Effects of duodenal–jejunal bypass surgery in ameliorating nonalcoholic steatohepatitis in diet-induced obese rats

Figures & data

Figure 1 Experimental design and oral glucose tolerance test.

Notes: (A) Animal experimental design and schematic of DJB. (B) Oral glucose tolerance test. DJB and PGZ reversed the glucose intolerance. *P<0.05.
Abbreviations: DJB, duodenal–jejunal bypass; DJB group, MCD–HF diet for 3 months followed by DJB and MCD–HF diet for subsequent 3 months; HF, high fat; HFD, high fat diet; HF group, MCD–HF diet; MCD, methionine–choline-deficient; NC group, normal chow; PGZ group, MCD–HF diet for 3 months followed by treatment with PGZ with MCD–HF diet for subsequent 3 months; PGZ, pioglitazone.

Table 1 Effects of DJB and PGZ on metabolic parameters in MCD and HF diet-induced rats of nonalcoholic steatohepatitis

Metabolic parameters	NC group	HF group	DJB group	PGZ group	P-valuea
Body weight (g)	574.5±11.3*	843.3±37.7	607.8±44.7*	649.2±30.6*	0.001
Food intake (g/day)	32.1±0.5	40.8±3.2	38.2±3.3	37.1±2.9	0.307
Liver weight (g)	12.3±0.6*	23.3±1.4	15.6±0.3*	13.1±1.5*	<0.001
Liver weight normalized to body weight (g/kg)	21.3±0.2	27.7±0.5	25.5±0.3	20.3±0.4	<0.001
ALT (U/L)	52.5±2.7*	79.3±2.7	57.0±4.2*	73.2±5.7	0.018
Insulin (μIU/mL)	10.6±0.3*	78.3±15.5	60.4±4.5	14.7±2.9*	0.002
Fasting glucose (mg/dL)	105.7±4.2*	254.8±25.5	142.5±10.4*	154.3±24.5*	0.004
HOMA-IR	2.73±0.02*	51.00±14.09	21.59±3.11*	5.95±1.80*	0.023
Triglycerides (mg/dL)	55.0±6.5*	168.3±25.8	75.0±2.6*	55.3±5.3*	0.001
Cholesterol (mg/dL)	72.2±4.8	92.0±11.0	103.3±10.3	78.2±6.3	0.226
Epididymal fat (g)	8.6±1.0*	19.4±1.5	10.1±1.1*	14.3±2.1*	0.010
Epididymal fat normalized to body weight (g/kg)	15.0±0.9	32.7±1.2	17.0±0.8	23.1±1.4	<0.001
IL-6 (pg/mL)	225.2±29.4*	439.8±10.3	418.8±0.5	439.8±4.1	0.137
TNF-α (pg/mL)	140.0±13.9*	540.1±49.2	395.8±66.2*	280.2±53.1*	0.004

Note:

* P-value <0.05 vs HF group.

a P-value indicated the significance among HF, DJB, and PGZ groups.

Abbreviations: ALT, alanine aminotransferase; DJB, duodenal–jejunal bypass; DJB group, MCD–HF diet for 3 months followed by DJB and MCD–HF diet for subsequent 3 months; HF, high fat; HF group, MCD–HF diet; HOMA-IR, homeostasis model assessment-insulin resistance; MCD, methionine–choline-deficient; NC group, normal chow; PGZ group, MCD–HF diet for 3 months followed by treatment with PGZ with MCD–HF diet for subsequent 3 months; PGZ, pioglitazone.

Figure 2 H&E staining of liver tissue after the 6-month protocol.

Notes: (A) NC group, normal liver histology; (B) HF group, development of hepatic steatosis with ballooning degeneration; (C, D) DJB and PGZ groups, reduced steatosis. The black arrow indicates a lipid droplet and white arrow indicates the infiltration of an inflammatory cell. Original magnification 40×. (E) Nonalcoholic fatty liver disease activity score (NAS). The DJB and PGZ groups had significantly lower NASs than HF group. *P<0.05.
Abbreviations: DJB, duodenal–jejunal bypass; DJB group, MCD–HF diet for 3 months followed by DJB and MCD–HF diet for subsequent 3 months; HF, high fat; HF group, MCD–HF diet; MCD, methionine–choline-deficient; NC group, normal chow; PGZ group, MCD–HF diet for 3 months followed by treatment with PGZ with MCD–HF diet for subsequent 3 months; PGZ, pioglitazone.

