, new approaches for quantitative image analysis, and new areas of potential application. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Live imaging of lung slices Support Protocol 1: Staining lung sections with fluorescent antibodies Basic Protocol 2: Live imaging in the mouse lung Support Protocol 2: Intratracheal instillations Support Protocol 3: Intravascular instillations Support Protocol 4: Monitoring vital signs of the mouse during live lung imaging Support Protocol 5: Antibodies Support Protocol 6: Fluorescent reporter mice Basic Protocol 3: Quantification of neutrophil-platelet aggregation in pulmonary vasculature Basic Protocol 4: Quantification of platelet-dependent pulmonary thrombosis Basic Protocol 5: Quantification of pulmonary vascular permeability.

Neutrophil Extracellular Traps promote joint damage in hemophilia

Hemophilic arthropathy (HA) is the pathophysiology resulting from recurrent joint bleeding in hemophilia. HA leads to joint damage, chronic pain and poor quality of life. Despite advances in the treatment to prevent joint bleeding, HA continues to be a major morbidity affecting hemophilia patients and the mechanism contributing to HA remains elusive. Recent evidence suggests that joint-bleeding may promote the release of erythrocyte and tissue-derived damage-associated-molecular-pattern molecules (DAMPs) that can trigger the sterile inflammation in the joints, however, the innate immune pathways remain unclear. We used a model of knee joint injury-induced HA in FVIII-total knockout (F8TKO) mice and samples from hemophilia patients diagnosed with HA. In vivo multiphoton-excitation fluorescence imaging of injured synovial cavity in live F8TKO or control mice was used to assess NETs formation within joint capsule. Imaging-flow-cytometry and ELISA assays were used to evaluate circulating NETs in HA patients and mice with knee-injury. Bleeding severity scoring, histology, IHC and confocal imaging of joints were conducted to assess the joint injury in mice. F8TKO but not control mice manifested knee-joint injury and severity of bleeding 5-days post knee-injury. Knee-joint injury was associated with increased neutrophil accumulation and NETs shedding within the synovium of F8TKO mice. Circulating NETs were abundant in the plasma of patients diagnosed with HA and F8TKO following injury but not plasma of controls. These findings are the first to suggest that NETs contribute to pathogenesis of HA. Currently, study is underway to identify the innate immune pathways that promote NETs shedding, leading to joint-damage in hemophilia.

Platelet-rich neutrophil-platelet micro-emboli contribute to cigarette smoke induced flu severity

Epidemiological evidence suggests that prior exposure to cigarette smoke (CS) or habitual smoking increases the risk of influenza A virus (IAV)-triggered respiratory failure. Although emerging evidence supports the role of thrombo-inflammation in the development of CS and IAV-triggered lung injury, the innate immune mechanism remains poorly understood. We have developed a two-hit model of CS-induced severe flu in mice. Mice were exposed to four weeks of room air (air) or CS followed by intra-nasal administration of A/PR/8/34 IAV. The body weight was measured every day for two weeks after IAV administration followed by assessment of lung injury at day 7. Lungs were harvested for histological assessment and viral titration by qPCR. Quantitative fluorescence intravital lung microscopy (qFILM) was conducted at 2-, 3- and 4-days post IAV-infection to visualize dynamics of neutrophil and platelet recruitment in the lung of mice IV administered with fluorescent dextran, anti-Ly6G Ab and anti-CD49Abs. Mice exposed to CS+IAV manifested significantly more weight loss, lung injury, lung congestion, hemorrhage and hypoxemia compared to mice administered IAV only. QFILM revealed that severity of lung injury was associated with significantly larger area with impaired blood flow and more vascular leakage secondary to vascular occlusion by platelet-rich neutrophil-platelet aggregates in the lung of CS+IAV than IAV administered mice. These initial results suggest that CS primes innate immune signaling in neutrophils and platelets to promote their recruitment in the lung following flu, leading to severe acute lung injury. Currently, studies are underway to identify innate immune pathways that drive hyper thrombo-inflammatory response.

