The mechanisms underlying the potentially beneficial effect of bone marrow stem cells (BMSCs) on spinal cord injury (SCI) are unknown. Therefore, the aim of the present study was to explore the protective effect of BMSCs in rats with SCI. A total of 45 adult male Sprague-Dawley rats were randomly divided into three groups; the SCI group (n=15), the BMSC group (n=15) and the sham-operation group (n=15). In the SCI and BMSC treatment groups, a modified Allen's weight-drop technique was used to induce SCI. The BMSC treatment group received an injection of BMSCs using a microneedle into the epicenter of the spinal cord 24 h after injury. Rats in the sham-operation group were not subjected to SCI; however, the corresponding vertebral laminae were removed. Seven days after transplantation, a rapid recovery was observed in the Basso, Beattie and Bresnahan (BBB) scores of the BMSC treatment group, whereas the BBB scores in the SCI group remained low (P<0.05). Caspase-12 expression in the SCI group was increased compared with that in the sham-operation group, whereas caspase-12 expression was attenuated 24 h after transplantation in the BMSC treatment group (P<0.05). In conclusion, the transplantation of BMSCs may improve locomotor function and attenuate caspase-12 expression following SCI. Therefore, it is likely to be an effective strategy for preventing severe injury of the spinal cord.

Osteosarcoma is the most common type of malignant bone tumor, which has an overall survival rate of only 15-30%. The present study aimed to investigate the effects of 15-hydroxy-6α,12-epoxy-7β,10αH,11βH-spiroax-4-ene-12-one (HESEO), a compound extracted from the endophytic fungus Penicillium sp. FJ-1 isolated from Avicennia marina, on the proliferation of osteosarcoma cells and to explore its underlying mechanisms of action. Cell number was counted to measure the cell proliferation. JC-1 reagent was used to measure mitochondrial membrane potential. ELISA was used to measure the cytochrome c level and caspase activities. Apoptosis was detected by Annexin V-Propidium Iodide staining. Gene and protein expression were measured by reverse-transcription-PCR and western blot analysis, respectively. Additionally, the anti-tumor effects of HESEO were explored within a syngeneic osteosarcoma tumor model. The results suggested that HESEO significantly inhibited the proliferation of osteosarcoma cells and induced apoptosis of MG-63 cells, evidenced by their decreased mitochondrial membrane potential, and increased cytochrome c release, caspase activities and percentage of apoptotic cells. In addition, HESEO increased the expression of pro-apoptotic genes and proteins compared with control cells. The results indicated that HESEO may act through increasing p53 upregulated modulator of apoptosis expression. Furthermore, HESEO treatment significantly increased the survival time and decreased the tumor burden of osteosarcoma tumor-bearing mice compared with vehicle treatment. Furthermore, combined treatment with HESEO enhanced the effects of the chemotherapeutic agent methotrexate on a lung metastasis osteosarcoma model. These data suggested that HESEO could be developed as a potential anti-tumor agent against osteosarcoma.

Hyperlipidemia may lead to endothelial injury, due to its effects on homocysteine and vascular endothelial growth factor in the serum, and the mRNA expression levels of peroxisome proliferator-activated receptor-γ (PPARγ), and caspase-3 and -8 in the vascular wall. In order to prevent and mitigate the high-fat state that results from endothelial injury, this study examined the effect of folic acid (FA) and vitamin B12 (VB12) on the expression of PPARγ and caspase-3 and -8 mRNA in the abdominal aortas of rats with hyperlipidemia. Sixty 4-week-old healthy male Sprague Dawley rats were randomly divided into five groups (each n=12): the normal control (NC), high-fat diet (HL), FA, VB12 and FA+VB12 groups. Following one week of adaptive feeding, the FA, VB12 and FA+VB12 groups were subject to the intraperitoneal injection of FA (0.5 mg/day), VB12 (0.05 mg/day) and FA+VB12 (0.5 mg/day and 0.05 mg/day), respectively, while fed a high-fat diet. The rats in the NC group were injected intraperitoneally with 0.9% NaCl solution (0.5 ml/day) and fed a normal diet, whereas those in the HL group were fed a high-fat diet only. A reverse transcription-polymerase chain reaction (RT-PCR) assay demonstrated that at the end of week 12, the FA treatment had effectively increased the PPARγ mRNA level, while reducing the caspase-3 and -8 mRNA levels, compared with the high-fat diet treatment (P<0.05). The effect of FA on the expression of PPARγ and caspase-3 and -8 was enhanced when used in combination with VB12 (P<0.05). These results revealed that the application of FA, alone or in combination with VB12, improves and mitigates the high-fat state that results from endothelial injury.

