A Rat Model of Rheumatoid Arthritis: TDZD-8 is Associated with the Protection Against the Induction of the Synovium Knee Joint IL-17A/GSK3β/ROS/α-SMA Axis of Fibrosis

SUMMARY: Rheumatoid arthritis (RA) that affects the synovial knee joint causes swelling of the synovial membrane and tissue damage. Interleukin-17A (IL-17A) and the enzyme glycogen synthase kinase-3β (GSK3β) are involved in the pathogenesis of RA. The link between IL-17A, GSK3β, the oxidative stress, and the profibrogenic marker alpha-smooth muscle actin (α-SMA) with and without TDZD-8, GSK3β inhibitor has not been studied before. Consequently, active immunization of rats was performed to induce RA after three weeks using collagen type II (COII) injections. The treated group received daily injection of 1 mg/kg TDZD-8 for 21 days following the immunization protocol (COII+TDZD-8). Blood and synovium tissue samples were harvested at the end of the experiment. RA development was confirmed as corroborated by a substantial increase in blood levels of the highly specific autoantibody for RA, anti-citrullinated protein antibody as well as augmentation of reactive oxidative species (ROS) levels measured as lipid peroxidation. RA induction also increased synovium tissue levels of IL-17A and the profibrogenic marker, α-SMA. All these parameters seemed to be significantly (p<0.0001) ameliorated by TDZD-8. Additionally, a significant correlation between IL-17A, ROS, and α-SMA and biomarkers of RA was observed. Thus, knee joint synovium RA induction augmented IL-17A/GSK3β/ROS/α-SMA axis mediated arthritis in a rat model of RA, which was inhibited by TDZD-8.

La artritis reumatoide (AR) que afecta la articulación sinovial de la rodilla provoca inflamación de la membrana sinovial y daño tisular. La interleucina-17A (IL-17A) y la enzima glucógeno sintasa quinasa-3β (GSK3β) están involucradas en la patogenia de la AR. No se ha estudiadol vínculo entre IL-17A, GSK3β, el estrés oxidativo y el marcador profibrogénico actina de músculo liso alfa (α-SMA) con y sin inhibidor de TDZD-8, GSK3β. En consecuencia, se realizó una inmunización activa de ratas para inducir la AR después de tres semanas usando inyecciones de colágeno tipo II (COII). El grupo tratado recibió una inyección diaria de 1 µg/ kg de TDZD-8 durante 21 días siguiendo el protocolo de inmunización (COII+TDZD-8). Se recogieron muestras de sangre y tejido sinovial al final del experimento. El desarrollo de AR se confirmó como lo corroboró el aumento sustancial en los niveles sanguíneos del autoanticuerpo altamente específico para AR, el anticuerpo antiproteína citrulinada, así como el aumento de los niveles de especies oxidativas reactivas (ROS) medidos como peroxidación lipídica. La inducción de AR también aumentó los niveles de tejido sinovial de IL-17A y el marcador profibrogénico, α-SMA. Todos estos parámetros parecían mejorar significativamente (p<0,0001) con TDZD-8. Además, se observó una correlación significativa entre IL- 17A, ROS y α-SMA y biomarcadores de AR. Por lo tanto, la inducción de AR en la sinovial de la articulación de la rodilla aumentó la artritis mediada por el eje IL-17A/GSK3β/ROS/α-SMA en un modelo de rata de AR, que fue inhibida por TDZD-8.

A rat model of rheumatoid arthritis: TDZD-8 is associated with the protection against the induction of the synovium knee joint IL-17A/GSK3beta/ROS/alpha-SMA axis of fibrosis / Un modelo de rata de artritis reumatoide: TDZD-8 está asociado con la protección contra la inducción del eje de fibrosis de la articulación sinovial de la rodilla IL-17A/GSK3ß/ROS/α-SMA