Single cell RNA sequencing identifies IGFBP5 and QKI as ciliated epithelial cell genes associated with severe COPD

Background

Whole lung tissue transcriptomic profiling studies in chronic obstructive pulmonary disease (COPD) have led to the identification of several genes associated with the severity of airflow limitation and/or the presence of emphysema, however, the cell types driving these gene expression signatures remain unidentified.

Methods

To determine cell specific transcriptomic changes in severe COPD, we conducted single-cell RNA sequencing (scRNA seq) on n = 29,961 cells from the peripheral lung parenchymal tissue of nonsmoking subjects without underlying lung disease (n = 3) and patients with severe COPD (n = 3). The cell type composition and cell specific gene expression signature was assessed. Gene set enrichment analysis (GSEA) was used to identify the specific cell types contributing to the previously reported transcriptomic signatures.

Results

T-distributed stochastic neighbor embedding and clustering of scRNA seq data revealed a total of 17 distinct populations. Among them, the populations with more differentially expressed genes in cases vs. controls (log fold change >|0.4| and FDR = 0.05) were: monocytes (n = 1499); macrophages (n = 868) and ciliated epithelial cells (n = 590), respectively. Using GSEA, we found that only ciliated and cytotoxic T cells manifested a trend towards enrichment of the previously reported 127 regional emphysema gene signatures (normalized enrichment score [NES] = 1.28 and = 1.33, FDR = 0.085 and = 0.092 respectively). Among the significantly altered genes present in ciliated epithelial cells of the COPD lungs, QKI and IGFBP5 protein levels were also found to be altered in the COPD lungs.

Conclusions

scRNA seq is useful for identifying transcriptional changes and possibly individual protein levels that may contribute to the development of emphysema in a cell-type specific manner.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01675-2.

Exploring the Complex Role of Coagulation Factor VIII in Chronic Liver Disease

Chronic liver disease is one of the leading causes of death in the United States. Coagulopathy is often a sequela of chronic liver disease, however, the role and regulation of coagulation components in chronic liver injury remain poorly understood. Clinical and experimental evidence indicate that misexpression of the procoagulant factor VIII (FVIII) is associated with chronic liver disease. Nevertheless, the molecular mechanism of FVIII-induced chronic liver injury progression remains unknown. This review provides evidence supporting a pathologic role for FVIII in the development of chronic liver disease using both experimental and clinical models.

The Assessment of Risk and Predictors of Sleep Disorders in Patients with Psoriasis-A Questionnaire-Based Cross-Sectional Analysis

Psoriasis is a chronic, inflammatory skin disease affecting 2-4% of the general population. Accompanying subjective symptoms (pruritus or pain) may cause decreased life quality including sleep disorders (SD). Sixty psoriatic patients fulfilled the following questionnaires: Pittsburgh Sleep Quality Index (PSQI), STOP BANG for the obstructive sleep apnea syndrome (OSAS) assessment, and Restless Legs Syndrome (RLS) Severity Scale. Patients' laboratory and clinical data were also investigated. All data obtained were compared to 40 participants without dermatoses. Mean PSQI, risk of OSAS, and RLS severity of psoriatics were significantly higher than in controls (p < 0.0001, p < 0.05, p < 0.05 respectively). There was a positive correlation between the time of suffering from psoriasis and the risk of OSAS (R = 0.286, p < 0.05). We did not observe any significant relationship between PSQI, risk of OSAS, or RLS and psoriasis severity assessed with PASI (Psoriasis Area and Severity Index). We identified four possible predictors of RLS: glucose, CRP and total cholesterol concentrations, and PSQI. SD are significantly more frequent in psoriatics than in people without chronic dermatological diseases but surprisingly they are not correlated with psoriasis severity. SD decrease patients' life quality and may result in serious consequences. Therefore, establishing recommendations concerning screening for SD and their predictors should be considered.