Saxagliptin (SAX) can protect against tissue damage caused by diabetic nephropathy. However, whether this compound can restore kidney function, and its specific mechanism of action remain unclear. The present study explored the therapeutic effects and mechanisms of SAX. Male Wistar rats (8 weeks old) were randomly divided into the following groups: A control group (n=10); a group with streptozocin-induced diabetes mellitus (DM) treated with saline (n=20); and a group with streptozocin-induced DM treated with SAX (n=20). Following 20 weeks of treatment, renal function and the extent of renal damage were assessed based on histological staining using hematoxylin and eosin, periodic acid-Schiff and Masson's trichrome staining. The experimental results indicated that Streptozocin induction of DM led to thicker basement membranes in mesangial cells and a more abundant extracellular matrix. These changes were ameliorated following treatment with SAX. The data demonstrated that renal tissue and renal cell apoptosis were ameliorated significantly following treatment with SAX. Furthermore, the expression levels of the apoptotic genes poly (ADP-ribose) polymerase-1 (PARP-1) and caspase 3 were significantly decreased following treatment with SAX. Therefore, SAX may reduce the extent of renal apoptosis and pathological outcomes in diabetic nephropathy by downregulating the expression of caspase 3 and PARP-1 in the death receptor pathway of apoptosis.

Effect of simvastatin on the expression of caspase-3 in myocardial ischemia reperfusion injury in rats was observed to explore the protective effect of caspase-3 through anti-apoptosis mechanism. A total of 48 healthy male SD rats weighing 160-240 g were selected and divided into 4 groups randomly, namely, the blank group, the sham operation group, the ischemia-reperfusion group and the simvastatin group, with 12 rats in each group. The model of SD rats was made by ligation. The loosen ligature made the reperfusion animal model, the occurrence of arrhythmia in the electrocardiogram of lead II in the experimental animal model was observed, and the area of myocardial infarction in the experimental animal models was detected. The number of apoptotic cells was detected by immunohistochemistry, and the expression of caspase-3 was detected by western blotting. The infarct area in the simvastatin group was significantly lower than the ischemia reperfusion group (P<0.05). The positive rate of the expression of caspase-3 and the positive rate of the expression of apoptotic cells in the ischemic reperfusion and simvastatin groups were significantly higher than that of the blank and sham operation groups, and the positive rate of the expression of caspase-3 and apoptotic cells in the simvastatin group was significantly lower than that of the ischemia-reperfusion group (P<0.05). The arrhythmia score of the simvastatin group was significantly lower than that of the ischemia-reperfusion group (P<0.05). Compared with the blank and sham operation groups, the expression of caspase-3 protein in the ischemia-reperfusion and simvastatin groups was significantly increased, and the expression of caspase-3 protein in the simvastatin group was significantly lower than that of the ischemia reperfusion group (P<0.05). Simvastatin has a protective effect on myocardial ischemia-reperfusion injury, which may be related to the reduction of caspase-3 expression and inhibition of apoptosis.

