Umbelliferone reduces inflammation and ligature-induced osteoclastic alveolar bone resorption in mice.

AIMS: This study aimed to investigate the effects of Umbelliferone (UMB) on the inflammation underlying alveolar bone resorption in mouse periodontitis. METHODS: Male Swiss mice subjected to a ligature of molars were grouped as non-treated (NT), received UMB (15, 45, or 135 mg/kg) or saline daily for 7 days, respectively, and were compared with naïve mice as control. Gingival tissues were evaluated by myeloperoxidase (MPO) activity and interleukin-1ß level by ELISA. The bone resorption was directly assessed on the region between the cement-enamel junction and the alveolar bone crest. Microscopically, histomorphometry of the furcation region, immunofluorescence for nuclear factor-kappa B (NF-ĸB), and immunohistochemistry for tartrate-resistant acid phosphatase (TRAP), and cathepsin K (CTSK) were performed. Systemically, body mass variation and leukogram were analyzed. RESULTS: Periodontitis significantly increased MPO activity, interleukin-1ß level, and NF-ĸB+ immunofluorescence, and induced severe alveolar bone and furcation resorptions, besides increased TRAP+ and CTSK+ cells compared with naïve. UMB significantly prevented the inflammation by reducing MPO activity, interleukin-1ß level, and NF-ĸB+ intensity, besides reduction of resorption of alveolar bone and furcation area, and TRAP+ and CTSK+ cells compared with the NT group. Periodontitis or UMB treatment did not affect the animals systemically. CONCLUSION: UMB improved periodontitis by reducing inflammation and bone markers.

Blockage of the fractalkine pathway reduces hyperalgesia and prevents morphological glial alterations-Comparison between inflammatory and neuropathic orofacial pain in male rats.

This study aimed to evaluate the effects of inhibitors of the fractalkine pathway in hyperalgesia in inflammatory and neuropathic orofacial pain in male rats and the morphological changes in microglia and satellite glial cells (SGCs). Rats were submitted to zymosan-induced arthritis of the temporomandibular joint or infraorbital nerve constriction, and treated intrathecally with a P2 X7 antagonist, a cathepsin S inhibitor or a p-38 mitogen-activated protein kinase (MAPK) inhibitor. Mechanical hyperalgesia was evaluated 4 and 6 h following arthritis induction or 7 and 14 days following nerve ligation. The expression of the receptor CX3 CR1 , phospho-p-38 MAPK, ionized calcium-binding adapter molecule-1 (Iba-1), and glutamine synthetase and the morphological changes in microglia and SGCs were evaluated by confocal microscopy. In both inflammatory and neuropathic models, untreated animals presented a higher expression of CX3 CR1 and developed hyperalgesia and up-regulation of phospho-p-38 MAPK, which was prevented by all drugs (p < .05). The number of microglial processes endpoints and the total branch length were lower in the untreated animals, but the overall immunolabeling of Iba-1 was altered only in neuropathic rats (p < .05). The mean area of SGCs per neuron was significantly altered only in the inflammatory model (p < .05). All morphological alterations were reverted by modulating the fractalkine pathway (p < .05). In conclusion, the blockage of the fractalkine pathway seemed to be a possible therapeutic strategy for inflammatory and neuropathic orofacial pain, reducing mechanical hyperalgesia by impairing the phosphorylation of p-38 MAPK and reverting morphological alterations in microglia and SGCs.

The role of adiposity, adipokines and polymorphisms of leptin and adiponectin in myelodysplastic syndromes.

