serum fgf21  (R&D Systems)

Journal: bioRxiv

Article Title: Inducible Impairment of Polymerase Gamma Activity in Cardiomyocytes Promotes Severe Cardiomyopathy with Cardiac Hepatopathy

doi: 10.64898/2026.02.17.706486

Figure Lengend Snippet: (A) Immunoblot of phosphorylated and total eIF2α in LV from PolG Mut and PolG Con mice at 30 weeks post-Tam (n=5/group), with (B) corresponding densitometry ratio of phosphorylated to total eIF2α. (C) Immunoblot of phosphorylated and total eIF2α was repeated in LV from PolG Mut and PolG Con mice at 20, 24 and 28 weeks post-Tam (n=4/group/timepoint) with (D) corresponding densitometry ratios. Expression of genes (qPCR) associated with (E) amino acid and 1-Carbon metabolism, and genes associated with folate metabolism within (F) the mitochondria and (G) the cytosol, in LV from PolG Mut and PolG Con mice at 30 weeks post-Tam, (n=9/group). Gene expression was repeated in LV from PolG Mut mice at 20 (n=5), 24 (n=5), and 28 weeks post-Tam (n=6) relative to PolG Con mice at 20 weeks post-Tam (n=5) for (H) amino acid and 1-Carbon metabolism, and genes associated with folate metabolism within (I) the mitochondria and (J) the cytosol. (K) Fgf21 and (L) Gdf15 gene expression (qPCR) in LV from PolG Mut mice at 20 (n=5), 24 (n=5) and 28 (n=6) weeks post-Tam and PolG Con mice at 20 (n=5), 24 (n=5) and 28 (n=5) weeks post-Tam (relative to PolG Con mice at 20 weeks post-Tam). Plasma protein concentration of (M) FGF21 and (N) GDF15 in PolG Mut and PolG Con mice at 3, 9, 13, 17, 20, 24, and 30 weeks post-Tam (FGF21: 3, 9, 13, 17 weeks n=4, 20, 24 weeks n=8, 30 weeks n=7; GDF15: 3, 9, 13, 17, 20, 24 weeks n=8, 30 weeks n=7). Data are presented as mean ± SEM, with P-value between control and mutant biological replicates determined by two-way ANOVA with correction for multiple comparisons (H-J: P-value compared with PolG Con mice at 20 weeks post-Tam) , unpaired welch t-test (D, E, G, K, L) or Mann-Whitney test (B, F, M, N) . Source data for these figures are provided in the Source Data file.

Article Snippet: Commercial ELISA kits for FGF21 (R&D Systems, #MF2100) and GDF15 (R&D Systems, #MGD150) were used to measure respective plasma concentration as per manufacturer’s instructions.

Techniques: Western Blot, Expressing, Gene Expression, Clinical Proteomics, Protein Concentration, Control, Mutagenesis, MANN-WHITNEY

Journal: The Journal of Biological Chemistry

Article Title: Rab2A modulates liver fibroblast growth factor 21 (FGF21) expression and systemic metabolism via apolipoprotein B–CREBH signaling

doi: 10.1016/j.jbc.2025.110977

Figure Lengend Snippet: Liver-specific inhibition of Rab2A increases FGF21 expression and secretion . A , serum FGF21 levels in shNC and shRab2A mice (male, n = 5 per group; samples from PMID: 35061665 ). B , serum FGF21 levels in Flox and LCK mice under “Random feed” and “Fasted” conditions (male, n = 5 per group). C , serum FGF21 levels in Flox and LCK mice after 12 weeks of HFHCD feeding (male, n = 6 versus 5). D , hepatic Fgf21 mRNA levels in “Random feed” Flox and LCK mice at 10 weeks of age (male, n = 5 per group). E , hepatic Fgf21 mRNA levels in “Fasted” Flox and LCK mice at 16 weeks of age (male, n = 5 per group). F , hepatic Fgf21 mRNA levels in Flox and LCK mice after 12 weeks of HFHCD feeding (male, n = 6 versus 5). G , representative immunoblots of hepatic FGF21 protein in “Fasted” Flox and LCK mice at 16 weeks of age. H , quantification of the immunoblots in ( G ). I , representative immunoblots of hepatic FGF21 protein in Flox and LCK mice after 12 weeks of HFHCD feeding. J , quantification of the immunoblots in ( I ). Data are presented as mean ± SD. p Values were determined using the unpaired two-tailed Student’s t test. FGF21, fibroblast growth factor 21; HFHCD, high-fat–high-cholesterol diet; LCK, liver-specific Rab2A knockout.

