OBJECTIVE: In this study, we investigated the mechanism of action of LIMK1 in cervical cancer progression.
METHODS: The biological role of LIMK1 in regulating the growth, invasion, and metastasis of cervical cancer was studied in SiHa, CaSki cells and nude mice tumor models. The role of LIMK1 in the growth of cervical cancer was evaluated by HE staining. The role of LIMK1 in the invasion, metastasis, and proliferation of cervical cancer was evaluated by cell scratch, Transwell, and monoclonal experiments. The interaction among LIMK1, ROS, and Src was evaluated by Western blotting. The effects of regulating ROS and p-Src expression on LIMK1 in the migration/invasion and proliferation of cervical cancer cells were evaluated through cellular functional assays.
RESULTS: Overexpression of LIMK1 promoted tumor growth in nude mice. Cell scratch, Transwell, and monoclonal experiments suggested that LIMK1 promoted the invasion, metastasis, and proliferation of cervical cancer cells. Western blotting suggested that LIMK1 can promote the expression of ROS-related proteins NOX2, NOX4, p-Src, and downstream proteins p-FAK, p-ROCK1/2, p-Cofilin-1, F-actin and inhibit the expression of p-SHP2 protein. Correction experiments showed that LIMK1 regulated the expression of p-FAK and p-Cofilin-1 proteins by regulating ROS and p-Src. Through the detection of cervical cancer cell functions, it was found that the activation of ROS and p-Src induced by LIMK1 is an early event that promotes the migration, proliferation, and invasion of cervical cancer cells.
CONCLUSIONS: LIMK1 promotes the expression of F-actin and promotes the development of cervical cancer by regulating the oxidative stress/Src-mediated p-FAK/p-ROCK1/2/p-Cofilin-1 pathway.

Rabies virus (RABV) is highly lethal and triggers severe neurological symptoms. The neuropathogenic mechanism remains poorly understood. Ras-related C3 botulinum toxin substrate 1 (Rac1) is a Rho-GTPase that is involved in actin remodeling and has been reported to be closely associated with neuronal dysfunction. In this study, by means of a combination of pharmacological inhibitors, small interfering RNA, and specific dominant-negatives, we characterize the crucial roles of dynamic actin and the regulatory function of Rac1 in RABV infection, dominantly in the viral entry phase. The data show that the RABV phosphoprotein interacts with Rac1. RABV phosphoprotein suppress Rac1 activity and impedes downstream Pak1-Limk1-Cofilin1 signaling, leading to the disruption of F-actin-based structure formation. In early viral infection, the EGFR-Rac1-signaling pathway undergoes a biphasic change, which is first upregulated and subsequently downregulated, corresponding to the RABV entry-induced remodeling pattern of F-actin. Taken together, our findings demonstrate for the first time the role played by the Rac1 signaling pathway in RABV infection and may provide a clue for an explanation for the etiology of rabies neurological pathogenesis.IMPORTANCEThough neuronal dysfunction is predominant in fatal rabies, the detailed mechanism by which rabies virus (RABV) infection causes neurological symptoms remains in question. The actin cytoskeleton is involved in numerous viruses infection and plays a crucial role in maintaining neurological function. The cytoskeletal disruption is closely associated with abnormal nervous symptoms and induces neurogenic diseases. In this study, we show that RABV infection led to the rearrangement of the cytoskeleton as well as the biphasic kinetics of the Rac1 signal transduction. These results help elucidate the mechanism that causes the aberrant neuronal processes by RABV infection and may shed light on therapeutic development aimed at ameliorating neurological disorders.

Peroxiredoxin 1 (PRDX1) is an important member of the peroxiredoxin family (PRDX) and is upregulated in a variety of tumors. Previous studies have found that high PRDX1 expression is closely related to the metastasis of oral squamous cell carcinoma (OSCC), but the specific molecular mechanism is elusive. To elucidate the role of PRDX1 in the metastasis process of OSCC, we evaluated the expression of PRDX1 in OSCC clinical specimens and its impact on the prognosis of OSCC patients. Then, the effect of PRDX1 on OSCC metastasis and cytoskeletal reconstruction was explored in vitro and in nude mouse tongue cancer models, and the molecular mechanisms were also investigated. PRDX1 can directly interact with the actin-binding protein Cofilin, inhibiting the phosphorylation of its Ser3 site, accelerating the depolymerization and turnover of actin, promoting OSCC cell movement, and aggravating the invasion and metastasis of OSCC. In clinical samples and mouse tongue cancer models, PRDX1 also increased lymph node metastasis of OSCC and was negatively correlated with the phosphorylation of Cofilin; PRDX1 also reduced the overall survival rate of OSCC patients. In summary, our study identified that PRDX1 may be a potential therapeutic target to inhibit OSCC metastasis.

