Uses of knockout, knockdown, and transgenic models in the studies of glucose transporter 4

Table 4 Recombinant DNA techniques to create tissue specific glucose transporter 4 overexpression in animals and cells, analysis performed, and observations reported

Techniques	Tissue/analysis	Observations	Ref.
A 6.3-kb genomic DNA fragment of human SLC2A4 gene is under the control of a 5.4-kb’ DNA fragment of mouse ap2 promoter using Gateway cloning	Adipose-specific overexpression/ Western blot was used to detect GLUT4 in BAT and WAT	Transgenic mice have lower glucose level in the fasting, insulin level in the fed state, higher body weight and body fat at 18 to 21 wk of age, and higher basal and insulin-stimulated glucose transport rates in epididymal, parametrial, and subcutaneous adipocytes than the controls	[50]
Same as in[50]	Adipose-specific overexpression/Only cited previous publications[50]	Transgenic mice have higher body weight, parametrial fat pad weight and adipocyte size, and glucose transport in both fasting and fed states, and lower plasma insulin and glucose levels after a glucose challenge than the controls	[51]
Same as in[50]	Adipose-specific overexpression/Only cited previous publications[50]	Transgenic mice have higher glucose disposal rate in a glucose tolerance test, and palmitic acid-hydroxy stearic acid levels in serum, WAT and BAT than the controls	[52]
Same as in[50]	Adipose-specific overexpression/Western blot was used to detect GLUT4 in BAT and WAT	Transgenic mice fed a high-fat diet have higher glucose disposal rate than those fed a low-fat diet, and stable GLUT4 expression in fat and no increase in body fat	[53]
Same as in[50]	Adipose-specific overexpression/Western blot was used to detect GLUT4 in BAT and WAT	Transgenic mice have higher gonadal adipose weight, basal and maximum insulin stimulated glucose transport in isolated adipocytes, glucose transport rate, triglyceride synthesis and CO2 production than the controls	[54]
A 4.5-kb DNA fragment of the mouse Slc4a2 gene is under the control of a 3-kb fragment of the mouse myosin light chain gene promoter	Hindlimb muscle overexpression/Northern blot and Western blot were used to detect Slc4a2mRNA and GLUT4 in different tissues respectively	Transgenic mice have higher basal and insulin-stimulated glucose uptake and turnover, higher glycogen content in the skeleton muscle, higher insulin sensitivity, higher levels of free fatty acid and ketone in both fasting and fed state, and lower fasting glucose level than the controls	[55]
The human SLC2A4 cDNA is driven by the CMV promoter in pCIS2 vector	Rat adipocytes overexpression/Immunofluorescence was used to detect GLUT4 overexpression	Rat adipose cell transfected with the GLUT4 construct had significantly higher antibody binding after insulin stimulation than the control cells	[56]

BAT: Brown adipose tissue; CMV: Cytomegalovirus; GLUT4: Glucose transporter 4; Ref: References; WAT: White adipose tissue.