Article Snippet: The following primary and secondary antibodies were used: goat anti FGF21 (R&D Systems; AF3057), mouse anti-Rab2A (Proteintech; 67501-1-Ig), mouse anti-tubulin (DUONENG-BIO; AB0178801), mouse anti-actin (Zen-Bioscience; 200068-8F10), rabbit anti-CREBH (Kerafast; EWS101), rabbit anti-GAPDH (Proteintech; 10494-1-AP), rabbit anti-APOB (Proteintech; 20578-1-AP), mouse anti-CHC (Santa Cruz; sc-12734), rabbit anti-GRP94 (Proteintech; 14700-1-AP), mouse anti-GRASP55 (Santa Cruz; sc-271840), HRP-conjugated goat anti-mouse IgG (Jackson ImmunoResearch; 115-035-003), HRP-conjugated goat anti-rabbit IgG (Jackson ImmunoResearch; 111-035-003), and HRP-conjugated rabbit anti-goat IgG (Jackson ImmunoResearch; 305-035-003).

Techniques: Inhibition, Expressing, Western Blot, Two Tailed Test, Knock-Out

Journal: The Journal of Biological Chemistry

Article Title: Rab2A modulates liver fibroblast growth factor 21 (FGF21) expression and systemic metabolism via apolipoprotein B–CREBH signaling

doi: 10.1016/j.jbc.2025.110977

Figure Lengend Snippet: CREBH knockdown rescues FGF21 expression and the metabolic phenotypes of LCK mice . A , schematic of the experimental timeline for adeno-associated virus (AAV) injection in Flox and LCK mice. B and C , representative immunoblots and quantification of hepatic CREBH protein levels after AAV-mediated knockdown. D – M , analyses performed after 7 weeks of AAV injection and subsequent euthanasia (male, n = 6 versus 6 versus 6): Hepatic mRNA levels of Creb3l3 , Fgf21 , Apoa4 , and Fsp27β ( D ). Representative immunoblots and quantification of hepatic FGF21 protein levels ( E and F ). Serum FGF21 levels ( G ). mRNA expression of thermogenic-related genes in epWAT ( H ) and scWAT ( I ). Representative H&E-stained sections of epWAT ( J ) and quantitative results ( K ). The weights of adipose tissues and the whole body ( L and M ). Data are presented as mean ± SD. p Values were determined using the unpaired two-tailed Student’s t test. ns indicates no significant difference ( p > 0.05). CREBH, cAMP-responsive element–binding protein H; epWAT, epididymal white adipose tissue; FGF21, fibroblast growth factor 21; LCK, liver-specific Rab2A knockout; scWAT, subcutaneous white adipose tissue.

Article Snippet: The following primary and secondary antibodies were used: goat anti FGF21 (R&D Systems; AF3057), mouse anti-Rab2A (Proteintech; 67501-1-Ig), mouse anti-tubulin (DUONENG-BIO; AB0178801), mouse anti-actin (Zen-Bioscience; 200068-8F10), rabbit anti-CREBH (Kerafast; EWS101), rabbit anti-GAPDH (Proteintech; 10494-1-AP), rabbit anti-APOB (Proteintech; 20578-1-AP), mouse anti-CHC (Santa Cruz; sc-12734), rabbit anti-GRP94 (Proteintech; 14700-1-AP), mouse anti-GRASP55 (Santa Cruz; sc-271840), HRP-conjugated goat anti-mouse IgG (Jackson ImmunoResearch; 115-035-003), HRP-conjugated goat anti-rabbit IgG (Jackson ImmunoResearch; 111-035-003), and HRP-conjugated rabbit anti-goat IgG (Jackson ImmunoResearch; 305-035-003).

