Plasma levels of alpha-1-antichymotrypsin are elevated in patients with chronic heart failure,but are of limited prognostic value

Background

There is increasing interest in utilising novel markers of cardiovascular disease risk in patients with chronic heart failure (HF). Recently, it was shown that alpha-1-antichymotrypsin (ACT), an acute-phase protein and major inhibitor of cathpesin G, plays a role in the pathophysiology of HF and may serve as a marker for myocardial distress.

Objective

To assess whether ACT is independently associated with long-term mortality in chronic HF patients.

Methods

ACT plasma levels were categorised into quartiles. Survival times were analysed using Kaplan-Meier curves and Cox proportional hazards regression, without and with correction for clinically relevant risk factors, including sex, age, duration of HF, kidney function (MDRD), ischaemic HF aetiology and NT-proBNP.

Results

Twenty healthy individuals and 224 patients (mean age 71 years, 72 % male, median HF duration 1.6 years) with chronic HF were included. In total, 159 (71 %) patients died. The median survival time was 5.3 (95 % CI 4.5–6.1) years. ACT was significantly elevated in patients (median 433 μg/ml, IQR 279–680) in comparison with controls (median 214 μg/ml, IQR 166–271; p < 0.001). Cox regression analysis demonstrated that ACT was not independently related to long-term mortality in chronic HF patients (crude HR = 1.03, 95 % CI 0.75–1.41, p = 0.871; adjusted HR = 1.12, 95 % CI 0.78–1.60, p = 0.552), which was confirmed by Kaplan-Meier curves.

Conclusion

ACT levels are elevated in chronic HF patients, but no independent association with long-term mortality can be established.     

Weight cycling enhances adipose tissue inflammatory responses in male mice

Background

Obesity is associated with low-grade chronic inflammation attributed to dysregulated production, release of cytokines and adipokines and to dysregulated glucose-insulin homeostasis and dyslipidemia. Nutritional interventions such as dieting are often accompanied by repeated bouts of weight loss and regain, a phenomenon known as weight cycling (WC).

Methods

In this work we studied the effects of WC on the feed efficiency, blood lipids, carbohydrate metabolism, adiposity and inflammatory markers in C57BL/6 male mice that WC two or three consecutive times by alternation of a high-fat (HF) diet with standard chow (SC).

Results

The body mass (BM) grew up in each cycle of HF feeding, and decreased after each cycle of SC feeding. The alterations observed in the animals feeding HF diet in the oral glucose tolerance test, in blood lipids, and in serum and adipose tissue expression of adipokines were not recuperated after WC. Moreover, the longer the HF feeding was (two, four and six months), more severe the adiposity was. After three consecutive WC, less marked was the BM reduction during SC feeding, while more severe was the BM increase during HF feeding.

Conclusion

In conclusion, the results of the present study showed that both the HF diet and WC are relevant to BM evolution and fat pad remodeling in mice, with repercussion in blood lipids, homeostasis of glucose-insulin and adipokine levels. The simple reduction of the BM during a WC is not able to recover the high levels of adipokines in the serum and adipose tissue as well as the pro-inflammatory cytokines enhanced during a cycle of HF diet. These findings are significant because a milieu with altered adipokines in association with WC potentially aggravates the chronic inflammation attributed to dysregulated production and release of adipokines in mice.     

Using matrix assisted laser desorption ionisation mass spectrometry (MALDI-MS) profiling in order to predict clinical outcomes of patients with heart failure

Background

Current risk prediction models in heart failure (HF) including clinical characteristics and biomarkers only have moderate predictive value. The aim of this study was to use matrix assisted laser desorption ionisation mass spectrometry (MALDI-MS) profiling to determine if a combination of peptides identified with MALDI-MS will better predict clinical outcomes of patients with HF.

