Enhanced LL-37 expression following vitamin D supplementation in patients with cirrhosis and spontaneous bacterial peritonitis

Cathelicidin hCAP18/LL-37 promotes cell proliferation and suppresses antitumor activity of 1,25(OH)2D3 in hepatocellular carcinoma

Cathelicidin hCAP18/LL-37 can resist infection from various pathogens and is an essential component of the human immune system. Accumulating evidence has indicated that hCAP18/LL-37 plays a tissue-specific role in human cancer. However, its function in hepatocellular carcinoma (HCC) is poorly understood. The present study investigated the effects of hCAP18/LL-37 on HCC in vitro and in vivo. Results showed that hCAP18/LL-37 overexpression significantly promoted the proliferation of cultured HCC cells and the growth of PLC/PRF-5 xenograft tumor. Transcriptome sequencing analyses revealed that the PI3K/Akt pathway was the most significant upregulated pathway induced by LL-37 overexpression. Further analysis demonstrated that hCAP18/LL-37 stimulated the phosphorylation of EGFR/HER2 and activated the PI3K/Akt pathway in HCC cells. Furthermore, stronger EGFR/HER2/Akt signals were observed in the PLC/PRF-5^LL-37 xenograft tumor. Interestingly, even though the expression of hCAP18/LL-37 was significantly downregulated in HCC cells and tumors, 1,25(OH)₂D₃ treatment significantly upregulated the hCAP18/LL-37 level both in HCC cells and xenograft tumors. Moreover, 1,25(OH)₂D₃ together with si-LL-37 significantly enhanced the antitumor activity of 1,25(OH)₂D₃ in the PLC/PRF-5 xenograft tumor. Collectively, these data suggest that hCAP18/LL-37 promotes HCC cells proliferation through stimulation of the EGFR/HER2/Akt signals and appears to suppress the antitumor activity of 1,25(OH)₂D₃ in HCC xenograft tumor. This implies that hCAP18/LL-37 may be an important target when aiming to improve the antitumor activity of 1,25(OH)₂D₃ supplementation therapy in HCC.

Effect of vitamin D deficiency on spontaneous peritonitis in cirrhosis: a meta-analysis

Introduction

Few studies have reported the relationship between spontaneous peritonitis in cirrhosis and vitamin D, and the result is not very convincing.

Aim

To conduct a meta-analysis to clarify the relationship between vitamin D and spontaneous peritonitis.

Material and methods

Articles published up to 1 October 2019 in the PubMed, Medline, and Embase databases were searched. According to the inclusion and exclusion criteria, relevant statistical data were extracted and analysed by STATA.

Results

Six articles met the inclusion criteria. It was demonstrated that the average 25(OH)D level in spontaneous peritonitis patients was 2.36 less than that in control individuals (SMD = -2.36, 95% CI: -3.92, -0.8, I ² = 97.2%, p < 0.01). Moreover, it found that spontaneous peritonitis patients were 4.33 times more likely to be vitamin D deficient than controls (OR = 4.33, 95% CI: 1.57, 11.93, I ² = 50.1%, p = 0.111). Sensitivity analysis showed that the meta-analysis results were stable and reliable.

Conclusions

Vitamin D may be an importantly protective factor in spontaneous peritonitis.

Is Serum-Ascites Vitamin D Gradient a Valid Marker for Diagnosing Spontaneous Bacterial Peritonitis in Patients with Cirrhotic Ascites?

OBJECTIVE

Spontaneous bacterial peritonitis (SBP) is considered the paradigmatic model of infection in patients with liver cirrhosis. Therefore, there is a need for an accurate and rapid method for SBP diagnosis. The aim of this study was to evaluate the validity of serum-ascites 25-hydroxyvitamin D (25-OH vitamin D) gradient (SADG) as a marker for diagnosing SBP in patients with cirrhotic ascites.

METHODS

We conducted a cross-sectional analytic study of 88 patients with portal hypertensive ascites resulting from liver cirrhosis of any etiology. The demographic, clinical, and laboratory characteristics of the patients were recorded. The level of 25-OH vitamin D in serum and ascitic fluid was measured using high-performance liquid chromatography autoanalyzer. The SADG was calculated with the formula: 25-OH vitamin D in serum - 25-OH vitamin D in ascites.

