Vitamin D and cathelicidin levels and susceptibility to Mycobacterium tuberculosis infection acquisition in household contacts / Niveles de vitamina D y catelicidina y susceptibilidad a la infección por Mycobacterium tuberculosis en contactos intradomiciliarios

Introduction Vitamin D deficiency has been proposed to confer susceptibility to acquiring tuberculosis infection by impairing the innate immune response. Methods In an exploratory study, we examined whether the levels of 25-hydroxyvitamin D3 (25(OH)D3) in serum, and cathelicidin – an antimicrobial peptide-induced under calcitriol – in the nasal fluid, would associate with the risk of acquiring tuberculosis infection. Results Within a prospective cohort of 231 tuberculosis household contacts tested with repeated interferon-gamma release assays, we serially analyzed all the uninfected contacts acquiring tuberculosis infection at follow-up (“converters”, n=18), and an age and sex-matched control group of contacts not acquiring tuberculosis infection (“non-converters”, n=36). The median levels of serum 25(OH)D3 did not differ between convertors and non-converters at baseline (14.9 vs. 13.2 ng/ml, p=0.41), nor at follow-up (19.0 vs 18.6ng/ml, p=0.83). Similarly, cathelicidin levels did not differ between both groups. Conclusion These data argue against a major role for hypovitaminosis D in tuberculosis infection susceptibility (AU)

Introducción Se ha propuesto que la deficiencia de vitamina D, al afectar la respuesta inmunitaria innata, aumentaría la susceptibilidad de adquirir una infección por Mycobacterium tuberculosis. Métodos En un estudio exploratorio, examinamos si los niveles de 25-hidroxivitamina D3 (25(OH)D3) y de catelicidina (péptido antimicrobiano inducido bajo calcitriol) en suero y fluido nasal, respectivamente, se asocian con el riesgo de contraer una infección tuberculosa. Resultados En una cohorte prospectiva de 231 contactos intradomiciliarios de tuberculosis en los que se realizaron ensayos de liberación de interferón-gamma en forma seriada, estudiamos a todos los contactos no infectados que adquirieron la infección al seguimiento («conversores», n=18), y a un grupo control pareado por edad y sexo que no adquirió la infección tuberculosa («no conversores», n=36). La mediana de los niveles séricos de 25(OH)D3 no difirió entre convestores y no conversores al inicio del estudio (14,9 vs. 13,2 ng/ml, p=0,41), ni al seguimiento (19,0 vs. 18,6 ng/ml, p=0,83). Igualmente, los niveles de catelicidina nasal no difirieron entre ambos grupos. Conclusión Estos resultados no apoyan la existencia de un papel significativo de la hipovitaminosis D en la susceptibilidad a la infección por tuberculosis (AU)

Cord blood antimicrobial peptide LL37 levels in preterm neonates and association with preterm complications.

BACKGROUND: Cathelicidin/LL-37 plays a significant role in the human immune defense reaction. Preterm human immature organs being exposed to inflammation-induced injury was the critical denominator leading to the common preterm associated complications. Previous study showed LL37 concentration in preterm neonates was lower in tracheal aspirates and breast milk as compared to term infants. An adults study showed decreased LL-37 levels was a risk factor for patients in developing severe chronic obstructive pulmonary disease (COPD). However, little is known about the regulation of human cord blood LL37 in preterm neonates and the association with preterm complications. This study was designed to investigate the concentration of LL37 in cord blood of preterm infants and correlation with preterm complications. METHODS: Singleton infants born in June 2017 to August 2021 in the study hospital were enrolled. Maternal and neonatal clinical characteristics were collected. LL37 levels, pro-inflammatory factor interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a) in cord blood and LL37 levels in serum 48-72 hours after birth were measured by enzyme-linked immunosorbent assay. The serum level of LL37 in preterm and term neonates were compared, the perinatal factors possibly affecting the LL37 levels were investigated and the relationship between LL37 level and preterm outcomes were analyzed. RESULTS: Cord blood LL37 levels in preterm infants were lower than that in term neonates. Cord blood LL37 level was positively correlated with gestational age in preterm. Prenatal steroid administration in preterm neonates decreased cord blood LL37 level. LL37 level was obviously lower in patients with bronchopulmonary dysplasia (BPD). Multiple line regression analysis showed higher LL37 level in cord blood was an independent protective factor for BPD. The concentration of pro-inflammatory factor IL-6 was negatively correlated with LL37. CONCLUSION: Cord blood LL37 levels increased during gestation and decreased after perinatal steroid usage. Very preterm infants who displayed higher cord blood LL37 level had reduced risk of developing BPD. Regulation of pro-inflammatory cytokine IL-6 may be associated with the protective effect of LL37 on BPD.

