Caloric restriction improves inflammation in different tissues of the Wistar rats with obesity and 2K1C renovascular hypertension.

Renovascular hypertension (RHV) is the cause of high blood pressure due to left renal ischemia, and obesity and hypertension cause an inflammatory response. This work analyzed the inflammatory and tissue repair profile in renal, hepatic, and cardiac tissues in an animal model of RVH associated with a high-fat diet and caloric restriction. The expressions of RORγ-t, IL-17, T-bet, and TNF-α decreased and IFN-γ increased in the right kidney. In relation to the left kidney, caloric restriction decreased the expression of IFN-γ. In the liver, caloric restriction decreased RORγ-t, IL-17, and T-bet. Hypertension associated with obesity decreased the expression of IFN-γ, while caloric restriction increased. In the right kidney, hypertension and obesity, associated or not with caloric restriction, increased the area of collagen fibers. In the heart and liver, caloric restriction reduced the area of collagen fibers. Caloric restriction increased vascular endothelial growth factor, reduced levels of growth transformation factor-ß1 (TGF-ß), and increased collagen I in the left kidney. Hypertension/obesity, submitted or not having caloric restriction, increased TGF-ß in liver. The results suggest that caloric restriction has beneficial effects in lowering blood pressure and regulating tissue proinflammatory cytokines. However, there was no change in the structure and composition of tissue repair markers.

Caloric restriction prevents inflammation and insulin dysfunction in middle-aged ovariectomized mice.

BACKGROUND: Loss of ovarian function is associated with increased visceral fat. In this study, we aimed to study the effects of caloric restriction (CR) on metabolism in ovariectomized mice. METHODS AND RESULTS: Female, 8-12-month-old mice were divided into three groups: OVX (ovariectomized mice), OVXR (40% CR) and Sham. CR increased insulin sensitivity and glucose tolerance. AMPK phosphorylation was observed in the liver of OVXR mice. CR also increased hepatic cholesterol and triglyceride levels. The reductions in the level of TBARS in the serum and liver and of H2O2 in the liver of OVXR mice suggested alterations in the redox state of the liver. Although expression of catalase protein was reduced by CR, expression of superoxide dismutase was not altered by CR. Although interleukin IL-6 and IL-10 levels in OVXR mice were similar to those in Sham mice, macrophage infiltration was reduced in OVXR mice. OVXR mice had increased sirtuin1 levels and decreased sirtuin3 levels in the liver. CONCLUSIONS: In conclusion, CR improved the condition of ovariectomized mice by reducing adiposity and increasing insulin sensitivity and glucose tolerance through a mechanism that may involve AMPK.

Arnica montana L. associated with microcurrent accelerates the dermis reorganisation of skin lesions.

The aim of this study was to test the effect of electrical stimulation in association with topical Arnica montana gel on organisational changes in the dermis during tissue repair. An experimental rat incisional skin lesion was used for the study. This involved making an incisional lesion on the dorsum of the animals using a scalpel. Ninety-six animals were used divided into the following groups: control (C), microcurrent (MC); topical treatment with Arnica montana gel (ARN); the ARN + microcurrent (ARN + MC). Treatments were administered daily, and injured tissue samples were collected and processed on Days 2, 6 and 10 for dermis analyses. Myeloperoxidase levels were greater in control than in treatment groups on Days 2 and 6. F4/80 expression was similar among all treatment groups and greater than that in control on Day 2. On Day 6, the expression of vascular endothelial growth factor was higher in the MC group than that in other groups, whereas transforming growth factor-ß expression increased in the MC and ARN + MC groups on Day 10. The expression of matrix metalloproteinase-2 was higher in the ARN + MC group when compared with other groups on Day 10. Expression levels of collagen I were increased in the ARN and ARN + MC groups when compared with control and MC groups on Day 6, while expression of collagen III was enhanced in MC, ARN, and ARN + MC groups when compared with the control. The protocol combining microcurrent with topical application of ARN reduces the inflammatory process, increases myofibroblasts proliferation and decreases the presence of macrophages in the dermis during skin repair in rats.