Methods

A cohort of 100 patients with HF were recruited in the biomarker discovery phase (50 patients who died or had a HF hospital admission vs. 50 patients who did not have an event). The peptide extraction from plasma samples was performed using reversed phase C18. Then samples were analysed using MALDI-MS. A multiple peptide biomarker model was discovered that was able to predict clinical outcomes for patients with HF. Finally, this model was validated in an independent cohort with 100 patients with HF.

Results

After normalisation and alignment of all the processed spectra, a total of 11,389 peptides (m/z) were detected using MALDI-MS. A multiple biomarker model was developed from 14 plasma peptides that was able to predict clinical outcomes in HF patients with an area under the receiver operating characteristic curve (AUC) of 1.000 (p?=?0.0005). This model was validated in an independent cohort with 100 HF patients that yielded an AUC of 0.817 (p?=?0.0005) in the biomarker validation phase. Addition of this model to the BIOSTAT risk prediction model increased the predictive probability for clinical outcomes of HF from an AUC value of 0.643 to an AUC of 0.823 (p?=?0.0021). Moreover, using the prediction model of fourteen peptides and the composite model of the multiple biomarker of fourteen peptides with the BIOSTAT risk prediction model achieved a better predictive probability of time-to-event in prediction of clinical events in patients with HF (p?=?0.0005).

Conclusions

The results obtained in this study suggest that a cluster of plasma peptides using MALDI-MS can reliably predict clinical outcomes in HF that may help enable precision medicine in HF.

     

Serum Angiopoietin-Like Protein 2 Concentrations Are Independently Associated with Heart Failure

Objective

Angiopoietin-like protein 2 (ANGPTL2), which is mainly expressed from adipose tissue, is demonstrated to be involved in obesity, metabolic syndrome, and atherosclerosis. Because several adipocytokines are known to be associated with heart failure (HF), here we investigated the association of ANGPTL2 and HF in Taiwanese subjects.

Methods and Results

A total of 170 symptomatic HF patients and 130 age- and sex-matched controls were enrolled from clinic. The echocardiography was analyzed in each patient, and stress myocardial perfusion study was performed for clinical suspicion of coronary artery disease. Detailed demographic information, medications, and biochemical data were recorded. Circulating adipocytokines, including tumor necrosis factor-alpha (TNF-α), adiponectin, adipocyte fatty acid-binding protein (A-FABP) and ANGPTL2, were analyzed. Compared with the control group subjects, serum ANGPTL2 concentrations were significantly higher in HF group patients. In correlation analyses, ANGPTL2 level was positively correlated to creatinine, fasting glucose, triglyceride, hsCRP, TNF-α, NT-proBNP and A-FABP levels, and negatively correlated with HDL-C and left ventricular ejection fraction. In multiple regression analysis, A-FABP, hsCRP, and HDL-C levels remained as independent predictors for ANGPTL2 level. To determine the association between serum ANGPTL2 concentrations and HF, multivariate logistic regression analyses were performed with subjects divided into tertiles by ANGPTL2 levels. For the subjects with ANGPTL2 levels in the highest tertile, their risk of HF was about 2.97 fold (95% CI = 1.24–7.08, P = 0.01) higher than those in the lowest tertile.

Conclusion

Our results demonstrate a higher circulating ANGPTL2 level in patients with HF, and the upregulating ANGPTL2 levels might be associated with metabolic derangements and inflammation.     

Estrogen rescues heart failure through estrogen receptor Beta activation

Background

Recently, we showed that exogenous treatment with estrogen (E2) rescues pre-existing advanced heart failure (HF) in mice. Since most of the biological actions of E2 are mediated through the classical estrogen receptors alpha (ERα) and/or beta (ERβ), and both these receptors are present in the heart, we examined the role of ERα and ERβ in the rescue action of E2 against HF.

Methods

Severe HF was induced in male mice by transverse aortic constriction-induced pressure overload. Once the ejection fraction (EF) reached ~?35%, mice were treated with selective agonists for ERα (PPT, 850 μg/kg/day), ERβ (DPN, 850 μg/kg/day), or E2 (30 μg/kg/day) together with an ERβ-antagonist (PHTPP, 850 μg/kg/day) for 10 days.