The long-term prognostic value of serum 25(OH)D, albumin, and LL-37 levels in acute respiratory diseases among older adults.

BACKGROUND: Older adults are more susceptible to respiratory tract infection than healthy working age adults. The increased susceptibility of older adults is thought to be interlinked with vitamin D status, nourishment, and immunological state in general. Data are scarce whether these parameters could serve as prognostic markers. AIM: To study whether serum 25(OH)D, albumin, and LL-37 level could give prognostic value of long-term survival in the older adults with multimorbidity and acute respiratory infection. METHODS: Consecutive episodes of hospital care of patients 65 years and older with respiratory symptoms were prospectively studied as a cohort. Standard clinical questionnaire was filled by the study physician. Laboratory markers included serum levels of 25(OH)D, albumin and LL-37, C-reactive protein (CRP), white blood cell count (WBC) and polymerase chain reaction diagnostics for 14 respiratory viruses. Pneumonia was confirmed by chest radiographs. Respiratory illness severity, death at ward, length of hospital stays, and 5-year survival were used as outcomes. RESULTS: In total, 289 older adult patients with mean age of 83 years were included in the study. Serum 25(OH)D deficiency (< 50 nmol/liter) was present in 59% and hypoalbuminemia (< 3.5 g/dL) in 55% of the study patients. Low serum albumin level was associated to one, two- and five-year mortality after hospital stay (all P < .05). In addition, it was associated with pneumonia, dyspnea, over 13-night long stay at ward and death at ward (all P < .05). No associations were seen between serum 25(OH)D and LL-37 levels and disease severity, short-term clinical outcome, or long-term survival. Associations between serum 25(OH)D, albumin, and LL-37 levels and respiratory virus presence were not seen. CONCLUSIONS: Serum albumin level on admission seems to give valuable information about the patients' general health and recovery potential in treating older adults with respiratory symptoms. Serum 25(OH)D and LL-37 had no associations with disease severity or long- and short-term prognosis among older adults hospitalized with respiratory symptoms.

Emerging Roles of Vitamin D-Induced Antimicrobial Peptides in Antiviral Innate Immunity.

Vitamin D deficiency, characterized by low circulating levels of calcifediol (25-hydroxyvitamin D, 25D) has been linked to increased risk of infections of bacterial and viral origin. Innate immune cells produce hormonal calcitriol (1,25-dihydroxyvitamin D, 1,25D) locally from circulating calcifediol in response to pathogen threat and an immune-specific cytokine network. Calcitriol regulates gene expression through its binding to the vitamin D receptor (VDR), a ligand-regulated transcription factor. The hormone-bound VDR induces the transcription of genes integral to innate immunity including pattern recognition receptors, cytokines, and most importantly antimicrobial peptides (AMPs). Transcription of the human AMP genes ß-defensin 2/defensin-ß4 (HBD2/DEFB4) and cathelicidin antimicrobial peptide (CAMP) is stimulated by the VDR bound to promoter-proximal vitamin D response elements. HDB2/DEFB4 and the active form of CAMP, the peptide LL-37, which form amphipathic secondary structures, were initially characterized for their antibacterial actively. Notably, calcitriol signaling induces secretion of antibacterial activity in vitro and in vivo, and low circulating levels of calcifediol are associated with diverse indications characterized by impaired antibacterial immunity such as dental caries and urinary tract infections. However, recent work has also provided evidence that the same AMPs are components of 1,25D-induced antiviral responses, including those against the etiological agent of the COVID-19 pandemic, the SARS-CoV2 coronavirus. This review surveys the evidence for 1,25D-induced antimicrobial activity in vitro and in vivo in humans and presents our current understanding of the potential mechanisms by which CAMP and HBD2/DEFB4 contribute to antiviral immunity.

