Colony stimulating factor-1 receptor drives glomerular parietal epithelial cell activation in focal segmental glomerulosclerosis.

Parietal epithelial cells (PECs) are kidney progenitor cells with similarities to a bone marrow stem cell niche. In focal segmental glomerulosclerosis (FSGS) PECs become activated and contribute to extracellular matrix deposition. Colony stimulating factor-1 (CSF-1), a hematopoietic growth factor, acts via its specific receptor, CSF-1R, and has been implicated in several glomerular diseases, although its role on PEC activation is unknown. Here, we found that CSF-1R was upregulated in PECs and podocytes in biopsies from patients with FSGS. Through in vitro studies, PECs were found to constitutively express CSF-1R. Incubation with CSF-1 induced CSF-1R upregulation and significant transcriptional regulation of genes involved in pathways associated with PEC activation. Specifically, CSF-1/CSF-1R activated the ERK1/2 signaling pathway and upregulated CD44 in PECs, while both ERK and CSF-1R inhibitors reduced CD44 expression. Functional studies showed that CSF-1 induced PEC proliferation and migration, while reducing the differentiation of PECs into podocytes. These results were validated in the Adriamycin-induced FSGS experimental mouse model. Importantly, treatment with either the CSF-1R-specific inhibitor GW2580 or Ki20227 provided a robust therapeutic effect. Thus, we provide evidence of the role of the CSF-1/CSF-1R pathway in PEC activation in FSGS, paving the way for future clinical studies investigating the therapeutic effect of CSF-1R inhibitors on patients with FSGS.

Sound-based cough peak flow estimation in patients with neuromuscular disorders.

INTRODUCTION/AIMS: Cough impairment is common in individuals with neuromuscular disorders and is associated with respiratory infections and shorter survival. Cough strength is assessed by measuring cough peak flow (CPF) using a flow meter, but this method requires a complex device setup and trained staff. The aim of the study is to evaluate the reliability of a smartphone app to estimate CPF based on cough sounds in a cohort of individuals with neuromuscular disorders. METHODS: Individuals with neuromuscular disorders underwent CPF measurement with a flow meter and a smartphone app. A CPF <270 L/min was considered abnormal. RESULTS: Of the 50 patients studied, 26 had amyotrophic lateral sclerosis (52%), 15 had hereditary myopathies (30%), and 9 had myasthenia gravis (18%). The intraclass correlation coefficient (ICC) between the CPF measured with a flow meter and CPF estimated with cough sounds was 0.774 (p < .001) even if the patients had orofacial weakness (ICC = 0.806, p < .001). The smartphone app had 94.4% sensitivity and 100% specificity to detect patients with CPF of less than 270 L/min. DISCUSSION: Our findings suggest that sounds measured with a smartphone app provide a reliable estimate of CPF in patients with neuromuscular disorders, even in the presence of with orofacial weakness. This may be a convenient way to monitor respiratory involvement in patients with neuromuscular disorders, but larger studies of more diverse patient cohorts are needed.

Dysphagia in hospitalized patients: Prevalence, related factors and impact on aspiration pneumonia and mortality.

BACKGROUND: Oropharyngeal dysphagia can be highly concerning in hospitalized patients, increasing morbidity and mortality, making its early identification essential. We aimed to characterize dysphagia and its association with aspiration pneumonia and mortality in a tertiary hospital in Barcelona, Spain. METHODS: Using data from all hospital discharges during the period 2018-2021, we identified the characteristics of patients with dysphagia and their distribution among hospital departments through the minimum data set, which codifies patients' diagnoses according to the International Classification of Diseases 10th Revision (ICD-10). We used logistic regression models to assess the association between dysphagia, aspiration pneumonia and mortality. RESULTS: Dysphagia was present in 2.4% of all hospital discharges and was more frequent in older patients and in men. The diagnoses most frequently associated with dysphagia were aspiration pneumonia (48.2%) and stroke (14%). Higher prevalence of dysphagia was found in the acute geriatric unit (10.3%), neurology (7.6%) and internal medicine (7.5%) wards. Dysphagia was associated with aspiration pneumonia, aOR = 8.04 (95%CI, 6.31-10.25), and independently increased the odds of death among hospitalized patients, aOR = 1.43 (95%CI, 1.19-1.73). CONCLUSIONS: We conclude that dysphagia is a prevalent and transversal condition, increasing the risk of mortality in all patients, and efforts should be intensified to increase its early detection and correct management.