The aim of the present study was to investigate the relationship between leptin and adiponectin gene polymorphisms, circulating levels of leptin and adiponectin, adiposity and clinical markers in patients with myelodysplastic syndrome (MDS). This cross-sectional study was conducted with 102 adults and elderly MDS patients and 102 age- and sex-matched controls. Clinical characteristics, co-morbidities, anthropometric data, laboratory evaluation and genetic analysis (polymorphisms -2548G > A/rs7799039 of the LEP gene and +276G > T/rs1501299 of the ADIPOQ gene) were investigated. Serum leptin was higher and adiponectin lower in MDS when compared with controls. There was a significant positive correlation between serum leptin levels and BMI (r = 0·264, P = 0·025), waist circumference (r = 0·235, P = 0·047), body fat percentage (BF %) (r = 0·373, P = 0·001) and the fat mass index (FMI) (r = 0·371, P < 0·001). A lower mean adiponectin was found among patients with high BF %, higher visceral adiposity index and metabolic syndrome. A significant association was found between the AA genotype (mutant) of the LEP polymorphism rs7799039 and male sex and blast excess (≥ 5 %). In addition, a significant association was observed between the TT genotype (mutant) of the ADIPOQ rs1501299 polymorphism and Fe overload. These results demonstrate the importance of a comprehensive and systematic evaluation in patients with MDS in order to identify and control negative factors not related to the disease at an early stage.

Effect of CYB2B6 (c.516G>T), CYP2C9 (c.1075A>C) and UGT1A9 (c.98T>C) polymorphisms on propofol pharmacokinetics in patients submitted to colonoscopy: a cohort study.

BACKGROUND: The aim of this study was to investigate the effect of CYB2B6 (c.516G>T, rs3745274), CYP2C9 (c.1075A>C, rs1057910) and UGT1A9 (c.98T>C, rs72551330) polymorphisms on the pharmacokinetics of single-drug propofol in adult patients undergoing intravenous sedation. METHODS: In this prospective clinical study, a total of 124 patients undergoing anaesthesia with propofol, as a single drug, were evaluated when undergoing colonoscopy procedure. Clinical variables were obtained from the patient's anamnesis prior to performing the anaesthetic procedure, in the moment of the patient's loss of consciousness, during the colonoscopy exam (recorded every 5 min) and in the awakening time. RESULTS: Polymorphic genotypes for the rs3745274 and rs1057910 polymorphisms were associated with bispectral index, target-controlled infusion (TCI)/effector concentration of propofol and TCI/plasma concentration of propofol values. Based on multivariate analysis, it was observed that weight, age, surgery time, systolic blood pressure and the rs1057910 polymorphism corresponded to predictive values for the dose of propofol used. Weight (B = 4.807±0.897), age (B = 1.834±0.834) and duration of surgery (B = 8.164±1.624) corresponded to factors associated with increased propofol dose, while systolic blood pressure (B = -1.892±0.679) and the genotypes (AA vs CA) of the single nucleotide polymorphism (SNP) rs1057910 CYPP2C9 gene (B = -74.161±26.820) decreased the total dose of propofol used. CONCLUSION: We concluded that the rs1057910 and rs3745274 polymorphisms affect the metabolism of propofol in patients exclusively submitted to this drug. Thus, the knowledge of the polymorphic genotypes of the CYPP2C9 and CYB2B6 genes may be predictive of different metabolising phenotypes, suggesting expected behaviours of BIS parameter in the anaesthetic procedure, which contributes to safer monitoring by anaesthesiologists during the clinical intervention.

Oral carcinogenesis triggers a nociceptive behavior and c-Fos expression in rats' trigeminal pathway.

OBJECTIVE: To recognize changes that occur along the trigeminal pathway in oral cancer in order to establish an effective approach to pain control. METHODS: Wistar rats were divided into control and 4-NQO groups for 8, 12, 16, or 20 weeks. 4-NQO suspension was administered on the animals' tongues. Mechanical hyperalgesia, assessment of facial expressions, and an open-field test were performed. After euthanasia, the animals' tongues were removed for macro- and microscopic analysis. c-Fos expression was analyzed in the trigeminal pathway structures. RESULTS: 4-NQO induced time-dependent macroscopic lesions that were compatible with neoplastic tumors. Histopathological analysis confirmed oral squamous cell carcinoma in 50% of the animals on the 20th week. There was a significant nociceptive threshold reduction during the first two weeks, followed by a threshold return to the baseline levels, decreasing again from the 12th week. Facial nociceptive expression scores were observed on the 20th week, while increased grooming and exploratory activity were observed on the 8th week. Trigeminal ganglion showed an increased c-Fos immunoexpression on the 20th week, and in the trigeminal subnucleus caudalis, it occurred on the 16th and 20th. The long-term carcinogenic exposure caused changes in the nociceptive behavior and c-Fos expression in the rats' trigeminal pathway.