Serum response factor (SRF) is important in muscle development, tissue repair, and neuronal regulation.
This research aims to thoroughly examine the effects of SRF on spinal cord injury (SCI) and its ability to significantly impact the recovery and regeneration of neuronal axons.
The researchers created rat models of SCI and scratch injury to primary spinal cord neurons to observe the expression of relevant factors after neuronal injury.
We found that the SRF, Ras, Raf, and cofilin levels increased after injury and gradually returned to normal levels. Afterward, researchers gave rats with SCI an SRF inhibitor (CCG1423) and studied the effects with nuclear magnetic resonance and transmission electron microscopy. The SRF inhibitor rodents had worse spinal cord recovery and axon regrowth than the control group. And the apoptosis of primary neurons after scratch injury was significantly higher in the SRF inhibitor group. Additionally, the researchers utilized lentiviral transfection to modify the SRF expression in neurons. SRF overexpression increased neuron migration while silencing SRF decreased it. Finally, Western blotting and RT-PCR were conducted to examine the expression changes of related factors upon altering SRF expression. The results revealed SRF overexpression increased Ras, Raf, and cofilin expression. Silencing SRF decreased Ras, Raf, and Cofilin expression.
Based on our research, the SRF promotes axonal regeneration by activating the \"Ras-Raf-Cofilin\" signaling pathway.

TNF acts as one pathogenic driver for inducing intestinal epithelial cell (IEC) death and substantial intestinal inflammation. How the IEC death is regulated to physiologically prevent intestinal inflammation needs further investigation. Here, we report that EF-hand domain-containing protein D2 (EFHD2), highly expressed in normal intestine tissues but decreased in intestinal biopsy samples of ulcerative colitis patients, protects intestinal epithelium from TNF-induced IEC apoptosis. EFHD2 inhibits TNF-induced apoptosis in primary IECs and intestinal organoids (enteroids). Mice deficient of Efhd2 in IECs exhibit excessive IEC death and exacerbated experimental colitis. Mechanistically, EFHD2 interacts with Cofilin and suppresses Cofilin phosphorylation, thus blocking TNF receptor I (TNFR1) internalization to inhibit IEC apoptosis and consequently protecting intestine from inflammation. Our findings deepen the understanding of EFHD2 as the key regulator of membrane receptor trafficking, providing insight into death receptor signals and autoinflammatory diseases.

Glioma is one of the most aggressive malignant brain tumors and is characterized by invasive growth and poor prognosis. TBC1D1, a member of the TBC family, is associated with the development of various malignancies. However, the role of TBC1D1 in glioma-genesis remains unclear.
The effect of TBC1D1 on the prognosis of glioma patients and related influencing factors were analyzed in the Chinese Glioma Genome Atlas (CGGA) and The Cancer Genome Atlas (TCGA) databases. Expression of TBC1D1 in glioma cell lines was detected by western blotting. Cell viability and proliferation were measured by EdU and Colony formation assays, respectively. Transwell and wound healing assays were performed to determine the cell migration and invasion capacities. Immunofluorescence was used to observe actin morphology in the cytoskeleton.
We discovered that high TBC1D1 expression in gliomas led to poor prognosis. Downregulation of TBC1D1 in glioma cells significantly inhibited multiple important functions, such as proliferation, migration, and invasion. We further demonstrated that the tumor-inhibitory effect of TBC1D1 might occur through the P-LIMK/cofilin pathway, destroying the cytoskeletal structure and affecting the depolymerization of F-actin, thereby inhibiting glioma migration.
TBC1D1 affects the balance and integrity of the actin cytoskeleton via cofilin, thereby altering the morphology and aggressiveness of glioma cells. This study provides a new perspective on its role in tumorigenesis, thereby identifying a potential therapeutic target for the treatment of gliomas.

A root hair is a polarly elongated single-celled structure that derives from a root epidermal cell and functions in uptake of water and nutrients from the surrounding environment. Previous reports have demonstrated that short periods of high pH inhibit root hair extension; but the effects of long-term high-pH treatment on root hair growth are still unclear. Here, we report that the duration of root hair elongation is significantly prolonged with increasing external pH, which counteracts the effect of decreasing root hair elongation rate and ultimately produces longer root hairs, whereas loss of actin-depolymerizing factor 8 and 11 (ADF8/11) function causes shortening of root hair length at high pH (pH 7.4). Accumulation of ADF8/11 at the tips of root hairs is inhibited by high pH, and increasing environmental pH affects the actin filament (F-actin) meshwork at the root hair tip. At high pH, the tip-focused F-actin meshwork is absent in root hairs of the adf8/11 mutant, actin filaments are disordered at the adf8/11 root hair tips, and actin turnover is attenuated. Secretory and recycling vesicles do not aggregate in the apical region of adf8/11 root hairs at high pH. Together, our results suggest that, under long-term exposure to high extracellular pH, ADF8/11 may establish and maintain the tip-focused F-actin meshwork to regulate polar trafficking of secretory/recycling vesicles at the root hair tips, thereby promoting root hair elongation.