Coumarins have attracted intense interest in recent years due to their apoptogenic effects. The aim of the present study was to determine whether 7-hydroxycoumarin (7-HC) induces changes in caspase-3 (C-3) activity in A549 human lung carcinoma cells. A range of analytical techniques, including colorimetric and fluorometric assays, western blotting, single-cell microinjection, fluorescence microscopy and image analysis were conducted to elucidate the effects of 7-HC. A 24-h exposure to 1.85 mM 7-HC induced a 65% increase in C-3 activity, and a notable conversion of procaspase-3 to C-3, in addition to poly(ADP-ribose)polymerase cleavage. Furthermore, morphological changes associated with apoptosis were observed. Exposure of the cells to 7-HC for 3 or 6 h increased calcium conductance by 27%. By performing the single-cell microinjection of a specific fluorescent substrate of C-3 into previously 7-HC-exposed cells, a typical enzymatic kinetic profile of C-3 activation was identified a number of hours prior to the morphological and biochemical changes associated with apoptosis being observed. These results suggest that the rapid in vivo activation of C-3 is induced by 7-HC, the most relevant biotransformation product of coumarin in humans.

The role of caspase-6 in heart disease is not well understood, particularly with respect to cardiac arrhythmia. Also, the function of syndecan-1 in the stimulation of inflammation or a regenerative response after cardiac injury is unclear. Leptin receptor-deficient (C57BL/KS-leprdb/leprdb) mice were used in the present study. In addition to developing type 2 diabetes, they also develop initial- and end-stage cardiac arrhythmia after 5 and 8 months, respectively. The initial and end-stage arrhythmias were confirmed through progressive variations in the PP intervals observable in electrocardiograms. Histopathological images of the cardiac tissue exhibited scattered and loosened cardiac cells at the initial stage of cardiac arrhythmia, whereas tissue hardness and extensive structural changes in cardiomyocytes were evident at the end stage. At the molecular level, the progressive upregulation of caspase-6 was observed as the cardiac arrhythmia progressed. In the initial stage of arrhythmia, immunohistochemistry revealed that caspase-6 was expressed at the surface of cardiac cells, suggesting that caspase-6 targeted the extracellular matrix, leading to a loosening of the cardiac tissue structure. In the end stage of cardiac arrhythmia, caspase-6 expression was abundant in the cytoplasm, as well as at the cell surface, suggesting that caspase-6 may have cleaved intermediate filaments, paving the way for cellular morphological changes and apoptosis. Notably, syndecan-1 was upregulated 5.8-fold in the initial stage of cardiac arrhythmia, but downregulated at the end stage. Syndecan-1 may restrict the expression of caspase-6 in the initial stage of cardiac arrhythmia, while its downregulation at the end stage may allow destructive changes via caspase-6 overexpression. Furthermore, the knockdown of syndecan-1 using small interfering RNA enhanced the expression of caspase-6 in the cardiac tissue by factors of 1.8 and 1.2 at the initial and end stages of cardiac arrhythmia, respectively, compared with that in non-silenced cardiac tissue. Therefore, it may be concluded that syndecan-1 plays a major role in the regulation of caspase-6 during the pathological stages of cardiac arrhythmia.

Numerous studies have demonstrated that neuronal cell death occurs via extrinsic (death receptors) and intrinsic (mitochondria) pathways. Radiation induces caspase activation fundamentally via the mitochondrial pathway. To investigate the role of caspase, a cell permeable pan-caspase inhibitor, z-VAD-fmk [N-benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone], was used to investigate the effects of caspase blockade in vivo following irradiation. Adult male Sprague-Dawley rats (weight, 250-300 g) underwent irradiation at room temperature with a 4-Gy dose of radiation. Since z-VAD-fmk does not penetrate the blood-brain barrier, it was applied intracerebroventricularly via a bolus injection (0.2 μg/h for 1 h). Terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) demonstrated that z-VAD-fmk reduced the numbers of TUNEL-positive cells within the hypoglossal nucleus, suggesting that intervention in the caspase cascade following radiation may have therapeutic applications. The caspase inhibitor z-VAD-fmk reduced the expression and activation of caspase-3, caspase-8 and caspase-9 in the irradiated rats, indicating that caspase may be a potential therapeutic target in the treatment of brain radiation injury. Treatment with z-VAD-fmk also reduced the appearance of cytochrome c within the cytosolic fraction following radiation. The hypoglossal nucleus may be used as a model of radiation-induced injury in the central nervous system, providing visual information and displaying apoptotic nuclear morphology.