A Novel Murine Model of a High Dose Brachytherapy-Induced Actinic Proctitis.

Background: Radiation proctitis affects 1-20% of cancer patients undergoing radiation exposure due to pelvic malignancies, including prostate, gynecological and rectum cancers. The patients manifest rectal discomfort, pain, discharge, and bleeding. Notably, the efficacy of prophylactic measures remains controversial due to the lack of adequate animal models that mimic this condition. Objective: The present study then aimed to develop a murine model of high-dose-rate (HDR) brachytherapy-induced proctitis. Material/Methods: C57BL/6 male mice were subjected to HDR (radiation source: iridium-192 [Ir-192]) through a cylindrical propylene tube inserted 2 cm far from the anal verge into the rectum. The animals received radiation doses once a day for three consecutive days (fractions of 9.5 Grays [Gy]), 3.0 mm far from the applicator surface. The sham group received only the applicator with no radiation source. The survival rate was recorded, and a colonoscopy was performed to confirm the tissue lesion development. Following euthanasia, samples of the rectum were collected for histopathology, cytokines dosage (IL-6 and KC), and immunohistochemical analysis (TNF-α and COX-2). Results: HDR significantly reduced animals' survival ten days post first radiation exposure (14% survival vs. 100% in the non-irradiated group). Day seven was then used for further investigation. Mice exposed to radiation presented with rectum injury confirmed by colonoscopy and histopathology (P < 0.05 vs. the control group). The tissue damage was accompanied by an inflammatory response, marked by increased KC and IL-6 tissue levels, and immunostaining for TNF-α and COX-2 (P < 0.05 vs. control group). Conclusions: We established a novel animal model of actinic proctitis induced by HDR brachytherapy, marked by inflammatory damage and low animal mortality.

Paraprobiotic Enterococcus faecalis EC-12 prevents the development of irinotecan-induced intestinal mucositis in mice.

AIMS: This study tested the protective effect of purified paraprobiotic Enterococcus faecalis (EC-12) and an E. faecalis-based formulation (Med LanS) on irinotecan-induced intestinal mucositis murine model. MAIN METHODS: C57BL/6 male mice received saline, irinotecan (75 mg/Kg, i.p.), EC-12 (0.3, 1, or 3 × 107 CFU/Kg, p.o.) + irinotecan or Med Lan-S (3 × 107 CFU/Kg, p.o.) + irinotecan. Body mass variation was assessed daily, and blood samples were collected for evaluating bacteremia and leukocyte count. The ileum was harvested for myeloperoxidase assay, histopathology, quantitative PCR, and immunofluorescence for macrophages (F4/80), TLR4, and IL-18 binding protein (IL-18BP). KEY FINDINGS: The best therapeutic strategy was EC-12 administration at 3 × 107 CFU/Kg, starting 1 week before irinotecan. EC-12 and Med Lan-S did not prevent the irinotecan-induced body mass loss or leukopenia but attenuated the neutrophil infiltration in the intestine and increased the villus/crypt ratio (P < 0.05). Additionally, EC-12 and Med Lan-S reduced the mRNA expression of Cldn-2, Ocln, and Tlr4 versus the irinotecan group (P < 0.05). Irinotecan also augmented the expression of Il-18, IL-18BP, the immunofluorescence of F4/80, and TLR4, while only EC-12 prevented the expression of all these markers. Remarkably, EC-12 and Med Lan inhibited the irinotecan-induced bacterial translocation to the blood. SIGNIFICANCE: Paraprobiotic E. faecalis EC-12 prevents the development of intestinal mucositis by downregulating the inflammatory response. Med Lan-S also protects from mucositis. Possibly, the complexity of the formulation accounts for an innate immune-driven protective mechanism.

Effect of CYB2B6 (c.516G>T), CYP2C9 (c.1075A>C) and UGT1A9 (c.98T>C) polymorphisms on propofol pharmacokinetics in patients submitted to colonoscopy: a cohort study.