Results

EF of HF mice was significantly improved to 45.3?±?2.1% with diarylpropionitrile (DPN) treatment, but not with PPT (31.1?±?2.3%). E2 failed to rescue HF in the presence of PHTPP, as there was no significant improvement in the EF at the end of the 10-day treatment (32.5?±?5.2%). The improvement of heart function in HF mice treated with ERβ agonist DPN was also associated with reduced cardiac fibrosis and increased cardiac angiogenesis, while the ERα agonist PPT had no significant effect on either cardiac fibrosis or angiogenesis. Furthermore, DPN improved hemodynamic parameters in HF mice, whereas PPT had no significant effect.

Conclusions

E2 treatment rescues pre-existing severe HF mainly through ERβ. Rescue of HF by ERβ activation is also associated with stimulation of cardiac angiogenesis, suppression of fibrosis, and restoration of hemodynamic parameters.

     

Real-world heart failure management in 10,910 patients with chronic heart failure in the Netherlands

Aims

Data from patient registries give insight into the management of patients with heart failure (HF), but actual data from unselected real-world HF patients are scarce. Therefore, we performed a cross sectional study of current HF care in the period 2013–2016 among more than 10,000 unselected HF patients at HF outpatient clinics in the Netherlands.

Methods

In 34 participating centres, all 10,910 patients with chronic HF treated at cardiology centres were included in the CHECK-HF registry. Of these, most (96%) were managed at a specific HF outpatient clinic. Heart failure was typically diagnosed according to the ESC guidelines 2012, based on signs, symptoms and structural and/or functional cardiac abnormalities. Information on diagnostics, treatment and co-morbidities were recorded, with specific focus on drug therapy and devices. In our cohort, the mean age was 73 years (SD 12) and 60% were male. Frequent co-morbidities reported in the patient records were diabetes mellitus 30%, hypertension 43%, COPD 19%, and renal insufficiency 58%. In 47% of the patients, ischaemia was the origin of HF. In our registry, the prevalence of HF with preserved ejection fraction was 21%.

Conclusion

The CHECK-HF registry will provide insight into the current, real world management of patient with chronic HF, including HF with reduced ejection fraction, preserved ejection fraction and mid-range ejection fraction, that will help define ways to improve quality of care. Drug and device therapy and guideline adherence as well as interactions with age, gender and co-morbidities will receive specific attention.

     

Prognostic value of nutrition status in the response of cardiac resynchronization therapy

Background

Cardiac resynchronization therapy (CRT) is indicated in symptomatic heart failure (HF) patients after achieving optimal medical therapy. However, there are still a large percentage of patients who do not respond to CRT. Malnutrition is a frequent comorbidity in patients with HF, and it is associated with a poorer prognosis. Here, we evaluate the nutritional status of patients assessed by Controlling Nutritional Status (CONUT) score and its association with structural remodeling and cardiovascular events.

The Prognostic Value of Plasma Soluble ST2 in Hospitalized Chinese Patients with Heart Failure

Background

sST2 has been shown to be a risk predictor in heart failure (HF). Our aim was to explore the characteristics and prognostic value of soluble ST2 (sST2) in hospitalized Chinese patients with HF.

Methods and Results

We consecutively enrolled 1528 hospitalized patients with HF. Receiver operating characteristic (ROC) and multivariable Cox proportional hazards analysis were used to assess the prognostic values of sST2. Adverse events were defined as all-cause death and cardiac transplantation. During a median follow-up of 19.1 months, 325 patients experienced adverse events. Compared with patients free of events, sST2 concentrations were significantly higher in patients with events (P<0.001). Univariable and multivariable Cox regression analyses showed sST2 concentrations were significantly associated with adverse events (per 1 log unit, adjusted hazard ratio 1.52, 95% confidence interval: 1.30 to 1.78, P<0.001). An sST2 concentration in the highest quartiles (>55.6 ng/mL) independently predicted events in comparison to the lowest quartile (≤25.2 ng/mL) when adjusted by multivariable model. In ROC analysis, the area under the curve for sST2 was not different from that for NT-proBNP in short and longer term. Over time, sST2 also improved discrimination and reclassification of risk beyond NT-proBNP.