The aim of the present study was to observe the dynamic changes of the growth arrest and DNA damage-inducible 153 (GADD153) gene and caspase-12 in the brain tissue of rats with cerebral ischemia-reperfusion injury (CIRI) and the impact of curcumin pretreatment. A total of 60 rats were randomly divided into the normal group (N), the sham operation group (S), the dimethyl sulfoxide control group (D) and the curcumin treatment group (C). For group D and C, 12 (T1), 24 (T2) and 72 h (T3) of reperfusion were performed after 2 h ischemia. The expression levels of GADD153 and caspase-12 in the brain tissue were detected and compared among the groups by immunohistochemistry, immunofluorescence double staining and western blotting. The expression levels of GADD153 and caspase-12 were increased at T1compared with groups N and S, and the expression of caspase-12 peaked at T2 in group D, while GADD153 was increased until T3 in group D. Compared with group D, the expression levels of GADD153 and caspase-12 in group C at T2 and T3 were significantly decreased (P<0.05). Endoplasmic reticulum stress is involved in the pathological process of CIRI. Curcumin may decrease the expression levels of the above two factors, thus exhibiting protective effects against CIRI in rats.

The protective effect of sevoflurane on apoptosis of rat H9c2 cardiomyocytes induced by H2O2 and the effect on the expression of glucose-regulated protein 78 (GRP78) were investigated. H9c2 cells were routinely cultured and divided into the control, model and sevoflurane groups. Cells in the model group were treated with 400 µM H2O2, and cells in the sevoflurane group were pretreated with sevoflurane prior to treatment with 400 µM H2O2. MTT assay was used to assess cell viability. Annexin V-propidium iodide (AV-PI) double staining flow cytometry was used to detect apoptosis. The intracellular free Ca2+ concentration was measured by the fluorescence-based assay using Fluo-3 AM as a calcium ion fluorescence probe. The mRNA expression level of GRP78 and protein expression levels of GRP78, CHOP and caspase-12 were measured using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis, respectively. The assays showed that after sevoflurane pretreatment the H9c2 cell viability was significantly increased, whereas the H2O2-induced apoptosis, intracellular Ca2+ concentration, mRNA expression of GRP78, and the protein expression of GRP78, CHOP and caspase-12 were all reduced. The results show that pretreatment with sevoflurane inhibited H2O2-induced apoptosis in H9c2 cells. The mechanism may be related to inhibition of the stress-related protein GRP78 expression in endoplasmic reticulum, resulting in decreased intracellular Ca2+ concentration and the downregulation of CHOP and caspase-12 expression levels.

Chronic intermittent hypoxia (CIH) has been shown to induce cell apoptosis in multiple organs of the human body. The present study aimed to assess the effects of exogenous klotho on CIH-induced genioglossus muscle injury, as well as the involvement of endoplasmic reticulum stress (ERS) in this process. A total of 36 adult C57BL/6 male mice were assigned to normoxia control (NC), CIH and CIH + klotho groups (n=12 mice/group). ELISA was performed to detect the level of klotho protein in the serum and in the genioglossus muscle tissue samples. Apoptosis was evaluated using the TUNEL assay. Reactive oxygen species (ROS) levels were quantified using a dihydroethidium assay kit, and the protein and mRNA levels of ERS-associated proteins (namely, glucoseregulated protein 78, C/EBP homologous protein, cleaved caspase-12 and cleaved caspase-3) in genioglossus samples were assessed using immunoblot assay and reverse transcription-quantitative PCR, respectively. Compared with the NC group, the quantities of klotho protein in the serum and genioglossus muscle tissue samples in the CIH group were significantly decreased, whereas the apoptotic rate, ROS levels and protein and mRNA levels of the ERS-associated proteins in the genioglossus muscle were significantly increased. Following supplementation with exogenous klotho protein, the klotho protein levels in the serum and genioglossus muscle tissue of mice were found to be markedly increased, and the apoptotic rate, ROS levels and protein and mRNA levels of the ERS-associated proteins in the genioglossus muscle were decreased compared with those in the CIH group. Taken together, the results of the present study have demonstrated that exogenous klotho may inhibit apoptosis of genioglossus myocytes in mice by inhibiting ROS-associated ERS.