Quercetin prevents insulin dysfunction in hypertensive animals.

Angiotensin II induced increase in hypertension enhances oxidative stress and compromises insulin action and pancreatic function. Quercetin-rich foods are beneficial for hypertensive and diabetic animals owing to their antioxidant function. The aim of this study was to evaluate the antioxidant effects of quercetin in hypertensive rats on insulin action, signaling, and secretion. Wistar rats were randomly divided into three groups: sham, hypertensive rats (H), and hypertensive rats supplemented with quercetin (HQ). After three months of initial hypertension, quercetin was administered at 50 mg/kg/day for 30 days. Our results indicate that hypertension and serum lipid peroxidation levels were reduced by quercetin supplementation. We observed increased insulin sensitivity in adipose tissue, corroborating the insulin tolerance test, HOMA index, and improvements in lipid profile. Despite normal insulin secretion at 2.8 and 20 mM of glucose, animals treated with quercetin exhibited increased number of islets per section; increased protein expression of muscarinic receptor type 3, VEGF, and catalase in islets; and hepatic mRNA levels of Ide were normalized. In conclusion, supplementation with quercetin improved insulin action and prevented pancreatic and metabolic dysfunction.

Effect of exercising in water on the fibrocartilage of the deep digital flexor tendon in rats with induced diabetes.

Individuals with diabetes mellitus (DM) are affected four times more by tendinopathies than non-diabetics. On the other hand, physical activity helps to DM control. However, the effects of physical exercise in water (PEW) on the fibrocartilages present in the tendons of animals affected by DM are unknown. In this sense, the aim of this study was to analyze the structural organization and chemical composition of fibrocartilage present in the intermediate region of the deep digital flexor tendon (DDFT) of Wistar rats with alloxan-induced DM. Diabetic and non-diabetic animals were randomly separated into four experimental groups (n = 10): Non-Trained Control (NTC), Trained Control (TC), Non-Trained Diabetic (NTD), and Trained Diabetic (TD). TC and TD animals underwent the exercise protocol (total weekly training load - week 1: 14,375; 2: 16,500; 3: 18,375; 4: 20,000) and then were euthanized to collect tendon samples for analysis. The matrix basophilia was more intense in the TC and TD groups. The Decorin immunohistochemical test results showed greater intensity in the NTD and TD groups. The wet weight of the fibrocartilaginous region of the tendon (NTC:19.9 ± 0.06; TC:22.3 ± 0.05; NTD:20.3 ± 0.08; TD:21.8 ± 0.04 mg - p = 0.048), glycosaminoglycan amounts (NTC:3.21 ± 0.18; TC:3.98 ± 0.44; NTD:3.32 ± 0.19; TD:3.79 ± 0.28 µg/mg of fresh tissue - p = 0.046), and intumescence in water (NTC:13.8 ± 3.8; TC:24.3 ± 3.9; NTD:14.9 ± 3.9; TD:28.2 ± 5.3 % w/w - p = 0.042) were higher in the TC and TD groups. The TD group showed the highest levels of type I collagen and matrix metalloproteinase (MMP)-13. The TC group showed the highest and TD the lowest TGF-ß1 levels. In conclusion, the PEW was able to stimulate the deposition of proteoglycans, without inducing chemical changes that would cause histopathological modifications in fibrocartilage in the DDFT of adult rats. Thus, PEW preserves the structural organization of these tissues in tendons of animals affected by DM.

Caloric restriction overcomes pre-diabetes and hypertension induced by a high fat diet and renal artery stenosis.

