Annexin A6 Polymorphism Is Associated with Pro-atherogenic Lipid Profiles and with the Downregulation of Methotrexate on Anti-Atherogenic Lipid Profiles in Psoriasis

Abstract

Background:
Annexin A6 (AnxA6) is a lipid-binding protein that regulates cholesterol homeostasis and secretory pathways. However, the correlation of AnxA6 polymorphism with lipometabolism has never been studied in psoriasis.

Objectives:
To investigate the impact of AnxA6 polymorphism on lipid profiles and the expression of AnxA6 protein in both peripheral blood mononuclear cells (PBMCs) and lipometabolism in psoriasis.

Methods:
A total of 265 psoriatic patients received methotrexate (MTX) treatment for 12 weeks, after which their lipid profiles were determined by measuring total cholesterol (TC), triglycerides (TGs), lipoprotein (a) [LP(a)], high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein (LDL), apolipoprotein (a)1 (ApoA1), and apolipoprotein B (ApoB). In addition, AnxA6 (rs11960458) was genotyped in 262 patients and the expression of AnxA6 in PBMCs was measured by Western blotting at baseline and week 8 post-MTX treatment.

Results:
The CC genotype carriers of rs11960458 had a lower expression of AnxA6 and lower levels of the pro-atherogenic lipids TC, LDL, and ApoB compared to TC genotype carriers. MTX significantly downregulated the levels of the anti-atherogenic lipids HDL-C and ApoA1 and the level of AnxA6 in TC genotype carriers, as well as the level of TGs in CC genotype carriers.

Conclusions:
The polymorphism of AnxA6, rs11960458, was statistically associated with the levels of pro-atherogenic lipids and with the downregulation of MTX on the levels of anti-atherogenic lipids and TGs in psoriasis.

Full text

Citation: Zhang, F.; Han, L.; Wang, B.;
Huang, Q.; Yawalkar, N.; Zhang, Z.;
Yan, K. Annexin A6 Polymorphism Is
Associated with Pro-atherogenic
Lipid Profiles and with the
Downregulation of Methotrexate on
Anti-Atherogenic Lipid Profiles in
Psoriasis. J. Clin. Med. 2022,11, 7059.
https://doi.org/10.3390/jcm11237059
Academic Editors: Masutaka Furue
and Stamatis Gregoriou
Received: 20 October 2022
Accepted: 26 November 2022
Published: 29 November 2022
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Attribution (CC BY) license (https://
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4.0/).
Journal of
Clinical Medicine
Article
Annexin A6 Polymorphism Is Associated with Pro-atherogenic
Lipid Profiles and with the Downregulation of Methotrexate on
Anti-Atherogenic Lipid Profiles in Psoriasis
Fuxin Zhang 1, †, Ling Han 1 ,† , Bing Wang 1,† , Qiong Huang 1, Nikhil Yawalkar 2, Zhenghua Zhang 1 ,*
and Kexiang Yan 1,*
1Department of Dermatology, Huashan Hospital, Fudan University, Shanghai Institute of Dermatology,
Shanghai 200040, China
2Department of Dermatology, Inselspital, Bern University Hospital, University of Bern,
CH-3000 Bern, Switzerland
*
Correspondence: verzhang@foxmail.com (Z.Z.); ykx2292002@aliyun.com (K.Y.); Tel.: +86-13501748188 (K.Y.);
Fax: +86-21-52887782 (K.Y.)
† These authors contributed equally to this work.
Abstract:
Background: Annexin A6 (AnxA6) is a lipid-binding protein that regulates cholesterol
homeostasis and secretory pathways. However, the correlation of AnxA6 polymorphism with
lipometabolism has never been studied in psoriasis. Objectives: To investigate the impact of AnxA6
polymorphism on lipid profiles and the expression of AnxA6 protein in both peripheral blood
mononuclear cells (PBMCs) and lipometabolism in psoriasis. Methods: A total of 265 psoriatic
patients received methotrexate (MTX) treatment for 12 weeks, after which their lipid profiles were
determined by measuring total cholesterol (TC), triglycerides (TGs), lipoprotein (a) [LP(a)], high-
density lipoprotein cholesterol (HDL-C), low-density lipoprotein (LDL), apolipoprotein (a)1 (ApoA1),
and apolipoprotein B (ApoB). In addition, AnxA6 (rs11960458) was genotyped in 262 patients and the
expression of AnxA6 in PBMCs was measured by Western blotting at baseline and week 8 post-MTX
treatment. Results: The CC genotype carriers of rs11960458 had a lower expression of AnxA6 and
lower levels of the pro-atherogenic lipids TC, LDL, and ApoB compared to TC genotype carriers.
MTX significantly downregulated the levels of the anti-atherogenic lipids HDL-C and ApoA1 and
the level of AnxA6 in TC genotype carriers, as well as the level of TGs in CC genotype carriers.
Conclusions: The polymorphism of AnxA6, rs11960458, was statistically associated with the levels of
pro-atherogenic lipids and with the downregulation of MTX on the levels of anti-atherogenic lipids
and TGs in psoriasis.
Keywords: psoriasis; Annexin A6; lipometabolism; rs11960458; methotrexate
1. Introduction
Psoriasis is a chronic, recurrent, systemic inflammatory disease with multiple comor-
bidities. The prevalence of psoriasis in Asia ranges from 0.12% to 1.49% [
1
]. Common
comorbidities, including cardiovascular diseases, metabolic syndrome, and high blood
pressure, are associated with abnormal blood composition [
2
]. Evidence to date suggests
that the inflammatory mediators produced by psoriatic skin lesions can enter the circulatory
system and cause systemic insulin resistance and abnormal fat metabolism, eventually
leading to dyslipidemia, which is a strong risk factor for atherosclerosis [
3
]. Dyslipidemia
is not only a comorbidity of psoriasis; it is also a repercussion of psoriasis treatment with
retinoids [
4
]. Studies have shown that psoriasis patients with arthritis (PsA) were more
likely to develop dyslipidemia, as well as higher burdens of comorbid diseases, especially
cardiovascular diseases [5,6].
Methotrexate (MTX) is a first-line oral, systemic therapy in treating psoriasis, especially
in PsA. A clinical trial analysis showed that psoriasis patients had different efficacies to MTX
J. Clin. Med. 2022,11, 7059. https://doi.org/10.3390/jcm11237059 https://www.mdpi.com/journal/jcm

