Histone deacetylase inhibitors decrease intra-abdominal adhesions with one intraoperative dose by reducing peritoneal fibrin deposition pathways

The role of KDR in intrauterine adhesions may involve the TGF-β1/Smads signaling pathway

The aim of this study was to investigate the role of kinase-insert domain-containing receptor (KDR) in intrauterine adhesions (IUA) and its mechanism. The Case group consisted of 92 patients diagnosed with IUA, and the Control group included 86 patients with uterine septum who had normal endometrium verified with an uteroscope. In addition, 50 rats were randomly assigned into Control, Sham, Model, NC-siRNA, and KDR-siRNA groups. Rats in the Model, NC-siRNA, and KDR-siRNA groups were induced by uterine curettage and lipopolysaccharide (LPS) treatment to establish the IUA model. Then, immunohistochemistry was applied for detection of VEGF and KDR expression, HE staining was used for observation of the endometrial morphology and gland counting, Masson staining for measurement of the degree of endometrial fibrosis, and qRT-PCR and western blot for the expression of KDR, VEGF, MMP-9, as well as TGF-β1/Smads pathway-related proteins. Compared with the Control group, the mRNA and protein expressions of KDR were significantly higher in IUA endometrial tissues, and the expression of KDR was positively correlated to the severity of IUA. In addition, the injection of si-KDR increased the number of endometrial glands, reduced the area of fibrosis, inhibited mRNA and protein expression of KDR and VEGF, up-regulated the expression of MMP-9 and Smad7, and decreased the expression level of TGF-β1, p-Smad2, p-Smad3, and Smad4 in rats with IUA. Highly-expressed KDR was related to patients' severity of IUA, and silencing KDR may prevent the occurrence and development of IUA via TGF-β1/Smads signaling pathway and up-regulating the expression of MMP-9.

Comparison of Different Histone Deacetylase Inhibitors in Attenuating Inflammatory Pain in Rats

Histone deacetylase inhibitors (HDACIs), which interfere with the epigenetic process of histone acetylation, have shown analgesic effects in animal models of persistent pain. The HDAC family comprises 18 genes; however, the different effects of distinct classes of HDACIs on pain relief remain unclear. The aim of this study was to determine the efficacy of these HDACIs on attenuating thermal hyperalgesia in persistent inflammatory pain. Persistent inflammatory pain was induced by injecting Complete Freund's Adjuvant (CFA) into the left hind paw of rats. Then, HDACIs targeting class I (entinostat (MS-275)) and class IIa (sodium butyrate, valproic acid (VPA), and 4-phenylbutyric acid (4-PBA)), or class II (suberoylanilide hydoxamic acid (SAHA), trichostatin A (TSA), and dacinostat (LAQ824)) were administered intraperitoneally once daily for 3 or 4 days. We found that the injection of SAHA once a day for 3 days significantly attenuated CFA-induced thermal hyperalgesia from day 4 and lasted 7 days. In comparison with SAHA, suppression of hyperalgesia by 4-PBA peaked on day 2, whereas that by MS-275 occurred on days 5 and 6. Fatigue was a serious side effect seen with MS-275. These findings will be beneficial for optimizing the selection of specific HDACIs in medical fields such as pain medicine and neuropsychiatry.

Tetramethylpyrazine Improves Postoperative Tissue Adhesion: A Drug Repurposing

Plants are known to possess plenty of pharmacological activities as a result of various phytoconstituents. Tetramethylpyrazine (TMP), one of the most widely used medicinal compound isolated from traditional Chinese herb, is usually employed for anti-oxidation, anti-inflammation, anti-platelet aggregation, anti-lipid, anti-fibrosis, as well as activating blood, removing stasis, dilating small arteries, improving microcirculation and antagonizing calcium. In the present paper, the anti-adhesion effect of TMP were reviewed. TMP was found to play a multi-target and muti-link role in anti-adhesion by inhibiting hyperplasia of collagen and overexpression of adhesion-related factors and reducing the concentration of white blood cells and fibrin in plasma. Because previous studies mostly focused on in vitro experiments and animal experiments, there is an urgent need for clinical research with abundant indicators to further prove its anti-adhesion potency. Future basic research should concentrate on the development of TMP as a biological material.

Combined intraoperative administration of a histone deacetylase inhibitor and a neurokinin-1 receptor antagonist synergistically reduces intra-abdominal adhesion formation in a rat model

BACKGROUND

Intra-abdominal adhesions are the most frequent postoperative complication after abdominopelvic surgery. Our laboratory has previously shown that an intraoperative peritoneal lavage containing either the histone deacetylase inhibitor valproic acid (VPA) or a neurokinin-1 receptor antagonist (NK-1RA) reduced adhesions by approximately 50% in a rat model. The objective of this study was to determine whether the combination of these 2 drugs was more effective in reducing adhesions than either alone.

METHODS

Rats underwent laparotomy with creation of peritoneal ischemic buttons to induce adhesions. A single dose of VPA (25 mg/kg), NK-1RA (50 mg/kg), a combination of both, or 0.9% saline was lavaged intraperitoneally just before wound closure. On postoperative day 7, adhesions were quantified. To investigate early mechanisms of adhesiogenesis, adhesions were created as described and adhesive button tissue was harvested at 30 minutes and 3 hours postoperatively and fibrinogen and vascular endothelial growth factor (VEGF) protein levels, both indices of peritoneal extravasations, were determined by Western blot analysis. Peritoneal fluid was collected in similar experiments at 30 minutes, and 3 and 6 hours to measure fibrinolytic activity, an index of the ability of the peritoneum to degrade fibrinous adhesions.

RESULTS

The coadministration of VPA plus NK-1RA reduces adhesions by 72.6% relative to saline (P < .001); this reduction was greater than either compound alone (P < .001). Peritoneal fibrinolytic activity was significantly increased at 3 and 6 hours postoperatively in animals administered the combination therapy versus saline (P = .01). VPA plus NK-1RA significantly decreased fibrinogen and VEGF protein levels at 3 and 6 hours compared with saline controls.

CONCLUSION

These results suggest that a combined pharmacologic approach targeting multiple adhesiogenic pathways provides optimal adhesion prevention.