Mammalian oocyte maturation is a unique asymmetric division, which is mainly due to actin-based spindle migration to the cortex. In present study, we reported that a kinesin motor KIFC1, which was associated with microtubules for the maintenance of spindle poles in mitosis, was also involved into actin dynamics in oocyte meiosis. KIFC1 co-localized with microtubules during mouse oocyte maturation. Depletion of KIFC1 caused the failure of polar body extrusion, and we found that meiotic spindle formation and chromosome alignment were disrupted. This might be due to the effects of KIFC1 on HDAC6 and NAT10-based tubulin acetylation, which further affected microtubule stability. Mass spectroscopy analysis revealed that KIFC1 also associated with several actin nucleation factors and we found that KIFC1 was essential for the distribution of actin filaments, which further affected spindle migration. Depletion of KIFC1 leaded to aberrant expression of Formin2 and ARP2/3 complex, and ER distribution was also disturbed. Exogenous KIFC1 mRNA supplement could rescue these defects. Taken together, besides its roles on tubulin acetylation, our study also reported a novel role of kinesin KIFC1 on the regulation of actin dynamics for spindle migration in mouse oocytes.

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Objectives RAB14 is a member of small GTPase RAB family which localizes at the endoplasmic reticulum (ER), Golgi apparatus and endosomal compartments. RAB14 acts as molecular switches that shift between a GDP‐bound inactive state and a GTP‐bound active state and regulates circulation of vesicles between the Golgi and endosomal compartments. In present study, we investigated the roles of RAB14 during oocyte meiotic maturation. Materials and methods Microinjection with siRNA and exogenous mRNA for knock down and rescue, and immunofluorescence staining, Western blot and real‐time RT‐PCR were utilized for the study. Results Our results showed that RAB14 localized in the cytoplasm and accumulated at the cortex during mouse oocyte maturation, and it was also enriched at the spindle periphery. Depletion of RAB14 did not affect polar body extrusion but caused large polar bodies, indicating the failure of asymmetric division. We found that absence of RAB14 did not affect spindle organization but caused the spindle migration defects, and this might be due to the regulation on cytoplasmic actin assembly via the ROCK‐cofilin signalling pathway. We also found that RAB14 depletion led to aberrant Golgi apparatus distribution. Exogenous Myc‐Rab14 mRNA supplement could significantly rescue these defects caused by Rab14 siRNA injection. Conclusions Taken together, our results suggest that RAB14 affects ROCK‐cofilin pathway for actin‐based spindle migration and Golgi apparatus distribution during mouse oocyte meiotic maturation.

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BackgroundColorectal cancer (CRC) is the most common malignant cancer worldwide. Sanguisorba officinalis has been shown to have anti-inflammatory, anti-bacterial, antioxidant, and anti-tumor effects, while its molecular mechanism against CRC remains unclear. The aim of this study is to explore the underlying mechanism of S. officinalis against CRC cell lines using network pharmacology and transcriptomic sequencing methods.MethodFirstly, the active ingredients and potential targets of S. officinalis against CRC were screened from databases. Secondly, the networks of ingredient–target, ingredient–target–CRC and protein–protein interaction were constructed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of network pharmacology and transcriptomic sequencing were performed. Finally, the effect of S. officinalis against CRC was verified by in vitro experiments.ResultsIn total, 14 active ingredients and 273 potential targets against CRC were identified in S. officinalis by network pharmacology. PI3K–Akt, HIF-1, and MAPK signaling pathways related to cell proliferation were regulated by S. officinalis in enrichment analyses and transcriptomic sequencing. In vitro, S. officinalis inhibited the proliferation and migration of CRC cells and arrested the cell cycle at the G0–G1 phase. The western blot showed that S. officinalis downregulated the expression of p-PI3K, p-Akt, HIF-1A, VEGFA, cyclin D1, c-Myc, and p-MAPK proteins in CRC cells.ConclusionIn conclusion, network pharmacology and transcriptomic sequencing analyses, in combination with in vitro studies, have been successfully applied to study the underlying mechanism of S. officinalis against CRC cells. Our results demonstrate that S. officinalis suppresses the proliferation, survival, and migration of CRC cells through regulating the PI3K–Akt, HIF-1, and MAPK signaling pathways.