The present study aimed to explore the pathogenesis behind post-traumatic epilepsy (PTE). In the present study, a chloride ferric injection-induced rat PTE model was established. The expression levels of apoptosis-antagonizing transcription factor (AATF), cleaved caspase-3, p53, Bcl-2 and Bax were measured by western blotting or immunofluorescence staining (IF). The expression of AATF in vivo was downregulated by microinjection of lentiviral-mediated short-hairpin RNA. Compared with control and sham groups, at day 5 after PTE, neuron apoptosis was significantly increased and the expression levels of AATF, p53, cleaved caspase-3 and Bax were significantly upregulated. In addition, IF revealed co-localization of AATF and cleaved caspase-3 in the cortex. Additionally, AATF was expressed mainly in neurons and astrocytes. Following AATF inhibition, the expression levels of p53 and cleaved caspase-3 were significantly reduced as compared with the control group. Taken together, these findings suggested that following PTE, AATF is involved in neuronal apoptosis and may serve as a potential target for its alleviation.

The effects of berberine on cardiac function of heart failure after myocardial infarction and its possible mechanism were investigated. The anterior descending branches of 50 female Wistar rats were ligatured to establish the model of heart failure after myocardial infarction. At 4 weeks after successful modeling, the rats were randomly divided into two groups receiving 4-week gavage with saline (Sal group) and berberine (Ber group), while the sham-operation group (Sham group) was set up. After 4 weeks, the hemodynamics and serum BNP in rats were measured. The hearts of rats were taken to detect the degree of myocardial fibrosis. The myocardial cell apoptosis was detected. The expressions and changes in myocardial apoptosis-related proteins, including Bcl-2, Bax and caspase-3, were detected. The expression and changes in GRP78, CHOP and caspase-12 in myocardial tissue were detected. The results showed that Berberine improved the cardiac function of rats after myocardial infarction. After myocardial infarction, myocardial fibrosis and apoptosis were observed around the infarction area, berberine improved the myocardial fibrosis and reduced cell apoptosis. Furthermore, berberine alleviated endoplasmic reticulum stress (ERS) after myocardial infarction. In conclusion, Berberine can inhibit the myocardium cell apoptosis of heart failure after myocardial infarction, and its mechanism may be realized by affecting the ERS in myocardial tissue of heart failure after myocardial infarction and CHOP and caspase-12 apoptotic signaling pathway, upregulating Bcl-2/Bax expression and downregulating caspase-3 expression, thus inhibiting the cardiac remodeling and protecting the cardiac function.

Diabetic cardiomyopathy is a common complication of diabetes, in which endoplasmic reticulum stress (ERS) serves an important role. Rutin can treat the myocardial dysfunction of diabetic rats. However, to the best of our knowledge, studies on the effects of Rutin on myocardial injury caused by diabetes from the perspective of ERS have not previously been reported. In the present study, the role of rutin in the regulation of ERS in myocardial injury was assessed. Different high glucose concentrations were used to treat H9C2 myoblast cells to establish a myocardial damage model. A cell counting kit-8 assay was used to determine cell viability. A lactate dehydrogenase kit was used to detect cytotoxicity. Apoptosis levels were determined using a TUNEL assay. Western blotting was used to determine the expression levels of apoptosis-related proteins and ERS-related proteins, including heat shock protein A family member 5, inositol-requiring enzyme-1α, X-box binding protein 1, activating transcription factor 6, C/EBP-homologous protein (CHOP), cleaved caspase-12 and caspase-12. The anti-apoptotic and anti-ERS effects of Rutin on H9C2 cardiac cells induced by high glucose were examined after the administration of the ERS activator thapsigargin (TG). The results indicated that rutin could dose-dependently inhibit the level of apoptosis and ERS induced by high glucose in H9C2 cells. After administration of the ERS activator TG, it was demonstrated that TG could reverse the anti-apoptotic and anti-ERS effects of rutin on H9C2 cells stimulated with high glucose. Collectively, the present results suggested that rutin may alleviate cardiomyocyte model cell injury induced by high glucose through the inhibition of apoptosis and ERS.