SUMMARY: Rheumatoid arthritis (RA) that affects the synovial knee joint causes swelling of the synovial membrane and tissue damage. Interleukin-17A (IL-17A) and the enzyme glycogen synthase kinase-3β (GSK3β) are involved in the pathogenesis of RA. The link between IL-17A, GSK3β, the oxidative stress, and the profibrogenic marker alpha-smooth muscle actin (α-SMA) with and without TDZD-8, GSK3β inhibitor has not been studied before. Consequently, active immunization of rats was performed to induce RA after three weeks using collagen type II (COII) injections. The treated group received daily injection of 1 mg/kg TDZD-8 for 21 days following the immunization protocol (COII+TDZD-8). Blood and synovium tissue samples were harvested at the end of the experiment. RA development was confirmed as corroborated by a substantial increase in blood levels of the highly specific autoantibody for RA, anti-citrullinated protein antibody as well as augmentation of reactive oxidative species (ROS) levels measured as lipid peroxidation. RA induction also increased synovium tissue levels of IL-17A and the profibrogenic marker, α-SMA. All these parameters seemed to be significantly (p<0.0001) ameliorated by TDZD-8. Additionally, a significant correlation between IL-17A, ROS, and α-SMA and biomarkers of RA was observed. Thus, knee joint synovium RA induction augmented IL-17A/GSK3β/ROS/α-SMA axis mediated arthritis in a rat model of RA, which was inhibited by TDZD-8.

La artritis reumatoide (AR) que afecta la articulación sinovial de la rodilla provoca inflamación de la membrana sinovial y daño tisular. La interleucina-17A (IL-17A) y la enzima glucógeno sintasa quinasa-3β (GSK3β) están involucradas en la patogenia de la AR. No se ha estudiadol vínculo entre IL-17A, GSK3β, el estrés oxidativo y el marcador profibrogénico actina de músculo liso alfa (α-SMA) con y sin inhibidor de TDZD-8, GSK3β. En consecuencia, se realizó una inmunización activa de ratas para inducir la AR después de tres semanas usando inyecciones de colágeno tipo II (COII). El grupo tratado recibió una inyección diaria de 1 µg/ kg de TDZD-8 durante 21 días siguiendo el protocolo de inmunización (COII+TDZD-8). Se recogieron muestras de sangre y tejido sinovial al final del experimento. El desarrollo de AR se confirmó como lo corroboró el aumento sustancial en los niveles sanguíneos del autoanticuerpo altamente específico para AR, el anticuerpo antiproteína citrulinada, así como el aumento de los niveles de especies oxidativas reactivas (ROS) medidos como peroxidación lipídica. La inducción de AR también aumentó los niveles de tejido sinovial de IL-17A y el marcador profibrogénico, α-SMA. Todos estos parámetros parecían mejorar significativamente (p<0,0001) con TDZD-8. Además, se observó una correlación significativa entre IL- 17A, ROS y α-SMA y biomarcadores de AR. Por lo tanto, la inducción de AR en la sinovial de la articulación de la rodilla aumentó la artritis mediada por el eje IL-17A/GSK3β/ROS/α-SMA en un modelo de rata de AR, que fue inhibida por TDZD-8.

TDZD-8 alleviates oxaliplatin induced neuropathic pain / 中国药理学通报

Aim To explore the effect of GSK-3β (glycogen synthase kinase-3 beta) inhibitor TDZD-8 on the neuropathic pain induced by side effects of chemotherapeutic drug oxaliplatin and the underlying mechanism. Methods The rat model of oxaliplatin-induced neuropathic pain was established by intraperitoneal injection of oxaliplatin for five consecutive days; the anti-nociception effect was detected by intrathecal injection of TDZD-8. The spontaneous flinches and mechanical pain threshold were used to detect the changes of pain behavior of rats; immunofluorescence and Western blot analysis were used to detect the changes of spinal inflammation and protein levels of rats. Results Intrathecally injection of TDZD-8 significantly alleviated oxaliplatin induced hyperalgesia in rats. TDZD-8 injection obviously inhibited the activation spinal microglia and the inflammatory reaction. TDZD-8 administration significantly inhibited GSK-3β activation. Conclusion TDZD-8 blocks GSK-3β activation, decreases NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) inflammasome mediated spinal inflammation and alleviates neuropathic pain.

GSK3ß inhibitor TDZD8 ameliorates brain damage through both ROS scavenging and inhibition of apoptosis in hyperglycaemic subarachnoid haemorrhage rats.

