• Users Online: 194
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2018  |  Volume : 30  |  Issue : 1  |  Page : 8-12

Is serum apelin related to portal hemodynamics in patients with liver cirrhosis?


1 Department of Internal Medicine, Faculty of Medicine, National Liver Institute, Menoufia University, Menoufia, Egypt
2 Department of Diagnostic Radiology, Faculty of Medicine, National Liver Institute, Menoufia University, Menoufia, Egypt
3 Department of Clinical Pathology, National Liver Institute, Menoufia University, Menoufia, Egypt

Date of Submission27-Sep-2017
Date of Acceptance20-Nov-2017
Date of Web Publication20-Mar-2018

Correspondence Address:
Ashraf G Dala
Department of Internal Medicine, Faculty of Medicine, Menoufia University, Menoufia
Egypt
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ejim.ejim_61_17

Rights and Permissions
  Abstract 

Background Apelin is the endogenous ligand of the angiotensin-like receptor. The expression of apelin–APJ (apelin receptor) signaling is associated with the development of portal hypertension (PH) and contributes toward the formation of Porto systemic collaterals and splanchnic neovascularization in PH.
Aims We aimed to study the relationship between apelin and portal hemodynamics in cirrhotic patients.
Patients and methods Thus study included 60 cirrhotic patients from Menoufia University Hospitals (Egypt) and 20 healthy volunteers as a control group. Participants underwent a physical examination and laboratory investigations [complete blood count, urea, creatinine, alanine transaminase, aspartate transaminase (AST), serum albumin, bilirubin, international normalized ratio, hepatitis C virus antibody, hepatitis B virus antigen, hepatitis C virus PCR, alpha feto protein (AFP), and serum level of apelin]. Abdominal ultrasonographic studies of portal vein diameter, splenic size, and portal hemodynamics were carried out for all participants. Child–Pugh score, model for end-stage liver disease score, and AST/platelet (PLT) index were calculated for all participants.
Results Serum apelin was highly significantly elevated in cirrhotics than in controls, with a P value of 0.001. Serum apelin was significantly correlated to some laboratory parameters in cirrhotics such as PLT count, alanine transaminase, AST, γ-glutamyl transferase, and bilirubin, with P value less than 0.05. There was a positive correlation between serum apelin level and the degree of liver fibrosis estimated by the AST/PLT index. Serum apelin was significantly correlated to portal vein diameter and portal flow velocity, with a P value less than 0.05, and highly significantly correlated to splenomegaly, with a P value of 0.001. The optimal cut-off point of serum apelin for the prediction of PH in cirrhotics is 2550 ng/dl, with a sensitivity of 89%, a specificity of 65%, and an accuracy of 81%.
Conclusion Serum apelin is elevated in patients with cirrhosis and PH, and a positive correlation is found between serum apelin and the degree of hepatic fibrosis. Measurement of serum apelin represents a rapid, noninvasive method for the prediction of PH in cirrhotics and can assess the degree of hepatic fibrosis.

Keywords: apelin, cirrhosis, portal hemodynamics


How to cite this article:
Dala AG, Ebied OM, Abo-Raia GY. Is serum apelin related to portal hemodynamics in patients with liver cirrhosis?. Egypt J Intern Med 2018;30:8-12

How to cite this URL:
Dala AG, Ebied OM, Abo-Raia GY. Is serum apelin related to portal hemodynamics in patients with liver cirrhosis?. Egypt J Intern Med [serial online] 2018 [cited 2018 Apr 21];30:8-12. Available from: http://www.esim.eg.net/text.asp?2018/30/1/8/227961


  Introduction Top


Portal hypertension (PH) is a hemodynamic outcome of liver cirrhosis in western countries. It causes severe alterations responsible for the onset of complications of cirrhosis. Hemodynamic alterations of PH involve portal–hepatic hemodynamics and also involve splanchnic and systemic circulation [1].

Apelin is a peptide isolated from bovine stomach extracts acts as an endogenous ligand for previously orphaned G protein-coupled receptors (APJ receptor). Now, putative receptor protein related to the type-1 angiotensin receptor [2]. Apelin receptors are expressed in vascular endothelial cells during early embryogenesis and apelin in combination with vascular endothelial growth factor, leading to angiogenesis through induction of the proliferation of endothelial cells and the formation of new blood vessels [3],[4].