Testicular torsion/detorsion causes severe tissue damage due to ischemia/reperfusion injury. The present study investigated the protective effect of erythropoietin and sildenafil against ischemia/reperfusion injury following unilateral testicular torsion/detorsion in adult rats. A total of 28 adult male rats were included, and were divided into the following groups: Group A (n=5), sham operated; groups B (n=5), C (n=5), D (n=5) and E (n=8), undergoing right testis torsion and detorsion after 90 min. Group B received no drug treatment. Rats in the groups C and D received low-dose (1,000 IU/kg) or high-dose (3,000 IU/kg) erythropoietin, while those in group E received sildenafil (0.7 mg/kg), through intraperitoneal injection after 60 min of torsion. The right testis was extracted 24 h after detorsion, and the tissue was subjected to histopathological examination and immunohistochemical assessment of cleaved caspase-3 expression. Histological alterations and the quality of spermatogenesis were scored according to the Cosentino and the Johnsen scoring systems, respectively. The results demonstrated normal testicular architecture in group A, while the other groups showed ischemic cellular damages, with the worst scores observed in group B. Groups D and E presented better scores compared with group C. Regarding the quality of spermatogenesis, the best scores were observed in group A, and the worst in group B. Groups C, D and E presented similar results, which were improved in comparison to group B, however, not compared to group A. Furthermore, cleaved caspase-3 levels were lower in groups A, D and E, with equal results observed. Group C had higher levels of cleaved caspase-3 compared with these groups, but lower than group B, which presented the highest cleaved caspase-3 levels. In conclusion, erythropoietin and sildenafil protect testis from ischemia/reperfusion injury by decreasing cellular damage and attenuating apoptosis.

The aim of the present study was to explore the effect of exogenous hydrogen sulphide (H2S) on endoplasmic reticulum (ER) stress (ERS) in a rat model of hepatic ischemia/reperfusion (I/R) injury. A total of 48 Sprague-Dawley rats were randomly divided into four groups (n=12/group) as follows: Sham, I/R, I/R preceded by NaHS (I/R-NaHS) and I/R preceded by L-C-propargylglycine (PAG), a H2S inhibitor (I/R-PAG). With the exception of the sham group, the rats in the other groups were subjected to 30 min hepatic warm ischemia followed by reperfusion for 6 or 12 h. Hepatic function was evaluated by serum concentrations of alanine aminotransferase (ALT). Apoptosis of hepatic cells was assessed by TUNEL staining and measurement of caspase-12 expression. The expression levels of ERS-associated proteins and mRNAs of pancreatic ER eukaryotic translation initiation factor-2a kinase (PERK), activating transcription factor-6 (ATF6), glucose-regulated protein (GRP) 78, TNF-receptor-associated factor (TRAF)-2, C/EBP homologous protein (CHOP) and caspase-12 were also measured by western blotting and reverse transcription-quantitative PCR. The serum concentrations of ALT in the I/R and I/R-PAG groups were found to be significantly higher compared with those in the sham and I/R-NaHS groups after 6 h of reperfusion; in addition, the ALT level returned to normal in the I/R group, while it increased further in the I/R-PAG group after 12 h of reperfusion. A higher cell apoptosis rate was observed in the I/R and I/R-PAG groups and the highest cell apoptosis rate was observed in the I/R-PAG group; correspondingly, the expression of caspase-12 was increased in the I/R and I/R-PAG groups. H2S appeared to significantly attenuate hepatic I/R-induced ERS response, as indicated by the decreased expression of ATF6, PERK, GRP78, TRAF2 and CHOP. Endogenous H2S may serve a hepatoprotective function after I/R, and inhibition of endogenous H2S results in aggravation of I/R damage. Exogenous H2S was shown to inhibit ERS-related gene expression, leading to suppression of inflammatory reaction and improvement of I/R damage. Therefore, exogenous H2S has therapeutic potential to alleviate hepatic I/R injury.