Conclusions

sST2 is a strong independent risk predictor in Chinese patients hospitalized with HF and can significantly provide additional prognostic value to NT-proBNP in risk prediction.     

High-fat diet accelerates progression of osteoarthritis after meniscal/ligamentous injury

Introduction  

Increasing obesity and type 2 diabetes, in part due to the high-fat (HF) Western diet, parallels an increased incidence of osteoarthritis (OA). This study was undertaken to establish a causal relation between the HF diet and accelerated OA progression in a mouse model and to determine the relative roles of weight gain and metabolic dysregulation in this progression.     

Heart rate variability after radiofrequency ablation of epicardial ganglionated plexuses on the ovine left atrium

Background

Ganglionated plexuses (GP) are terminal parts of cardiac autonomous nervous system (ANS). Radiofrequency ablation (RFA) for atrial fibrillation (AF) possibly affects GP. Changes in heart rate variability (HRV) after RFA can reflect ANS modulation.

Methods

Epicardial RFA of GP on the left atrium (LA) was performed under the general anesthesia in 15 mature Romanov sheep. HRV was used to assess the alterations in autonomic regulation of the heart. A 24???hour ECG monitoring was performed before the ablation, 2 days after it and at each of the 12 following months. Ablation sites were evaluated histologically.

Results

There was an instant change in HRV parameters after the ablation. A standard deviation of all intervals between normal QRS (SDNN), a square root of the mean of the squared differences between successive normal QRS intervals (RMSSD) along with HRV triangular index (TI), low frequency (LF) power and high frequency (HF) power decreased, while LF/HF ratio increased. Both the SDNN, LF power and the HF power changes persisted throughout the 12???month follow???up. Significant decrease in RMSSD persisted only for 3 months, HRV TI for 6 months and increase in LF/HF ratio for 7 months of the follow???up. Afterwards these three parameters were not different from the preprocedural values.

Conclusions

Epicardial RFA of GP’s on the ovine left atrium has lasting effect on the main HRV parameters (SDNN, HF power and LF power). The normalization of RMSSD, HRV TI and LF/HF suggests that HRV after epicardial RFA of GPs on the left atrium might restore over time.

     

Roles of shoots and roots in cadmium uptake and distribution in tubers of potato (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L)

Aims

We investigated whether density fractionation can be used to determine the distribution of organic phosphorus (OP) between free and mineral-associated soil organic matter (SOM).

Methods

We performed density fractionations using sodium polytungstate solution (specific gravity 1.6 g cm^?3) on 20 soils from UK semi-natural and pasture ecosystems, to obtain a light fraction (LF) and a heavy fraction (HF) for each soil. The fractions were quantified by weight, and analysed for organic carbon (OC), total N (TN), total P (TP), inorganic P (IP), and OP (by difference).

Results

Good recoveries of soil mass (96%), OC and TN (both ~ 90%) were obtained, but recovery of OP only averaged 56%. The average P:C ratio of HF SOM exceeded that of LF SOM by a factor of six, greater than the factor of two obtained for TN:OC. For the soils studied, the elements of SOM were predominantly in the HF, with averages of 75% for C, 82% for N, and 90% for P.

Conclusions

The incomplete recovery of OP demands further work. Nonetheless, the results show that HF SOM is much richer in P than LF SOM.