Expression of endogenous apelin–APJ (apelin receptor) signaling is associated with the development of PH, and contributes toward the formation of porto systemic collaterals and splanchnic neovascularization in PH rats [5]. Apelin signaling has been known to contribute toward angiogenesis [6]; thus, apelin and its receptor APJ are essential for any embryonic angiogenesis [4],[7],[8] and are needed for retinal vessels’ formation [3],[9],[10],[11],[12]. Furthermore, apelin pitch angiogenesis in vivo and in vitro [4],[11],[12],[13],[14]. Principe et al. [15] had shown that the endogenous apelin system could be involved in intrahepatic remodeling in cirrhotic rats. Thus, apelin signaling could represent a future therapeutic target during any pathological neovascularization associated with PH [16].

The role of apelin in the pathogenesis of liver cirrhosis is complex as described in a report linking apelin to the initiation and maintenance of the inflammatory and fibrogenic processes occurring in liver fibrosis [17] as well as the hemodynamic and vascular abnormalities in liver cirrhosis and its complications [15],[18]. However, there are limited clinical data showing the role of apelin in liver cirrhosis, as reported by Bertolani and Marra [19]. Therefore, highlighting the apelin system would present a potential therapeutic target for liver disease. Thus, this study aimed to determine whether there is a relation between serum apelin and portal hemodynamics in liver cirrhosis.


  Patients and methods Top


This study included 60 patients with liver cirrhosis and 20 healthy volunteers as a control group from Menoufia University Hospitals and the National Liver Institute in Menoufia University (Egypt) in the period from April 2014 to April 2015. They underwent physical examination and laboratory investigations such as complete blood count, urea, creatinine, liver profile [alanine transaminase (ALT), aspartate transaminase (AST), serum albumin, bilirubin, international normalized ratio (INR)], hepatitis C virus antibody, hepatitis B virus antigen, PCR for hepatitis C virus RNA, alpha feto protein (AFP), and serum level of apelin. Abdominal ultrasonographic studies of portal vein diameter, splenic size, and portal hemodynamics were carried out for all participants. Child–Pugh score, model for end-stage liver disease score, and the AST/PLT index were calculated for all patients. The exclusion criteria were as follows: patients with hypertension, diabetes mellitus, alcoholics, cardiopulmonary disorders, hepatocellular carcinoma, renal disorders, and smokers.

Approval

The Menoufia Faculty of Medicine Committee for Medical Research Ethics reviewed and formally approved the study before it was started and a written consent was obtained from all participants of the study.

Statistical analysis

The data collected were tabulated and analyzed using the SPSS statistical package version 11 (SPSS, version 11; SPSS Inc., Chicago, Illinois, USA) on IBM compatible computer. Descriptive statistics was presented as mean±SD, and number and percentage and analyzed using the χ2-test. Student’s t-test was used to compare two groups of normally distributed variables; the Mann–Whitney U-test, the correlation co-efficient test (r-test), and regression analysis were also carried out whenever appropriate. Results were considered significant at a P value of less than 0.05 and highly significant at a P value of less than 0.001.


  Results Top


Apelin level was highly significantly increased in cirrhotic patients than in controls, with a P value of 0.001 as shown in [Table 1].
Table 1 Comparison between the groups studied in apelin levels (n=80)

Click here to view


Apelin level was significantly correlated to some laboratory parameters in cirrhotic patients such as platelet (PLT) count, ALT, AST, γ-glutamyl transferase, and bilirubin, with a P value of less than 0.05 as shown in [Table 2].
Table 2 Correlation between apelin and laboratory parameters in the cirrhotic group

Click here to view


Apelin level was significantly correlated to portal vein diameter and portal flow velocity, with a P value of less than 0.05, and highly significantly correlated to splenomegaly, with a P value of 0.001, as shown in [Table 3].
Table 3 Correlation between apelin and ultrasound parameters in the cirrhotic group

