Summary

Krüppel‐like factor 4 (KLF4) is a multifunctional transcription factor whose activity is tightly regulated in a context‐dependent manner. In pluripotent and reprogramming settings, KLF4 is one of the core factors that, together with Oct4, Sox2, and c‐Myc, can induce somatic cells to acquire a pluripotent state.^1-5 In this context KLF4 not only contributes to the resetting of cell identity but also collaborates with other family members to maintain embryonic stem cell self‐renewal. Moreover, post‐transcriptional regulation by microRNAs – for instance, miR‐145 directly targeting KLF4 – forms part of a double‐negative feedback loop that modulates the balance between pluripotency and differentiation.

Outside of pluripotency, KLF4 exerts critical roles in adult tissues. In the vasculature, conditional knockout of Klf4 in smooth muscle cells leads to a reduction in mesenchymal stem cell– and macrophage–like cell phenotypes within atherosclerotic lesions, thereby impacting lesion size and plaque stability.⁶ In the innate immune system, KLF4 is induced in M2-polarized macrophages and cooperates with Stat6 to promote an antiinflammatory genetic program while repressing proinflammatory responses, underscoring its importance in regulating macrophage polarization.⁷

In the nervous system, KLF4 functions as a transcriptional repressor of axon growth. Its elevated expression in central nervous system neurons limits regenerative capacity, indicating that modulation of KLF4 activity may be a key determinant in neuronal repair after injury.⁸

Furthermore, in epithelial tissues of the gastrointestinal tract, in vivo studies demonstrate that KLF4 is essential for terminal differentiation, as exemplified by its role in driving goblet cell maturation in the colon.⁹ In cancer, KLF4 exhibits context-dependent functions. Depending on the cellular context, it can act either as a tumor suppressor or an oncogene. Its ability to modulate key cell-cycle regulators such as p53 and p21 underscores a dual function in governing cell proliferation and senescence. In this regard, dysregulation of KLF4 is linked to altered cancer stem cell properties when microRNA networks that target KLF4 (among other stem cell factors such as Sox2) become disrupted.¹⁰

Collectively, these studies reveal that KLF4 is a pivotal transcriptional regulator that integrates signals for cellular reprogramming, maintenance of self-renewal, and lineage-specific differentiation. Its activities in controlling proliferation, determining cell fate, and influencing tissue-specific responses underscore its broad impact on development, regeneration, and disease.

This summary was generated by summarizing the top 50 most cited paper abstracts that mention this gene using gpt4o-mini (DeepDive).