The Level of FGF 21 as a New Risk Factor for the Occurrence of Cardiometabolic Disorders amongst the Psoriatic Patients

Fibroblast growth factors 21 and 23 are used as markers of cardiometabolic disorders which are common comorbidities in psoriasis. The study aimed to evaluate the serum level of these factors in psoriatic patients and elucidate the possible interplay between disease activity, metabolic or inflammatory parameters, and systemic treatment. A total of 33 patients with active plaque-type psoriasis and 11 healthy controls were enrolled in the study. Patients were divided into subgroups based on their BMI, disease severity, and treatment. Blood samples were collected at the beginning of the study and after 3 months of systemic treatment with acitretin or methotrexate. Serum FGF21 levels in psoriatic patients were higher versus control group (p < 0.05). FGF21 levels regarding psoriasis activity were significantly increased in all three subgroups compared to the controls (p < 0.05). Regarding FGF23, no significant changes were found beside positive correlation with aspartate transferase (p < 0.05). No significant effect of systemic treatment on FGF21 and FGF23 levels was found. Interestingly, a nearly threefold decrease in FGF21 concentration after acitretin-based treatment was observed (p < 0.05). After methotrexate therapy, FGF21 levels remained unchanged. FGF21 levels might be helpful in prediction of the risk of cardiometabolic comorbidities development especially in patients with severe psoriasis and obesity.

The impact of antihypertensive pharmacotherapy on interplay between protein-bound uremic toxin (indoxyl sulfate) and markers of inflammation in patients with chronic kidney disease

Purpose

Indoxyl sulfate (IS) is one of the most potent uremic toxins involved in chronic kidney disease (CKD) progression, induction of inflammation, oxidative stress, and cardiovascular diseases occurrence. It is proved that hypertension is a common CVD complication and a major death risk factor as well as contributes for decline in a renal function. The aim of our study was to investigate how implementing of antihypertensive therapy impact IS concentrations and the associations between IS and markers of renal function, inflammation and oxidative stress.

Methods

Study was conducted on 50 patients diagnosed with CKD and hypertension, divided into three groups: without hypotensive therapy (CKD-NONE), hypotensive monotherapy (CKD-MONO), and hypotensive polypharmacotherapy (CKD-POLI), and 18 healthy volunteers. The markers of inflammation [interleukin-6, tumor necrosis factor-alpha (TNF-α), high-sensitive C-reactive protein (hs-CRP), neopterin, ferritin], oxidative status [superoxide dismutase (Cu/Zn-SOD), antibodies against oxidized low-density lipoprotein (oxLDL-abs)], and selectins were determinate using immunoenzymatic methods. IS levels were assayed using high-performance liquid chromatography and other parameters were analysed using routine laboratory techniques. Then cross-sectional analysis was performed.

Results

Elevated levels of IS, indicators of kidney function, markers of inflammation and blood pressure values were observed in each CKD subgroups. There was no effect of antihypertensive therapy on IS levels between studied groups, as well as there was no clear relationship between IS and blood pressure values in each studied group. The positive associations between IS and Cu/Zn SOD, neopterin, hs-CRP, creatinine and neutrophils/lymphocytes ratio were observed in CKD-NONE and CKD-POLI subgroups. Additionally, in CKD-POLI group IS positively correlated with TNF-α, ferritin and neutrophils. In CKD-MONO group, IS was positively related to oxLDL-abs, neopterin, E-selectin and creatinine, whereas it was inversely associated with hs-CRP.

Conclusions

Our study showed for the first time that the antihypertensive therapy has no impact on IS levels in CKD patients with hypertension. However, the introduction of the antihypertensive therapy modified the dependencies between IS and the studied markers of kidney function, inflammation, oxidative stress and hematological parameters that are crucial for mortality and morbidity amongst the CKD patients with hypertension.

Electronic supplementary material

The online version of this article (10.1007/s11255-018-02064-3) contains supplementary material, which is available to authorized users.

