Myeloid-derived growth factor suppresses VSMC dedifferentiation and attenuates postinjury neointimal formation in rats by activating S1PR2 and its downstream signaling.

Restenosis after angioplasty is caused usually by neointima formation characterized by aberrant vascular smooth muscle cell (VSMC) dedifferentiation. Myeloid-derived growth factor (MYDGF), secreted from bone marrow-derived monocytes and macrophages, has been found to have cardioprotective effects. In this study we investigated the effect of MYDGF to postinjury neointimal formation and the underlying mechanisms. Rat carotid arteries balloon-injured model was established. We found that plasma MYDGF content and the level of MYDGF in injured arteries were significantly decreased after balloon injury. Local application of exogenous MYDGF (50 µg/mL) around the injured vessel during balloon injury markedly ameliorated the development of neointimal formation evidenced by relieving the narrow endovascular diameter, improving hemodynamics, and reducing collagen deposition. In addition, local application of MYDGF inhibited VSMC dedifferentiation, which was proved by reversing the elevated levels of osteopontin (OPN) protein and decreased levels of α-smooth muscle actin (α-SMA) in the left carotid arteries. We showed that PDGF-BB (30 ng/mL) stimulated VSMC proliferation, migration and dedifferentiation in vitro; pretreatment with MYDGF (50-200 ng/mL) concentration-dependently eliminated PDGF-BB-induced cell proliferation, migration and dedifferentiation. Molecular docking revealed that MYDGF had the potential to bind with sphingosine-1-phosphate receptor 2 (S1PR2), which was confirmed by SPR assay and Co-IP analysis. Pretreatment with CCG-1423 (Rho signaling inhibitor), JTE-013 (S1PR2 antagonist) or Ripasudil (ROCK inhibitor) circumvented the inhibitory effects of MYDGF on VSMC phenotypic switching through inhibiting S1PR2 or its downstream RhoA-actin monomers (G-actin) /actin filaments (F-actin)-MRTF-A signaling. In summary, this study proves that MYDGF relieves neointimal formation of carotid arteries in response to balloon injury in rats, and suppresses VSMC dedifferentiation induced by PDGF-BB via S1PR2-RhoA-G/F-actin-MRTF-A signaling pathway. In addition, our results provide evidence for cross talk between bone marrow and vasculature.

Abscisic acid biosynthesis, metabolism and signaling in ripening fruit.

Fruits are highly recommended nowadays in human diets because they are rich in vitamins, minerals, fibers and other necessary nutrients. The final stage of fruit production, known as ripening, plays a crucial role in determining the fruit's quality and commercial value. This is a complex physiological process, which involves many phytohormones and regulatory factors. Among the phytohormones involved in fruit ripening, abscisic acid (ABA) holds significant importance. ABA levels generally increase during the ripening process in most fruits, and applying ABA externally can enhance fruit flavor, hasten softening, and promote color development through complex signal regulation. Therefore, gaining a deeper understanding of ABA's mechanisms in fruit ripening is valuable for regulating various fruit characteristics, making them more suitable for consumption or storage. This, in turn, can generate greater economic benefits and reduce postharvest losses. This article provides an overview of the relationship between ABA and fruit ripening. It summarizes the effects of ABA on ripening related traits, covering the biochemical aspects and the underlying molecular mechanisms. Additionally, the article discusses the interactions of ABA with other phytohormones during fruit ripening, especially ethylene, and provides perspectives for future exploration in this field.

[Inhibition of postharvest decay and induction of defensive enzymes by pure oxygen in Chinese bayberry fruit].

Chinese bayberry fruits were stored in air (control) or pure oxygen atmosphere for up to 12 days at 5 degrees C to investigate the effects of high oxygen on decay control and its relation to the induction of defensive enzyme activities. The results showed that exposure of Chinese bayberry to pure oxygen significantly prevented fruit decay. At the end of the storage period, the decay index of fruits exposed to pure oxygen was only 17% while that of control fruits reached 54% (Fig.1). Pure oxygen caused a significant increase in chitinase and beta-1,3-glucanase activities which reached a peak on the 6th day of storage (Fig.2). Phenylalanine ammonium-lyase (Fig.3A) and peroxidase (Fig.4) activities as well as total phenolic content (Fig.3B) increased more quickly and stayed at significantly higher levels in fruits exposed to pure oxygen during storage than the control fruits. These results suggest that the inhibition of postharvest fruit decay by high oxygen was related to the induction of defensive enzyme activities. The induced disease resistance may be involved in the mechanisms by which high oxygen treatment inhibited fruit decay in Chinese bayberry.

[Diagnosis and surgical management of Hangman's fracture combined with intervertebral disc injury].

OBJECTIVE: To study the pathology characteristics and management of Hangman's fracture combined with intervertebral disc injury. METHODS: Twenty-one patients suffered from this special injury were converged in this study. All patients underwent anterior C(2 - 3) discectomy and fusion, 18 cases were fixed by anterior cervical plate. The type of fractures, radiology characteristics, and clinical outcomes were investigated. RESULTS: No graft displacement or absorption, infection and neurologic deterioration occurred. All fresh dislocation of axis and C(2 - 3) angulation were corrected. Fusion of C(2 - 3) intervertebral space and pedicle fracture were acquired in all of the patients. After a mean follow-up of 31 months, ranging from 8 to 48 months, nearly all of the complains disappeared after operation. CONCLUSIONS: Hangman's fracture is not restricted at pedicle of the axis. Fracture combined with intervertebral disc injury is a special type of Hangman's fracture. Anterior discectomy and fusion of C(2 - 3) intervertebral disc is an effective operation method in accord with the pathophysiology of this special injury.