     

Comparison of Baseline versus Posttreatment Left Ventricular Ejection Fraction in Patients with Acute Decompensated Heart Failure for Predicting Cardiovascular Outcome: Implications from Single-Center Systolic Heart Failure Cohort

Aims

The prognostic values of left ventricular ejection fraction (LVEF) during heart failure (HF) with acute decompensation or after optimal treatment have not been extensively studied. We hypothesized that posttreatment LVEF has superior predictive value for long-term prognosis than LVEF at admission does.

Methods and Results

In Protocol 1, 428 acute decompensated HF (ADHF) patients with LVEF ≤35% in a tertiary medical center were enrolled and followed for a mean period of 34.7 ± 10.8 months. The primary and secondary end points were all-cause mortality and HF readmission, respectively. In total, 86 deaths and 240 HF readmissions were recorded. The predictive values of baseline LVEF at admission and LVEF 6 months posttreatment were analyzed and compared. The posttreatment LVEFs were predictive for future events (P = 0.01 for all-cause mortality, P < 0.001 for HF readmission), but the baseline LVEFs were not. In Protocol 2, the outcomes of patients with improved LVEF (change of LVEF: ≥+10%), unchanged LVEF (change of LVEF: –10% to +10%), and reduced LVEF (change of LVEF: ≤–10%) were analyzed and compared. Improved LVEF occurred in 171 patients and was associated with a superior long-term prognosis among all groups (P = 0.02 for all-cause mortality, P < 0.001 for HF readmission). In Protocol 3, independent predictors of improved LVEF were analyzed, and baseline LV end-diastolic dimension (LVEDD) was identified as a powerful predictor in ADHF patients (P < 0.001).

Conclusions

In patients with ADHF, posttreatment LVEF but not baseline LVEF had prognostic power. Improved LVEF was associated with superior long-term prognosis, and baseline LVEDD identified patients who were more likely to have improved LVEF. Therefore, baseline LVEF should not be considered a relevant prognosis factor in clinical practice for patients with ADHF.     

A comparison of the prognostic value of BNP versus NT-proBNP after hospitalisation for heart failure

Aims

Concentrations of circulating B?type natriuretic peptides provide important prognostic information in heart failure (HF) patients. We directly compared the prognostic performance of brain natriuretic peptide (BNP) versus N?terminal-proBNP (NT-proBNP) measurements in a large population of HF patients at hospital discharge after an admission for decompensated HF.

Methods and results

BNP and NT-proBNP were measured in 563 stable HF patients before discharge. All patients were followed for a fixed period of 18 months. The primary endpoint was time to first major event (HF hospitalisation or death).Patients were in NYHA class II (47%) or III/IV (53%) at discharge and the mean age of the patients was 71?±?11 years, 217 (39%) females, mean left ventricular ejection fraction was 0.32?±?0.14 and 234 (42%) had an ischaemic aetiology of HF. During the study, 236 patients (42%) reached the primary endpoint. Multivariate odds ratios of the primary endpoint for doubling of baseline levels of BNP and NT-proBNP were 1.46 (95% CI 1.19–1.80, p?<?0.001) and 1.45 (95% CI 1.18–1.78, p?<?0.001), respectively. The multivariable adjusted areas under the receiver-operating characteristic curve for prediction of the primary endpoint for doubling of BNP and NT-proBNP were 0.69 and 0.68, respectively. Direct comparison of the prognostic value of BNP and NT-proBNP did not reveal significant differences.

Conclusions

BNP and NT-proBNP at discharge for hospitalisation for HF are powerful, and equally strong and independent predictors of all-cause death and HF rehospitalisation.

     

Endocardial Endothelial Dysfunction Progressively Disrupts Initially Anti then Pro-Thrombotic Pathways in Heart Failure Mice

Objective

An experimental model of endocardial thrombosis has not been developed and endocardial endothelial dysfunction in heart failure (HF) is understudied. We sought to determine whether disruption of the endothelial anti-coagulant activated protein C (APC) pathway in CREB_A133 HF mice promotes endocardial thrombosis in the acute decompensated phase of the disease, and whether alterations in von Willebrand factor (vWF) secretion from HF endocardium reduces thrombus formation as HF stabilizes.