BACKGROUND: Calorie restriction (CR) is a type of dietary intervention that is essential in weight loss through modulation of critical metabolic control pathways, is well established and understood in cases of systemic arterial hypertension, however, its role in renovascular hypertension is still unclear. METHODS: Rats were divided into three groups: SHAM, and two groups that underwent surgery to clip the left renal artery and induce renovascular hypertension (OH and OHR). The SHAM diet was as follows: 14 weeks normolipidic diet; OH: 2 weeks normolipidic diet + 12 weeks hyperlipidic diet, both ad libitum; OHR, 2 weeks normolipidic diet + 8 weeks ad libitum high-fat diet + 4 weeks 40% calorie-restricted high-fat diet. RESULTS: Rats in the OHR group had decreased blood pressure, body weight, and glucose levels. Reductions in insulinemia and in lipid and islet fibrotic areas in the OHR group were observed, along with increased insulin sensitivity and normalization of insulin-degrading enzyme levels. The expression of nicotinamide phosphoribosyltransferase (NAMPT), insulin receptor (IR), sirtuin 1 (SIRT1), and complex II proteins were increased in the liver tissue of the OHR group. Strong correlations, whether positive or negative, were evaluated via Spearman's model between SIRT1, AMPK, NAMPT, PGC-1α, and NNMT expressions with the restoration of normal blood pressure, weight loss, glycemic and lipid panel, and mitochondrial adaptation. CONCLUSION: CR provided short-term beneficial effects to recover the physiological parameters induced by a high-fat diet and renal artery stenosis in obese and hypertensive animals. These benefits, even in the short term, can provide physiological benefits in the long term.

Laser treatment of synovial inflammatory process in experimentally induced microcrystalline arthritis in Wistar rats.

The presence of intra-articular crystals is detected in different articular pathologies of acute or chronic nature. The aim of this work was to analyze the action of the indium gallium aluminum and phosphorus (InGaAlP) (λ = 670 nm) laser on the synovial membrane present in the knee joint in experimentally induced microcrystalline arthritis in male adult Wistar rats. The animals were divided into three experimental groups (n = 24): control (A), experimentally induced arthritis (B), experimentally induced arthritis+InGaAlP laser therapy (C). The laser treatment was made daily in the patellar region of the right knee after 48 h of the experimental induction. After 7, 14, and 21 days of therapy, the rats were euthanized and the right knees were removed and processed for histomorphometric, immunohistochemical, ultrastructural, and biochemical investigation of the synovium. The number of granulocytes on the 14th and 21st days was higher in B and lower in C and, lastly, in A. The number of fibroblasts on the 14th and 21st days was similar between A and C and below B. The number of blood vessels on the 21st day was higher in B than in the other groups. The positive number of cells for the TUNEL test was higher on the 14th and 21st days in B compared to the others. The percentage of tissue area occupied by birefringent collagen fibers was higher in B on the 21st day than in the others. The ultrastructure of cells showed fibroblast-like morphology in all groups and periods evaluated. The quantification of glycosaminoglycans did not present significant differences between the groups in all the experimental periods. The amount of hydroxyproline was higher in B compared to the other groups on the 14th and 21st days. The content of non-collagen proteins was higher in B on the 21st day in relation to the other groups. Quantification of TNF-α on the 21st day was higher in A and B than in C. For TGF-ß on the 21st day, groups B and C presented similar and higher values than A. For MMP-13, groups A and B presented data similar to and above C. In relation to ADAMT-S4, on the 21st day, groups B and C presented data similar to and lower than A. InGaAlP-670 nm therapy reduced the inflammatory process and tissue injuries of the synovial membrane in comparison to the untreated group, indicating its potential utilization in clinical studies aiming in the recovery of acute arthritis in patients.

Short-term effects induced by nicotinamide in ovariectomized females.

