Elevated CTSL Gene Expression Correlated with Proinflammatory Cytokines in Omental Adipose Tissue of Patients with Obesity

Figures & data

Table 1 Demographic and Clinical Characteristics of Study Population

	NOB	OB	t/Z/Χ^2-value	P-value
Participants	12	51
Gender (F/M)	5/7	34/17	2.575	0.109
Age(years)	31.92±6.90	33.29±5.28	−0.298	0.766
BMI (kg/m2)	24.39±1.85	36.10±4.62	−13.977	<0.001
Fasting glucose (mM)	4.94±0.71	6.02±2.24	−2.293	0.022
Fasting insulin (mU/L)	9.90±3.73	27.85±18.52	−3.406	0.001
HOMA-IR	2.11±0.60	7.95±7.85	−5.024	<0.001
HbA1c (%)	5.25±0.34	5.81±1.00	−3.406	0.001
TG (mM)	1.98±1.44	2.59±3.25	−0.945	0.345
TC (mM)	4.51±0.69	4.87±0.95	−1.103	0.270
LDL (mM)	2.53±0.62	3.03±0.72	−2.210	0.031
HDL (mM)	1.12±0.21	1.12±0.20	−0.063	0.950

Notes: Data given as n (participants) or mean ± SD.

Abbreviations: F, female; BMI, body mass index; HOMA-IR, Model Assessment of Insulin Resistance; HbA1c, glycated hemoglobin; TG, triglycerides; TC, total cholesterol; LDL, low-density lipoproteins; HDL, high-density lipoproteins. NOB, patients without obesity; OB, patients with obesity.

Figure 1 Increased adipose tissue associated CCL-2, IL-6 and IL-1β gene expression in OB group. (A-C) qRT-PCR analysis for CCL-2, IL-6 and IL-1β of omental adipose tissue from NOB and OB groups. (D-F) CCL-2, IL-6 and IL-1β gene expression are respectively positively associated with BMI and Ln(HOMA-IR).

Table 2 Pearson’s Correlation Coefficients for CTSB and CTSL Gene Expression and Clinical Characters

	Ln CTSB	Ln CTSL
Age (years)	0.104	0.156
BMI (kg/m^2)	0.283*	0.210
Fasting glucose (mM)	−0.084	−0.056
TG (mM)	0.288*	0.264*
TC (mM)	0.456**	0.439**
HDL (mM)	−0.035	−0.035
LDL (mM)	0.401**	0.368*
HbA1c (%)	0.121	0.105
Ln (HOMA-IR)	0.184	0.170

Notes: *P<0.05, **P<0.01. Ln (CTSB), ln-transformed of CTSB; Ln (CTSL), ln-transformed of CTSL.

Table 3 Relationship Between CTSB, CTSL Gene Expression in Omental Adipose Tissues and Adiposity

Dependent Variables	Ln CTSB			Ln CTSL
	Std. β	P value	Adj.R^2	Std. β	P value	Adj.R^2
BMI	0.261	0.023	0.251		0.108	0.179
TC	0.443	0.000		0.439	0.000
TG		0.923			0.824
LDL		0.648			0.388

Notes: Stepwise multiple linear regression analysis. Dependent variables: Ln CTSB or Ln CTSL; independent variables: BMI, TC, TG, LDL.

Figure 2 Increased CTSB and CTSL gene expression in omental adipose tissue of obese individuals. (A-B) qRT-PCR for CTSB and CTSL mRNA of omental adipose tissue from NOB and OB group. (C) In the study cohort, CTSL expression correlated positively with CTSB gene expression.

Table 4 Relationship Between Gene Expression Between CTSB/CTSL and Pro-Inflammatory Cytokines in Omental Adipose Tissues

Dependent Variable	Ln CCL-2			Ln IL-6			Ln IL-1β
	Std. β	P value	Adj.R^2	Std. β	P value	Adj.R^2	Std. β	P value	Adj.R^2
BMI	0.404	0.001	0.391	0.376	0.001	0.397		0.090	0.165
CTSL	0.352	0.002		0.365	0.002		0.426	0.000
CTSB		0.091			0.229			0.108
TG	0.276	0.023		0.290	0.010			0.055
TC		0.983			0.897			0.161
LDL		0.284			0.215			0.188

Notes: Stepwise linear regression analysis. Ln CCL-2, Ln IL-6 and Ln IL-1β were ln-transformed of CCL-2, IL-6 and IL-1β respectively. Dependent variables: Ln CCL-2, Ln IL-6 or Ln IL-1β. Independent variables: BMI, CTSL, CTSB, TG, TC, LDL.