J. Clin. Med. 2022,11, 7059 2 of 9
treatment under different dosages, indicating that individualized drug administration is
needed for MTX treatment and that an underlying genetic background might be responsible
for it [
7
]. Previous research has found that MTX increased serum high-density lipoprotein-
cholesterol (HDL-C), low-density lipoprotein (LDL), and total cholesterol (TC) levels [
8
].
However, other studies have reported that MTX exerted an atheroprotective effect by
promoting cholesterol outflow from artery wall cells, thereby protecting patients from
cardiovascular diseases [
9
,
10
]. A study in rats with adjuvant-induced arthritis reported
that MTX did not affect blood lipids [
11
]. Thus, the effect of MTX on blood lipid profiles
remains controversial, and the mechanism behind it is elusive. Considering the unique
economic advantages of MTX, it is urgent to explore the mechanism underlying the clinical
efficacy of MTX, thus increasing its application value.
AnnexinA6 (AnxA6) belongs to a family of calcium-dependent membrane- and
phospholipid-binding proteins, and it is mainly located at the plasma membrane and
endosomal compartments that serve as a scaffold protein to help recruit signaling pro-
teins and regulate cholesterol homeostasis and adiponectin release during membrane
transport [
12
,
13
]. The gene encoding AnxA6 has been reported to be one of the psoriasis
susceptibility genes in the Chinese Han population [
14
–
16
]. Our previous study identified
significant associations for the AnxA6 single nucleotide polymorphisms (SNPs) rs11960458
and rs960709 with MTX efficacy, of which only the rs11960458 polymorphism significantly
impacted the long-term treatment outcome [
17
]. Another study demonstrated that elevated
expression levels of protein AnxA6 could affect the intracellular distribution of choles-
terol [
18
]. Considering the role of AnxA6 in lipometabolism, a relationship may exist
between AnxA6 and the blood lipid profiles of psoriasis patients during MTX treatment.
However, to date, no study has evaluated the role of the rs11960458 polymorphism of
AnxA6 in lipid changes following MTX treatment of psoriasis. Therefore, we sought to de-
termine the impact of the rs11960458 genotype on the expression of the AnxA6 protein, and
the role of this SNP in the lipometabolism of psoriasis patients following MTX treatment.
2. Materials and Methods
2.1. Patients and Study Design
A total of 265 psoriatic patients aged
≥
18 years, who received MTX treatment, and
whose lipid levels were monitored, were recruited from clinics of the Dermatology De-
partment, Fudan Huashan Hospital, between February 2015 and August 2019. Only
262 psoriatic patients were successfully genotyped as carrying the rs11960458 SNP in the
ANXA6 gene. Using the CASPAR criteria, 138 patients (52.7%) were diagnosed with psori-
atic arthritis. Erythrodermic psoriasis and pustular psoriasis are not included. All patients
received oral MTX therapy for 12 weeks. The medical ethics committee of Huashan Hospital
approved the protocol (approval MTX201501), and all patients provided written informed
consent. The diagnoses were based on typical clinical features and/or histopathological
criteria. Patients who received systemic treatments (acitretin, cyclosporin, glucocorticoids)
for arthritis or psoriasis at 1 month were excluded. The topical treatments had been stopped
for more than one week before the beginning of the study. The therapeutic regimen fol-
lowed the European guidelines on contraindications and restrictions on MTX. None of the
patients used lipid-lowering drugs.
2.2. Treatment
The initial dose of oral MTX was 7.5–10 mg once per week, and the dose was increased
by 2.5 mg every 2–4 weeks. The maximum dose was 15 mg/week, and it also depended
on the patient’s clinical response, side effects, and hematological or chemical tests. If liver
enzymes were elevated >2-fold and <3-fold, the dose of MTX was reduced by 2.5 mg/week
and given once again 2–4 weeks later. If liver enzymes were elevated >3-fold, the use of
MTX was ceased.