Nicotinamide adenine dinucleotide (NAD)+ precursors such as nicotinamide activate sirtuins and enhance energy metabolism. The aim of this study was to evaluate the metabolic effects of nicotinamide in ovariectomized (OVX) female rats to establish molecular targets against obesity, which support the safe therapeutic application of nicotinamide. The OVX animals were divided into groups: SHAM (simulated surgery), SHAMn (two weeks of 35 mg·kg-1 nicotinamide per day, by gavage), OVX, and OVXn (two weeks of 35 mg·kg-1 nicotinamide per day, by gavage). The results indicated that nicotinamide favored lipolysis, as evidenced by an increase in free fatty acid and hepatic triglyceride levels, which were not fully normalized during the treatment period. The lipolysis appeared to be due to increased SIRT1 and mitochondrial oxidative phosphorylation in muscle and adipose tissue. There were decreases in muscle and fat nicotinamide N-methyltransferase (NNMT), which were associated with decreases in mass and triglyceride, low-density lipoprotein cholesterol (LDLc), and total cholesterol content. Nicotinamide appeared to be beneficial for the glycemic profile, with normal hepatic glycogen storage and a tendency towards insulin sensitivity in the OVXn. In the SHAMn group, nicotinamide led to glucose intolerance, together with reduced muscle expressions of nicotinamide phosphoribosyltransferase (NAMPT) and SIRT3, suggesting that there were no short-term benefits. Supplementation with nicotinamide led to tissue-specific adaptive lipid and molecular changes in OVX rats.

Regulation of connexins genes expression contributes to reestablishes tissue homeostasis in a renovascular hypertension model.

Connexins (Cx) are essential for cardiovascular regulation and maintenance of cardio-renal response involving the natriuretic peptide family. Changes in the expression of connexins promote intercellular communication dysfunction and may induce hypertension, atherosclerosis, and several other vascular diseases. This study analyzed the expression of the genes involved in the renin-angiotensin system (RAS) and the relation of the connexins gene expression with the renovascular hypertension 2K1C in different tissues. The insertion of a silver clip induced renovascular hypertension 2K1C into the left renal artery. Biochemical measurements were made using commercial kits. Gene expression was evaluated in the liver, heart, and kidneys by RT-PCR. The genes investigated were LDLr, Hmgcr, Agt, Ren, Ace, Agtr1a, Anp, Bnp, Npr1, Cx26, Cx32, Cx37, Cx40 and Cx43. All genes involved in the RAS presented increased transcriptional levels in the 2K1C group, except hepatic Agt. The natriuretic peptides (Anp; Bnp) and the receptor genes (Npr1) appeared to increase in the heart, however, Npr1 decreased in the kidneys. In hepatic tissue, hypertension promoted increased expression of Cx32, Cx37, and Cx40 genes however, Cx26 and Cx43 genes were not influenced. Expression was upregulated for Cx37 and Cx43 in cardiac tissue in the 2K1C group, but Cx40 did not demonstrate any difference between groups. The stenotic kidney showed an upregulated expression for Cx37 vs Sham and contralateral kidney, although Cx40 and Cx43 were downregulated. Hypertension did not modify the transcriptional expression of Cx26 and Cx32. Therefore, this study indicated that RAS and cardiac response were regulated transcriptionally by renovascular hypertension 2K1C. Moreover, the results of connexin gene expression demonstrated differential transcriptional regulation in different tissues studied and suggest a relationship between cardiac and renal physiological changes as an adaptive mechanism to the hypertensive state.

Physiological profile regulation during weight gain and loss by ovariectomized females: importance of SIRT1 and SIRT4.

Obesity in menopausal women occurs because of the systemic effects of loss of ovarian function, resulting in increased body weight and oxidative stress. Caloric restriction (CR) is essential for weight loss, since it provides benefits associated with metabolic normalization resulting from the action of sirtuins. The aim of this work was to evaluate the physiological effects of weight cycling in ovariectomized females. Females aged 2 mo (n = 8/group) were submitted to simulated surgery, ovariectomy (OVX group), and ovariectomy with weight fluctuation (WF group). In the WF group, weight cycling was performed two times, using 21 days of ad libitum commercial feed and 21 days of caloric restriction with 40% of the feed consumed by the OVX group. After 17 wk, the animals were evaluated experimentally. Weight fluctuations reduced triacylglycerol and the adipose tissue index of the WF animals, while increasing the expression of antioxidant proteins. In addition to causing fluctuations in the physiological parameters, the weight cycling led to increases of adipocyte number and serum fatty acids. These effects were reflected in increased expression of the sirtuin (SIRT) 1 and SIRT4 proteins, as well as protein complexes of the mitochondrial electron transport chain, especially in the liver and adipose tissues. The weight-cycling results suggested that mitochondrial and nuclear sirtuins were active in cellular signaling for the control of lipid metabolism, oxidative phosphorylation, and redox status. Weight cycling was able to restore the health characteristics of lean animals.