Ultrasonographic and manometric study of the tongue as biomarkers of dysphagia in patients with amyotrophic lateral sclerosis.

BACKGROUND: The possibility of having methods to assess dysphagia in amyotrophic lateral sclerosis (ALS) patients in a minimally invasive manner could facilitate follow-up and allow performing of therapeutic interventions at earlier stages of the disease. The aim of the study was to analyze the role of tongue strength and thickness in ALS patients and their correlation with dysphagia and bulbar function. METHODS: A sample of outpatients with ALS was evaluated for demographic and clinical features. Tongue thickness and strength have been measured for each patient, and quantitative and qualitative data of the videofluoroscopy swallow study have been analyzed. RESULTS: Of the 38 ALS patients studied, 47.4% were women, and 26.3% had bulbar onset. The median time between symptom onset and the study was 24 months (IQR 11.5-48), and 55.3% of the patients were carriers of non-invasive mechanical ventilation. Tongue strength identified patients with impaired oral and pharyngeal transit and those with bolus residue scale (BRS) > 1 or penetration-aspiration scale (PAS) ≥ 3. In contrast, tongue thickness is only associated with impaired oral transit. Finally, anterior tongue strength ≤ 34 kPa and posterior tongue strength ≤ 34.5 kPa detected ALS penetrators/aspirators (PAS ≥ 3) and patients with ALS with post-swallow residue (BRS > 1). CONCLUSIONS: Our results suggest that measures that assess the functionality (strength) of the tongue are more valuable than morphological measurements (thickness) for the follow-up of patients with ALS. Alterations of the anterior and posterior lingual strength correlate with the presence of bronchoaspiration and post-swallowing residue (BRS > 1).

Molecular Mechanisms of Kidney Injury and Repair.

Chronic kidney disease (CKD) will become the fifth global cause of death by 2040, thus emphasizing the need to better understand the molecular mechanisms of damage and regeneration in the kidney. CKD predisposes to acute kidney injury (AKI) which, in turn, promotes CKD progression. This implies that CKD or the AKI-to-CKD transition are associated with dysfunctional kidney repair mechanisms. Current therapeutic options slow CKD progression but fail to treat or accelerate recovery from AKI and are unable to promote kidney regeneration. Unraveling the cellular and molecular mechanisms involved in kidney injury and repair, including the failure of this process, may provide novel biomarkers and therapeutic tools. We now review the contribution of different molecular and cellular events to the AKI-to-CKD transition, focusing on the role of macrophages in kidney injury, the different forms of regulated cell death and necroinflammation, cellular senescence and the senescence-associated secretory phenotype (SAPS), polyploidization, and podocyte injury and activation of parietal epithelial cells. Next, we discuss key contributors to repair of kidney injury and opportunities for their therapeutic manipulation, with a focus on resident renal progenitor cells, stem cells and their reparative secretome, certain macrophage subphenotypes within the M2 phenotype and senescent cell clearance.

Macrophage-Derived Iron-Bound Lipocalin-2 Correlates with Renal Recovery Markers Following Sepsis-Induced Kidney Damage.

During the course of sepsis in critically ill patients, kidney dysfunction and damage are among the first events of a complex scenario toward multi-organ failure and patient death. Acute kidney injury triggers the release of lipocalin-2 (Lcn-2), which is involved in both renal injury and recovery. Taking into account that Lcn-2 binds and transports iron with high affinity, we aimed at clarifying if Lcn-2 fulfills different biological functions according to its iron-loading status and its cellular source during sepsis-induced kidney failure. We assessed Lcn-2 levels both in serum and in the supernatant of short-term cultured renal macrophages (MΦ) as well as renal tubular epithelial cells (TEC) isolated from either Sham-operated or cecal ligation and puncture (CLP)-treated septic mice. Total kidney iron content was analyzed by Perls' staining, while Lcn-2-bound iron in the supernatants of short-term cultured cells was determined by atomic absorption spectroscopy. Lcn-2 protein in serum was rapidly up-regulated at 6 h after sepsis induction and subsequently increased up to 48 h. Lcn-2-levels in the supernatant of TEC peaked at 24 h and were low at 48 h with no change in its iron-loading. In contrast, in renal MΦ Lcn-2 was low at 24 h, but increased at 48 h, where it mainly appeared in its iron-bound form. Whereas TEC-secreted, iron-free Lcn-2 was associated with renal injury, increased MΦ-released iron-bound Lcn-2 was linked to renal recovery. Therefore, we hypothesized that both the cellular source of Lcn-2 as well as its iron-load crucially adds to its biological function during sepsis-induced renal injury.