Serum level of cathelicidin LL-37 is increased in euthymic patients with bipolar disorder irrespective of their cardio-metabolic status

Abstract Background Antimicrobial peptides are components of the innate immune system. Cathelicidin LL-37 plays an important role in antimicrobial defense, exerts proinflammatory effect and strongly affects the immune system functioning. Our recent study revealed that serum concentration of LL-37 is increased in patients with bipolar disorder. Objectives The aim of this study is to re-evaluate serum LL-37 levels in patients with euthymic bipolar disorder and in healthy controls, matched for anthropometric and body composition parameters. Methods 36 adult patients with euthymic bipolar disorder and 68 non-depressed adults were included into the study. Concentration of LL-37 in serum was assessed using ELISA method. Detailed anthropometric measurements, body composition and biochemical analyses were performed. Results There was a statistically significant difference (p = 0.01) in serum LL-37 level between patients with bipolar disorder (4.97 ± 7.98 ng/mL) and control subjects (1.78 ± 2.69 ng/mL). Discussion Results of this study indicate that LL-37 serum level is increased in euthymic bipolar disorder patients. We found that this increase could not be attributed to analyzed anthropometric or body composition parameters.

Association between vitamin D, antimicrobial peptides and urinary tract infection in infants and young children.

AIM: Vitamin D stimulates production of the endogenous antimicrobial peptides cathelicidin and ß-defensin-2, which are expressed in the urinary tract. We investigated vitamin D status and levels of cathelicidin and ß-defensin-2 and their association with urinary tract infection (UTI). METHODS: The study included 120 children under three years of age: 76 children with UTIs and 44 otherwise healthy children with congenital hydronephrosis. Serum 25-hydroxycholecalciferol levels were measured by direct competitive electro-chemiluminescence immunoassay, and plasma cathelicidin and ß-defensin-2 concentrations were analysed by enzyme-linked immunosorbent assay. RESULTS: We found that vitamin D insufficiency and deficiency are prevalent in young children (21%). Serum vitamin D levels negatively correlated with age and were significantly lower in girls. Levels of vitamin D positively correlated with levels of cathelicidin but not with ß-defensin-2. Low concentrations of vitamin D were associated with UTIs in girls, but we did not see any correlation with the recurrence of infection at one-year follow-up. CONCLUSION: Vitamin D deficiency is common and may prove to be a risk factor for UTIs especially in girls. We hypothesise that adequate supplementation with vitamin D may become a way to prevent first-time UTIs.

Association between Mycobacterium avium complex lung disease and serum vitamin D status, antimicrobial peptide levels, and bone mineral density.

Vitamin D maintains calcium balance and has immunomodulatory effects. Only few studies have revealed the relationship between vitamin D and its associated factors in Mycobacterium avium complex (MAC) infection. This study aimed to investigate the effects of MAC infection on serum vitamin D, human cationic antimicrobial protein 18, its C-terminal 37 amino acid fragment (hCAP18/LL-37) levels, and bone mineral density (BMD).We enrolled 58 patients with MAC lung disease and 15 control participants. Serum 25-hydroxyvitamin D and hCAP18/LL-37 levels were measured via enzyme-linked immunosorbent assay. Lastly, computed tomography scan density readings of the BMD of the thoracic and lumbar vertebral bones (Th4, Th7, Th10, and L1) were assessed.No significant differences in patient characteristics and serum vitamin D levels were observed. Patients with MAC lung disease had significantly low serum hCAP18/LL-37 levels (P = .049). Moreover, low BMD of the mean thoracic and lumbar vertebrae was observed (mean Th, P = .012; L1, P = .48, respectively). A higher prevalence of scoliosis (P = .031) was observed in the participants with low BMD compared with the control participants. Based on a multivariate analysis, patients with MAC lung disease had significantly lower body mass index [odds ratio (OR), 19.1; 95% confidence interval (CI), 2.0-419.0; P < .01] and vertebral BMD (OR, 12.4; 95% CI, 1.7-160.6; P = .012) than control participants.Serum hCAP18/LL-37 level and BMD were significantly decreased in patients with MAC lung disease without relation to serum vitamin D level. The vitamin D-independent pathway might affect the waning of antimicrobial peptides and decrease in BMD.