Caloric restriction recovers impaired ß-cell-ß-cell gap junction coupling, calcium oscillation coordination, and insulin secretion in prediabetic mice.

Caloric restriction can decrease the incidence of metabolic diseases, such as obesity and Type 2 diabetes mellitus. The mechanisms underlying the benefits of caloric restriction involved in insulin secretion and glucose homeostasis are not fully understood. Intercellular communication within the islets of Langerhans, mediated by Connexin36 (Cx36) gap junctions, regulates insulin secretion dynamics and glucose homeostasis. The goal of this study was to determine whether caloric restriction can protect against decreases in Cx36 gap junction coupling and altered islet function induced in models of obesity and prediabetes. C57BL6 mice were fed with a high-fat diet (HFD), showing indications of prediabetes after 2 mo, including weight gain, insulin resistance, and elevated fasting glucose and insulin levels. Subsequently, mice were submitted to 1 mo of 40% caloric restriction (2 g/day of HFD). Mice under 40% caloric restriction showed reversal in weight gain and recovered insulin sensitivity, fasting glucose, and insulin levels. In islets of mice fed the HFD, caloric restriction protected against obesity-induced decreases in gap junction coupling and preserved glucose-stimulated calcium signaling, including Ca2+ oscillation coordination and oscillation amplitude. Caloric restriction also promoted a slight increase in glucose metabolism, as measured by increased NAD(P)H autofluorescence, as well as recovering glucose-stimulated insulin secretion. We conclude that declines in Cx36 gap junction coupling that occur in obesity can be completely recovered by caloric restriction and obesity reversal, improving Ca2+ dynamics and insulin secretion regulation. This suggests a critical role for caloric restriction in the context of obesity to prevent islet dysfunction.

Inhibitory effect of red LED irradiation on fibroblasts and co-culture of adipose-derived mesenchymal stem cells.

The objective of this study was to evaluate the effects of red Light Emiting Diode (red LED) irradiation on fibroblasts in adipose-derived mesenchymal stem cells (ASC) co-culture on the scratch assay. We hypothesized that red LED irradiation could stimulate paracrine secretion of ASC, contributing to the activation of genes and molecules involved in cell migration and tissue repair. ASC were co-cultured with NIH/3T3 fibroblasts through direct contact and subjected to red LED irradiation (1.45 J/cm2/5min6s) after the scratch assay, during 4 days. Four groups were established: fibroblasts (F), fibroblasts + LED (FL), fibroblasts + ASC (FC) and fibroblasts + LED + ASC (FLC). The analyzes were based on Ctgf and Reck expression, quantification of collagen types I and III, tenomodulin, VEGF, TGF-ß1, MMP-2 and MMP-9, as well as viability analysis and cell migration. Higher Ctgf expression was observed in FC compared to F. Group FC presented higher amount of tenomodulin and VEGF in relation to the other groups. In the cell migration analysis, a higher number of cells was observed in the scratched area of the FC group on the 4th day. There were no differences between groups considering cell viability, Reck expression, amount of collagen types I and III, MMP-2 and TGF-ß1, whereas TGF-ß1 was not detected in the FC group and the MMP-9 in none of the groups. Our hypothesis was not supported by the results because the red LED irradiation decreased the healing response of ASC. An inhibitory effect of the LED irradiation associated with ASC co-culture was observed with reduction of the amount of TGF-ß1, VEGF and tenomodulin, possibly involved in the reduced cell migration. In turn, the ASC alone seem to have modulated fibroblast behavior by increasing Ctgf, VEGF and tenomodulin, leading to greater cell migration. In conclusion, red LED and ASC therapy can have independent effects on fibroblast wound healing, but the combination of both does not have a synergistic effect. Therefore, future studies with other parameters of red LED associated with ASC should be tested aiming clinical application for tissue repair.