Techniques: Knockdown, Expressing, Virus, Injection, Western Blot, Staining, Two Tailed Test, Binding Assay, Knock-Out

Journal: The Journal of Biological Chemistry

Article Title: Rab2A modulates liver fibroblast growth factor 21 (FGF21) expression and systemic metabolism via apolipoprotein B–CREBH signaling

doi: 10.1016/j.jbc.2025.110977

Figure Lengend Snippet: APOB knockdown rescues CREBH activation, FGF21 expression, and the metabolic phenotypes of LCK mice . A , schematic of the experimental timeline for adeno-associated virus (AAV) injection in Flox and LCK mice. B , representative immunoblots of hepatic APOB protein levels after AAV-mediated knockdown. C and D , representative immunoblots and quantification of hepatic CREBH cleavage levels after APOB knockdown. E – M , analyses performed after 8 weeks of AAV injection and subsequent euthanasia (male, n = 5 versus 5 versus 5): hepatic mRNA levels of Creb3l3 , Fgf21 , Apoa4 , Fsp27β , and Apoc2 ( E ). Representative immunoblots and quantification of hepatic FGF21 protein levels ( F and G ). Serum FGF21 levels ( H ). mRNA expression of thermogenic-related genes in scWAT ( I ). Representative H&E-stained sections of epWAT ( J ) and quantitative results ( K ). The weights of adipose tissues and the whole body ( L and M ). Data are presented as mean ± SD. p Values were determined using the unpaired two-tailed Student’s t test. ns indicates no significant difference ( p > 0.05). AAV, adeno-associated virus; APOB, apolipoprotein B; CREBH, cAMP-responsive element–binding protein H; epWAT, epididymal white adipose tissue; FGF21, fibroblast growth factor 21; LCK, liver-specific Rab2A knockout; scWAT, subcutaneous white adipose tissue.

Article Snippet: The following primary and secondary antibodies were used: goat anti FGF21 (R&D Systems; AF3057), mouse anti-Rab2A (Proteintech; 67501-1-Ig), mouse anti-tubulin (DUONENG-BIO; AB0178801), mouse anti-actin (Zen-Bioscience; 200068-8F10), rabbit anti-CREBH (Kerafast; EWS101), rabbit anti-GAPDH (Proteintech; 10494-1-AP), rabbit anti-APOB (Proteintech; 20578-1-AP), mouse anti-CHC (Santa Cruz; sc-12734), rabbit anti-GRP94 (Proteintech; 14700-1-AP), mouse anti-GRASP55 (Santa Cruz; sc-271840), HRP-conjugated goat anti-mouse IgG (Jackson ImmunoResearch; 115-035-003), HRP-conjugated goat anti-rabbit IgG (Jackson ImmunoResearch; 111-035-003), and HRP-conjugated rabbit anti-goat IgG (Jackson ImmunoResearch; 305-035-003).

Techniques: Knockdown, Activation Assay, Expressing, Virus, Injection, Western Blot, Staining, Two Tailed Test, Binding Assay, Knock-Out

Journal: The Journal of Biological Chemistry

Article Title: Rab2A modulates liver fibroblast growth factor 21 (FGF21) expression and systemic metabolism via apolipoprotein B–CREBH signaling

doi: 10.1016/j.jbc.2025.110977

Figure Lengend Snippet: Starvation-induced APOB trafficking defects activate the CREBH–FGF21 axis . Wildtype C57BL/6J mice were fasted for 16 h or not prior to analysis. A , hepatic triglyceride (TG) levels (n = 6 per group). B , VLDL–TG secretion rates (n = 5 per group). C , representative immunoblots of total hepatic APOB. D , quantification of APOB protein levels from ( C ). E , representative immunoblots of APOB distribution in the endoplasmic reticulum (ER) and Golgi apparatus fractions. F , quantification of APOB levels in subcellular fractions from ( E ). G , representative immunoblots of CREBH cleavage. H , quantification of cleaved CREBH from ( G ). I , hepatic mRNA levels of Fgf21 , Fsp27β , and Apoa4 (n = 4 per group). J , representative immunoblots of hepatic FGF21 proteins. K , quantification of FGF21 protein levels from ( J ). L , serum FGF21 levels (n = 5 per group). Data are presented as mean ± SD. p Values were determined using the unpaired two-tailed Student’s t test. APOB, apolipoprotein B; CREBH, cAMP-responsive element–binding protein H; FGF21, fibroblast growth factor 21; TG, triglyceride; VLDL, very low–density lipoprotein.