J. Clin. Med. 2022,11, 7059 3 of 9
2.3. Assessment of Lipid Levels and Disease Characteristics
Two certified dermatologists graded the severity and extent of psoriasis using the
Psoriasis Area Severity Index (PASI) and body surface area (BSA) scores. Lipid profiles at
baseline and 12 weeks after MTX treatment, and fasting blood glucose at baseline, were
measured using conventional laboratory techniques at Huashan Hospital. Sex, age, age
at disease onset, smoking and alcohol intake, hypertension, diabetes, height, weight, and
body mass index (BMI) were recorded.
2.4. DNA Extraction and Genotyping
Five milliliters of EDTA-anticoagulated whole blood were collected from all patients
and stored at –80
◦
C. Genomic DNA was extracted from peripheral blood lymphocytes
using the FlexiGene DNA Purification Kit (Qiagen, Hilden, Germany) and diluted to
20 ng/
µ
L. All DNA samples were stored at
−
20
◦
C. The rs11960458 SNP of AnxA6 was
genotyped using a SequenomMassARRAY. The SequenomMassARRAY Assay Design 3.0
Software (Sequenom Inc., San Diego, CA, USA). was used to design the PCR parameters and
detection primers. The PCR products were subsequently used as templates for locus-specific
single-base extension reactions. The resulting products were desalted and transferred to a
384-element SpectroCHIP array (Sequenom Inc.). MALDI-TOF MS (Sequenom Inc.) was
used for allele detection. The mass spectrograms were analyzed using MassARRAY Type
software (Sequenom Inc., San Diego, CA, USA). We performed quality control of SNPs and
samples at a call rate of 99.2% and analyzed the distribution of the SNPs in the HCs with
the Hardy–Weinberg equilibrium (p> 0.0001).
2.5. Western Blot Assay
For SDS gel electrophoresis, samples were boiled to reduce 2
×
Loading buffer (120 mM
Tris-HCl, 4% SDS, 20% glycerol, 2%
β
-mercaptoethanol, 0.2% bromophenol blue, pH 6.8).
Equal protein amounts (~10
µ
g per lane) were separated with 10% SDS-Page using running
buffer (25 mM Tris, 192 mM glycine, 0.1% SDS). After electrophoresis, gels were blotted
onto PVDF membranes with the Trans-Blot Turbo transfer system (Bio-Rad, Hercules,
CA, USA). Membranes were blocked for 1 h with 5% non-fat dried milk in TBST (20 mM
Tris
·
HCl, 137 mM NaCl, 0.05% Tween-20, pH 7.6). After overnight incubation of primary
antibodies ANXA6 (1:250 dilution, PA5-27462, sigma) and Tublin (1:1000 dilution, 2148, cell
signaling) at 4
◦
C, membranes were washed and incubated with the secondary antibodies.
SuperSignal West Femto chemiluminescence reagent (Pierce) was used for detection in a
ChemiDoc MP system (Bio-Rad, Hercules, CA, USA), and signal intensities were quantified
with Image Lab software v2.1.4.7 (National Institutes of Health, Bethesda, MD, USA).
2.6. Statistical Analysis
The statistical analyses were performed with the statistical software GraphPad Prism
v.5 (Graph Pad Software, San Diego, CA, USA) and SPSS v.23.0 software (SPSS Inc., Chicago,
IL, USA). The quantitative data were expressed as mean
±
standard deviation, and qualita-
tive data were presented as percentages. The association of genotypes with serum lipid
levels was tested by covariance analysis (ANOVA). Stepwise multiple regression analysis
was used to adjust sex, age, age at disease onset, disease duration, height, weight, body
mass index (BMI), hypertension, diabetes, smoking and alcohol intake, and PASI score at
baseline. p-values < 0.05 were considered statistically significant.
3. Results
3.1. The CC Genotype of AnxA6, rs11960458, Is Associated with Lower Levels of Pro-Atherogenic
Lipids in Psoriatic Patients
The rs11960458 SNP in AnxA6 was successfully genotyped in 262 of the 265 psoriatic
patients. Their clinical characteristics and their lipid levels are summarized in Table 1.
The levels of the pro-atherogenic lipids TC (4.56
±
0.87 vs. 4.88
±
0.94, p= 0.0215), LDL
(
2.79 ±0.69
vs. 3.07
±
0.87, p= 0.0161), and ApoB (0.71
±
0.16 vs. 0.77
±
0.18, p= 0.0279)

J. Clin. Med. 2022,11, 7059 4 of 9
in CC genotype carriers (i.e., carriers of the rs11960458 SNP in AnxA6) were significantly
lower than those in TC genotype carriers. No statistical difference was observed in other
clinical characteristics and the levels of serum TGs, HDL-C, ApoA1, and Lp(a) between
different genotype carriers.
Table 1.
Clinical characteristic and the lipid levels according to the rs11960458 genotype of AnxA6 in
262 psoriatic patients.
TT (n= 40) TC (n= 127) CC (n= 95) p-Value
Age, mean (SD), year 50.8 ±16.62
47.94
±
14.60 46.35
±
14.96
0.2903
Age at disease onset, mean (SD), year
36.47
±
16.65 34.34
±
15.99 34.27
±
15.12
0.7286
Disease duration, mean (SD), year
14.33
±
11.17 13.59
±
10.69
12.2 ±10.28 0.4800
Weight, mean (SD), kg
69.86
±
13.48 68.41
±
11.83 69.03
±
12.77
0.8077
BMI, kg/m224.91 ±3.67 24.26 ±3.39 24.29 ±3.71 0.5866
PASI score at baseline 12.21 ±6.05 13.65 ±7.99 15.4 ±7.50 0.0580
The mean PASI improvement at
12 w 59.7 ±32.05
60.34
±
31.88
68.84 ±31.7 0.1082
PASI 50 response at 12 w 25 (62.50) 87 (68.50) 73 (76.84) 0.1904
PASI 75 response at 12 w 19 (47.50) 52 (40.94) 51 (53.68) 0.1685
PASI 90 response at 12 w 7 (17.50) 24 (18.90) 26 (27.37) 0.2474
Male, n(%) 31(77.50) 91 (71.65) 63 (66.320 0.4013
Arthritis, n(%) 24 (60.00) 66 (51.97) 48 (50.52) 0.5879
Smoking, n(%) 14 (35.00) 38 (29.92) 29 (30.52) 0.1795
Hypertension, n(%) 21 (52.50) 53 (41.73) 32 (33.68) 0.1163
Diabetes, n(%) 10 (25.00) 29 (22.83) 14 (14.74) 0.2376
TC, mmol/L 4.92 ±0.97 4.88 ±0.94 4.56 ±0.87 * 0.0215
TG, mmol/L 1.73 ±0.98 1.56 ±0.88 1.63 ±1.04 0.6122
HDL-C, mmol/L 1.20 ±0.26 1.19 ±0.28 1.16 ±0.31 0.5863
LDL-C, mmol/L 3.11 ±0.76 3.07 ±0.87 2.79 ±0.69 * 0.0161
ApoA1, g/L 1.06 ±0.18 1.06 ±0.18 1.03 ±0.18 0.5198
ApoB, g/L 0.78 ±0.15 0.77 ±0.18 0.71 ±0.16 * 0.0279
Lp(a), mg/L
156.6
±
176.5 165.4
±
196.9 138.1
±
133.3
0.5097
Abbreviations: BMI, body mass index (kg/m
2
); BSA, body surface area; PASI, Psoriasis Area Severity Index; TC,
total cholesterol; TG, triglyceride; HDL-C, high-density lipoprotein-cholesterol; LDL, low-density lipoprotein;
ApoA1, apolipoprotein A1; ApoB, apolipoprotein B; Lp(a), lipoprotein (a). Data are presented as the number
(percentage) of patients unless otherwise indicated. One-way ANOVA or Chi-square was used when appropriate.
p< 0.05 was considered statistically significant. Significant p-values are shown in bold. * represents a significant
difference between TC- and CC-genotype carriers.
As shown in Table 2, univariate analysis demonstrated that age (p= 0.000), age at
disease onset (p= 0.013), gender (p= 0.036), arthritis (p= 0.048), diabetes (p= 0.008), and
the rs11960458 SNP (p= 0.012) were significantly associated with TC levels. However, only
age (p= 0.000), gender (p= 0.008), and the rs11960458 SNP (p= 0.015) were significantly
correlated with TC levels. Furthermore, univariate analysis showed that age (p= 0.001),
age at disease onset (p= 0.003), arthritis (p= 0.014), weight (p= 0.000), BMI (p= 0.000),
hypertension (p= 0.002), and the rs11960458 SNP in AnxA6 (p= 0.014) were significantly
associated with ApoB levels. However, only age (p= 0.006), BMI (p= 0.000), and the
rs11960458 SNP (p= 0.039) were statistically correlated with the level of ApoB. In addition,
univariate analysis revealed that diabetes (p= 0.002), age (p= 0.041), weight (p= 0.021),
and the rs11960458 SNP (p= 0.009) were significantly associated with LDL levels, but only
diabetes (p= 0.003) and the rs11960458 SNP (p= 0.021) were statistically significant.