Approach and results

Echocardiography was used to follow HF development and to detect endocardial thrombi in CREB_A133 mice. Endocardial thrombi incidence was confirmed with immunohistochemistry and histology. In early and acute decompensated phases of HF, CREB_A133 mice had the highest incidence of endocardial thrombi and these mice also had a shorter tail-bleeding index consistent with a pro-thrombotic milieu. Both APC generation, and expression of receptors that promote APC function (thrombomodulin, endothelial protein C receptor, protein S), were suppressed in the endocardium of acute decompensated HF mice. However, in stable compensated HF mice, an attenuation occurred for vWF protein content and secretion from endocardial endothelial cells, vWF-dependent platelet agglutination (by ristocetin), and thrombin generation on the endocardial surface.

Conclusions

CREB_A133 mice develop HF and endocardial endothelial dysfunction. Attenuation of the anti-coagulant APC pathway promotes endocardial thrombosis in early and acute decompensated phases of HF. However, in stable compensated HF mice, disruptions in endothelial vWF expression and extrusion may actually reduce the incidence of endocardial thrombosis.     

Exercise training prevents oxidative stress and ubiquitin-proteasome system overactivity and reverse skeletal muscle atrophy in heart failure

Background

Heart failure (HF) is known to lead to skeletal muscle atrophy and dysfunction. However, intracellular mechanisms underlying HF-induced myopathy are not fully understood. We hypothesized that HF would increase oxidative stress and ubiquitin-proteasome system (UPS) activation in skeletal muscle of sympathetic hyperactivity mouse model. We also tested the hypothesis that aerobic exercise training (AET) would reestablish UPS activation in mice and human HF.

Methods/Principal Findings

Time-course evaluation of plantaris muscle cross-sectional area, lipid hydroperoxidation, protein carbonylation and chymotrypsin-like proteasome activity was performed in a mouse model of sympathetic hyperactivity-induced HF. At the 7^th month of age, HF mice displayed skeletal muscle atrophy, increased oxidative stress and UPS overactivation. Moderate-intensity AET restored lipid hydroperoxides and carbonylated protein levels paralleled by reduced E3 ligases mRNA levels, and reestablished chymotrypsin-like proteasome activity and plantaris trophicity. In human HF (patients randomized to sedentary or moderate-intensity AET protocol), skeletal muscle chymotrypsin-like proteasome activity was also increased and AET restored it to healthy control subjects’ levels.

Conclusions

Collectively, our data provide evidence that AET effectively counteracts redox imbalance and UPS overactivation, preventing skeletal myopathy and exercise intolerance in sympathetic hyperactivity-induced HF in mice. Of particular interest, AET attenuates skeletal muscle proteasome activity paralleled by improved aerobic capacity in HF patients, which is not achieved by drug treatment itself. Altogether these findings strengthen the clinical relevance of AET in the treatment of HF.     

Heart failure and preserved left ventricular function: long term clinical outcome

Background

Patients with heart failure (HF) have a poor prognosis. The proportion of patients with HF and preserved left ventricular function (LVF) is increasing. Long term prognosis of HF with preserved LVF may not be so benign.

Objectives

To evaluate the long term clinical outcome of patients with HF and preserved LVF and predictors of outcome.

Methods

We prospectively evaluated 309 patients hospitalized with a definite clinical diagnosis of HF. Patients were followed for a mean of 6.5 years for clinical outcome.

Results

More than a third (36%) of the patients had preserved systolic LVF based on echocardiography. The long term survival rate in this group was poor and not significantly different from patients with reduced LVF (28% vs 23% respectively, P = 0.2). The adjusted survival rate by Cox regression analysis was also not significantly different (hazard ratio 1.16, 95% confidence interval 0.87–1.55, P = 0.31). The event free survival from death or heart failure re-hospitalization was also low in both groups and not significantly different between patients with preserved vs. reduced LVF (12% vs. 10% respectively, P = 0.2). Predictors of mortality in patients with preserved LVF were age, functional capacity and serum urea levels.