Vitamin D3 Status and the Association with Human Cathelicidin Expression in Patients with Different Clinical Forms of Active Tuberculosis.

Low vitamin D (vitD3) is one of the most common nutritional deficiencies in the world known to be associated with numerous medical conditions including infections such as tuberculosis (TB). In this study, vitD3 status and its association with the antimicrobial peptide, human cathelicidin (LL-37), was investigated in Ethiopian patients with different clinical forms of TB. Patients with active TB (n = 77) and non-TB controls (n = 78) were enrolled in Ethiopia, while another group of non-TB controls (n = 62) was from Sweden. Active TB included pulmonary TB (n = 32), pleural TB (n = 20), and lymph node TB (n = 25). Concentrations of 25-hydroxyvitamin D3 (25(OH)D3) were assessed in plasma, while LL-37 mRNA was measured in peripheral blood and in samples obtained from the site of infection. Median 25(OH)D3 plasma levels in active TB patients were similar to Ethiopian non-TB controls (38.5 versus 35.0 nmol/L) and vitD3 deficiency (.

Status of cathelicidin IL-37, cytokine TNF, and vitamin D in patients with pulmonary tuberculosis.

Development of Mycobacterium tuberculosis (Mtb) infection depends on the ability of the host to elicit the protective immune response to the pathogen. Cathelicidin plays a role in antibacterial innate immunity mechanisms. This peptide contributes to the barrier function of respiratory epithelium and takes part in controlling pulmonary bacterial infections. LL-37 (leucine-leucine-37) is involved in host defense and innate immune response to mycobacterial infections, as well. This study aims to evaluate the serum concentrations of LL-37 in individuals with active pulmonary tuberculosis (TB) and to determine whether any correlations between peptide LL-37, tumor necrosis factor (TNF) and vitamin D serum levels exist. A total of 46 adults with pulmonary TB were recruited for the study. Sixty-one controls were randomly selected as control group. Serum concentrations of cathelicidin LL-37, vitamin D (25(OH)D), as well as TNF, were measured using an enzyme-linked immunosorbent assay (ELISA) kit. The mean (± SEM) level of LL-37 was significantly higher in the TB group (7.45±1.58) compared with healthy controls (1.41±0.22) (p less than 0.001). Mean serum concentration of TNF was significantly higher in the TB group (8.51±1.92) compared with healthy controls (2.69±0.19) (p less than 0.001). There was no significant difference in mean serum levels of vitamin D between healthy (26.10±1.74) and TB subjects (24.18±1.95). No correlations between LL-37, TNF, and vitamin D levels in patients with TB were observed. Our results indicated that serum levels of peptide LL-37 during TB is raised significantly, and this observation is compatible with the general view of the important role of this cathelicidin in defense mechanisms against Mtb infection.

The impact of cathelicidin, the human antimicrobial peptide LL-37 in urinary tract infections.