J. Clin. Med. 2022,11, 7059 5 of 9
Table 2.
Univariate and multivariate analyses of clinical factors and AnxA6 polymorphism associated
with the levels of pro-atherogenic lipids in 262 psoriatic patients.
Univariate Analysis Multivariate Analysis
Predictors OR (95%CI) p-Value OR (95%CI) p-Value
TC rs11960458 −
0.209 (
−
0.372~
−
0.046)
0.012 −0.198 (−0.358~−0.039) 0.015
gender −
0.264 (
−
0.511~
−
0.017)
0.036 −
0.324 (
−
0.563~
−
0.0830)
0.008
age 0.0137 (0.006~0.021) 0.000 0.0136 (0.006~0.021) 0.000
arthritis 0.228 (0.002~0.454) 0.048
onset 0.009 (0.002~0.0160 0.013
diabetes 0.381 (0.103~0.660) 0.008
ApoB
rs11960458 −
0.037 (
−
0.067~
−
0.007)
0.014 −0.031 (−0.061~−0.002) 0.039
age 0.002 (0.001~0.004) 0.001 0.002 (0.001~0.003) 0.006
BMI 0.011 (0.005~0.016) 0.000 0.010 (0.005~0.015) 0.000
arthritis 0.052 (0.011~0.093) 0.014
weight 0.003 (0.001~0.004) 0.000
onset 0.002 (0.001~0.003) 0.003
hypertension 0.067 (0.026~0.109) 0.002
LDL
rs11960458 −0.187 (−0.328~0.047) 0.009 −0.169 (−0.312~−0.026) 0.021
diabetes 0.380 (0.142~0.619) 0.002 0.367 (0.124~0.610) 0.003
age 0.007 (0.000~0.013) 0.041
weight 0.009 (0.001~0.016) 0.021
Abbreviations: TC, total cholesterol; LDL: low-density lipoprotein; ApoA1, apolipoprotein A1; ApoB, apolipopro-
tein B; Lp(a), lipoprotein (a). Multiple regression analysis was performed after adjustment for age, age at disease
onset, disease duration, weight, BMI, hypertension, diabetes, arthritis, and the genotype of rs11960458 in AnxA6.
Only the significant variables are shown. p< 0.05 is considered statistically significant (shown in bold).
3.2. The Reduction of MTX on the Levels of Anti-Atherogenic Lipids and TGs Was Associated with
the rs11960458 Genotype
As shown in Table 3, MTX significantly decreased the levels of the pro-atherogenic
lipids TC (p< 0.05), LDL (p< 0.05), ApoB (p< 0.001), and Lp(a) (p< 0.001) in TC and CC
genotype carriers of rs11960458 and ApoB (p= 0.0419) in TT genotype carriers. However,
the significant downregulations of MTX treatment on the anti-atherogenic lipids HDL-C
(1.19
±
0.28 vs. 1.15
±
0.25, p= 0.0068) and ApoA1 (1.06
±
0.18 vs. 1.04
±
0.16, p
= 0.0434
)
were only observed in TC genotype carriers of rs11960458. Moreover, the significant
reduction of MTX treatment on the level of TG was only observed in the CC genotype
carriers (1.63 ±1.04 vs. 1.41 ±0.84, p= 0.0108).
Table 3.
The effect of 12-week MTX treatment on lipid levels according to the genotype of AnxA6
rs11960458 in 262 psoriatic patients.
TT (n= 40) TC (n= 127) CC (n= 95)
0 week 12 week p-Value 0 week 12 week p-Value 0 week 12 week p-Value
TC,
mmol/L 4.92 ±0.97 4.69 ±1.02 0.0816 4.88 ±0.94 4.65 ±0.94 <0.001 4.56 ±0.87 4.40 ±0.80 0.0111
TG,
mmol/L 1.73 ±0.98 1.59 ±0.91 0.1344 1.56 ±0.88 1.64 ±1.03 0.2784 1.63 ±1.04 1.41 ±0.84 0.0108
HDL-C,
mmol/L 1.20 ±0.26 1.16 ±0.26 0.4109 1.19 ±0.28 1.15 ±0.25 0.0068 1.16 ±0.31 1.17 ±0.32 0.4519
LDL,
mmol/L 3.11 ±0.76 2.97 ±0.82 0.1501 3.07 ±0.87 2.94 ±0.86 0.0028 2.79 ±0.69 2.68 ±0.62 0.0353
ApoA1,
g/L 1.06 ±0.18 1.04 ±0.15 0.4569 1.06 ±0.18 1.04 ±0.16 0.0434 1.03 ±0.18 1.02 ±0.18 0.2467
ApoB, g/L 0.78 ±0.15 0.73 ±0.16 0.0419 0.77 ±0.18 0.72 ±0.16 <0.001 0.71 ±0.16 0.67 ±0.15 0.0001
Lp(a),
mg/L 156.6 ±176.5 133.5 ±137.9 0.0503 165.4 ±196.9 149.2 ±176.9 0.0069 138.1 ±133.3 120.5 ±130.2 0.0005
Abbreviation: TC, total cholesterol; TG, triglyceride; HDL-C, high-density lipoprotein-cholesterol; LDL, low-
density lipoprotein; ApoA1, apolipoprotein A1; ApoB, apolipoprotein B; Lp(a), lipoprotein (a). Paired t-test was
used. p< 0.05 is considered to be statistically significant. Significant pvalues are shown in bold.