BACKGROUND: The aim of this study was to investigate the effect of CYB2B6 (c.516G>T, rs3745274), CYP2C9 (c.1075A>C, rs1057910) and UGT1A9 (c.98T>C, rs72551330) polymorphisms on the pharmacokinetics of single-drug propofol in adult patients undergoing intravenous sedation. METHODS: In this prospective clinical study, a total of 124 patients undergoing anaesthesia with propofol, as a single drug, were evaluated when undergoing colonoscopy procedure. Clinical variables were obtained from the patient's anamnesis prior to performing the anaesthetic procedure, in the moment of the patient's loss of consciousness, during the colonoscopy exam (recorded every 5 min) and in the awakening time. RESULTS: Polymorphic genotypes for the rs3745274 and rs1057910 polymorphisms were associated with bispectral index, target-controlled infusion (TCI)/effector concentration of propofol and TCI/plasma concentration of propofol values. Based on multivariate analysis, it was observed that weight, age, surgery time, systolic blood pressure and the rs1057910 polymorphism corresponded to predictive values for the dose of propofol used. Weight (B = 4.807±0.897), age (B = 1.834±0.834) and duration of surgery (B = 8.164±1.624) corresponded to factors associated with increased propofol dose, while systolic blood pressure (B = -1.892±0.679) and the genotypes (AA vs CA) of the single nucleotide polymorphism (SNP) rs1057910 CYPP2C9 gene (B = -74.161±26.820) decreased the total dose of propofol used. CONCLUSION: We concluded that the rs1057910 and rs3745274 polymorphisms affect the metabolism of propofol in patients exclusively submitted to this drug. Thus, the knowledge of the polymorphic genotypes of the CYPP2C9 and CYB2B6 genes may be predictive of different metabolising phenotypes, suggesting expected behaviours of BIS parameter in the anaesthetic procedure, which contributes to safer monitoring by anaesthesiologists during the clinical intervention.

Endocannabinoid System Attenuates Oxaliplatin-Induced Peripheral Sensory Neuropathy Through the Activation of CB1 Receptors.

Oxaliplatin-induced neurotoxicity is expressed as a dose-limiting peripheral sensory neuropathy (PSN). Cannabinoid substances have been investigated for the analgesic effect. This study aimed to investigate the role of cannabinoid receptors in oxaliplatin-associated PSN. Swiss male mice received nine oxaliplatin injections (2 mg/kg, i.v.). Mechanical and thermal nociceptive tests were performed for 56 days. CB1, CB2, and c-Fos expression were assessed in dorsal root ganglia (DRG), spinal cord (SC), trigeminal ganglia (TG), spinal trigeminal nucleus caudalis (Sp5C), and periaqueductal gray (PAG). Iba-1 expression was assessed in DRG and ATF3 in TG. Cannabidiol (10 mg/kg, p.o.) or a CB1/CB2 non-selective agonist (WIN 55,212-2; 0.5 mg/kg, s.c.) or AM251 (CB1 antagonist) or AM630 (CB2 antagonist) (3 mg/kg, i.p.) were injected before oxaliplatin. Oxaliplatin increased CB1 in DRG, SC, TG, Sp5C, and ventrolateral PAG, with no interference in CB2 expression. Cannabidiol increased CB1 in DRG, reduced mechanical hyperalgesia and c-Fos expression in DRG and SC. Additionally, WIN 55,212-2 increased CB1 in DRG, reduced mechanical hyperalgesia, cold allodynia and c-Fos expression in DRG and SC. CB1 blockage hastened the cold allodynia response, but the CB2 antagonist failed to modulate the oxaliplatin-induced nociceptive behavior. Oxaliplatin also increased Iba-1 in DRG, suggesting immune response modulation which was reduced by cannabidiol and enhanced by AM630. The modulation of the endocannabinoid system, through the CB1 receptor, attenuates the oxaliplatin-associated PNS. The activation of the endocannabinoid system could be considered as a therapeutic target for controlling oxaliplatin-associated neuropathy.

Cancerous and non-neoplastic stem cells in the stomach similarly express CD44 and CD133.