Exploring macrophage cell therapy on Diabetic Kidney Disease.

Alternatively activated macrophages (M2) have regenerative properties and shown promise as cell therapy in chronic kidney disease. However, M2 plasticity is one of the major hurdles to overcome. Our previous studies showed that genetically modified macrophages stabilized by neutrophil gelatinase-associated lipocalin (NGAL) were able to preserve their M2 phenotype. Nowadays, little is known about M2 macrophage effects in diabetic kidney disease (DKD). The aim of the study was to investigate the therapeutic effect of both bone marrow-derived M2 (BM-фM2) and ф-NGAL macrophages in the db/db mice. Seventeen-week-old mice with established DKD were divided into five treatment groups with their controls: D+BM-фM2; D+ф-BM; D+ф-NGAL; D+ф-RAW; D+SHAM and non-diabetic (ND) (db/- and C57bl/6J) animals. We infused 1 × 106 macrophages twice, at baseline and 2 weeks thereafter. BM-фM2 did not show any therapeutic effect whereas ф-NGAL significantly reduced albuminuria and renal fibrosis. The ф-NGAL therapy increased the anti-inflammatory IL-10 and reduced some pro-inflammatory cytokines, reduced the proportion of M1 glomerular macrophages and podocyte loss and was associated with a significant decrease of renal TGF-ß1. Overall, our study provides evidence that ф-NGAL macrophage cell therapy has a therapeutic effect on DKD probably by modulation of the renal inflammatory response caused by the diabetic milieu.

CPT1a gene expression reverses the inflammatory and anti-phagocytic effect of 7-ketocholesterol in RAW264.7 macrophages.

BACKGROUND: Macrophage are specialized cells that contributes to the removal of detrimental contents via phagocytosis. Lipid accumulation in macrophages, whether from phagocytosis of dying cells or from circulating oxidized low-density lipoproteins, alters macrophage biology and functionality. It is known that carnitine palmitoyl transferase 1-a (CPT1a) gene encodes an enzyme involved in fatty acid oxidation and, therefore, lipid content. However, the potential of CPT1a to activate macrophage phagocytic function have not been elucidated. METHODS: Using a murine macrophage cell line, RAW264.7, we determine if intracellular accumulation of 7-ketocholesterol (7-KC) modulates macrophage phagocytic function through CPT1a gene expression. In addition, the effects of CPT1a genetic modification on macrophage phenotype and phagocytosis has been studied. RESULTS: Our results revealed that CPT1a gene expression decreased by the accumulation of 7-KC at the higher dose of 7-KC. This was concomitant with an impair ability to phagocytize bioparticles and an inflammatory phenotype. GW3965 treatment, which have shown to facilitate the efflux of cholesterol, eliminated the intracellular lipid droplets of 7-KC-laden macrophages, increased the gene expression of CPT1a, diminished the gene expression of the inflammatory marker iNOS and restored macrophage phagocytosis. Furthermore, CPT1a Knockdown per se was detrimental for macrophage phagocytosis whereas transcriptional activation of CPT1a heightened the uptake of bioparticles. CONCLUSIONS: Altogether, our findings indicate that downregulation of CPT1a by lipid content modulates macrophage phagocytosis and inflammatory phenotype.

Urinary Neuropilin-1: A Predictive Biomarker for Renal Outcome in Lupus Nephritis.

At present, Lupus Nephritis (LN) is still awaiting a biomarker to better monitor disease activity, guide clinical treatment, and predict a patient's long-term outcome. In the last decade, novel biomarkers have been identified to monitor the disease, but none have been incorporated into clinical practice. The transmembrane receptor neuropilin-1 (NRP-1) is highly expressed by mesangial cells and its genetic deletion results in proteinuric disease and glomerulosclerosis. NRP-1 is increased in kidney biopsies of LN. In this work we were interested in determining whether urinary NRP-1 levels could be a biomarker of clinical response in LN. Our results show that patients with active LN have increased levels of urinary NRP-1. When patients were divided according to clinical response, responders displayed higher urinary and tissue NRP-1 levels at the time of renal biopsy. Areas under the receiver operating characteristic curve, comparing baseline creatinine, proteinuria, urinary NRP-1, and VEGFA protein levels, showed NRP-1 to be an independent predictor for clinical response. In addition, in vitro studies suggest that NRP-1could promote renal recovery through endothelial proliferation and migration, mesangial migration and local T cell cytotoxicity. Based on these results, NRP-1 may be used as an early prognostic biomarker in LN.