Indoxyl Sulfate Promotes Arterial Thrombosis in Rat Model via Increased Levels of Complex TF/VII, PAI-1, Platelet Activation as Well as Decreased Contents of SIRT1 and SIRT3

Patients suffering from chronic kidney disease (CKD) are at a 20-fold higher risk of dying due to cardiovascular diseases (CVDs), primarily thrombosis following vascular injury. CKD is connected with retention of uremic toxins, especially indoxyl sulfate (IS), which are currently considered as a non-classical CKD-specific risk factor for CVDs. The present study aimed to examine the effect of chronic exposure to IS on the hemostatic system and arterial thrombosis in a model without greater interferences from the uremic milieu consisting of additional uremic toxins. Forty-eight male Wistar Crl:WI (cmdb) rats were divided into three groups: one control group and two experimental groups, which were exposed to 100 or 200 mg/kg of b.w./day of IS in drinking water for a period of 28 days. The control group received water without IS. At the end of the experiment, the induction of arterial thrombosis was performed. We investigated the impact of IS on thrombosis incidence, kinetics and strength of clot formation, platelet activity, aortic contents of sirtuin (SIRT) 1 and sirtuin 3 (SIRT3), hemostatic system, cardiorespiratory parameters, biochemistry of plasma and urine as well as histology of the thrombus, kidney, and liver. Obtained data revealed that chronic exposure to IS promotes arterial thrombosis via increased levels of complex tissue factor/factor VII, plasminogen activator inhibitor-1 (PAI-1), platelet activation, as well as decreased aortic levels of SIRT1 and SIRT3. Therefore, we hypothesize that IS enhances primary hemostasis leading to augmented formation of platelet plug with increased amounts of fibrin and affects secondary hemostasis through the influence on plasma coagulation and fibrinolysis factors, which results in the increased kinetics and strength of clot formation. The findings described may contribute to a better understanding of the mechanisms leading to increased thrombotic events in patients with CKD with elevated levels of IS.

New insight into organic anion transporters from the perspective of potentially important interactions and drugs toxicity

The family of organic anion transporters (OATs) includes a group of over 10 transmembrane transporting proteins belonging to the solute carrier 22 subfamilies of the major facilitator superfamily. Their function is related to the transport of a great variety of organic anions against the electrical and chemical gradient. OATs are present in most types of human tissues, including the kidneys, liver, placenta, olfactory epithelium, retina, and choroid plexus tissues. The OATs family plays an important role in the cellular uptake, distribution, excretion, and detoxification of many water-soluble drugs, endogenous compounds, nutrition ingredients, environmental contaminants and toxins, and significantly impacts their efficacy, pharmacokinetics and toxicity, both in a preferable and unfavorable way. OATs demonstrated great potential to participate in many potentially relevant interactions, which may lead to unexpected, but not always detrimental, effects. Wider knowledge about their specific functions in the body, role in disease states, pharmacokinetics interactions, and intraindividual response to therapeutic treatment will allow to predict and prevent OAT-related adverse effects or use favorable interactions in pharmacotherapy, as well as to rationally design therapeutics targeted at individual transporter drugs with improved bioavailability, prolonged half-life or reduced toxicity, and improve safety guidelines concerning drug dosage. This review gathers recent reports regarding OAT-related essential interactions involving components of popular therapeutic herbal products, dietary supplements, and clinically important drugs, their significance and potential suitability in modulating the severity of drug-related side effects and toxicity mechanisms.

Association between uremic toxin-anthranilic acid and fibrinolytic system activity in predialysis patients at different stages of chronic kidney disease

PURPOSE

Chronic kidney disease (CKD) is an estimated risk factor for increased mortality and morbidity due to fibrinolytic system disturbances. Progressive loss of renal function leads to retention of uremic toxins. Anthranilic acid (AA) is a tryptophan-derived uremic toxin with multidirectional properties that can affect the hemostatic system. The goal of this study was to examine the association between AA and the parameters of fibrinolysis at different stages of CKD.

METHODS

Patients with CKD were divided into two groups: mild-to-moderate (n = 20) and severe-to-end-stage CKD (n = 28). Seventeen healthy volunteers served as an additional control group. Parameters of fibrinolysis, inflammation, and monocytes activation were determined by ELISA immune-enzymatic kits. AA levels were evaluated using high-performance liquid chromatography.

RESULTS

AA concentration and parameters of fibrinolysis: urokinase-type plasminogen activator (uPA), its soluble receptor (suPAR), tissue plasminogen activator (tPA), tissue plasminogen activator inhibitor-1 (PAI-1) and plasmin-antiplasmin complex (PAP) were significantly elevated in the CKD groups compared with the controls. The markers of inflammation, monocyte activation, and impaired kidney function were also increased in those with CKD. AA was positively correlated with the uPA/suPAR system in the early stages of CKD, whereas during severe-to-end-stage CKD, inverse relationships were observed between AA, tPA and PAI-1. Additionally, AA was an independent variable associated with tPA in patients with CKD overall and with uPA levels in the mild-to-moderate CKD group.