Acupuncture and moxibustion stimulate fibroblast proliferation and neoangiogenesis during tissue repair of experimental excisional injuries in adult female Wistar rats.

OBJECTIVE: To investigate the effects of acupuncture and moxibustion on the repair of excisional skin injuries on the back of adult female Wistar rats. METHODS: 90 animals were divided into three groups: C, control; A, acupuncture treatment (needled at traditional acupuncture points BL13, BL17 and ST36); M, moxibustion treatment (overlying same traditional acupuncture points). They were euthanased on days 7, 14 and 21 after injury for removal and preparation of tissue for analysis. RESULTS: The treated groups (A and M) showed no changes regarding the structural analysis relative to the control (C) group. The total number of fibroblast cells in the A and M groups were significantly higher than those in the C group on days 14 and 21. The number of granulocytes was significantly less in the A and M groups compared with the C group on days 14 and 21. The total number of newly formed vessels increased on day 21 and was significantly higher in the A and M groups. The amount of birefringent collagen fibre detected on day 21 was significantly higher in the C group. The amount of glycosaminoglycan and hydroxyproline was similar between the groups. The amount of collagen I did not differ between the groups in any period, despite the increased amount detected over time. The amount of type III collagen did not differ between the groups but the detected amount decreased over the course of the experiment. The amount of transforming growth factor ß1 (TGF-ß1) and vascular endothelial growth factor (VEGF) in the A and M rats was similar but inferior to C rats across all experimental periods. CONCLUSIONS: Acupuncture and moxibustion stimulated fibroblast proliferation and neoangiogenesis, and extended the period of collagen fibre reorganisation in the repair of excisional injuries in adult female rats.

ARHGAP21 deficiency impairs hepatic lipid metabolism and improves insulin signaling in lean and obese mice.

ARHGAP21 is a Rho-GAP that controls GTPases activity in several tissues, but its role on liver lipid metabolism is unknown. Thus, to achieve the Rho-GAP role in the liver, control and ARHGAP21-haplodeficient mice were fed chow (Ctl and Het) or high-fat diet (Ctl-HFD and Het-HFD) for 12 weeks, and pyruvate and insulin tolerance tests, insulin signaling, liver glycogen and triglycerides content, gene and protein expression, and very-low-density lipoprotein secretion were measured. Het mice displayed reduced body weight and plasma triglycerides levels, and increased liver insulin signaling. Reduced gluconeogenesis and increased glycogen content were observed in Het-HFD mice. Gene and protein expression of microsomal triglyceride transfer protein were reduced in both Het mice, while the lipogenic genes SREBP-1c and ACC were increased. ARHGAP21 knockdown resulted in hepatic steatosis through increased hepatic lipogenesis activity coupled with decreases in CPT1a expression and very-low-density lipoprotein export. In conclusion, liver of ARHGAP21-haplodeficient mice are more insulin sensitive, associated with higher lipid synthesis and lower lipid export.

Effects of low-level laser therapy on the organization of articular cartilage in an experimental microcrystalline arthritis model.

The aim of this study was to evaluate the effects of low-level laser therapy using the gallium arsenide laser (λ = 830 nm) on the articular cartilage (AC) organization from knee joint in an experimental model of microcrystalline arthritis in adult male Wistar rats. Seventy-two animals were divided into three groups: A (control), B (induced arthritis), and C (induced arthritis + laser therapy). The arthritis was induced in the right knee using 2 mg of Na4P2O7 in 0.5 mL of saline solution. The treatments were daily applied in the patellar region of the right knee after 48 h of induction. On the 7th, 14th, and 21st days of treatment, the animals were euthanized and their right knees were removed and processed for structural and biochemical analysis of the AC. The chondrocytes positively labeled for the TUNEL reaction were lower in C than in B on the 14th and 21st days. The content of glycosaminoglycans and hydroxyproline in A and C was higher than B on the 21st day. The amount of tibial TNF-α in B and C was lower than in A. The amount of tibial BMP-7 in B and C was higher than in A. The femoral MMP-13 was lower in B and C than for A. The tibial TGF-ß for C was higher than the others. The femoral ADAMT-S4 content of A and C presented similar and inferior data to B on the 21st day. The AsGa-830 nm therapy preserved the content of glycosaminoglycans, reduced the cellular changes and the inflammatory process compared to the untreated group.