Lipocalin-2 abrogates epithelial cell cycle arrest by PPARγ inhibition.

Macrophage-epithelial cross-talk regulates cell cycle progression and represents an important factor in rescuing epithelial cells from cell cycle arrest in order to maintain a healthy epithelial phenotype. However, the underlying mechanisms are still not well defined. We provide evidence that macrophage-secreted lipocalin-2 (Lcn-2) plays a key role during this process. In a co-culture setup using cell cycle arrested NRK52e renal epithelial cells and primary bone marrow-derived macrophages, Lcn-2 restores proliferation through inhibition of peroxisome proliferator-activated receptor (PPAR)-γ. Lcn-2 overexpression in macrophages overcomes epithelial cell cycle arrest and enhances epithelial markers via megalin and the downstream activation of PI3K/Akt signalling pathway, whereas a knockdown of Lcn-2 in macrophages prevented this effect. Our results show that macrophage-secreting Lcn-2 is crucial in rescuing epithelial cells from cell cycle arrest and in promoting epithelial proliferation.

Macrophage Overexpressing NGAL Ameliorated Kidney Fibrosis in the UUO Mice Model.

BACKGROUND/AIMS: Alternatively activated macrophages (AAM) have regenerative and anti-inflammatory characteristics. Here, we sought to evaluate whether AAM cell therapy reduces renal inflammation and fibrosis in the unilateral ureteral obstruction (UUO) mice model. METHODS: We stabilized macrophages by adenoviral vector NGAL (Neutrophil gelatinase-associated lipocalin-2) and infused them into UUO mice. To ascertain whether macrophages were capable of reaching the obstructed kidney, macrophages were stained and detected by in vivo cell tracking. RESULTS: We demonstrated that some infused macrophages reached the obstructed kidney and that infusion of macrophages overexpressing NGAL was associated with reduced kidney interstitial fibrosis and inflammation. This therapeutic effect was mainly associated with the phenotype and function preservation of the transferred macrophages isolated from the obstructed kidney Conclusions: Macrophage plasticity is a major hurdle for achieving macrophage therapy success in chronic nephropathies and could be overcome by transferring lipocalin-2.

Respiratory muscle strength training and neuromuscular electrical stimulation in subacute dysphagic stroke patients: a randomized controlled trial.

OBJECTIVE: To evaluate the effectiveness of inspiratory/expiratory muscle training (IEMT) and neuromuscular electrical stimulation (NMES) to improve dysphagia in stroke. DESIGN: Prospective, single-blind, randomized-controlled trial. SETTING: Tertiary public hospital. SUBJECTS: Sixty-two patients with dysphagia were randomly assigned to standard swallow therapy (SST) (Group I, controls, n=21), SST+ IEMT (Group II, n=21) or SST+ sham IEMT+ NMES (Group III, n=20). INTERVENTIONS: All patients followed a 3-week standard multidisciplinary rehabilitation program of SST and speech therapy. The SST+IEMT group's muscle training consisted of 5 sets/10 repetitions, twice-daily, 5 days/week. Group III's sham IEMT required no effort; NMES consisted of 40-minute sessions, 5 days/week, at 80Hz. MAIN OUTCOMES: Dysphagia severity, assessed by Penetration-Aspiration Scale, and respiratory muscle strength (maximal inspiratory and expiratory pressures) at the end of intervention and 3-month follow-up. RESULTS: Maximal respiratory pressures were most improved in Group II: treatment effect was 12.9 (95% confidence interval 4.5-21.2) and 19.3 (95% confidence interval 8.5-30.3) for maximal inspiratory and expiratory pressures, respectively. Swallowing security signs were improved in Groups II and III at the end of intervention. No differences in Penetration-Aspiration Scale or respiratory complications were detected between the 3 groups at 3-month follow-up. CONCLUSION: Adding IEMT to SST was an effective, feasible, and safe approach that improved respiratory muscle strength. Both IEMT and NMES were associated with improvement in pharyngeal swallowing security signs at the end of the intervention, but the effect did not persist at 3-month follow-up and no differences in respiratory complications were detected between treatment groups and controls.