Click here to view


There was a positive correlation between serum apelin level and degree of liver fibrosis estimated by the AST/PLT index as shown in [Table 4].
Table 4 Correlation between apelin and the aspartate transaminase/platelet index, child score, and model for end-stage liver disease score in the cirrhotic group

Click here to view


The optimal cut-off point of serum apelin in cirrhotic patients for the prediction of PH is 2550 ng/dl with a sensitivity of 89%, a specificity of 65%, and an accuracy of 81% as shown in [Table 5].
Table 5 Validity of serum apelin for the prediction of portal hypertension

Click here to view



  Discussion Top


Chronic liver disease (CLD) including cirrhosis can be induced by various etiologies, such as hepatitis viruses, alcohol, autoimmune, or metabolic causes. Through these stimulation and inflammatory injuries, intrahepatic fibrotic change occurs and is followed by intrahepatic vascular changes, angiogenesis, and development of PH [20].

Some emerging studies have pointed to the possible effects of the apelinergic system in the liver and related it to inflammation [21], fibrosis [17], angiogenesis as well as vascular and hemodynamic disturbances [15],[18]. Other emerging studies speculated that activated hepatic stellate cells represent a potential source for hepatic apelin [15] and that apelin contributes toward the proliferation of hepatic stellate cells induced by PLT-derived growth factors in vitro [18]. Furthermore, apelin could be an essential mediator of the profibrogenic gene induction that markedly initiates collagen-I synthesis [17], all of which are known to contribute largely toward deposition of extracellular matrix and progression of fibrosis [22],[23]. Melgar-Lesmes et al. [17] pointed to the decrease in apelin expression induced by tumor necrosis factor-α in hematopoietic stem cell cultures and explained that it could represent a homeostatic protective response toward reducing the overactivated hepatic apelin system in advanced cirrhosis. These findings point to the possible role of apelin in CLD progression. In addition, this provides a rationale to investigate new drugs targeting the apelin–APJ signaling pathway to reduce fibrosis and to improve hemodynamics in these patients.

In the present study, the mean value of serum apelin was significantly higher in cirrhotic patients than in the control group. This result is in line with previous studies of Lim et al. [20], Principe et al. [15], and El-Mesallamy et al. [24], who reported that patients with cirrhosis showed a significant increase in apelin circulating levels than normal participants.

Another finding of the present study is the increased serum apelin level in patients with cirrhosis and PH and this is in agreement with Tiani et al. [5], who suggested that the expression of endogenous apelin–APJ signaling is associated with the development of PH and contributes toward the formation of Porto systemic collateral blood vessels and splanchnic neovascularization in PH rats. Moreover, Lim et al. [20] reported that serum apelin showed an increase with an increase in portal pressure. Yokomori et al. [18] reported that apelin protein and mRNA were overexpressed in human cirrhotic liver compared with normal liver, and the magnitude increased as cirrhosis progressed from early to advanced stage. In early-stage cirrhotic liver, apelin expression was increased in hepatic sinusoidal endothelial cells and in proliferated arterial capillaries directly connecting to the sinusoids. In end-stage cirrhosis, apelin was strongly expressed in proliferated arterial capillaries. These findings suggest a role of apelin in the capillarization of hepatic sinusoid and the proliferation of arterial capillaries in cirrhosis.

Tiani et al. [5] reported that the administration of apelin receptor blocker (F13A) effectively decreased splanchnic neovascularization and the formation of Porto systemic collateral vessels as well as the expression of proangiogenic factors vascular endothelial growth factor, PLT-derived growth factor, and angiopoietin-2. These findings strongly suggested a possibility of the apelin antagonist (F13A) as a new therapeutic target in terms of both fibrosis and PH. Principe et al. [15] also reported that rats with cirrhosis treated with the apelin receptor antagonist showed decreased hepatic fibrosis and vessel density, improved cardiovascular performance, and renal function and lost ascites. These findings suggest that the apelin–APJ system could be a candidate for a therapeutic target of antifibrosis and antiportal hypertension treatment.

Our present data also found a significant positive correlation between serum apelin level and both AST and ALT, which is similar to the result of Sagiroglu et al. [25], who found that ALT and AST levels were significantly higher in rats injected with apelin intraperitoneally and then exposed to ischemia/reperfusion injury than the control group.

