Prognostic impact of red blood cell distribution width in chronic heart failure patients with left ventricular dysfunction.

AIMS: Red blood cell (RBC) distribution width (RDW) measures RBC variations in size. Higher RDW values have been associated with poor outcome in acute heart failure (HF). We aimed to assess the prognostic impact of the RDW in chronic HF. METHODS: We retrospectively analysed a cohort of chronic HF patients with left ventricular systolic dysfunction followed in our HF clinic between January 2012 and May 2018. Patients with missing data concerning RDW were excluded. Patients were categorized according to RDW tertiles: ≤13.5%; between 13.5 and 14.7%; and >14.7%. Patients were followed until January 2021; all-cause mortality was the end point analysed. The association of RDW with all-cause mortality was assessed with a Cox-regression analysis. Two multivariate models were built. RESULTS: We studied 860 chronic HF patients, 66.4% males, mean age 70 (standard deviation, SD 13) years. Patients were followed for a median of 49 (29-82) months. During this period, 423 (49.2%) patients died. Mortality increased with increasing RDW tertiles. Patients with RDW >14.7% had a HR of mortality of 1.95 (1.47-2.58), p < 0.001 (model 1) and of 1.81 (1.35-2.41), p < 0.001 (model 2) when compared with those with RDW ≤13.5. Patients in the second RDW tertile had an all-cause death HR of 1.47 (1.12-1.93) and of 1.44 (1.09-1.90) in models 1 and 2, respectively. CONCLUSIONS: Chronic HF patients with RDW values >14.7% presented an almost 2-fold higher risk of dying in the long term than those with RDW <13.5%. RDW is a widely available and easily measured parameter that can help clinicians in the risk stratification of chronic HF patients.

Influence of weight variation on long-term mortality of patients with heart failure.

BACKGROUND: In heart failure, weight loss predicts dismal prognosis. Weight variations have not been addressed in obese patients with heart failure. AIM: To study the impact of weight variation on heart failure mortality according to body mass index strata. METHODS: Retrospective study of patients with chronic heart failure with left ventricular ejection fraction<50%. Only patients with ≥1 year of follow-up were included. Patients with missing data for body mass index at the index and 1-year appointments were excluded. Patients were classified into three groups according to weight variation: weight gain>5%; weight loss>5%; and weight stability. Follow-up was set from the 1-year appointment. Cox-regression analysis was used to assess the prognostic impact of weight variation. RESULTS: We studied 589 patients: 69.8% male; mean age, 69 years. Over 1 year, 148 patients (25.1%) gained>5% weight, 97 (16.5%) lost>5% weight and the remaining 344 were weight-stable. During 49 months of median follow-up, 248 patients died. Patients who lost>5% of their weight presented a higher death risk than the others (hazard ratio 1.61, 95% confidence interval 1.18-2.19). After multivariable adjustment, the hazard ratio for death for low/normal-weight patients who lost>5% of their weight was 1.81 (95% confidence interval 1.02-3.21; P=0.04) compared with the others. Among the overweight, those who lost>5% of their weight had a hazard ratio of 2.34 (95% confidence interval 1.32-4.12). In the initially obese subgroup, weight loss>5% was not associated with prognosis (hazard ratio 1.08, 95% confidence interval 0.53-2.19). CONCLUSIONS: Weight loss predicted mortality in low/normal-weight and overweight patients with heart failure. However, in obese patients, significant weight loss did not predict poorer survival. Weight loss should not be discouraged in obese patients with heart failure.

Prognostic impact of neurohormonal modulation in very old patients with chronic heart failure.