CONCLUSIONS

Obtained results suggest for the first time the association between AA and the fibrinolytic system in CKD patients. The distinct relationship between AA and individual parameters of fibrinolysis appears to be dependent on CKD stage.

The Uremic Toxin Indoxyl Sulfate Accelerates Thrombotic Response after Vascular Injury in Animal Models

Chronic kidney disease (CKD) patients are at high risk for thrombotic events. Indoxyl sulfate (IS) is one of the most potent uremic toxins that accumulates during CKD. Even though IS is associated with an increased risk for cardiovascular disease, its impact on thrombotic events still remains not fully understood. The purpose of the study was to evaluate the direct effect of IS on thrombotic process. We examined the impact of acute exposure to IS on thrombus development induced by electric current in Wistar rats, intravital thrombus formation after laser-induced injury in the mice endothelium, coagulation profile, clot formation dynamics, platelet aggregations, and erythrocyte osmotic resistance. IS doses: 10, 30 and 100 mg/kg body weight (b.w.) increased weight of thrombus induced by electric current in dose-dependent manner (p < 0.001). Furthermore, two highest IS doses increased laser-induced thrombus formation observed via confocal system (increase in fluorescence intensity and total thrombus area (p < 0.01)). Only the highest IS dose decreased clotting time (p < 0.01) and increased maximum clot firmness (p < 0.05). IS did not affect blood morphology parameters and erythrocyte osmotic resistance, but augmented collagen-induced aggregation. Obtained data indicate that IS creates prothrombotic state and contributes to more stable thrombus formation. Thus, we concluded that IS may be one of crucial uremic factors promoting thrombotic events in CKD patients.

An acoustic startle alters knee joint stiffness and neuromuscular control

Growing evidence suggests that the nervous system contributes to non-contact knee ligament injury, but limited evidence has measured the effect of extrinsic events on joint stability. Following unanticipated events, the startle reflex leads to universal stiffening of the limbs, but no studies have investigated how an acoustic startle influences knee stiffness and muscle activation during a dynamic knee perturbation. Thirty-six individuals were tested for knee stiffness and muscle activation of the quadriceps and hamstrings. Subjects were seated and instructed to resist a 40-degree knee flexion perturbation from a relaxed state. During some trials, an acoustic startle (50 ms, 1000 Hz, 100 dB) was applied 100 ms prior to the perturbation. Knee stiffness, muscle amplitude, and timing were quantified across time, muscle, and startle conditions. The acoustic startle increased short-range (no startle: 0.044 ± 0.011 N·m/deg/kg; average startle: 0.047 ± 0.01 N·m/deg/kg) and total knee stiffness (no startle: 0.036 ± 0.01 N·m/deg/kg; first startle 0.027 ± 0.02 N·m/deg/kg). Additionally, the startle contributed to decreased [vastus medialis (VM): 13.76 ± 33.6%; vastus lateralis (VL): 6.72 ± 37.4%] but earlier (VM: 0.133 ± 0.17 s; VL: 0.124 ± 0.17 s) activation of the quadriceps muscles. The results of this study indicate that the startle response can significantly disrupt knee stiffness regulation required to maintain joint stability. Further studies should explore the role of unanticipated events on unintentional injury.

Effect of strength and proprioception training on eversion to inversion strength ratios in subjects with unilateral functional ankle instability

OBJECTIVES

To examine the effect of six weeks of strength and proprioception training on eversion to inversion isokinetic strength ratios (E/I ratios) in subjects with unilateral functional ankle instability.