Usefulness of citric cough test for screening of silent aspiration in subacute stroke patients: a prospective study.

OBJECTIVE: To detect silent aspiration in a homogeneous sample of stroke patients using the citric acid cough test. DESIGN: Prospective study. SETTING: Public university tertiary hospital. PARTICIPANTS: Consecutive subacute stroke patients (N=134; 74 men, 60 women; mean age ± SD, 62.2±11.9y; 11.7±9.9d after stroke) who had complained of dysphagic symptoms, referred for rehabilitation from December 2010 to October 2012. INTERVENTION: All patients were administered a citric acid cough test and underwent a videofluoroscopic swallowing study (VFSS). A reduced or an absent response on the citric acid cough test was considered when cough peaks were ≤4. A control group of healthy volunteers was also screened. MAIN OUTCOME MEASURES: The citric acid cough test results were compared with the VFSS results, which were used as a criterion standard. RESULTS: There were 36 patients with a positive citric acid cough test, of which the VFSS revealed penetration in 14 cases (38.9%), aspiration in 5 (13.9%), silent aspiration in 5 (13.9%), and normality in 12 patients (33.3%). The sensitivity and specificity indexes for the reliability of citric acid cough test as a screening method for silent aspiration in comparison with the VFSS were .19 and .71, respectively. Other comparisons were made between silent aspirators (Penetration Aspiration Scale=8) and different subgroups of patients, but values remained poor. CONCLUSIONS: The citric acid cough test using 1.0 (weight by volume)% for 1 minute does not seem to be a useful standalone tool to screen for silent aspiration in subacute stroke patients with suspected dysphagia.

Therapeutic approach to dysphagia in post-COVID patients in a rehabilitation unit: a descriptive longitudinal study.

BACKGROUND: A high rate of hospitalized patients for COVID-19 had dysphagia, frequently underdiagnosed, and not treated, inducing a prolonged dysphagia with protracted recovery. Specific treatments and protocols have not been well described yet. AIM: Given the potential benefits of respiratory muscle training (IEMT) and neuromuscular stimulation (NMES) in dysphagia treatment, this study aimed to assess the feasibility of the protocol used for treating dysphagia in patients who experienced prolonged hospitalization for COVID-19. DESIGN: Observational, descriptive, prospective study. SETTING: Department of Physical Medicine and Rehabilitation of a tertiary University hospital. POPULATION: Fifty-eight COVID-19 patients were admitted for intensive rehabilitation (March 2020 to October 2021) were prospectively studied. METHODS: Dysphagia was diagnosed using videofluoroscopy and treated with a 3-week protocol adapted from neuromuscular stimulation (NMES) in a motor threshold and inspiratory/expiratory muscle strength training (IEMST), five sets of five repetitions three times daily for 3 weeks. Feasibility was assessed with adherence, outcomes achieved, and occurrence of adverse/unexpected events. Respiratory function (peak cough flow, maximal inspiratory/expiratory pressures) and swallow function (Penetration-Aspiration Scale and Bolus Residue Scale measured by videofluoroscopy) were recorded descriptive statistics, Student's t test for numerical data, and Wilcoxon Test for ordinal variables were applied. SPPSS vs28 and STATA version 15.1 (StataCorp, College Station, TX, USA) were used for statistical analysis. P values 0.05 were considered significant. RESULTS: Dysphagia was highly prevalent in severe COVID-19 patients (86.6%); all respiratory and swallow parameters improved after a 3-week intervention and 12 of 18 patients dependent on tube feeding resumed a normal diet (66.7%; McNemar P=0.03), and 84.09% attended a no restriction diet at discharge. Adherence to treatment was 85%. No significant adverse events were detected. CONCLUSIONS: We conclude that a structured swallowing-exercise training intervention based on IEMT and NMES is feasible and safe in prolonged hospitalization post-COVID patients. CLINICAL REHABILITATION IMPACT: To describe rehabilitation protocols used to treat dysphagia in post-COVID patients will help us to optimize the available techniques in each center and to induce a faster recovery avoiding potential complications.

The effect of a motor relearning on balance and postural control in patients after stroke: An open-label randomized controlled trial.