BACKGROUND: The defense mechanisms of the urinary tract are attributed mainly to the innate immune system and the urinary tract urothelium which represent the first line of defense against invading pathogens and maintaining sterility of the urinary tract. There are only a few publications regarding cathelicidin (LL-37) and a urinary tract infection (UTI). This study was done to investigate the plasma and urine levels of human LL-37 in patients with UTI. METHODS: A case-control study was conducted at Omdurman Hospital, Sudan during the period from August 2014 to May 2017. The cases were patients with confirmed UTI and the controls were healthy volunteers without UTI. Sociodemographic and clinical data were obtained from each participant using questionnaires. Urine cultures and antimicrobial susceptibility were tested. Plasma and urine levels of LL-37 were determined using an enzyme-linked immunosorbent assay (ELISA) kit. SPSS (version 16.0) was used for analyses. RESULTS: Cases and controls (87 in each arm) were matched according to their basic characteristics. Compared with controls, the median (inter-quartile) LL-37 level in plasma [2.100 (1.700-2.700) vs. 1.800 (1.000-2.200) ng/ml, P = 0.002] and in urine [0.900 (0.300-1.600) vs. 0.000 (0.000-1.000) ng/mg creatinine, P < 0.001] was significantly higher in cases. There was no significant difference in the median plasma [2.1 (1.7-2.9) vs. 2.000 (1.700-2.400) ng/ml, P = 0.561] and urine [0.850 (0.275-2.025) vs. 0.900 (0.250-1.350) ng/mg creatinine, P = 0.124]. The uropathogenic Escherichia coli (UPEC) was the predominant isolate, n = 38 (43.7%). LL-37 levels between the E. coli isolates and the other isolated organisms. There was no significant correlation between plasma and urine LL-37 levels (r = 0.221), even when the data of the cases were analyzed separately. CONCLUSION: LL-37 is notably increased among patients with UTI compared with normal control subjects. Severity of UTI increases the levels of LL-37. The increased level was not only in the patient's urine, but has also been observed in the patient's plasma. Detection of increased levels of LL-37 could help to differentiate subjects with suspected UTI. Accordingly, LL-37 could act as a good marker for diagnosing UTIs.

Is cathelicidin a novel marker of diabetic microangiopathy in patients with type 1 diabetes?

AIM: The aim was to evaluate the relationship between higher serum cathelicidin levels with the occurrence of chronic microangiopathic complications in patients with diabetes mellitus type 1 (DM1). METHODS: The study group consisted of 62 patients with DM1 (35 men), aged 30 (24-38) years and with duration of DM1 12 (9-17) years. Patients were divided into two groups depending on the level of cathelicidin, with cut-off point 24.5ng/ml (median value for the whole group) and according to the presence or absence of any microangiopathy. RESULTS: The group with higher serum level of cathelicidin (n=31) in comparison with patients with lower levels (n=31) had higher serum level of total cholesterol [5.0(4.5-5.6) vs 4.5(3.9-5.0) mmol/l; p=0.04], HDL cholesterol [1.9(1.5-2.1) vs 1.4(1.3-1.8) mmol/l; p=0.009], LDL cholesterol [2.6(2.2-3.1) vs 2.3(1.9-2.8) mmol/l; p=0.03] and higher TSH value [1.8(1.5-2.6) vs 1.4(0.9-2.1) mIU/L; p=0.01]. Moreover, higher serum levels of cathelicidin were in women than men (58% vs 29%, p=0.02) and in patients with vs without microangiopathy (45% vs 19%, p=0.03). In the multiple regression model higher serum level of cathelicidin was related to the presence of microangiopathy, independently from sex, waist to hip ratio, serum total cholesterol level and TSH. CONCLUSIONS: Patients with type 1 diabetes and presence of microangiopathy characterize higher level of serum cathelicidin. This observation may have important clinical implication and needs further investigations.

Serum level of cathelicidin LL-37 in patients with active tuberculosis and other infectious diseases.

A growing body of evidence indicates the role of cathelicidin LL-37, a member of the antimicrobial peptide family, in host innate defense mechanisms. The important role of this peptide in infectious diseases is also suggested, however, to date, data relating to LL-37 expression in the course of bacterial infections are far from complete. Therefore, the aim of the present study was to determine LL-37 serum levels in adult patients with pulmonary tuberculosis (TB). For comparison, circulating LL-37 levels in patients with pneumonia induced by Gram-positive or Gram-negative bacteria species and in healthy subjects were evaluated. Fifty patients with pulmonary TB, 31 patients with pneumonia caused by gram-positive bacteria, 68 individuals with pneumonia caused by Gram-negative bacteria, and 61 randomly selected healthy subjects were enrolled in the study. Serum LL-37 concentration was measured using an enzyme-linked immunosorbent assay (ELISA). We established that the mean level of LL-37 was statistically significantly higher in TB patients than that in patients with Gram-positive bacteria-induced pneumonia (p < 0.001), in patients with Gram-negative bacteria-induced pneumonia (p < 0.001), and in healthy controls (p < 0.001). In patients with TB, no statistically significant correlations between serum LL-37 and CRP concentrations (r = -0.2042; p = 0.189) and between serum LL-37 concentration and WBC count (r = -0.1277; p = 0.414) were observed. Our observations clearly documented that cathelicidin LL-37 plays a role in defense mechanisms against infectious agents, and is particularly important when the infection is caused by an intracellular pathogen.