J. Clin. Med. 2022,11, 7059 6 of 9
3.3. The Level of AnxA6 Protein in PBMCs Was Significantly Increased in TC Genotype Carriers
and Was Significantly Downregulated after MTX Treatment
Figure 1shows the expression of AnxA6 protein in PBMCs from 22 psoriatic patients
(4 patients with TT genotype, 9 patients with TC genotype, and 9 patients with CC geno-
type) before and after MTX treatment for 8 weeks. The expression of AnxA6 protein was
significantly higher in TC genotype carriers of rs11960458 than in CC genotype carriers
(p< 0.05). MTX treatment significantly downregulated the expression of AnxA6 in TC
genotypes carriers of rs11960458 (p< 0.05).
J. Clin. Med. 2022, 11, x FOR PEER REVIEW 6 of 10
LDL,
mmol/L 3.11 ± 0.76 2.97 ± 0.82 0.1501 3.07 ± 0.87 2.94 ± 0.86 0.0028 2.79 ± 0.69 2.68 ± 0.62 0.0353
ApoA1, g/L 1.06 ± 0.18 1.04 ± 0.15 0.4569 1.06 ± 0.18 1.04 ± 0.16 0.0434 1.03 ± 0.18 1.02 ± 0.18 0.2467
ApoB, g/L 0.78 ± 0.15 0.73 ± 0.16 0.0419 0.77 ± 0.18 0.72 ± 0.16 <0.001 0.71 ± 0.16 0.67 ± 0.15 0.0001
Lp(a), mg/L 156.6 ± 176.5 133.5 ± 137.9 0.0503 165.4 ± 196.9 149.2 ± 176.9 0.0069 138.1 ±
133.3
120.5 ±
130.2 0.0005
Abbreviation: TC, total cholesterol; TG, triglyceride; HDL-C, high-density lipoprotein-cholesterol;
LDL, low-density lipoprotein; ApoA1, apolipoprotein A1; ApoB, apolipoprotein B; Lp(a), lipopro-
tein (a). Paired t-test was used. p < 0.05 is considered to be statistically significant. Significant p val-
ues are shown in bold.
3.3. The Level of AnxA6 Protein in PBMCs Was Significantly Increased in TC Genotype
Carriers and Was Significantly Downregulated after MTX Treatment
Figure 1 shows the expression of AnxA6 protein in PBMCs from 22 psoriatic patients
(4 patients with TT genotype, 9 patients with TC genotype, and 9 patients with CC geno-
type) before and after MTX treatment for 8 weeks. The expression of AnxA6 protein was
significantly higher in TC genotype carriers of rs11960458 than in CC genotype carriers (p
< 0.05). MTX treatment significantly downregulated the expression of AnxA6 in TC gen-
otypes carriers of rs11960458 (p < 0.05).
Figure 1. The effect of MTX and the rs11960458 genotype on the expression of AnxA6 in PBMCs.
(A) Western blots showing the expression of AnxA6 at baseline and at week 8, according to the
Figure 1.
The effect of MTX and the rs11960458 genotype on the expression of AnxA6 in PBMCs.
(
A
) Western blots showing the expression of AnxA6 at baseline and at week 8, according to the
rs11960458 genotype after MTX treatment in 22 psoriatic patients (4 patients with TT genotype,
9 patients with TC genotype, and 9 patients with CC genotype); (
B
) The expression of AnxA6 in
PBMCs was significantly higher in TC genotype carriers of rs11960458 than in CC genotype carriers,
and it was significantly decreased in TC genotype carriers after MTX treatment. * p< 0.05, one-way
ANOVA (Tukey’s multiple comparisons test) and paired t-test were used).
4. Discussion
Our study demonstrated that the CC genotype carriers of rs11960458 in AnxA6 had
significantly lower levels of the pro-atherogenic lipids TC, LDL, and ApoB than TC geno-
type carriers. Moreover, multiple regression analysis demonstrated that the rs11960458 SNP
of AnxA6 was significantly associated with the levels of TC, LDL, and ApoB after adjusting
for age, gender, age at disease onset, weight, BMI, arthritis, diabetes, and hypertension.