METHODS

Thirty eight subjects were randomly assigned to one of four treatment groups: strength training (S); proprioception training (P); strength + proprioception training (B); control (C). Isokinetic strength was tested before and after training using a Kin Com 125 automatic positioning isokinetic dynamometer. Subtalar joint eversion and inversion motions were tested both concentrically and eccentrically through a range of motion involving 40 degrees. All peak torque and average torque values were normalised for body mass. E/I ratios were calculated from average torque and peak torque measures by taking the concentric eversion value and combining it with the eccentric inversion value. Data were analysed using a mixed model analysis of variance with repeated measures on the test factor. Average torque and peak torque E/I ratios at 30 and 120 degrees/s were analysed separately.

RESULTS

There were no significant differences in average torque and peak torque E/I ratios of the functionally unstable ankle for any of the groups after training compared with before.

CONCLUSIONS

Six weeks of strength and proprioception training (either alone or combined) had no effect on isokinetic measures of strength in subjects with self reported unilateral functional instability. Further studies examining this agonist (concentric) to antagonist (eccentric) muscle group strength ratio are needed.

Impact forces and neck muscle activity in heading by collegiate female soccer players

Three soccer header types (shooting, clearing and passing) and two heading approaches (standing and jumping) were manipulated to quantify impact forces and neck muscle activity in elite female soccer players. The 15 participants were Division I intercollegiate soccer players. Impact forces were measured by a 15-sensor pressure array secured on the forehead. The electromyographic (EMG) activity of the left and right sternocleidomastoid and trapezius muscles was recorded using surface electrodes. Maximum impact forces and impulses as well as the EMG data were analysed with separate repeated-measures analyses of variance. Impact forces and impulses did not differ among the header types or approaches. Higher values were found for jumping versus standing headers in the mean normalized EMG for the right sternocleidomastoid. In addition, the integrated EMG was greater for the right sternocleidomastoid and right and left trapezius (P < 0.05). The sternocleidomastoid became active earlier than the trapezius and showed greater activity before ball contact. The trapezius became active just before ball contact and showed greater activity after ball contact. The increased muscle activity observed in the neck during the jumping approach appears to stabilize the connection between the head and body, thereby increasing the stability of the head-neck complex.

Differential control during maximal concentric and eccentric loading revealed by characteristics of the electromyogram

Maximal eccentric loading has been associated with higher levels of spindle afferent activity but lower levels of integrated EMG as compared to maximal concentric loading. Elbow flexor EMG was recorded from 17 subjects during concentric (CONC) and eccentric (ECC) elbow flexion at 70 degrees s(-1) using a Kin-Com dynamometer. We hypothesized that peak EMG amplitude would be more sensitive to fluctuations in facilitation by the spindle primary afferents via the segmental stretch reflex pathway, and that the mean EMG would be more reflective of the ongoing level of muscle activation. A ratio of peak to mean EMG (P/M EMG ratio) was predicted to be larger during maximal eccentric loading than maximal concentric loading. The peak EMG (P<0.013) and the P/M EMG ratio (P<0.001) were significantly greater during the ECC condition than the CONC condition. In a subgroup of three subjects who underwent 3 weeks of eccentrically biased weight training, EMG, peak torque and torque variability were assessed before and after training. P/M EMG ratio decreased, while peak torque and torque variability increased following the training. Differences in the P/M EMG ratio appear to reflect differences in the way eccentric and concentric muscle actions are controlled and do not simply represent less control during the eccentric task.

High-intensity dynamic human muscle performance enhanced by a metabolic intervention

PURPOSE

The purpose of this study was to quantify the effects of a metabolic treatment on human muscle dynamic performance (strength, work, and fatigue) measured under conditions of acute, exhaustive high-intensity anaerobic isokinetic exercise.

METHODS

Unilateral prefatigue and postfatigue peak torque and work values were measured in the quadriceps femoris of 13 subjects using a computer-controlled isokinetic dynamometer, over a 23-d interval. The two experimental treatments were: 1) a glycine and L-arginine salt of alpha-ketoisocaproic acid calcium ("GAKIC"); and 2) isocaloric sucrose (control). Based on a randomized double-blind cross-over repeated measures design, measurements were made before and during an exhaustive anaerobic fatigue protocol to calculate a Fatigue Resistance Index (FRI = [peri-exhaustion torque]\[baseline peak torque]), as well as total work.