Double fertilization in many flowering plants (angiosperms) often occurs during the hot summer season, but the mechanisms that enable angiosperms to adapt specifically to high temperatures are largely unknown. The actin cytoskeleton is essential for pollen germination and the polarized growth of pollen tubes, yet how this process responds to high temperatures remains unclear. Here, we reveal that the high thermal stability of 11 Arabidopsis (Arabidopsis thaliana) actin-depolymerizing factors (ADFs) is significantly different: ADFs that specifically accumulate in tip-growing cells (pollen and root hairs) exhibit high thermal stability. Through ancestral protein reconstruction, we found that subclass II ADFs (expressed specifically in pollen) have undergone a dynamic wave-like evolution of the retention, loss, and regeneration of thermostable sites. Additionally, the sites of AtADF7 with high thermal stability are conserved in ADFs specific to angiosperm pollen. Moreover, the high thermal stability of ADFs is required to regulate actin dynamics and turnover at high temperatures to promote pollen germination. Collectively, these findings suggest strategies for the adaptation of sexual reproduction to high temperature in angiosperms at the cell biology level.

Neuroligins are transmembrane cell adhesion proteins well-known for their genetic links to autism spectrum disorders. Neuroligins can function by regulating the actin cytoskeleton, however the factors and mechanisms involved are still largely unknown. Here, using the Drosophila neuromuscular junction as a model, we reveal that F-Actin assembly at the Drosophila NMJ is controlled through Cofilin signaling mediated by an interaction between DNlg2 and RACK1, factors not previously known to work together. The deletion of DNlg2 displays disrupted RACK1-Cofilin signaling pathway with diminished actin cytoskeleton proteo-stasis at the terminal of the NMJ, aberrant NMJ structure, reduced synaptic transmission, and abnormal locomotion at the third-instar larval stage. Overexpression of wildtype and activated Cofilin in muscles are sufficient to rescue the morphological and physiological defects in dnlg2 mutants, while inactivated Cofilin is not. Since the DNlg2 paralog DNlg1 is known to regulate F-actin assembly mainly via a specific interaction with WAVE complex, our present work suggests that the orchestration of F-actin by Neuroligins is a diverse and complex process critical for neural connectivity.

Diabetic cognitive impairment is a central nervous complication of diabetes mellitus. Its specific pathogenesis is unknown, and no effective treatment strategy is currently available. An imbalance in actin dynamics is an important mechanism underlying cognitive impairment. Transient receptor potential channel 7 (TRPM7) mediates actin dynamics imbalance through calcineurin (CaN) and cofilin cascades involved in various neurodegenerative diseases. We previously demonstrated that TRPM7 expression is increased in diabetic cognitive impairment, and troxerutin has been shown to ameliorate diabetic cognitive impairment. However, the relationship between troxerutin and TRPM7 remains unclear. In this study, we hypothesize that troxerutin may improve diabetic cognitive impairment by enhancing actin dynamics through downregulation of the TRPM7/CaN/cofilin pathway. To test this hypothesis, we divided db/m and db/db mice into the following groups: normal control group (NC), normal + troxerutin group (NT), diabetic group (DM), diabetic + troxerutin group (DT) and diabetic + troxerutin + bradykinin group (DTB). The results showed that diabetic mice exhibited cognitive impairment at 17 weeks of age, TRPM7, CaN, cofilin and G-actin were highly expressed in the CA1 region of hippocampus, while p-cofilin and F-actin expression decreased. Furthermore, hippocampal neuronal cellsshowed varying degrees of damage. The length of synaptic active zone, the width of synaptic cleft, and the number of synapses per high-power field were decreased. Troxerutin intervention alleviated these manifestations in the DT group; however, the effect of troxerutin was weakened in the DTB group. In conclusion, our findings suggest that diabetes leads to cognitive impairment, activation of the TRPM7/CaN/cofilin pathway, actin dynamics imbalance, and destruction of hippocampal neuronal cells and synapses. Troxerutin can downregulate TRPM7/CaN/cofilin, improve actin dynamics imbalance, and ameliorate cognitive impairment in diabetic mice. This study provides a new avenue for exploring and treating cognitive impairment in diabetes.