J. Clin. Med. 2022,11, 7059 7 of 9
Interestingly, the reduction of MTX treatment on the levels of the anti-atherogenic lipids
HDL-C and ApoA1 was only observed in TC genotype carriers of rs11960458, and on the
level of TG was observed in CC genotype carriers. Furthermore, the expression of AnxA6
in PBMCs was significantly higher in TC genotype carriers than in CC genotype carriers
and was significantly downregulated in TC genotype carriers, after MTX treatment.
A previous study reported that AnxA6 was upregulated in the monocytes of over-
weight and obese patients [
19
]. Cholesterol efflux capacity is a functional property of
HDL, reflecting the efficiency of the atheroprotective reverse cholesterol transport process
in humans [
20
]. Several studies showed that cholesterol efflux capacity was impaired
in psoriasis patients and correlated with disease severity [
21
,
22
]. Cubells et al. reported
that high expression levels of AnxA6 perturbed cholesterol efflux. Therefore, the higher
levels of AnxA6 protein in patients with TC genotypes of rs11960458 may lead to impaired
cholesterol efflux capacity, thereby increasing the levels of proatherogenic lipids. In ad-
dition, our results demonstrated that BMI and diabetes were positively correlated with
the increased levels of ApoB and LDL, respectively, which may be due to the fact that
AnxA6 stimulates endocytosis and is involved in the trafficking of LDL to the pre-lysosomal
compartment [23].
Our results also demonstrated that the significant downregulation of MTX on the level
of TG was only observed in CC genotype carriers of rs11960458. However, the expression
of AnxA6 in PBMCs was not significantly changed in CC genotype carriers of rs11960458
after MTX treatment. AnxA6 has been linked to TG storage in adipocytes in recent years.
Proteomic approaches identified AnxA6 as associated with lipid droplets (LDs), located
in the LD membrane of hepatocytes and adipocytes [
24
,
25
]. Another study also showed
the co-localization of AnxA6 with LDs in differentiated 3T3-L1 adipocytes [
26
]. Stable
AnxA6 overexpression increases LD numbers and size in HuH7 hepatocytes and promotes
lipid accumulation in LDs. AnxA6-deficient primary hepatocytes and AnxA6 mouse liver
sections display reduced LD numbers and increased serum adiponectin levels. In contrast,
AnxA6 overexpression in 3T3-L1 adipocytes lowered cellular TG levels and adiponectin
secretion, which means that higher levels of AnxA6 expression are associated with a higher
level of lipolysis. Therefore, the decreased level of TG after MTX treatment in CC genotype
carriers may be caused by the relatively low and stable expression of AnxA6, as well as
the lower level of lipolysis and less lipid accumulation. Moreover, the lower expression of
AnxA6 increased adiponectin secretion, which will decrease TG levels as well [27].
Furthermore, our results revealed that MTX significantly downregulated the levels of
the anti-atherogenic lipids HDL-C and ApoA1 and the expression of AnxA6 in PBMCs in
TC genotype carriers of rs11960458; however, the underlying mechanism remains unclear.
Considering that cholesterol efflux capacity could be impaired by AnxA6 expression levels,
the function and composition of HDL-C and ApoA1 in TT and TC genotype carriers may
be dysregulated [
21
]. It has been reported that MTX restored cholesterol efflux capacity
and, thereby, increased its protection against atherosclerosis and thrombosis [
28
]. MTX
also regulated lipid metabolism by enhancing AMPK activation, thereby increasing the
expression of adiponectin in perivascular adipose tissue [
29
]. Moreover, research reported
that adiponectin lowers monocyte AnxA6 levels
in vitro
[
19
]. Thus, the downregulation
of AnxA6 might stem from MTX, and the decreased levels of HDL-C and ApoA1 may be
explained by their restored function. Overall, AnxA6 controls cholesterol and membrane
transport in endocytosis and exocytosis and modulates TG accumulation and storage.
5. Conclusions
In conclusion, the CC genotype of AnxA6 rs11960458 was related to a lower level of
AnxA6 protein in PBMCs and with lower levels of pro-atherogenic lipids compared to
TC genotype carriers. MTX treatment significantly downregulated the expression level of
AnxA6 in PBMCs and the levels of the anti-atherogenic lipids ApoA1 and HDL-C in TC
genotype carriers. The mechanism of MTX treatment on the effect of blood lipids remains
to be elucidated.