The present study aimed to investigate the effects of sericin on the p38MAPK signaling pathway and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in the kidney of rats with type 2 diabetes mellitus (T2DM). A total of 36 male Sprague-Dawley rats were randomly divided into the normal group, T2DM model group and sericin group (n=12 rats/group). A T2DM model was developed through intraperitoneal injection of streptozotocin (35 mg·kg-1·d-1 for 2 consecutive days), and a high-fat and high-sugar diet. The T2DM rats in the sericin group were administered 2.4 g·kg-1·d-1 sericin for 35 days, and rats in the other groups were administered an equal volume of normal saline for 35 days. Fasting blood glucose was measured using the glucose oxidase method. Kidney tissue morphology was observed by H&E staining. Immunohistochemistry, western blotting, ELISA and reverse transcription-quantitative PCR were used to detect the levels of MKK6, p38MAPK, phosphorylated (p)-p38MAPK, NF-κB, IL-1β, IL-6, NLRP3 and caspase-1 in rat kidney tissues. The results revealed that blood glucose concentration, and the expression levels of MKK6, p-p38MAPK, NF-κB, IL-1β, IL-6, NLRP3 and caspase-1 were significantly increased in the T2DM group compared with those in the normal group (P<0.05). In addition, obvious pathological changes were observed in the T2DM group. Conversely, glucose concentration, and the expression levels of MKK6, p-p38MAPK, NF-κB, IL-1β, IL-6, NLRP3 and caspase-1 were significantly reduced in the sericin group compared with those in the T2DM group (P<0.05). The pathological changes were also obviously reduced. Notably, there was no significant difference in p38MAPK expression among the three groups (P>0.05). Collectively, the present study revealed that sericin may downregulate the expression levels of MKK6, p-p38MAPK, NF-κB, IL-1β, IL-6, NLRP3 and caspase-1, and inhibit activation of renal p38MAPK signaling and NLRP3-associated inflammation, which in turn may protect against kidney damage caused by T2DM.

Ischemia-reperfusion (I/R) often leads to acute kidney injury, chronic renal failure and kidney transplantation failure. Glycyrrhizin is extracted from Glycyrrhiza glabra roots and is the predominant active component, which exhibits anti-inflammatory effects. However, to the best of our knowledge, the effect of glycyrrhizin on I/R-induced renal injury has not been investigated. In the present study, glycyrrhizin was demonstrated to attenuate renal I/R injury in mice via administration of glycyrrhizin, which suppressed the serum levels of creatinine and blood urea nitrogen 6 h following reperfusion; furthermore, the superoxide anions as well as the activity of superoxide dismutase within renal tissues was reduced by glycyrrhizin pretreatment. Moreover, the protein level of cleaved caspase-3, as well as its activity in renal tissue, was suppressed as a result of the glycyrrhizin pretreatment, indicating that glycyrrhizin inhibits I/R-induced renal cell apoptosis. In addition, glycyrrhizin pretreatment appeared to ameliorate I/R-induced renal injury via inhibition of inflammatory cell infiltration, as well as the production of pro-inflammatory cytokines, including tumor necrosis factor-α, interferon-γ, interleukin (IL)-1β and IL-6. The underlying molecular mechanism was investigated and it was shown that the activity of p38 mitogen-activated protein kinase signaling was downregulated as a result of glycyrrhizin administration. In conclusion, the present study indicated that glycyrrhizin provided significant protection against I/R-induced renal injury in mice by inhibiting inflammatory responses and renal cell apoptosis. Therefore, glycyrrhizin may be used in abdominal surgery and kidney transplantation for the prevention of renal I/R damage.