Heightened circulating levels of antimicrobial peptides in tuberculosis-Diabetes co-morbidity and reversal upon treatment.

BACKGROUND: The association of antimicrobial peptides (AMPs) with tuberculosis-diabetes comorbidity (PTB-DM) is not well understood. METHODS: To study the association of AMPs with PTB-DM, we examined the systemic levels of cathelicidin (LL37), human beta defensin- 2 (HBD2), human neutrophil peptides 1-3, (HNP1-3) and granulysin in individuals with either PTB-DM, PTB, latent TB (LTB) or no TB infection (NTB). RESULTS: Circulating levels of cathelicidin and HBD2 were significantly higher and granulysin levels were significantly lower in PTB-DM compared to PTB, LTB or NTB, while the levels of HNP1-3 were significantly higher in PTB-DM compared to LTB or NTB individuals. Moreover, the levels of cathelicidin and/or HBD2 were significantly higher in PTB-DM or PTB individuals with bilateral and cavitary disease and also exhibited a significant positive relationship with bacterial burden. Cathelidin, HBD2 and HNP1-3 levels exhibited a positive relationship with HbA1c and/or fasting blood glucose levels. Finally, anti-tuberculosis therapy resulted in significantly diminished levels of cathelicidin, HBD2, granulysin and significantly enhanced levels of HNP1-3 and granulysin in PTB-DM and/or PTB individuals. CONCLUSION: Therefore, our data demonstrate that PTB-DM is associated with markedly enhanced levels of AMPs and diminished levels of granulysin.

Genomewide Analysis of the Antimicrobial Peptides in Python bivittatus and Characterization of Cathelicidins with Potent Antimicrobial Activity and Low Cytotoxicity.

In this study, we sought to identify novel antimicrobial peptides (AMPs) in Python bivittatus through bioinformatic analyses of publicly available genome information and experimental validation. In our analysis of the python genome, we identified 29 AMP-related candidate sequences. Of these, we selected five cathelicidin-like sequences and subjected them to further in silico analyses. The results showed that these sequences likely have antimicrobial activity. The sequences were named Pb-CATH1 to Pb-CATH5 according to their sequence similarity to previously reported snake cathelicidins. We predicted their molecular structure and then chemically synthesized the mature peptide for three putative cathelicidins and subjected them to biological activity tests. Interestingly, all three peptides showed potent antimicrobial effects against Gram-negative bacteria but very weak activity against Gram-positive bacteria. Remarkably, ΔPb-CATH4 showed potent activity against antibiotic-resistant clinical isolates and also was observed to possess very low hemolytic activity and cytotoxicity. ΔPb-CATH4 also showed considerable serum stability. Electron microscopic analysis indicated that ΔPb-CATH4 exerts its effects via toroidal pore preformation. Structural comparison of the cathelicidins identified in this study to previously reported ones revealed that these Pb-CATHs are representatives of a new group of reptilian cathelicidins lacking the acidic connecting domain. Furthermore, Pb-CATH4 possesses a completely different mature peptide sequence from those of previously described reptilian cathelicidins. These new AMPs may be candidates for the development of alternatives to or complements of antibiotics to control multidrug-resistant pathogens.

Human Umbilical Cord Mesenchymal Stromal Cells Improve Survival and Bacterial Clearance in Neonatal Sepsis in Rats.