BACKGROUND: A gap in evidence exists concerning the survival-benefit of neurohormonal blockade in older patients with chronic heart failure (HF). The purpose of our study was to investigate the neurohormonal modulation therapy in older HF patients. METHODS: We retrospectively analysed data on chronic HF patients with systolic dysfunction from January 2012 to May 2018 at a central tertiary academic hospital in Porto, Portugal. Very old (VO) patients were those ≥80 years. Endpoint under analysis: all-cause mortality; patients were followed until January 2021. The prognostic impact of beta-blockers (BBs) and renin-angiotensin system inhibitors (RASi) use was assessed with a Cox-regression analysis adjusting for confounders. RESULTS: We studied 934 patients, 65.5% male; 45.3% had ischemic HF. BBs were used in 92.2% and RASi in 83.5%; 255 (27.3%) were VO patients. VO more often presented co-morbidities, were more symptomatic, presented worse renal function and higher BNP levels. BB prescription was similar in VO and non-VO patients, however RASi were less used in VO: 74.9% versus 86.7%, respectively. During a median follow-up of 47 months, 479 (51.3%) patients died: 71.4% among VO versus 43.7% in non-VO. BBs increased survival both in non-VO and VO-multivariate adjusted HRs of 0.57 (95% CI: 0.38-0.85) and 0.59 (0.36-0.97), respectively. A survival-benefit was also observed with RASi-adjusted HR of 0.71 (0.50-1.01) and 0.59 (0.42-0.83) in non-VO and VO. CONCLUSIONS: VO patients with chronic HF with systolic dysfunction have a very ominous outcome. Neurohormonal modulation therapy appears to portend survival-benefit also in this particularly vulnerable subgroup of patients.

Swollen Finger - An Atypical Place for a Metastatic Lesion.

Acrometastasis, referring to metastases located distal to the elbow and knee, is a rare observation. The most common primary cancer site is the lungs, followed by colorectal, breast and genitourinary tract locations. We present a case of a 54-year-old woman with a 25-pack-year smoking history, chronic obstructive pulmonary disease and squamous cell carcinoma of the lung diagnosed at age 50. Upon physical examination, in the distal phalanx of the fourth finger of the right hand, there was a hypervascularized swelling, purplish and painful. Distal amputation of the fourth finger was performed with pathological anatomy compatible with acrometastasis of primary squamous cell carcinoma of the lung. Clinicians should be aware of this type of metastasis because it is sometimes difficult to distinguish from tuberculous dactylitis and other types of osteomyelitis in patients with undiagnosed cancer. The presence of acrometastasis confers a poor prognosis. LEARNING POINTS: Acrometastasis is a rare presentation of bone metastases.The diagnosis of acrometastasis is a challenge, due to the large number of differential diagnoses and the difficulty in detecting them early.The presence of acrometastasis confers a poor prognosis.

BDNF pro-peptide actions facilitate hippocampal LTD and are altered by the common BDNF polymorphism Val66Met.

Most growth factors are initially synthesized as precursor proteins and subsequently processed into their mature form by proteolytic cleavage, resulting in simultaneous removal of a pro-peptide. However, compared with that of mature form, the biological role of the pro-peptide is poorly understood. Here, we investigated the biological role of the pro-peptide of brain-derived neurotrophic factor (BDNF) and first showed that the pro-peptide is expressed and secreted in hippocampal tissues and cultures, respectively. Interestingly, we found that the BDNF pro-peptide directly facilitates hippocampal long-term depression (LTD), requiring the activation of GluN2B-containing NMDA receptors and the pan-neurotrophin receptor p75(NTR). The BDNF pro-peptide also enhances NMDA-induced α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor endocytosis, a mechanism crucial for LTD expression. Thus, the BDNF pro-peptide is involved in synaptic plasticity that regulates a mechanism responsible for promoting LTD. The well-known BDNF polymorphism valine for methionine at amino acid position 66 (Val66Met) affects human memory function. Here, the BDNF pro-peptide with Met mutation completely inhibits hippocampal LTD. These findings demonstrate functional roles for the BDNF pro-peptide and a naturally occurring human BDNF polymorphism in hippocampal synaptic depression.

Mitogen-activated protein kinase (MAPK) pathway regulates branching by remodeling epithelial cell adhesion.

Although the growth factor (GF) signaling guiding renal branching is well characterized, the intracellular cascades mediating GF functions are poorly understood. We studied mitogen-activated protein kinase (MAPK) pathway specifically in the branching epithelia of developing kidney by genetically abrogating the pathway activity in mice lacking simultaneously dual-specificity protein kinases Mek1 and Mek2. Our data show that MAPK pathway is heterogeneously activated in the subset of G1- and S-phase epithelial cells, and its tissue-specific deletion results in severe renal hypodysplasia. Consequently to the deletion of Mek1/2, the activation of ERK1/2 in the epithelium is lost and normal branching pattern in mutant kidneys is substituted with elongation-only phenotype, in which the epithelium is largely unable to form novel branches and complex three-dimensional patterns, but able to grow without primary defects in mitosis. Cellular characterization of double mutant epithelium showed increased E-cadherin at the cell surfaces with its particular accumulation at baso-lateral locations. This indicates changes in cellular adhesion, which were revealed by electron microscopic analysis demonstrating intercellular gaps and increased extracellular space in double mutant epithelium. When challenged to form monolayer cultures, the mutant epithelial cells were impaired in spreading and displayed strong focal adhesions in addition to spiky E-cadherin. Inhibition of MAPK activity reduced paxillin phosphorylation on serine 83 while remnants of phospho-paxillin, together with another focal adhesion (FA) protein vinculin, were augmented at cell surface contacts. We show that MAPK activity is required for branching morphogenesis, and propose that it promotes cell cycle progression and higher cellular motility through remodeling of cellular adhesions.