Article Snippet: The following primary and secondary antibodies were used: goat anti FGF21 (R&D Systems; AF3057), mouse anti-Rab2A (Proteintech; 67501-1-Ig), mouse anti-tubulin (DUONENG-BIO; AB0178801), mouse anti-actin (Zen-Bioscience; 200068-8F10), rabbit anti-CREBH (Kerafast; EWS101), rabbit anti-GAPDH (Proteintech; 10494-1-AP), rabbit anti-APOB (Proteintech; 20578-1-AP), mouse anti-CHC (Santa Cruz; sc-12734), rabbit anti-GRP94 (Proteintech; 14700-1-AP), mouse anti-GRASP55 (Santa Cruz; sc-271840), HRP-conjugated goat anti-mouse IgG (Jackson ImmunoResearch; 115-035-003), HRP-conjugated goat anti-rabbit IgG (Jackson ImmunoResearch; 111-035-003), and HRP-conjugated rabbit anti-goat IgG (Jackson ImmunoResearch; 305-035-003).

Techniques: Western Blot, Two Tailed Test, Binding Assay

Journal: The Journal of Biological Chemistry

Article Title: Rab2A modulates liver fibroblast growth factor 21 (FGF21) expression and systemic metabolism via apolipoprotein B–CREBH signaling

doi: 10.1016/j.jbc.2025.110977

Figure Lengend Snippet: Summary of results and work model . A graphical abstract was created to summarize the key findings of this study, outlining a multistep regulatory pathway. VLDL assembly and maturation (steps 1–3): newly assembled VLDL 2 particles are transported from the ER to the Golgi via COPII vesicles. At the Golgi, the Rab2A–HSD17B13 complex mediates lipid droplet–Golgi contacts, facilitating lipid transfer to support VLDL 1 maturation. CREBH activation and signaling (steps 4–6): full-length CREBH resides in the ER and is transported to the Golgi under specific conditions, where its proteolytic cleavage—partially dependent on APOB availability—generates the active N-terminal fragment. This fragment translocates to the nucleus and drives transcription of Fsp27β , Fgf21 , and Apoa4 . Systemic metabolic regulation (steps 7–9): secreted FGF21 promotes adipose tissue lipolysis; ApoA-IV enhances VLDL lipidation and expansion in the Golgi; and lipid droplet–localized FSP27β facilitates hepatic lipid storage. Pathophysiological perturbations: in Rab2A-deficient hepatocytes, disrupted lipid droplet–Golgi contacts reduce lipid flux to the Golgi, impairing VLDL maturation. This leads to APOB accumulation in the Golgi, which promotes CREBH cleavage and elevates FGF21 expression. During fasting, AMPK-mediated suppression of Rab2A activity, combined with partial inhibition of APOB ER-to-Golgi transport, further reduces VLDL secretion. These changes are sensed by CREBH, enhancing its activation and driving a transcriptional program that adaptively regulates systemic lipid homeostasis. Graphical abstract created with BioRender (Chen, 2025; https://BioRender.com/7gyj0x2 ). AMPK, AMP-activated protein kinase; APOB, apolipoprotein B; COPII, coat protein complex II; CREBH, cAMP-responsive element–binding protein H; ER, endoplasmic reticulum; VLDL, very low–density lipoprotein.

Article Snippet: The following primary and secondary antibodies were used: goat anti FGF21 (R&D Systems; AF3057), mouse anti-Rab2A (Proteintech; 67501-1-Ig), mouse anti-tubulin (DUONENG-BIO; AB0178801), mouse anti-actin (Zen-Bioscience; 200068-8F10), rabbit anti-CREBH (Kerafast; EWS101), rabbit anti-GAPDH (Proteintech; 10494-1-AP), rabbit anti-APOB (Proteintech; 20578-1-AP), mouse anti-CHC (Santa Cruz; sc-12734), rabbit anti-GRP94 (Proteintech; 14700-1-AP), mouse anti-GRASP55 (Santa Cruz; sc-271840), HRP-conjugated goat anti-mouse IgG (Jackson ImmunoResearch; 115-035-003), HRP-conjugated goat anti-rabbit IgG (Jackson ImmunoResearch; 111-035-003), and HRP-conjugated rabbit anti-goat IgG (Jackson ImmunoResearch; 305-035-003).

Techniques: Activation Assay, Expressing, Activity Assay, Inhibition, Binding Assay