INTRODUCTION: Balance and postural control impairments are common in stroke patients, increasing fall risk and limiting their daily and social activities. Current research lacks comprehensive studies evaluating the efficacy and long-term effects of task-specific training on balance and postural control among stroke patients, especially when considering biomechanical and posturographic assessments. PATIENTS AND METHODS: A randomized controlled trial included 63 subacute stroke patients recruited from the outpatient rehabilitation department. Participants were randomly assigned to the MRP group (n=32), receiving task-specific training based on MRP, or the CPT group (n=31), receiving conventional physical therapy. Both groups completed an 8-week intervention (3 sessions/week; 1 h./session). Balance and postural control were assessed at baseline, post-intervention, and 3-month follow-up using the Berg Balance Scale (BBS) and posturography. RESULTS: The MRP group exhibited significantly larger improvements than the CPT group in both BBS scores (p=0.001, d=2.98, 95% CI [2.25, 3.70]) and Balance Index scores (p=0.001, d=2.83, 95% CI [2.12, 3.53]) after the intervention. These improvements were sustained at 3-month follow-up. DISCUSSION: The findings suggest that task-specific training based on MRP is more effective than CPT for improving balance and postural control. The MRP intervention may enhance the motor learning and neural plasticity of the patients, leading to better functional outcomes. However, the study's open-label design represents a limitation, and further research with adequate blinding is needed. CONCLUSION: Task-specific training based on MRP was superior to CPT for improving balance and postural control in subacute stroke patients. Participants undergoing MRP exhibited significant and clinically relevant improvements that were sustained at follow-up.

Prognostic value of serum neutrophil gelatinase-associated lipocalin in metastatic and nonmetastatic colorectal cancer.

BACKGROUND: Neutrophil gelatinase-associated lipocalin (NGAL) expression is increased in epithelial cancer patients, but studies showing its relation to prognosis are scarce. We aimed to test the ability of preoperative serum NGAL levels (pNGAL) to predict recurrence in metastatic and nonmetastatic colorectal cancer (CRC) patients. METHODS: This retrospective study determined pNGAL levels in 60 healthy individuals, 47 patients with nonmetastatic CRC, and 70 patients with metastatic CRC undergoing curative neoplastic resection. Patients were divided into low- and high-pNGAL groups using a median series-based cutoff. RESULTS: The mean ± SD pNGAL in CRC patients (nonmetastatic and metastatic) was 102.3 ± 66.6 (median 91.4). Nonmetastatic CRC and metastatic CRC patients had higher pNGAL than healthy controls (88 ± 64 and 112 ± 67 vs. 0.6 ± 0.3, respectively, both p < 0.0001). Nonmetastatic CRC patients with deeper tumor invasion and metastatic CRC patients with shorter disease-free interval after CRC resection had higher pNGAL. pNGAL levels correlated with neoplastic tissue volume. CRC patients with recurrence had higher pNGAL than those without recurrence (118 ± 64 vs. 88 ± 66, p = 0.013), and high-pNGAL patients had a higher recurrence rate (59.3 vs. 36.2 %, p = 0.016). Median pNGAL-based risk classification had a sensitivity of 62.5 % for predicting neoplastic progression in CRC patients and 74.3 % for predicting neoplastic progression during the first year after metastatic CRC resection. CONCLUSIONS: pNGAL is higher in CRC patients than in the healthy population, which indicates a potential screening role. High-pNGAL levels are associated with higher neoplastic tissue volume, characteristics of neoplastic invasion, and recurrence, showing a prognostic utility mainly in metastatic CRC patients.

Accuracy of the volume-viscosity swallow test for clinical screening of dysphagia in post COVID-19 patients.

BACKGROUND & AIMS: Up to 30% of patients hospitalized for COVID-19 had oropharyngeal dysphagia, particularly those in the ICU. Many cases remained underdiagnosed due to difficulties in conducting instrumental evaluations during the pandemic. Consequently, screening tests were mandatory during this period. OBJECTIVES: To evaluate the accuracy of the volume-viscosity swallow test (V-VST), compared to gold standard videofluoroscopy, for screening dysphagia in a post-COVID cohort of patients. MATERIAL AND METHODS: We conducted a prospective single-center study involving 58 post-COVID adult patients with no previous history of dysphagia. Blinded raters performed the index V-VST upon admission and a standardized videofluoroscopy (VFSS, the reference test) within 72 h of patient intake. Oropharyngeal residue was considered a sign of impaired efficacy. Cough, decreased oxygen saturation, and voice changes were noted as signs of impaired safety. Accuracy, sensitivity, specificity, positive, and negative predictive values, and likelihood ratios were calculated for V-VST results and compared to the gold standard. RESULTS: Patients (aged 59.98 (SD11.53) years) spent a mean of 46.98 (SD 28.43) days in ICU, 33.76 (SD34.88) days with tracheostomy, and 19.46 (SD13.26) days in the NeuroRehabilitation Unit. The V-VST showed the following properties, compared to VFSS: sensitivity 55.6%, specificity 62.9%, positive predictive value 44.5%, negative predictive value 37.1%, and accuracy 61.5%. CONCLUSION: The V-VST showed mild accuracy, sensitivity, and specificity, compared to VFSS. Therefore, it should not be used as a stand-alone test for screening dysphagia in patients with a history of COVID.