CD44 and CD133 have been considered as cancer stem cell (CSC) markers. Stem cell markers are rarely described in healthy stomach tissues. However, the clinicopathological and prognostic value of CD44 and CD133 in gastric cancer remains controversial. This study investigated the expression of CD44 and CD133 in gastric cancer and non-neoplastic gastric mucosa. We used samples of primary gastric adenocarcinomas (n = 69), metastatic lymph nodes (n = 30), intestinal metaplasia (n = 17), and histologically normal gastric tissues of surgical margins (n = 54). The expression of CD44 and CD133 were studied in samples by immunohistochemistry. Fisher's exact test and a logistic regression model were used in this study. CD44 expression was observed in 12% of samples with intestinal metaplasia, 20% with lymph node metastases, 22% with normal mucosa, to 30% of samples with primary tumors. Most of these positive tumors showed immunostaining in less than 4% of cancerous cells, mainly in the diffuse type. CD133 expression was observed in 7% (intestinal metaplasia) to 46% (normal mucosa). In the positive cases of cancer (24%), in most of them, less than 3% of cells were marked. CD44 and CD133 expression in the histologically normal gastric mucosa was restricted to the deeper regions of the gastric crypts at the level where stem cells and progenitor cells are usually found. CD44 and CD133 expression occurs in few gastric cancer cells, mainly in diffuse carcinomas, and are expressed in histologically normal gastric mucosae. None of the markers are specific for cancer and are also present in intestinal metaplasia and the normal mucosa.

TLR4 deficiency upregulates TLR9 expression and enhances irinotecan-related intestinal mucositis and late-onset diarrhoea.

BACKGROUND AND PURPOSE: Severe diarrhoea, a common gastrointestinal manifestation of anticancer treatment with irinotecan, might involve single nucleotide polymorphisms (SNPs) of toll-like receptors (TLRs), described as critical bacterial sensors in the gut. Here, colorectal cancer patients carrying missense TLR4 A896G (rs4986790) or C1,196T (rs4986791) SNPs and Tlr4 knockout (Tlr4-/-) mice were given irinotecan to investigate the severity of the induced diarrhoea. EXPERIMENTAL APPROACH: Forty-six patients treated with irinotecan-based regimens had diarrhoea severity analysed according to TLR4 genotypes. In the experimental setting, wild-type (WT) or Tlr4-/- mice were given irinotecan (45 or 75 mg·kg-1 , i.p.) or saline (3 ml·kg-1 ). Diarrhoea severity was evaluated by measuring intestinal injury and inflammatory markers expression after animals were killed. KEY RESULTS: All patients with TLR4 SNPs chemotherapy-treated presented diarrhoea, whereas gastrointestinal toxicity was observed in 50% of the wild homozygous individuals. Mice injected with irinotecan presented systemic bacterial translocation and increased TLR4 immunostaining in the intestine. In line with the clinical findings, Tlr4 gene deficiency enhanced irinotecan-related diarrhoea and TLR9 expression in mice. An increased myeloperoxidase activity and Il-18 expression along with IL-10 decreased production in Tlr4-/- mice also indicated an intensified intestinal damage and inflammatory response. CONCLUSION AND IMPLICATIONS: TLR4 deficiency upregulates TLR9 expression and enhances intestinal damage and the severity of late-onset diarrhoea during irinotecan-based treatment. Identifying patients genetically predisposed to chemotherapy-associated diarrhoea is a strategy toward precision medicine.

Bothrops pauloensis snake venom-derived Asp-49 and Lys-49 phospholipases A2 mediates acute kidney injury by oxidative stress and release of inflammatory cytokines.