To explore the influence of hyperhomocysteinemia (hHcys) on the tibial fracture healing in rats and its effect on the phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (AKT) signaling pathway. A total of 36 Sprague-Dawley rats were randomly divided into sham group (n=12), tibial fracture group (n=12) and hHcys + fracture group (n=12). The rats in tibial fracture group underwent the tibial fracture surgery, while the model of tibial fracture and hHcys was established in hHcys + fracture group. The level of plasma homocysteine (Hcy) in each group was analyzed using the full-automatic biochemical analyzer, the fracture stress biomechanical measurement was performed, and the ultimate bending strength and torque were calculated. Moreover, the protein expressions of PI3K and phosphorylated (p)-AKT in tibial tissues were detected using western blotting, the messenger ribonucleic acid (mRNA) levels of Bcl-2 associated X protein (Bax) and caspase-3 were detected using quantitative polymerase chain reaction (qPCR), the apoptosis was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, and the expressions of inflammatory factors were detected via immunohistochemistry. Compared with sham group, tibial fracture group and hHcys + fracture group had a significantly increased level of plasma Hcy, significantly decreased ultimate bending strength and torque, obviously decreased relative protein expressions of PI3K and p-AKT, increased mRNA levels of Bax and caspase-3 and an increased expression of pro-inflammatory factor tumor necrosis factor-α (TNF-α). Compared with tibial fracture group, hHcys + fracture group had a higher level of plasma Hcy, lower ultimate bending strength and torque, lower relative protein expressions of PI3K and p-AKT, higher mRNA levels of Bax and caspase-3, a higher apoptosis rate and a higher expression of TNF-α. hHcys blocks the downstream apoptotic signal transduction, promotes apoptosis and inflammatory response, and affects fracture healing through affecting the PI3K/AKT signaling pathway.

Central poststroke pain (CPSP) is a central neuropathic pain syndrome that occurs following a stroke and mainly manifests as pain and paresthesia in the body region corresponding to the brain injury area. At present, due to the lack of clinical attention given to CPSP, patients suffer from long-term pain that seriously affects their quality of life. Current literature indicates that microRNA (miR)-223 can impede inflammation and prevent collateral damage. The NLR family pyrin domain containing 3 (NLRP3) inflammasome induces IL-18 and IL-1β secretion and maturation and participates in the inflammatory response. Previous evidence has confirmed that miR-223 can negatively regulate NLRP3 in the development of inflammatory responses. However, whether the miR-223 targeting of NLRP3 is involved in CPSP remains unclear. In the present study, the expression of miR-223 was detected by reverse transcription-quantitative PCR analysis. The expression levels of NLRP3, caspase-1, ASC, IL-18, IL-1β, ERK1/2, p-ERK1/2 and GFAP were detected by western blot analysis. The results demonstrated that thalamic hemorrhagic stroke triggered by microinjection of collagenase Ⅳ (Coll IV) into the ventral posterior lateral (VPL) nucleus results in pain hypersensitivity. miR-223 expression level were significantly reduced in the CPSP model. The expression levels of NLRP3, caspase-1, ASC, IL-18 and IL-1β were significantly increased in the CPSP model. The expression level of GFAP was detected to determine astrocyte activation. The results demonstrated that astrocyte activation induced by Coll IV produced a CPSP model. The p-ERK1/2 expression level was demonstrated to be significantly increased in the CPSP model. The introduction of an miR-223 agomir significantly attenuated thalamic pain and significantly decreased the levels of NLRP3, caspase-1, ASC and proinflammatory cytokines (IL-18 and IL-1β). Furthermore, introducing a miR-223 antagomir into the VPL nucleus of naïve mice mimicked thalamic pain and significantly increased the levels of NLRP3, caspase-1, ASC and proinflammatory cytokine levels (IL-18 and IL-1β). These results indicated that miR-223 inhibited NLRP3 inflammasome activity (caspase-1, NLRP3 and ASC), which ameliorated thalamus hemorrhage-induced CPSP in mice via NLRP3 downregulation. In conclusion, these results may determine the mechanisms underlying CPSP and facilitate development of targeted therapy for CPSP.