Also, our study found a significant positive correlation between serum apelin and liver fibrosis estimated by the AST/PLT index. These results are in agreement with Farid et al. [26], who analyzed the pattern of apelin expression in different stages of human CLD. In the early stage of hepatic fibrosis (F1 and F2), apelin was almost undetectable as in nonparenchymatous cells, such as sinusoidal endothelial cells/hepatic stellate cells, myofibroblasts, and endothelial cells. With progression of liver fibrosis (F3), apelin-positive cells were located in sinusoidal endothelial cells/hepatic stellate cells. In cirrhosis (F4), apelin-positive cells shifted to the fibrotic septa and spread as linear staining in the septa and on the proliferated capillary endothelial cells.


  Conclusion Top


Serum apelin is elevated in patients with cirrhosis and PH, and a positive correlation was found between serum apelin and degree of hepatic fibrosis. Measurement of serum apelin levels can represent a rapid, noninvasive method for the prediction of PH in cirrhotic patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

1.
Gatta A, Bolognesi M, Merkel C. Vasoactive factors and hemodynamic mechanisms in the pathophysiology of portal hypertension in cirrhosis. Mol Aspects Med 2008; 29:119–129.  Back to cited text no. 1
    
2.
Altinkaya SÖ, Nergiz S, Küçük M, Yüksel H. Apelin levels in relation with hormonal and metabolic profile in patients with polycystic ovary syndrome. Eur J Obstet Gynecol Reprod Biol 2014; 176:168–172.  Back to cited text no. 2
    
3.
Kasai A, Shintani N, Kato H, Matsuda S, Gomi F, Haba R et al. Retardation of retinal vascular development in apelin-deficient mice. Arterioscler Thromb Vasc Biol 2008; 28:1717–1722.  Back to cited text no. 3
    
4.
Cox CM, D’Agostino SL, Miller MK, Heimark RL, Krieg PA. Apelin, the ligand for the endothelial G-protein-coupled receptor, APJ, is a potent angiogenic factor required for normal vascular development of the frog embryo. Dev Biol 2006; 296:177–189.  Back to cited text no. 4
    
5.
Tiani C, Garcia-Pras E, Mejias M, de Gottardi A, Berzigotti A, Bosch J et al. Apelin signaling modulates splanchnic angiogenesis and portosystemic collateral vessel formation in rats with portal hypertension. J Hepatol 2009; 50:296–305.  Back to cited text no. 5
    
6.
Masri B, Knibiehler B, Audigier Y. Apelin signalling: a promising pathway from cloning to pharmacology. Cell Signal 2005; 17:415–426.  Back to cited text no. 6
    
7.
Devic E, Rizzoti K, Bodin S, Knibiehler B, Audigier Y. Amino acid sequence and embryonic expression of MSR/APJ, the mouse homolog of Xenopus X-msr and human APJ. Mech Dev 1999; 84:199–203.  Back to cited text no. 7
    
8.
Inui M, Fukui A, Ito Y, Asashima M. Xapelin and Xmsr are required for cardiovascular development in Xenopus laevis. Dev Biol 2006; 298:188–200.  Back to cited text no. 8
    
9.
Saint-Geniez M, Masri B, Malecaze F, Knibiehler B, Audigier Y. Expression of the murine MSR/APJ receptor and its ligand apelin is upregulated during formation of the retinal vessels. Mech Dev 2002; 110:183–186.  Back to cited text no. 9
    
10.
Saint-Geniez M, Argence CB, Knibiehler B, Audigier Y. The MSR/APJ gene encoding the apelin receptor is an early and specific marker of the venous phenotype in the retinal vasculature. Gene Expr Patterns 2003; 3:467–472.  Back to cited text no. 10
    
11.
Kasai A, Shintani N, Oda M, Kakuda M, Hashimoto H, Matsuda T et al. Apelin is a novel angiogenic factor in retinal endothelial cells. Biochem Biophys Res Commun 2004; 325:395–400.  Back to cited text no. 11
    