The envenomation caused by the Bothrops pauloensis snake leads to severe local and systemic effects including acute kidney injury. In this study, we investigated the renal effects by phospholipases A2 (PLA2s), divided into two main subgroups, Asp-49 and Lys-49, isolated from the Bothrops pauloensis snake venom (BpV) in isolated rat kidney system. Both PLA2s (3 µg/mL), added alone to the perfusion system and analyzed for 120 min, had significant effects on isolated rat kidney. Asp-49 reduced Glomerular Filtration Rate (GFR) at 60, 90 and 120 min, and the percentage of total tubular sodium transport (%TNa+) and potassium transport (%TK+) at 120 min. Lys-49 increased Perfusion Pressure (PP) at 120 min and reduced GFR, %TNa+ and the percentage of total tubular chloride transport (%TCl-) at 60, 90 and 120 min. Cytokine release in the kidney tissues were increased with Asp-49 PLA2 (IL-10) and Lys-49 PLA2 (TNF-α, IL-1ß, IL-10). Both increased MPO activity. Asp-49 PLA2 decreased Glutathione (GSH) and increased nitrite levels, while Lys-49 PLA2 increased Malondialdehyde (MDA), GSH and nitrite levels. Histological analysis of the perfused kidneys revealed the presence of glomerular degeneration and atrophy, deposit of proteinaceous material in Bowman's space and intratubular with both PLA2s. These findings indicated that both PLA2s modified the functional parameters in an isolated perfused kidney model with increased oxidative stress and cytokine release. PLA2s are one of the components at high concentration in BpV and our results provide important knowledge about their involvement with the nephrotoxic mechanism.

Cytoplasmic CCR7 (CCR7c) immunoexpression is associated with local tumor recurrence in triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) is a subtype of cancer, which tests negative for estrogen receptors, progesterone receptors, and lacks overexpression of the human epidermal growth factor 2 (C-erbB2, HER2/neu) gene. The expression of chemokines and their receptors, including CCR7, has been described in several types of cancer, contributing to tumor progression. AIM OF THE STUDY: This study investigated the association between the membrane and cytoplasmic CCR7 expression and the prognosis of TNBC. MATERIALS AND METHODS: Surgical paraffin histopathology blocks and clinico-pathological data were assessed from 133 patients. Samples were analyzed by immunohistochemistry and immunofluorescence using the Tissue Microarray technique for scoring the intensity of CCR7 expression. RESULTS: TNBC patients in which the CCR7 labeling was predominantly in the cytoplasm of tumor cells presented increased local tumor recurrence (P = 0.033). Conversely, there was no statistical difference in five-year overall survival between the patients with low (77%) versus high (80%) cytoplasmic CCR7 expression (P = 0.7104). Additionally, the risk of death between these groups was 1.19 (95% CI = 0.48-2.91). CONCLUSION: The cytoplasmic CCR7 expression associates with an increased incidence of tumor relapse in TNBC, not affecting patients survival. Consequently, the cell compartment in which the CCR7 localizes could serve as a prognostic marker in this cancer subtype.

Paradoxical interaction between cancer and long-term postsepsis disorder: impairment of de novo carcinogenesis versus favoring the growth of established tumors.

BACKGROUND: Previous data have reported that the growth of established tumors may be facilitated by postsepsis disorder through changes in the microenvironment and immune dysfunction. However, the influence of postsepsis disorder in initial carcinogenesis remains elusive. METHODS: In the present work, the effect of postsepsis on inflammation-induced early carcinogenesis was evaluated in an experimental model of colitis-associated colorectal cancer (CAC). We also analyzed the frequency and role of intestinal T regulatory cells (Treg) in CAC carcinogenesis. RESULTS: The colitis grade and the tumor development rate were evaluated postmortem or in vivo through serial colonoscopies. Sepsis-surviving mice (SSM) presented with a lower colonic DNA damage, polyp incidence, reduced tumor load, and milder colitis than their sham-operated counterparts. Ablating Treg led to restoration of the ability to develop colitis and tumor polyps in the SSM, in a similar fashion to that in the sham-operated mice. On the other hand, the growth of subcutaneously inoculated MC38luc colorectal cancer cells or previously established chemical CAC tumors was increased in SSM. CONCLUSION: Our results provide evidence that postsepsis disorder has a dual effect in cancer development, inhibiting inflammation-induced early carcinogenesis in a Treg-dependent manner, while increasing the growth of previously established tumors.

Influence of infliximab therapy on bone healing post-dental extraction in rats.