Do electrical current and laser therapies improve bone remodeling during an orthodontic treatment with corticotomy?

OBJECTIVES: Evaluate the bone remodeling during orthodontic movement with corticotomy when submitted to low-intensity electrical stimulation application (microcurrent-MC) and low-level laser therapy (LLLT). MATERIAL AND METHODS: One hundred and fifty Wistar rats were divided into the following 5 groups: (C) submitted to tooth movement; (Cort) tooth movement/corticotomy; (Cort-L) tooth movement/corticotomy/laser AsGaAl 808 nm (4.96J/50s); (Cort-Mc) tooth movement/corticotomy/microcurrent (10 µA/5 min); (Cort-L-Mc) tooth movement/corticotomy and laser/microcurrent alternated. Inflammation, angiogenesis, and osteogenesis were evaluated in the periodontal ligament (PDL) and alveolar bone on the 7th, 14th, and 21st days of orthodontic movement. RESULTS: The quantification of inflammatory infiltrate, angiogenesis and expression of TGF-ß1, VEGF, and collagen type I were favorably modulated by the application of therapies such as low-level laser therapy (LLLT), MC, or both combined. However, electrical stimulation increased fibroblasts, osteoclasts and RANK numbers, birefringent collagen fiber organization, and BMP-7 and IL-6 expression. CONCLUSIONS: Low-level laser therapy (LLLT) and MC application both improved the process of bone remodeling during orthodontic treatment with corticotomy. Still, electrical current therapy promoted a more effective tooth displacement but presented expected root resorption similar to all experimental treatments. CLINICAL RELEVANCE: It is important to know the effects of minimally invasive therapies on cellular and molecular elements involved in the bone remodeling of orthodontic treatment associated with corticotomy surgery, in order to reduce the adverse effects in the use of this technique and to establish a safer clinical routine.

Activators of SIRT1 in wound repair: an animal model study.

Caloric restriction (CR) and resveratrol activate SIRT1 and induce anti-inflammatory and antioxidant properties. We perform excisional lesion on the dorsum of four groups anesthetized animals: ad libitum-AL diet, AL diet with topical application of 2% resveratrol-Rv, 30% calorie restricted, and finally 30% calorie restricted with 2% resveratrol and we examine CR and Rv effects in wound repair. Restricted animals remained with CR for 31 days. The lesion was performed on day 18 of CR, and resveratrol application was started on day 19. Lesion samples were then collected on days 3 and 10 of treatment for structural, morphometric, and protein analyses. Our results showed that CR and Rv group as well as R group had enhanced numbers of blood vessels, VEGF, fibroblast, birefringent collagen fiber areas in the lesion. We conclude that effects in wound repair suggests that both CR and resveratrol may modulate angiogenesis, fibroplasia, and collagenesis, which could be ascribed to the action of SIRT1.

Transected Tendon Treated with a New Fibrin Sealant Alone or Associated with Adipose-Derived Stem Cells.