SorLA controls neurotrophic activity by sorting of GDNF and its receptors GFRα1 and RET.

Glial cell-line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor that has reached clinical trials for Parkinson's disease. GDNF binds to its coreceptor GFRα1 and signals through the transmembrane receptor tyrosine kinase RET, or RET independently through NCAM or syndecan-3. Whereas the GDNF signaling cascades are well described, cellular turnover and trafficking of GDNF and its receptors remain poorly characterized. Here, we find that SorLA acts as sorting receptor for the GDNF/GFRα1 complex, directing it from the cell surface to endosomes. Through this mechanism, GDNF is targeted to lysosomes and degraded while GFRα1 recycles, creating an efficient GDNF clearance pathway. The SorLA/GFRα1 complex further targets RET for endocytosis but not for degradation, affecting GDNF-induced neurotrophic activities. SorLA-deficient mice display elevated GDNF levels, altered dopaminergic function, marked hyperactivity, and reduced anxiety, all of which are phenotypes related to abnormal GDNF activity. Taken together, these findings establish SorLA as a critical regulator of GDNF activity in the CNS.

Characterization of the intracellular localization, processing, and secretion of two glial cell line-derived neurotrophic factor splice isoforms.

Endocrine and neuronal cells have highly developed secretion mechanisms, and the secretion can be either constitutive or regulated by physiological stimuli. In the constitutive pathway, intracellular transport vesicles undergo immediate fusion reactions after arrival at the target. In regulated secretion, vesicles accumulate near the target membrane until triggered to fuse, typically by a local rise in free Ca(2+). In the present study, we characterize the processing and secretion mechanisms of the glial cell line-derived neurotrophic factor (GDNF). Although the function of GDNF has been extensively studied, very little is known about the basic cell biology of GDNF and its precursor forms (alpha)pro-GDNF and (beta)pro-GDNF that have different pro-regions. Our results show that both (alpha)pro-GDNF and (beta)pro-GDNF are secreted. We demonstrate that KCl-induced depolarization increases the secretion of (beta)pro-GDNF and corresponding mature GDNF, but not (alpha)pro-GDNF and corresponding mature GDNF, to the cell medium in a Ca(2+)-dependent manner. In parallel with this, immunofluorescence analysis of cells show that (alpha)pro-GDNF/GDNF is localized mostly in the Golgi complex, whereas (beta)pro-GDNF/GDNF is localized primarily in secretogranin II and Rab3A-positive vesicles of the regulated secretory pathway. In addition, we find that matrix metalloproteinases and plasmin that cleave pro-BDNF and pro-NGF are not responsible for the cleavage of pro-GDNF, whereas furin endoproteinase, PACE4, and proprotein convertases PC5A, PC5B, and PC7 can cleave pro-GDNF into mature GDNF. Thus, the processing and secretion mechanisms of GDNF are different from those of BDNF and NGF.

Neurotrophic factors switch between two signaling pathways that trigger axonal growth.

Integration of multiple inputs from the extracellular environment, such as extracellular matrix molecules and growth factors, is a crucial process for cell function and information processing in multicellular organisms. Here we demonstrate that co-stimulation of dorsal root ganglion neurons with neurotrophic factors (NTFs) - glial-cell-line-derived neurotrophic factor, neurturin or nerve growth factor - and laminin leads to axonal growth that requires activation of Src family kinases (SFKs). A different, SFK-independent signaling pathway evokes axonal growth on laminin in the absence of the NTFs. By contrast, axonal branching is regulated by SFKs both in the presence and in the absence of NGF. We propose and experimentally verify a Boolean model of the signaling network triggered by NTFs and laminin. Our results demonstrate that NTFs provide an environmental cue that triggers a switch between separate pathways in the cell signaling network.