OBJECTIVE: TNF-α, which acts directly on osteoclastogenesis, may modify bone turnover. Thus, the objective of this study was to evaluate the influence of infliximab on extraction socket healing. MATERIAL AND METHODS: Eighty-four Wistar rats were randomized into two groups (infliximab EV 5 mg / kg or saline EV 1 ml / kg) and submitted to lower first molar extraction protocol. The animals were sacrificed 1, 3, 7, 14, 21 and 28 days after surgery. The jaws were subjected to radiographic, histomorphometric, histochemical (picrosirius red) and immunohistochemical (TNF-α, RANKL and OPG) analysis. RESULTS: No differences were observed between the groups in surgical difficulty parameters: mass of teeth, number of root fractures and surgical time. Lower area filling with bone as well as increased amounts of remaining cicatricial tissue were observed in the infliximab group at 14 days (p < 0.001). Lower scores for polymorphonuclear neutrophils were seen at 3 (p < 0.01) and 7 days (p < 0.001), lower mononuclear counts at 7 days (p < 0.01) and lower osteoclast counts at 7 and 14 days (p < 0.01 and p < 0.001, respectively). Additionally, reduced TNF-α, RANKL and OPG immunoreactivity were observed, especially at 7 days (p < 0.05). CONCLUSION: TNF-α inhibitor may alter the bone repair capacity after tooth extraction, especially in the initial repair periods, by lower expression of TNF α, RANKL and OPG. Thus, additional caution may be needed in patients who use this class of medication after dental extraction.

Metformin reduces c-Fos and ATF3 expression in the dorsal root ganglia and protects against oxaliplatin-induced peripheral sensory neuropathy in mice.

Oxaliplatin is a third-generation platinum drug commonly used as the first line treatment of metastatic colorectal cancer. Oxaliplatin-based anticancer regimens course with dose-limiting neurotoxicity. The pharmacological strategies used to manage such side effect are not totally effective. Metformin is an anti-diabetic drug that is described to negatively modulate painful diabetic neuropathy. Then, this study aimed to assess the effect of metformin in the oxaliplatin-induced peripheral sensory neuropathy in mice. For that purpose, Swiss male mice were injected with oxaliplatin (1, 2 or 4 mg/kg, i.v., twice a week with a total of nine injections) alone or in combination with daily administration of metformin (250 mg/kg, p.o.). Thermal and mechanical nociceptive tests were performed once a week for five weeks. Then, the animals were euthanized on day 35 post-first injection of oxaliplatin and the dorsal root ganglia were harvested for the assessment of c-Fos and ATF3 expressions. Oxaliplatin caused a nociceptive response accompanied by the increased expression of c-Fos and ATF3 in the dorsal root ganglia and spinal cord. In addition, the oxaliplatin-associated nociception was significantly attenuated by metformin (P < 0.05), which also reduced the expression of c-Fos and ATF3 (P < 0.05). Therefore, metformin protected from the peripheral sensory neuropathy induced by oxaliplatin, which was confirmed by the reduction of c-Fos and ATF3 expression, two known neuronal activation and damage markers, respectively.

Involvement of Endothelin Receptors in Peripheral Sensory Neuropathy Induced by Oxaliplatin in Mice.

The aim of this study was to evaluate the participation of the endothelin ETA and ETB receptors and the effects of bosentan in oxaliplatin-induced peripheral sensory neuropathy (OIN) in mice. Adult male Swiss mice received 1 mg/kg of oxaliplatin intravenously, twice a week for 5 weeks. Dorsal root ganglia (DRG) and spinal cords were removed for evaluation of the endothelin ETA and ETB receptor expression. Afterwards, selective (BQ-123 and BQ-788; 10 nmol in 30 µL, intraplantarly) and non-selective (bosentan, 100 mg/kg, orally) antagonists were administered in order to evaluate the involvement of the endothelin receptors in OIN. Mechanical and thermal nociception tests were performed once a week for 56 days. Oxaliplatin induced mechanical and thermal hypersensitivity and increased the endothelin ETA receptor expression in both the DRG and spinal cord (P < 0.05). Endothelin ETB receptor expression was increased in the DRG (P < 0.05) but not in the spinal cord. Both endothelin ETA and ETB receptor selective antagonists partially prevented mechanical hyperalgesia in mice with OIN (P < 0.05). Moreover, bosentan prevented mechanical and thermal hypersensitivity in oxaliplatin-treated mice (P < 0.05). In conclusion, both endothelin ETA and ETB receptors seem to be involved in the OIN in mice and they should be considered possible targets for the management of this clinical feature.