Table 2 NAFLD activity score (NAS) in each group

Group	NAS range	Average	SEM	P-value
NC (n=6)	0–1	0.17	0.167	<0.001
HF (n=6)	6–8	6.83	0.307	<0.001
DJB (n=6)	1–2	1.33	0.211	<0.001
PGZ (n=6)	2–5	3.17	0.497	<0.001*

Notes:P-value represents significance compared to HF group.

* Significant P-value among groups.

Abbreviations: DJB, duodenal–jejunal bypass; DJB group, MCD–HF diet for 3 months followed by DJB and MCD–HF diet for subsequent 3 months; HF, high fat; HF group, MCD–HF diet; MCD, methionine–choline-deficient; NAFLD, nonalcoholic fatty liver disease; NC group, normal chow; PGZ group, MCD–HF diet for 3 months followed by treatment with PGZ with MCD–HF diet for subsequent 3 months; PGZ, pioglitazone.

Figure 3 H&E staining of visceral epididymal fat tissue after 6 months.

Notes: (A) NC group, normal adipocyte size; (B) HF group, markedly increased size; (C) DJB group, reduced adipocyte size; (D) PGZ group, slightly reduced adipocyte size. Original magnification 20×. (E) Quantitative evaluation of adipocyte size by fold change. *P<0.05.
Abbreviations: DJB, duodenal–jejunal bypass; DJB group, MCD–HF diet for 3 months followed by DJB and MCD–HF diet for subsequent 3 months; HF, high fat; HF group, MCD–HF diet; MCD, methionine–choline-deficient; NC group, normal chow; PGZ group, MCD–HF diet for 3 months followed by treatment with PGZ with MCD–HF diet for subsequent 3 months; PGZ, pioglitazone.

Figure 4 α-SMA expression after 6 months.

Notes: (A) NC group, no enhancement; (B) HF group, enhanced expression; (C, D) DJB or PGZ group, returned to normal expression. Original magnification 40×.
Abbreviations: DJB, duodenal–jejunal bypass; DJB group, MCD–HF diet for 3 months followed by DJB and MCD–HF diet for subsequent 3 months; HF, high fat; HF group, MCD–HF diet; MCD, methionine–choline-deficient; NC group, normal chow; PGZ group, MCD–HF diet for 3 months followed by treatment with PGZ with MCD–HF diet for subsequent 3 months; PGZ, pioglitazone.

Figure 5 Masson’s trichrome stain for collagen bundle.

Notes: (A, B) NC and HF groups, increase of collagen bundle. (C, D) DJB or PGZ group, returned to normal condition. Original magnification 20×. (E) Quantitative evaluation of collagen bundle by fold change. *P<0.05.
Abbreviations: DJB, duodenal–jejunal bypass; DJB group, MCD–HF diet for 3 months followed by DJB and MCD–HF diet for subsequent 3 months; HF, high fat; HF group, MCD–HF diet; MCD, methionine–choline-deficient; NC group, normal chow; PGZ group, MCD–HF diet for 3 months followed by treatment with PGZ with MCD-HF diet for subsequent 3 months; PGZ, pioglitazone.

Figure 6 (A) mRNA expression of fibrogenesis gene. TGF-β1 was significantly downregulated by DJB and PGZ. (B) mRNA expression of lipogenesis gene. SREBF-1 was not improved by DJB or PGZ. Each value is expressed as mean ± standard error of the mean (n=6). *P<0.05. (C) DJB increased LC3 expression (lane 1: NC group; lanes 2 and 3: DJB group; lane 4: HF group). The presenting grouping blots [LC3 or β-actin] were cropped from the same field of the same gel. (D) Quantitative evaluation of LC3 expression by fold change. *P<0.05.

Abbreviations: DJB, duodenal–jejunal bypass; DJB group, MCD–HF diet for 3 months followed by DJB and MCD–HF diet for subsequent 3 months; HF, high fat; HF group, MCD–HF diet; MCD, methionine–choline-deficient; NC group, normal chow; PGZ group, MCD–HF diet for 3 months followed by treatment with PGZ with MCD–HF diet for subsequent 3 months; PGZ, pioglitazone.