Tissue engineering and cell-based therapy combine techniques that create biocompatible materials for cell survival, which can improve tendon repair. This study seeks to use a new fibrin sealant (FS) derived from the venom of Crotalus durissus terrificus, a biodegradable three-dimensional scaffolding produced from animal components only, associated with adipose-derived stem cells (ASC) for application in tendons injuries, considered a common and serious orthopedic problem. Lewis rats had tendons distributed in five groups: normal (N), transected (T), transected and FS (FS) or ASC (ASC) or with FS and ASC (FS + ASC). The in vivo imaging showed higher quantification of transplanted PKH26-labeled ASC in tendons of FS + ASC compared to ASC on the 14th day after transection. A small number of Iba1 labeled macrophages carrying PKH26 signal, probably due to phagocytosis of dead ASC, were observed in tendons of transected groups. ASC up-regulated the Tenomodulin gene expression in the transection region when compared to N, T and FS groups and the expression of TIMP-2 and Scleraxis genes in relation to the N group. FS group presented a greater organization of collagen fibers, followed by FS + ASC and ASC in comparison to N. Tendons from ASC group presented higher hydroxyproline concentration in relation to N and the transected tendons of T, FS and FS + ASC had a higher amount of collagen I and tenomodulin in comparison to N group. Although no marked differences were observed in the other biomechanical parameters, T group had higher value of maximum load compared to the groups ASC and FS + ASC. In conclusion, the FS kept constant the number of transplanted ASC in the transected region until the 14th day after injury. Our data suggest this FS to be a good scaffold for treatment during tendon repair because it was the most effective one regarding tendon organization recovering, followed by the FS treatment associated with ASC and finally by the transplanted ASC on the 21st day. Further investigations in long-term time points of the tendon repair are needed to analyze if the higher tissue organization found with the FS scaffold will improve the biomechanics of the tendons.

Electrical stimulation: Complementary therapy to improve the performance of grafts in bone defects?

The limitations of bone reconstruction techniques have stimulated the tissue engineering for the repair of large bone defects using osteoconductive materials and osteoinductive agents. This study evaluated the effects of low intensity electric current on the inorganic bovine graft in calvaria defects. Bone defects were performed with piezoelectric system in the calvaria of Wistar rats divided into four groups (n = 24): (C) without grafting and without electrical stimulation; (E) with grafting; (MC) without grafting and submitted to electrical stimulation; (MC + E) with grafting and submitted to electrical stimulation. Inflammatory, angiogenic and osteogenic events during bone repair at the 10th, 30th, 60th, and 90th days were considered. Several inflammatory markers demonstrated the efficacy of grafting in reducing inflammation, particularly when subjected to electrical stimulation. Angiogenesis and collagen organization were more evident by electrical stimulation application on the grafts. Moreover, the osteogenic cell differentiation process indicated that the application of microcurrent on grafting modulated the homeostasis of bone remodeling. It is concluded that microcurrent favored the performance of grafts in calvarial rat model. Low-intensity electrical current might improve the osteoconductive property of grafting in bone defects. Therefore, electrical current becomes an option as complementary therapy in clinical trials involving bone surgeries and injuries. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 924-932, 2019.

Vitamin E supplementation and caloric restriction promotes regulation of insulin secretion and glycemic homeostasis by different mechanisms in rats.

Vitamin E and caloric restriction have antioxidant effects in mammals. The aim of this study was to evaluate effects of vitamin E supplementation and caloric restriction upon insulin secretion and glucose homeostasis in rats. Male Wistar rats were distributed among the following groups: C, control group fed ad libitum; R, food quantity reduction of 40%; CV, control group supplemented with vitamin E [30 mg·kg-1·day-1]; and RV, food-restricted group supplemented with vitamin E. The experiments ran for 21 days. Glucose tolerance and insulin sensitivity was higher in the CV, R, and RV groups. Insulin secretion stimulated with different glucose concentrations was lower in the R and RV groups, compared with C and CV. In the presence of glucose and secretagogues, insulin secretion was higher in the CV group and was lower in the R and RV groups. An increase in insulin receptor occurred in the fat pad and muscle tissue of groups CV, R, and RV. Levels of hepatic insulin receptor and phospho-Akt protein were higher in groups R and RV, compared with C and CV, while muscle phospho-Akt was increased in the CV group. There was a reduction in hepatic RNA levels of the hepatocyte growth factor gene and insulin degrading enzyme in the R group, and increased levels of insulin degrading enzyme in the CV and RV groups. Thus, vitamin E supplementation and caloric restriction modulate insulin secretion by different mechanisms to maintain glucose homeostasis.