RESULTS

The FRI and total work for each of the exhaustion sets measured at 0, 5, and 15 min after oral GAKIC treatment were greater than values obtained for isocaloric control treatment (P < 0.02). GAKIC treatment increased the mean resistance to fatigue (FRI) up to 28% over isocaloric control. Overall gain in total muscle work attributable to GAKIC was 10.5 +/- 0.8% greater than control, sustained for at least 15 min. After 24 h, both GAKIC and control concentric forces returned to the same absolute values (P > 0.05): mean FRI = 0.42 +/- 0.05 and mean total work = 4600 +/- 280 J. There were no significant differences attributable to random order of testing.

CONCLUSIONS

Compared with isocaloric carbohydrate, oral GAKIC treatment increased muscle torque and work sustained during intense acute anaerobic dynamic exercise; additionally, it increased overall muscle performance by delaying muscle fatigue during the early phases of anaerobic dynamic exercise.

Eversion strength analysis of uninjured and functionally unstable ankles

OBJECTIVE

Functional ankle instability (FAI) afflicts many athletes. Several causes of FAI have been implicated, including peroneal muscle weakness. Traditional musculoskeletal rehabilitation programs have focused on concentric muscle strength. The purpose of our study was to compare concentric and eccentric isokinetic and isometric eversion ankle strength measurements between subjects identified as having unilateral FAI and subjects having no history of inversion ankle sprain.

DESIGN AND SETTING

Employing a matched-pairs technique, subjects with no history of ankle injury were compared with subjects with unilateral FAI using isokinetic and isometric measures of eversion ankle strength. Strength testing was performed in a sports medicine clinic setting.

SUBJECTS

Forty-two subjects volunteered for this study: 21 subjects suffered from unilateral FAI (age = 19.3 +/- 1.1 years, wt = 84.0 +/- 9.5 kg, ht = 181.5 +/- 9.2 cm), while 21 subjects served as matched-paired controls (age = 19.5 +/- 1.2 years, wt = 82.5 +/- 10.9 kg, ht = 179.5 +/- 7.9 cm).

MEASUREMENTS

Ankle eversion concentric and eccentric strength (peak torque) was assessed at 0 degrees /s, 30 degrees /s, 60 degrees /s, 90 degrees /s, 120 degrees /s, 150 degrees /s, and 180 degrees /s using an isokinetic dynamometer.

RESULTS

We found no significant differences in concentric, eccentric, or isometric eversion ankle strength between the 2 groups of subjects.

CONCLUSIONS

The exact cause of FAI remains elusive. Based on our results, those who suffer from unilateral FAI do not appear to have eversion strength deficits. Unless clear evidence of weakness exists, clinicians may find that eversion strength training exercises are unnecessary. Future research should examine other causes of FAI, including reciprocal muscle group strength ratios and proprioception deficits.

Contrast therapy does not cause fluctuations in human gastrocnemius intramuscular temperature

OBJECTIVE

Contrast therapy has a long history of use in sports medicine. Edema and ecchymosis reduction, vasodilation and vasoconstriction of blood vessels, blood flow changes, and influences on the inflammatory response are physiologic effects attributed to the ability of this modality to evoke tissue temperature fluctuations. Our purpose was to measure the change in human gastrocnemius intramuscular tissue temperature during a typical contrast therapy treatment.

DESIGN AND SETTING

A randomized-group design was used to examine differences between 2 groups of subjects following a 31-minute warm whirlpool (control) and a 31-minute contrast therapy (experimental) treatment. A hydrotherapy room in a small- college sports medicine facility served as the test environment.

SUBJECTS

Twenty (7 females and 13 males) healthy college students (age = 20.9 +/- 1.2 years; ht = 178.5 +/- 11.1 cm; wt = 79.2 +/- 21.7 kg) volunteered to participate in this study. Subjects were randomly assigned to either a control or a treatment group.

MEASUREMENTS

Intramuscular tissue temperatures in the gastrocnemius were recorded every 30 seconds.