Sepsis is the main cause of morbidity and mortality in neonates. Mesenchymal stromal cells (MSCs) are potent immune-modulatory cells. Their effect in neonatal sepsis has never been explored. We hypothesized that human umbilical cord-derived MSCs (hUC-MSCs) improve survival in experimental neonatal sepsis. Sepsis was induced in 3-day-old rats by intravenous injection of Escherichia coli (5 × 105/rat). One hour after infection, rats were treated intravenously with normal saline, hUC-MSCs, or with interferon-γ preconditioned hUC-MSCs (107 cells/kg). Eighteen hours after infection, survival, bacterial counts, lung neutrophil and macrophage influx, phagocytosis and apoptosis of splenocytes plasma, and LL-37 concentration were evaluated. Animals were observed for survival for 72 h after E. coli injection. Treatment with either hUC-MSCs or preconditioned hUC-MSCs significantly increased survival (hUC-MSCs, 81%; preconditioned hUC-MSCs, 89%; saline, 51%; P < 0.05). Both hUC-MSCs and preconditioned hUC-MSCs enhanced bacterial clearance. Lung neutrophil influx was decreased with preconditioned hUC-MSCs. The number of activated macrophages (CD206+) in the spleen was increased with hUC-MSCs and preconditioned hUC-MSCs; preconditioned hUC-MSCs increased the phagocytic activity of CD206+ macrophages. hUC-MSCs and preconditioned hUC-MSCs decreased splenocyte apoptosis in E. coli infected rats. Finally, LL-37 plasma levels were elevated in neonatal rats treated with hUC-MSCs or preconditioned hUC-MSCs. hUC-MSCs enhance survival and bacterial clearance in experimental neonatal sepsis. hUC-MSCs may be an effective adjunct therapy to reduce neonatal sepsis-related morbidity and mortality.

Cathelicidin (LL-37) and human ß2-defensin levels of children with post-infectious bronchiolitis obliterans.

INTRODUCTION: The antimicrobial peptides (AMPs) human ß-defensins and cathelicidin (LL-37) are key factors in innate and adaptive immune responses of the respiratory tract and play an important role in many respiratory diseases. No data are available in the literature about the levels of these AMPs in paediatric patients with post-infectious bronchiolitis obliterans (BO). This study aimed to determine human ß-defensin 2 (hBD2) and LL-37 levels and compare between post-infectious BO patients and the control group. METHOD: The patients diagnosed with post-infectious BO between September 2012 and 2013 and age- and-gender matched healthy controls were enrolled in this multi-center study. Serum hBD2 and LL37 levels were determined with the enzyme-linked immunosorbent assay method. RESULTS: Sixty-three post-infectious BO patients and 65 healthy children (median age 73 ± 55 and 78.74 ± 36.32 months, respectively) were enrolled in the study. The mean of hBD2 levels in patients and the control group were 1.06 ± 0.24 and 0.67 ± 0.72 ng/mL, respectively (P < 0.001). The mean of LL-37 levels in patients and the control group were 72.13 ± 29.06 and 50.10 ± 21.98 ng/mL, respectively (P < 0.001). No correlation was found between these AMPs levels and chronological age, age at the time of diagnosis, gender, Z-scores of weight and length, hospitalization numbers, the disease history before diagnosis and 25-OH D vitamin levels. CONCLUSION: This is the first study to demonstrate the higher levels of serum hBD2 and LL-37 levels in paediatric post-infectious BO patients. These AMPs may have important roles in the immune systems and pathogenesis of these patients.

Susceptibility for cigarette smoke-induced DAMP release and DAMP-induced inflammation in COPD.