RESULTS

Vitamin D deficiency was detected in 89.8% of the studied patients. The SADG values ranged between 0 and 69.2 ng/mL, with a median value of 5.58 ng/mL. It was significantly lower in patients with SBP than in those without SBP (P = .004). The area under the curve for SADG in exclusion of SBP was 0.67 at a cutoff value of ≥5.57 ng/mL.

CONCLUSION

We found that SADG may be a valid marker of SBP in patients with cirrhotic ascites.

p62 functions as an oncogene in colorectal cancer through inhibiting apoptosis and promoting cell proliferation by interacting with the vitamin D receptor

Objectives

The role of p62 in cancer is controversial. Evidence has shown that p62 is upregulated in different cancers and promotes tumour growth, such as in liver cancer and lung cancer. However, a recent study showed that the downregulation of p62 in hepatic stellate cells (HSCs) promotes hepatocellular carcinoma (HCC) development. How p62 is regulated in colorectal cancer (CRC) remains largely unknown. In this study, we aimed to investigate the roles and molecular mechanisms of p62 in CRC.

Materials and Methods

The expression levels of p62 in CRC tissues and adjacent non‐tumour tissues were determined by immunohistochemistry (IHC). Stable p62‐overexpression HCT116 cells and p62‐knockdown SW480 cells were established with lentiviral vectors. The role of p62 in CRC was investigated in in vitro and in vivo functional studies. The relationship between p62 and the vitamin D receptor (VDR) was investigated by coimmunoprecipitation (Co‐IP) assays.

Results

p62 was significantly upregulated in CRC, and a high p62 level was an independent risk factor for a poor prognosis in CRC patients. p62 promoted CRC migration and invasion by inhibiting apoptosis and promoting cell proliferation in vitro, and p62 aggravated tumour growth and metastasis in vivo. Co‐IP assays indicated that p62 interacts with the VDR and may target the NRF2‐NQO1 axis.

Conclusions

Our study suggested that p62 functions as an oncogene in CRC through inhibiting apoptosis and promoting cell proliferation by interacting with the VDR.

Reassessing the Host Defense Peptide Landscape

Current research has demonstrated that small cationic amphipathic peptides have strong potential not only as antimicrobials, but also as antibiofilm agents, immune modulators, and anti-inflammatories. Although traditionally termed antimicrobial peptides (AMPs) these additional roles have prompted a shift in terminology to use the broader term host defense peptides (HDPs) to capture the multi-functional nature of these molecules. In this review, we critically examined the role of AMPs and HDPs in infectious diseases and inflammation. It is generally accepted that HDPs are multi-faceted mediators of a wide range of biological processes, with individual activities dependent on their polypeptide sequence. In this context, we explore the concept of chemical space as it applies to HDPs and hypothesize that the various functions and activities of this class of molecule exist on independent but overlapping activity landscapes. Finally, we outline several emerging functions and roles of HDPs and highlight how an improved understanding of these processes can potentially be leveraged to more fully realize the therapeutic promise of HDPs.

Role of vitamin D deficiency as a risk factor for infections in cirrhotic patients

BACKGROUND

Vitamin D plays a role in innate and acquired immunity. The risk for bacterial infections is increased in cirrhotic patients due to low levels of vitamin D. This study aimed to determine serum 25-(OH) vitamin D levels among cirrhotic patients in the presence and absence of infections and correlate this level with liver disease severity.

METHODS

This cross-sectional analytic study recruited 87 hospitalised cirrhotic patients who were divided into the following groups: group with evidence of infection (45 cases) and group without infection (42 cases). Urine analysis, ascetic fluid study and chest X-rays were performed to find the site of infection. Serum 25-(OH) vitamin D was also measured.

RESULTS

Vitamin D levels were lower in the cirrhotic with infection group than in the cirrhotic without infection group (17.3 ± 2.5 vs. 41.1 ± 3.1, respectively) (P-value < 0.001). Approximately 71.4% cirrhotic patients without infection had sufficient vitamin D levels, while 60% of cirrhotic patients with infection had insufficient vitamin D levels, and 28.9% had vitamin D deficiency (P-value < 0.001). Spontaneous bacterial peritonitis was the most common infection (62.2%). The cutoff point of vitamin D levels for cirrhotic patients with infection was 21 ng/mL.