RESULTS

There was a significant difference in mean overall temperature change between the experimental group (0.85 degrees C +/- 0.60 degrees C) and the control group (2.10 degrees C +/- 1.50 degrees C). In addition, there were significant differences between the 2 groups at 10, 15, 16, 20, 21, 25, 26, 30, and 31 minutes. At each recording point, the control group temperature change was significantly higher than that of the experimental group. There was no difference in absolute temperatures at the 11-minute recording point between the groups.

CONCLUSIONS

Contrast therapy did not lead to significant fluctuations in muscle tissue temperature at 4 cm below the skin's surface. Therefore, it seems unlikely that the physiologic effects attributed to these fluctuations occur. A 1-minute exposure to a cold whirlpool during a typical contrast treatment does not appear to be long enough to significantly decrease tissue temperature after exposure to the warm hydrotherapy environment.

Concentric versus enhanced eccentric hamstring strength training: clinical implications

OBJECTIVE

Hamstring injuries can be quite debilitating and often result in chronic problems. Eccentric muscle actions are often the last line of defense against muscle injury and ligament disruption. Traditionally, the focus of hamstring strength rehabilitation has been on concentric muscle actions. The purpose of our study was to compare hamstring muscle strength gains in concentric and eccentric hamstring strength training.

DESIGN AND SETTING

A randomized-group design was used to examine differences in 1-repetition maximum (1 RM) and isokinetic strength values among 3 groups of subjects. Subjects were tested in a biomechanics laboratory using an isokinetic dynamometer, while training was carried out in a physical therapy outpatient clinic.

SUBJECTS

Twenty-seven healthy male subjects (age = 22.9 +/- 3.1 years, wt = 81.8 +/- 12.9 kg, ht = 178.6 +/- 7.2 cm) participated in this study. Subjects were randomly assigned to 1 of 3 treatment groups: eccentric training, concentric training, or control.

MEASUREMENTS

Subjects performed hamstring curls using an isotonic weight training device. Pretest 1 RM weight values were determined for all subjects using a standardized 1 RM protocol. In addition, maximum concentric and eccentric isokinetic strength values for knee-flexion strength were determined. Control group subjects refrained from weight training for 6 weeks. Subjects in the training groups trained 2 days per week for 6 weeks (12 sessions). After 6 weeks of training, all subjects returned for 1RM and isokinetic posttesting.

RESULTS

The concentric group improved 19%, while the eccentric group improved 29%. The control group subjects did not show any significant change over the 6 weeks. In addition, there were improvements in eccentric isokinetic peak torque/ body weight ratios at both 60 degrees s and 180 degrees from pretesting to posttesting in the eccentric training group only.

CONCLUSIONS

Our results demonstrate the effectiveness of isotonic strength training on the development of hamstring muscle strength. More important is the dramatic effect of eccentric strength training on overall hamstring muscle strength, both isotonic and isokinetic. Clinicians should consider using eccentric hamstring strengthening as part of their rehabilitation protocols for hamstring and knee injuries.

Effect of prophylactic knee bracing on balance and joint position sense

Prophylactic knee braces are designed to prevent and reduce the severity of ligamentous injuries to the knee. Conflicting evidence is reported concerning their efficacy. The purpose of this study was to determine the effect of prophylactic knee bracing on the proprioceptive parameters of balance and joint position sense. Active and passive joint position sense were assessed using the Cybex II + Isokinetic Dynamometer (Cybex Division of Lumex, Inc, Ronkonkoma, NY). Sway index and center of balance were assessed using the Chattecx Dynamic Balance System (Chattanooga Group, Hixson, TN). Thirty-six male subjects were measured with and without prophylactic knee braces. Joint position sense was measured in degrees of error from four preselected target angles. Sway index and center of balance measures were recorded in centimeters under the following platform conditions: stable, plantar flexion/dorsiflexion, and inversion/eversion. Separate repeated measures ANOVAs were performed to determine if there were differences between the braced and unbraced conditions for center of balance, sway index, and joint position sense. Center of balance with the platform moving in a dorsi/plantar flexion direction was improved while wearing the knee braces. In addition, differences in both center of balance and sway were recorded across the three platform conditions with and without knee bracing. Bracing did not affect joint position sense. The results of this study suggest that prophylactic knee braces have very little impact on proprioceptive feedback mechanisms.