Iron accumulation drives fibrosis, senescence and the senescence-associated secretory phenotype.

Fibrogenesis is part of a normal protective response to tissue injury that can become irreversible and progressive, leading to fatal diseases. Senescent cells are a main driver of fibrotic diseases through their secretome, known as senescence-associated secretory phenotype (SASP). Here, we report that cellular senescence, and multiple types of fibrotic diseases in mice and humans are characterized by the accumulation of iron. We show that vascular and hemolytic injuries are efficient in triggering iron accumulation, which in turn can cause senescence and promote fibrosis. Notably, we find that senescent cells persistently accumulate iron, even when the surge of extracellular iron has subdued. Indeed, under normal conditions of extracellular iron, cells exposed to different types of senescence-inducing insults accumulate abundant ferritin-bound iron, mostly within lysosomes, and present high levels of labile iron, which fuels the generation of reactive oxygen species and the SASP. Finally, we demonstrate that detection of iron by magnetic resonance imaging might allow non-invasive assessment of fibrotic burden in the kidneys of mice and in patients with renal fibrosis. Our findings suggest that iron accumulation plays a central role in senescence and fibrosis, even when the initiating events may be independent of iron, and identify iron metabolism as a potential therapeutic target for senescence-associated diseases.

Infusion of IL-10-expressing cells protects against renal ischemia through induction of lipocalin-2.

Ischemia/reperfusion injury is a leading cause of acute renal failure triggering an inflammatory response associated with infiltrating macrophages, which determine disease outcome. To repair the inflammation we designed a procedure whereby macrophages that overexpress the anti-inflammatory agent interleukin (IL)-10 were adoptively transferred. These bone marrow-derived macrophages were able to increase their intracellular iron pool that, in turn, augmented the expression of lipocalin-2 and its receptors. Infusion of these macrophages into rats after 1 h of reperfusion resulted in localization of the cells to injured kidney tissue, caused increases in regenerative markers, and a notable reduction in both blood urea nitrogen and creatinine. Furthermore, IL-10 therapy decreased the local inflammatory profile and upregulated the expression of pro-regenerative lipocalin-2 and its receptors. IL-10-mediated protection and subsequent renal repair were dependent on the presence of iron and lipocalin-2, since the administration of a neutralizing antibody for lipocalin-2 or administration of IL-10 macrophages pretreated with the iron chelating agent deferoxamine abrogated IL-10-mediated protective effects. Thus, adoptive transfer of IL-10 macrophages to ischemic kidneys blunts acute kidney injury. These effects are mediated through the action of intracellular iron to induce lipocalin-2.

Sphingosine-1-phosphate signalling induces the production of Lcn-2 by macrophages to promote kidney regeneration.

Inflammatory reactions are initiated to eliminate pathogens, but also to promote repair of damaged tissue after acute inflammation is terminated. In this regard, macrophages play a prominent role during induction as well as resolution of inflammation and injury in various organs including the kidney. The present study describes a mechanism for renal tissue regeneration after ischaemia/reperfusion injury. Following injury, apoptotic cell-derived sphingosine-1-phosphate (S1P) or exogenously administered sphingosine analogue FTY720 activates macrophages to support the proliferation and healing of renal epithelium, once inflammatory conditions are terminated. Both suppression of inflammation and renal regeneration might require S1P receptor 3 (S1P3) signalling and downstream release of neutrophil gelatinase-associated lipocalin (NGAL/Lcn-2) from macrophages. Overall, our data point to a macrophage-dependent S1P-S1P3-Lcn-2 axis that might be beneficial for restoration of kidney function after an ischaemic insult.