Revision 2

#77397Store at -20C

1 Kit

(9 x 20 microliters)

Cell Signaling Technology

Orders: 877-616-CELL (2355) [email protected]

Support: 877-678-TECH (8324)

Web: [email protected]

3 Trask LaneDanversMassachusetts01923USA
For Research Use Only. Not for Use in Diagnostic Procedures.
Product Includes Product # Quantity Mol. Wt Isotype/Source
α-Smooth Muscle Actin (D4K9N) XP® Rabbit mAb 19245 20 µl 42 kDa Rabbit IgG
COL1A1 (E8I9Z) Rabbit mAb 91144 20 µl 220 kDa Rabbit IgG
SMAD2/3 (D7G7) XP® Rabbit mAb 8685 20 µl 52, 60 kDa Rabbit IgG
Smad2 (D43B4) XP® Rabbit mAb 5339 20 µl 60 kDa Rabbit IgG
Phospho-SMAD2 (Ser465/Ser467) (E8F3R) Rabbit mAb 18338 20 µl 60 kDa Rabbit IgG
YKL-40 (E2L1M) Rabbit mAb 47066 20 µl 30-40 kDa Rabbit IgG
Phospho-SMAD2 (Ser465/467)/SMAD3 (Ser423/425) (D27F4) Rabbit mAb 8828 20 µl 52, 60 kDa Rabbit IgG
TGF-β (56E4) Rabbit mAb 3709 20 µl 12, 45-60 kDa Rabbit IgG
TGF-β Receptor II (E5M6F) Rabbit mAb 41896 20 µl 85 kDa Rabbit IgG
Anti-rabbit IgG, HRP-linked Antibody 7074 100 µl Goat 

Please visit for individual component applications, species cross-reactivity, dilutions, protocols, and additional product information.


The TGF-β Fibrosis Pathway Antibody Sampler Kit provides an economical means of investigating activation of TGF-β/ SMAD2/3 signaling pathways in cells or tissues that lead to the expression of profibrotic genes, including expression of α-Smooth Muscle Actin in activated fibroblasts, and upregulation of Collagen1A1, Col11A1, and YKL-40. The kit includes enough antibodies to perform at least two western blot experiments with each primary antibody.


Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02% sodium azide. Store at –20°C. Do not aliquot the antibody.


Transforming growth factor-β (TGF-β) superfamily members are critical regulators of cell proliferation and differentiation, developmental patterning and morphogenesis, and disease pathogenesis (1-4). In the context of fibrosis, TGF-β signaling to SMAD2/3 is one of the biggest drivers of the profibrotic program (5).

TGF-β elicits signaling through three cell surface receptors: type I (RI), type II (RII), and type III (RIII). In response to ligand binding, the type II receptors form stable heterotrimeric complexes with the type I receptors, allowing phosphorylation and activation of type I receptor kinase. Activated type I receptors associate with SMAD2/3 and phosphorylate them on a conserved carboxy terminal SSXS motif. The phosphorylated SMADs dissociate from the receptor and form a heterotrimeric complex with the co-Smad (Smad4), allowing translocation of the complex to the nucleus. Once in the nucleus, phosphorylated SMAD2/3 targets a subset of DNA binding proteins to regulate the transcriptional program (6-8).

In the context of fibrosis, SMAD2/3 activation upregulates expression of profibrotic genes such as COL1A1 and other ECM modulators that modify the extracellular matrix of the tissue. (9). TGF-β/ SMAD2/3 signaling also induces expression of α-Smooth Muscle Actin in fibroblasts, causing transformation of these cells to myofibroblasts (10). Myofibroblasts further modify the ECM, causing excessive accumulation of collagens and other ECM components. Injury to the tissue attracts macrophages and other immune cells and the fibrotic tissue soon becomes a site of inflammation (11). In this pro-fibrotic, pro-inflammatory environment, YKL-40, also known as Chitinase-3-like protein 1 (CHI3L1), is secreted. YKL-40 is a pro-inflammatory glycoprotein that also contributes to the progression of fibrosis (12). Measurement of collagen content, α-Smooth Muscle Actin, and the release of YKL-40 are predictive of fibrotic activity.

  1. Massagué, J. et al. (2000) Cell 103, 295-309.
  2. de Caestecker, M.P. et al. (2000) J Natl Cancer Inst 92, 1388-402.
  3. Derynck, R. et al. (2001) Nat Genet 29, 117-29.
  4. Miyazono, K. et al. (2000) Adv Immunol 75, 115-57.
  5. Meng, X.M. et al. (2016) Nat Rev Nephrol 12, 325-38.
  6. Wu, G. et al. (2000) Science 287, 92-7.
  7. Attisano, L. and Wrana, J.L. (2002) Science 296, 1646-7.
  8. Moustakas, A. et al. (2001) J Cell Sci 114, 4359-69.
  9. Bagalad, B.S. et al. J Oral Maxillofac Pathol 21, 462-3.
  10. Mack, M. (2018) Matrix Biol 68-69, 106-21.
  11. Johansen, J.S. (2006) Dan Med Bull 53, 172-209.

Background References

    Trademarks and Patents

    Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.
    CST is a registered trademark of Cell Signaling Technology, Inc.
    XP is a registered trademark of Cell Signaling Technology, Inc.
    U.S. Patent No. 5,675,063.
    All other trademarks are the property of their respective owners. Visit for more information.

    Limited Uses

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    Products are labeled with For Research Use Only or a similar labeling statement and have not been approved, cleared, or licensed by the FDA or other regulatory foreign or domestic entity, for any purpose. Customer shall not use any Product for any diagnostic or therapeutic purpose, or otherwise in any manner that conflicts with its labeling statement. Products sold or licensed by CST are provided for Customer as the end-user and solely for research and development uses. Any use of Product for diagnostic, prophylactic or therapeutic purposes, or any purchase of Product for resale (alone or as a component) or other commercial purpose, requires a separate license from CST. Customer shall (a) not sell, license, loan, donate or otherwise transfer or make available any Product to any third party, whether alone or in combination with other materials, or use the Products to manufacture any commercial products, (b) not copy, modify, reverse engineer, decompile, disassemble or otherwise attempt to discover the underlying structure or technology of the Products, or use the Products for the purpose of developing any products or services that would compete with CST products or services, (c) not alter or remove from the Products any trademarks, trade names, logos, patent or copyright notices or markings, (d) use the Products solely in accordance with CST Product Terms of Sale and any applicable documentation, and (e) comply with any license, terms of service or similar agreement with respect to any third party products or services used by Customer in connection with the Products.