CONCLUSION

Vitamin D deficiency was found to be an independent predictor of infection in cirrhotic patients suggesting that vitamin D supplementation may be useful in these patients. No significant correlations were found between the vitamin D level and the Child-Pugh class and MELD score among the infected group and non-infected group.

Lipopolysaccharide and cAMP modify placental calcitriol biosynthesis reducing antimicrobial peptides gene expression

PROBLEM

Calcitriol, the hormonal form of vitamin D₃ (VD), stimulates placental antimicrobial peptides expression; nonetheless, the regulation of calcitriol biosynthesis in the presence of bacterial products and its consequence on placental innate immunity have scarcely been addressed.

METHOD OF STUDY

We investigated how some bacterial products modify placental VD metabolism and its ability to induce antimicrobial peptides gene expression.

RESULTS

Cultured human trophoblasts biosynthesized calcitriol only in the presence of its precursor calcidiol, a process that was inhibited by cyclic-AMP but stimulated by lipopolysaccharide (LPS). Intracrine calcitriol upregulated cathelicidin, S100A9, and β-defensins (HBDs) gene expression, while LPS further stimulated HBD2 and S100A9. Unexpectedly, LPS significantly repressed cathelicidin basal mRNA levels and drastically diminished calcidiol ability to induce it. Meanwhile, cyclic-AMP, which is used by many microbes to avoid host defenses, suppressed calcitriol biosynthesis, resulting in significant inhibition of most VD-dependent microbicidal peptides gene expression.

CONCLUSION

While LPS stimulated calcitriol biosynthesis, cyclic-AMP inhibited it. LPS downregulated cathelicidin mRNA expression, whereas cyclic-AMP antagonized VD-dependent-upregulation of most antimicrobial peptides. These findings reveal LPS and cyclic-AMP involvement in dampening placental innate immunity, highlighting the importance of cyclic-AMP in the context of placental infection and suggesting its participation to facilitate bacterial survival.

Effect of replenishment of vitamin D on survival in patients with decompensated liver cirrhosis: A prospective study

AIM

To assess the vitamin D (VD) deficiency as a prognostic factor and effect of replenishment of VD on mortality in decompensated cirrhosis.

METHODS

Patients with decompensated liver cirrhosis were screened for serum VD levels. A total of 101 VD deficient patients (< 20 ng/mL) were randomly enrolled in two groups: Treatment group (n = 51) and control group (n = 50). Treatment group received VD treatment in the form of intramuscular cholecalciferol 300000 IU as loading dose and 800 IU/d oral as maintenance dose along with 1000 mg oral calcium supplementation. The VD level, clinical parameters and survival of both the groups were compared for 6-mo.

RESULTS

Prevalence of vitamin D deficiency (VDD) in decompensated CLD was 84.31%. The mean (SD) age of the patients in the treatment group (M:F: 40:11) and control group (M:F: 37:13) were 46.2 (± 14.93) years and 43.28 (± 12.53) years, respectively. Baseline mean (CI) VD (ng/mL) in control group and treatment group were 9.15 (8.35-9.94) and 9.65 (8.63-10.7), respectively. Mean (CI) serum VD level (ng/mL) at 6-mo in control group and treatment group were 9.02 (6.88-11.17) and 29 (23-35), respectively. Over the period of time the VD, calcium and phosphorus level was improved in treatment group compared to control group. There was non-significant trend seen in greater survival (69% vs 64%; P > 0.05) and longer survival (155 d vs 141 d; P > 0.05) in treatment group compared to control group. VD level had no significant association with mortality (P > 0.05). In multivariate analysis, treatment with VD supplement was found significantly (P < 0.05; adjusted hazard ratio: 0.48) associated with survival of the patients over 6-mo.

CONCLUSION

VD deficiency is very common in patients of decompensated CLD. Replenishment of VD may improve survival in patients with decompensated liver cirrhosis.