Cigarette smoke (CS) exposure is a major risk factor for chronic obstructive pulmonary disease (COPD). We investigated whether CS-induced damage-associated molecular pattern (DAMP) release or DAMP-mediated inflammation contributes to susceptibility for COPD. Samples, including bronchial brushings, were collected from young and old individuals, susceptible and nonsusceptible for the development of COPD, before and after smoking, and used for gene profiling and airway epithelial cell (AEC) culture. AECs were exposed to CS extract (CSE) or specific DAMPs. BALB/cByJ and DBA/2J mice were intranasally exposed to LL-37 and mitochondrial (mt)DAMPs. Functional gene-set enrichment analysis showed that CS significantly increases the airway epithelial gene expression of DAMPs and DAMP receptors in COPD patients. In cultured AECs, we observed that CSE induces necrosis and DAMP release, with specifically higher galectin-3 release from COPD-derived compared with control-derived cells. Galectin-3, LL-37, and mtDAMPs increased CXCL8 secretion in AECs. LL-37 and mtDAMPs induced neutrophilic airway inflammation, exclusively in mice susceptible for CS-induced airway inflammation. Collectively, we show that in airway epithelium from COPD patients, the CS-induced expression of DAMPs and DAMP receptors in vivo and the release of galectin-3 in vitro is exaggerated. Furthermore, our studies indicate that a predisposition to release DAMPs and subsequent induction of inflammation may contribute to the development of COPD.

Intermittent exercises reduce the hypertension syndromes and improve the quality of life.

BACKGROUND: Hypertension is one of the most common causes for cardiovascular mortality in China and physical exercises have been well recognized for its prevention and treatment. Recent studies indicated that the methods of exercise differed in improving cardiorespiratory fitness, endothelial function, etc. METHODS: In the present study, we compared the effects of high-intensity intermittent exercise and moderate-intensity continuous exercise on the blood pressure, plasma CRAMP level and living quality of hypertensive patients. We measured the basic characteristics of all the individuals and made intermittent/continuous exercise plans according to each of their conditions. RESULTS: The whole training lasted for 16 weeks and the CRAMP level of each patient was recorded by blood sampling and ELISA test. The patients' quality of life (QoL) was also surveyed to determine their physical and psychological health. Our result suggested that the intermittent exercise significantly reduced the blood pressure and the CRAMP level of the hypertensive patients. Although the physical pain and social function were not improved by either exercises training, the other six dimensions of QoL, including physical function, physical role, general health condition, vitality, emotional role and mental health, were significant improved by exercises, especially by intermittent exercises. CONCLUSIONS: To sum up, the high-intensity intermittent exercise and moderate-intensity continuous exercise could both improve the living quality of hypertensive patients, but the effect of intermittent exercise was more obvious that it reduced the blood pressure and the CRAMP level of hypertensive patients and improve the living quality in a higher level.

The Anti-Microbial Peptide LL-37/CRAMP Is Elevated in Patients with Liver Diseases and Acts as a Protective Factor during Mouse Liver Injury.

BACKGROUND: Antimicrobial peptides (AMP) are an important defense mechanism of the innate immune system and can modulate the course of various diseases. However, their significance during liver pathogenesis is currently not well defined. METHODS: Patients with liver diseases were analyzed for LL-37/CRAMP, human beta-defensin-2 (hBD2), and complement 5a (C5a) serum levels. Mice deficient in CRAMP (Cathelicidin-related Antimicrobial Peptide), the mouse homolog for human LL-37, were fed with a methionine- and choline-deficient diet (MCD) and underwent bile-duct ligation (BDL). RESULTS: First, serum samples from patients with chronic liver diseases were investigated. Therefore, significantly enhanced levels for LL-37, hBD2, and complement C5a were detected, all of which comprise antimicrobial properties. Next, CRAMP-knockout (CRAMP-KO) mice were investigated, to better define a functional role of LL-37/CRAMP in animal models of liver diseases. MCD feeding and bile-duct ligation of CRAMP-KO mice resulted in an enhanced degree of liver injury during the early treatment phase. MCD feeding in CRAMP-KO mice led to stronger intrahepatic fat accumulation and significantly enhanced matrix remodeling, whereas BDL caused more extensive liver necrosis. At the late 28 days time point, MCD-fed CRAMP-KO mice displayed a higher intrahepatic fat load. Long-term changes in bile-duct-ligated mice included higher collagen content as a sign of enhanced fibrosis progression if CRAMP was absent. CONCLUSION: The study shows a clear correlation of antimicrobial peptide serum levels in patients with chronic liver diseases. Furthermore, we were able to demonstrate protective functions of LL-37/CRAMP in two independent mouse models of chronic liver injury.