Conclusions

The long term clinical outcome of patients with heart failure and preserved LVF is poor and not significantly different from patients with reduced LVF.     

The Relationship between Type D Personality,Affective Symptoms and Hemoglobin Levels in Chronic Heart Failure

Background

Anemia is associated with poor prognosis in heart failure (HF) patients. Contributors to the risk of anemia in HF include hemodilution, renal dysfunction and inflammation. Hemoglobin levels may also be negatively affected by alterations in stress regulatory systems. Therefore, psychological distress characterized by such alterations may adversely affect hemoglobin in HF. The association between hemoglobin and Type D personality and affective symptomatology in the context of HF is poorly understood.

Aim

To examine the relationship between Type D personality and affective symptomatology with hemoglobin levels at inclusion and 12-month follow-up, controlling for relevant clinical factors.

Methods

Plasma levels of hemoglobin and creatinine were assessed in 264 HF patients at inclusion and at 12-month follow-up. Type D personality and affective symptomatology were assessed at inclusion.

Results

At inclusion, hemoglobin levels were similar for Type D and non-Type D HF patients (p = .23), and were moderately associated with affective symptomatology (r = –.14, p = .02). Multivariable regression showed that Type D personality (β = –.15; p = .02), was independently associated with future hemoglobin levels, while controlling for renal dysfunction, gender, NYHA class, time since diagnosis, BMI, the use of angiotensin-related medication, and levels of affective symptomatology. Change in renal function was associated with Type D personality (β = .20) and hemoglobin at 12 months (β = –.25). Sobel mediation analysis showed significant partial mediation of the Type D – hemoglobin association by renal function deterioration (p = .01). Anemia prevalence increased over time, especially in Type D patients. Female gender, poorer baseline renal function, deterioration of renal function and a longer HF history predicted the observed increase in anemia prevalence over time, while higher baseline hemoglobin was protective.

Conclusion

Type D personality, but not affective symptomatology, was associated with reduced future hemoglobin levels, independent of clinical factors. The relation between Type D personality and future hemoglobin levels was mediated by renal function deterioration.     

Spermidine promotes human hair growth and is a novel modulator of human epithelial stem cell functions

Background

Rapidly regenerating tissues need sufficient polyamine synthesis. Since the hair follicle (HF) is a highly proliferative mini-organ, polyamines may also be important for normal hair growth. However, the role of polyamines in human HF biology and their effect on HF epithelial stem cells in situ remains largely unknown.

Methods and Findings

We have studied the effects of the prototypic polyamine, spermidine (0.1–1 µM), on human scalp HFs and human HF epithelial stem cells in serum-free organ culture. Under these conditions, spermidine promoted hair shaft elongation and prolonged hair growth (anagen). Spermidine also upregulated expression of the epithelial stem cell-associated keratins K15 and K19, and dose-dependently modulated K15 promoter activity in situ and the colony forming efficiency, proliferation and K15 expression of isolated human K15-GFP+ cells in vitro. Inhibiting the rate-limiting enzyme of polyamine synthesis, ornithine decarboyxlase (ODC), downregulated intrafollicular K15 expression. In primary human epidermal keratinocytes, spermidine slightly promoted entry into the S/G2-M phases of the cell cycle. By microarray analysis of human HF mRNA extracts, spermidine upregulated several key target genes implicated e.g. in the control of cell adherence and migration (POP3), or endoplasmic reticulum and mitochondrial functions (SYVN1, NACA and SLC25A3). Excess spermidine may restrict further intrafollicular polyamine synthesis by inhibiting ODC gene and protein expression in the HF''s companion layer in situ.

Conclusions

These physiologically and clinically relevant data provide the first direct evidence that spermidine is a potent stimulator of human hair growth and a previously unknown modulator of human epithelial stem cell biology.