12.
Masri B, Morin N, Cornu M, Knibiehler B, Audigier Y. Apelin (65-77) activates p70 S6 kinase and is mitogenic for umbilicalendothelial cells. FASEB J 2004; 18:1909–1911.  Back to cited text no. 12
    
13.
Kidoya H, Ueno M, Yamada Y, Mochizuki N, Nakata M, Yano T et al. Spatial and temporal role of the apelin/APJ system in the caliber size regulation of blood vessels during angiogenesis. EMBO J 2008; 27:522–534.  Back to cited text no. 13
    
14.
Sorli SC, Le Gonidec S, Knibiehler B, Audigier Y. Apelin is a potent activator of tumour neoangiogenesis. Oncogene 2007; 26:7692–7699.  Back to cited text no. 14
    
15.
Principe A, Melgar-Lesmes P, Fernandez-Varo G, Ruiz del Arbol L, Ros J, Morales-Ruiz M et al. The hepatic apelin system: a new therapeutic target for liver disease. Hepatology 2008; 48:1193–1201.  Back to cited text no. 15
    
16.
Sorli SC, van den Berghe L, Masri B, Knibiehler B, Audigier Y. Therapeutic potential of interfering with apelin signalling. Drug Discov Today 2006; 11:1100–1106.  Back to cited text no. 16
    
17.
Melgar-Lesmes P, Casals G, Pauta M, Ros J, Reichenbach V, Batallar R et al. Apelin mediates the induction of profibrogenic genes in human hepatic stellate cells. Endocrinology 2010; 151:5306–5314.  Back to cited text no. 17
    
18.
Yokomori H, Oda M, Yoshimura K, Machida S, Kaneko F, Hibi T. Overexpression of apelin receptor (APJ/AGTRL1) on hepatic stellate cells and sinusoidal angiogenesis in human cirrhotic liver. J Gastroenterol 2011; 46:222–231.  Back to cited text no. 18
    
19.
Bertolani C, Marra F. The role of adipokines in liver fibrosis. Pathophysiology 2008; 15:91–101.  Back to cited text no. 19
    
20.
Lim YL, Choi E, Jang YO, Cho YZ, Kang YS, Baik SK et al. Clinical implications of the serum apelin level on portal hypertension and prognosis of liver cirrhosis. Gut Liver 2016; 10:109–116.  Back to cited text no. 20
    
21.
Garica-Diaz D, Campion J, Milagro FI, Martinez JA. Adiposity dependent apelin gene expression: relationships with oxidative and inflammation markers. Mol Cell Biochem 2007; 305:87–94.  Back to cited text no. 21
    
22.
Bataller R, Sancho-Bru P, Ginès P, Lora JM, Al-Garawi A, Sole M et al. Activated human hepatic stellate cells express the renin-angiotensin system and synthesize angiotensin II. Gastroenterology 2003; 125:117–125.  Back to cited text no. 22
    
23.
Lindahl P, Johansson BR, Levéen P, Betsholtz C. Pericyte loss and microaneurysm formation in PDGF-B deficient mice. Science 1997; 277:242–245.  Back to cited text no. 23
    
24.
El-Mesallamy HO, Hamdy NM, Rizk HH, El-Zayadi AR. Apelin serum level in Egyptian patients with chronic hepatitis C. Mediators Inflamm 2011; 703031:7.  Back to cited text no. 24
    
25.
Sagiroglu T, Aksoy MB, Sagiroglu G, Tozkir H, Oguz S, Yalta T et al. Effect of leptin and apelin preconditioning on hepatic ischemia reperfusion injury in rats. Indian J Surg 2014; 76:111–116. ‏  Back to cited text no. 25
    
26.
Farid RM, Abu-Zeid RM, El-Tawil A. Emerging role of adipokine apelin in hepatic remodelling and initiation of carcinogensis in chronic hepatitis C patients. Int J Clin Exp Pathol 2014; 7:2707–2717.  Back to cited text no. 26
    



 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Patients and methods
Results
Discussion
Conclusion
References
Article Tables

 Article Access Statistics
    Viewed88    
    Printed3    
    Emailed0    
    PDF Downloaded31    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]