SN-38, the active metabolite of irinotecan, inhibits the acute inflammatory response by targeting toll-like receptor 4.

PURPOSE: Anticancer-drug efficacy seems to involve the direct interaction with host immune cells. Although topoisomerase I (Top I) inhibitors have been suggested to block LPS-evoked inflammation, the interaction between these drugs and toll-like receptor 4 (TLR4) is unaddressed. METHODS: SN-38, the active metabolite of the Top I inhibitor irinotecan, and TLR4 interaction was assessed using the in vitro luciferase nuclear factor-κB reporter assay, neutrophil migration to murine air-pouch, in silico simulation, and the thermal shift assay (TSA). Topotecan was used as a positive anti-inflammatory control. RESULTS: Non-cytotoxic concentrations of SN-38 attenuated LPS (a TLR4 agonist)-driven cell activation without affecting peptidoglycan (a TLR2 agonist)-activating response. Similarly, topotecan also prevented LPS-induced inflammation. Conversely, increasing concentrations of LPS reversed the SN-38 inhibitory effect. In addition, SN-38 abrogated LPS-dependent neutrophil migration and reduced TNF-α, IL-6, and keratinocyte chemoattractant levels in the air-pouch model, but failed to inhibit zymosan (a TLR2 agonist)-induced cell migration. A two-step molecular docking analysis indicated two potential binding sites for the SN-38 in the MD-2/TLR4 complex, the hydrophobic MD-2 pocket (binding energy of - 8.1 kcal/mol) and the rim of the same molecule (- 6.9 kcal/mol). The topotecan also bound to the MD-2 pocket. In addition, not only the lactone forms, but also the carboxylate conformations of both Top I inhibitors interacted with the MD-2 molecule. Furthermore, the TSA suggested the interaction of SN-38 with MD-2. CONCLUSIONS: Therefore, SN-38 inhibits acute inflammation by blocking LPS-driven TLR4 signaling. This mechanism seems to be shared by other Top I inhibitors.

Neutrophils contribute to the pathogenesis of hemorrhagic cystitis induced by ifosfamide.

Ifosfamide (IFO) is an antineoplastic drug that is commonly used to treat gynecological and breast cancers. Hemorrhagic cystitis (HC) is a common side effect associated with IFO injection, which courses with neutrophil accumulation and affects 6-50% of patients depending on dose intensity. Here, we investigated the role of neutrophils in this inflammatory process. Female Swiss mice (n = 8/group) were injected with saline, IFO (400 mg/kg, i.p.), fucoidan (a P- and L-selectins inhibitor, 100 mg/kg, i.v.) or IFO + fucoidan (1-100 mg/kg) alone or combined with mesna (80 mg/kg i.p.). Another group of mice received anti-Ly6G antibody (500 µg/mouse, once daily for 2 days) for neutrophil depletion before IFO injection. In another experimental setting, animals received granulocyte colony-stimulating factor (G-CSF, 400 µg/kg), IFO (200 mg/kg), G-CSF (25-400 µg/kg, for 5 days) + IFO (200 mg/kg, i.p.) or fucoidan + G-CSF + IFO. Bladder injury was evaluated 12 h after IFO injection. IFO 400 mg/kg significantly increased visceral hyperalgesia, bladder edema, hemorrhage, vascular permeability, MPO, IL-1ß and IL-6 tissue levels, and COX-2 immunostaining and expression versus the saline group (P < 0.05). Conversely, fucoidan (100 mg/kg) significantly attenuated these parameters compared to IFO-injected mice (P < 0.05). Additionally, fucoidan potentiated mesna protective effect when compared with IFO + mesna group (P < 0.05). Accordingly, neutrophil depletion with anti-Ly6G reduced inflammatory parameters and bladder injury compared to IFO (P < 0.05). In contrast, G-CSF enhanced IFO (200 mg/kg)-induced HC, which was significantly attenuated by treatment with fucoidan (P < 0.05). Therefore, neutrophils contribute to the pathogenesis of HC.