J. Clin. Med. 2022,11, 7059 8 of 9
Author Contributions:
Conceptualization, L.H., Z.Z. and K.Y.; methodology, Q.H. and K.Y.; software,
K.Y.; validation, B.W., F.Z. and K.Y.; formal analysis, B.W. and K.Y.; investigation, K.Y., Q.H. and
L.H.; resources, B.W. and Q.H.; data curation, B.W. and K.Y.; writing—original draft preparation, F.Z.
and L.H.; writing—review and editing, K.Y. and N.Y.; visualization, B.W.; supervision, K.Y. and Z.Z.;
project administration, K.Y. and Z.Z.; funding acquisition, K.Y. and Z.Z. All authors have read and
agreed to the published version of the manuscript.
Funding:
This research was financially supported by the National Natural Science Foundation of
China (No. 81773322, 82173420, 81673054, 81673073, and 81974471), the Key Project in Basic Research
Advocated by the Shanghai Science and Technology Commission (13JC1402300), and the Clinical
Research Plan of SHDC (No. SHDC2020CR6022, SHDC2020CR1014B, and SHDC22022302).
Institutional Review Board Statement:
The studies involving human participants were reviewed
and approved by Huashan Hospital, Fudan University (approval MTX201501).
Informed Consent Statement:
The patients/participants provided their written informed consent to
participate in this study.
Data Availability Statement:
The dataset used and analyzed in this present study is available from
the corresponding author.
Acknowledgments: We thank Le Du for statistical assistance in this study.
Conflicts of Interest: The authors declare no conflict of interest.
Abbreviations
AnxA6 AnnexinA6
ApoA1 Apolipoprotein A1
ApoB Apolipoprotein B
BMI Body mass index
BSA Body surface area
HDL-C High-density lipoprotein–cholesterol
LDL Low-density lipoprotein
LP(a) Lipoprotein (a)
MTX Methotrexate
PASI Psoriasis area severity index
PBMCs Peripheral blood mononuclear cells
SNPs Single-nucleotide polymorphisms
TC Total cholesterol
TG Triglyceride
References
1.
Michalek, I.M.; Loring, B.; John, S.M. A systematic review of worldwide epidemiology of psoriasis. J. Eur. Acad. Dermatol. Venereol.
2017,31, 205–212. [CrossRef] [PubMed]
2.
Dobrzy´nska, I.; Szachowicz-Petelska, B.; Wro ´nski, A.; Jarocka-Karpowicz, I.; Skrzydlewska, E. Changes in the Physicochemical
Properties of Blood and Skin Cell Membranes as a Result of Psoriasis Vulgaris and Psoriatic Arthritis Development. Int. J. Mol.
Sci. 2020,21, 9129. [CrossRef] [PubMed]
3.
Oliveira Mde, F.; Rocha Bde, O.; Duarte, G.V. Psoriasis: Classical and emerging comorbidities. An. Bras. Dermatol.
2015
,90, 9–20.
[CrossRef] [PubMed]
4.
Khalil, S.; Bardawil, T.; Stephan, C.; Darwiche, N.; Abbas, O.; Kibbi, A.G.; Nemer, G.; Kurban, M. Retinoids: A journey from the
molecular structures and mechanisms of action to clinical uses in dermatology and adverse effects. J. Dermatol. Treat.
2017
,28,
684–696. [CrossRef]
5.
Oh, E.H.; Ro, Y.S.; Kim, J.E. Epidemiology and cardiovascular comorbidities in patients with psoriasis: A Korean nationwide
population-based cohort study. J. Dermatol. 2017,44, 621–629. [CrossRef]
6. Edson-Heredia, E.; Zhu, B.; Lefevre, C.; Wang, M.; Barrett, A.; Bushe, C.J.; Cox, A.; Wu, J.J.; Maeda-Chubachi, T. Prevalence and
incidence rates of cardiovascular, autoimmune, and other diseases in patients with psoriatic or psoriatic arthritis: A retrospective
study using Clinical Practice Research Datalink. J. Eur. Acad. Dermatol. Venereol. 2015,29, 955–963. [CrossRef]
7.
Saurat, J.H.; Langley, R.G.; Reich, K.; Unnebrink, K.; Sasso, E.H.; Kampman, W. Relationship between methotrexate dosing and
clinical response in patients with moderate to severe psoriasis: Subanalysis of the CHAMPION study. Br. J. Dermatol. 2011,165,
399–406. [CrossRef]

J. Clin. Med. 2022,11, 7059 9 of 9
8.
Ronda, N.; Greco, D.; Adorni, M.P.; Zimetti, F.; Favari, E.; Hjeltnes, G.; Mikkelsen, K.; Borghi, M.O.; Favalli, E.G.; Gatti, R.; et al.
Newly identified antiatherosclerotic activity of methotrexate and adalimumab: Complementary effects on lipoprotein function
and macrophage cholesterol metabolism. Arthritis Rheumatol. 2015,67, 1155–1164. [CrossRef]
9.
Reiss, A.B.; Carsons, S.E.; Anwar, K.; Rao, S.; Edelman, S.D.; Zhang, H.; Fernandez, P.; Cronstein, B.N.; Chan, E.S. Athero-
protective effects of methotrexate on reverse cholesterol transport proteins and foam cell transformation in human THP-1
monocyte/macrophages. Arthritis Rheum. 2008,58, 3675–3683. [CrossRef]
10.
Westlake, S.L.; Colebatch, A.N.; Baird, J.; Kiely, P.; Quinn, M.; Choy, E.; Ostor, A.J.; Edwards, C.J. The effect of methotrexate on
cardiovascular disease in patients with rheumatoid arthritis: A systematic literature review. Rheumatology
2010
,49, 295–307.
[CrossRef]
11.
Bordy, R.; Verhoeven, F.; Tournier-Nappey, M.; Wendling, D.; Demougeot, C.; Totoson, P. Methotrexate did not improve endothelial
function in rheumatoid arthritis: A study in rats with adjuvant-induced arthritis. Clin. Exp. Rheumatol.
2019
,37, 81–88. [PubMed]
12.
Grewal, T.; Hoque, M.; Conway, J.R.W.; Reverter, M.; Wahba, M.; Beevi, S.S.; Timpson, P.; Enrich, C.; Rentero, C. Annexin A6-A
multifunctional scaffold in cell motility. Cell Adhes. Migr. 2017,11, 288–304. [CrossRef] [PubMed]
13.
Enrich, C.; Rentero, C.; de Muga, S.V.; Reverter, M.; Mulay, V.; Wood, P.; Koese, M.; Grewal, T. Annexin A6-Linking Ca
2+
signaling
with cholesterol transport. Biochim. Biophys. Acta 2011,1813, 935–947. [CrossRef] [PubMed]
14.
Sun, L.D.; Cheng, H.; Wang, Z.X.; Zhang, A.P.; Wang, P.G.; Xu, J.H.; Zhu, Q.X.; Zhou, H.S.; Ellinghaus, E.; Zhang, F.R.; et al.
Association analyses identify six new psoriasis susceptibility loci in the Chinese population. Nat. Genet.
2010
,42, 1005–1009.
[CrossRef] [PubMed]
15.
Yin, X.Y.; Cheng, H.; Wang, W.J.; Wang, W.J.; Fu, H.Y.; Liu, L.H.; Zhang, F.Y.; Yang, S.; Zhang, X.J. TNIP1/ANXA6 and CSMD1
variants interacting with cigarette smoking, alcohol intake affect risk of psoriasis. J. Dermatol. Sci. 2013,70, 94–98. [CrossRef]
16.
Villarreal-Martinez, A.; Gallardo-Blanco, H.; Cerda-Flores, R.; Torres-Munoz, I.; Gomez-Flores, M.; Salas-Alanis, J.; Ocampo-
Candiani, J.; Martinez-Garza, L. Candidate gene polymorphisms and risk of psoriasis: A pilot study. Exp. Ther. Med.
2016
,11,
1217–1222. [CrossRef]
17.
Fan, Z.; Zhang, Z.; Huang, Q.; Han, L.; Fang, X.; Yang, K.; Wu, S.; Zheng, Z.; Yawalkar, N.; Wang, Z.; et al. The Impact of ANxA6
Gene Polymorphism on the Efficacy of Methotrexate Treatment in Psoriasis Patients. Dermatology
2021
,237, 579–587. [CrossRef]
18.
Cubells, L.; Vilàde Muga, S.; Tebar, F.; Wood, P.; Evans, R.; Ingelmo-Torres, M.; Calvo, M.; Gaus, K.; Pol, A.; Grewal, T.; et al.
Annexin A6-induced alterations in cholesterol transport and caveolin export from the Golgi complex. Traffic
2007
,8, 1568–1589.
[CrossRef]
19.
Stogbauer, F.; Weigert, J.; Neumeier, M.; Wanninger, J.; Sporrer, D.; Weber, M.; Schaffler, A.; Enrich, C.; Wood, P.; Grewal, T.; et al.
Annexin A6 is highly abundant in monocytes of obese and type 2 diabetic individuals and is downregulated by adiponectin
in vitro. Exp. Mol. Med. 2009,41, 501–507. [CrossRef]
20.
Talbot, C.P.J.; Plat, J.; Ritsch, A.; Mensink, R.P. Determinants of cholesterol efflux capacity in humans. Prog. Lipid Res.
2018
,69,
21–32. [CrossRef]
21.
Mehta, N.N.; Li, R.; Krishnamoorthy, P.; Yu, Y.; Farver, W.; Rodrigues, A.; Raper, A.; Wilcox, M.; Baer, A.; DerOhannesian, S.;
et al. Abnormal lipoprotein particles and cholesterol efflux capacity in patients with psoriasis. Atherosclerosis
2012
,224, 218–221.
[CrossRef] [PubMed]
22.
Ferraz-Amaro, I.; Hernandez-Hernandez, M.V.; Armas-Gonzalez, E.; Sanchez-Perez, H.; Machado, J.D.; Diaz-Gonzalez, F. HDL
cholesterol efflux capacity is related to disease activity in psoriatic arthritis patients. Clin. Rheumatol.
2020
,39, 1871–1880.
[CrossRef] [PubMed]
23.
Grewal, T.; Heeren, J.; Mewawala, D.; Schnitgerhans, T.; Wendt, D.; Salomon, G.; Enrich, C.; Beisiegel, U.; Jackle, S. Annexin VI
stimulates endocytosis and is involved in the trafficking of low density lipoprotein to the prelysosomal compartment. J. Biol.
Chem. 2000,275, 33806–33813. [CrossRef] [PubMed]
24.
Ding, Y.; Wu, Y.; Zeng, R.; Liao, K. Proteomic profiling of lipid droplet-associated proteins in primary adipocytes of normal and
obese mouse. Acta Biochim. Biophys. Sin. 2012,44, 394–406. [CrossRef] [PubMed]
25.
Turro, S.; Ingelmo-Torres, M.; Estanyol, J.M.; Tebar, F.; Fernandez, M.A.; Albor, C.V.; Gaus, K.; Grewal, T.; Enrich, C.; Pol, A.
Identification and characterization of associated with lipid droplet protein 1: A novel membrane-associated protein that resides
on hepatic lipid droplets. Traffic 2006,7, 1254–1269. [CrossRef]
26.
Krautbauer, S.; Haberl, E.M.; Eisinger, K.; Pohl, R.; Rein-Fischboeck, L.; Rentero, C.; Alvarez-Guaita, A.; Enrich, C.; Grewal, T.;
Buechler, C.; et al. Annexin A6 regulates adipocyte lipid storage and adiponectin release. Mol. Cell. Endocrinol.
2017
,439, 419–430.
[CrossRef] [PubMed]
27.
Yanai, H.; Yoshida, H. Beneficial Effects of Adiponectin on Glucose and Lipid Metabolism and Atherosclerotic Progression:
Mechanisms and Perspectives. Int. J. Mol. Sci. 2019,20, 1190. [CrossRef]
28.
Mangoni, A.A.; Zinellu, A.; Sotgia, S.; Carru, C.; Erre, G.L. Methotrexate and Cardiovascular Protection: Current Evidence and
Future Directions. Clin. Med. Insights Ther. 2017,9, 1179559X17741289. [CrossRef]
29.
Ma, Y.; Li, L.; Shao, Y.; Bai, X.; Bai, T.; Huang, X. Methotrexate improves perivascular adipose tissue/endothelial dysfunction via
activation of AMPK/eNOS pathway. Mol. Med. Rep. 2017,15, 2353–2359. [CrossRef]