Hyperglycaemia is known to be associated with unfavourable outcomes in subarachnoid haemorrhage (SAH), but the pathogenic mechanism is unclear, and there is also a lack of effective therapeutic drugs in clinical practice. Phosphorylation of GSK3ß at serine 9 can inhibit its activity to further worsen SAH. The aim of the present study was to evaluate the protective effect and the potential mechanism of the GSK3ß inhibitor TDZD8 on brain injury in a hyperglycaemic SAH rat model. Hyperglycaemia was induced by intraperitoneal injection of streptozocin for 3 days. The SAH model was established by injecting fresh autologous femoral artery blood into the prechiasmatic cistern. p-GSK3ß (Ser9) expression was induced by intraperitoneal injection of TDZD8 (30 min post-SAH). The expression levels of GSK3ß, p-GSK3ß, SOD1/2, caspase 3, Bax and Bcl-2 were detected by western blot analysis. Terminal deoxynucleotidyl transferase dUTP nick end-labelling (TUNEL) staining was used to detect neuronal apoptosis of basal temporal lobe. Neurological scores were calculated to determine behavioural recovery. Neuronal survival was detected by Nissl staining. Hyperglycaemia significantly decreased p-GSK3ß expression, further exacerbated neurobehavioural deficits and increased oxidative stress and neuronal apoptosis in the brain after SAH compared to normal glycaemic SAH rats and hyperglycaemic rats. In addition, hyperglycaemic SAH rats had obvious oxidative stress and apoptosis. However, TDZD8 effectively decreased cleaved caspase 3 expression and TUNEL-positive cells and increased the Bcl2/Bax ratio, expression of SOD1/2 and activity of superoxide dismutase (SOD) enzyme compared with hyperglycaemic SAH rats. The GSK3ß inhibitor TDZD8 has therapeutic potential for hyperglycaemic SAH. The neuroprotective effect of TDZD8 appears to be mediated through its antioxidative and antiapoptotic activity.

[Effects of GSK3ß/eEF2K signaling pathway on pulmonary fibrosis in mice].

Objective: To investigate the effects of glycogen synthase kinase-3ß (GSK3ß)/eukaryotic extension factor kinase 2 (eEF2K) signaling pathway on the process of pulmonary fibrosis through in vivo experiments, and find new ideas for clinical treatment of pulmonary fibrosis. Methods: The pulmonary fibrosis model of C57BL/6 male mice was induced by bleomycin with intratracheal injection at the dose of 2 mg/kg. After 14 days of modeling, animals were divided into model group, negative inhibition group and inhibition group (n=5 for each group), and control group was not processed. The inhibition group was treated with TDZD-8 (4 mg/kg) after modeling, the negative inhibition group was given DMSO solution after modeling, and the samples were collected after 28 days. Hematoxylin-eosin staining method was used to detect lung fibrosis in mice and scored according to Ashcroft scale. Expression levels of GSK3ß, p-GSK3ß, eEF2K, p-eEF2K (Ser70, Ser392, Ser470), precursor protein of matrix metalloproteinase-2 (pro-MMP-2), matrix metalloproteinase-2 (MMP-2), collagen I (Col I), collagen Ⅲ (Col Ⅲ) and α-smooth muscle actin (α-SMA) were detected by Western blot. Results: Compared with control group, the fibrosis score was up-regulated, the expression levels of GSK3ß, p-GSK3ß, p-eEF2K (Ser70, Ser392, Ser470), pro-MMP-2, MMP-2, Col I, Col Ⅲ and α-SMA were increased, while that of eEF2K was decreased in model group (P＜0.05). Compared with model group, the fibrosis score, expression levels of GSK3ß, p-GSK3ß, p-eEF2K (Ser70, Ser392, Ser470), pro-MMP-2, MMP-2, Col I, Col Ⅲ and α-SMA were decreased, but the expression level of eEF2K was increased in inhibition group (P＜0.05). Conclusion: GSK3ß can activate eEF2K by phosphorylation at the sites of Ser70, Ser392 and Ser470, increase the contents of fibrosis indicators, promote the formation of pulmonary fibrosis, and aggravate lung tissue lesions.

Suppression of nitrosative stress and inflammation of the knee joint synovium in collagen type ii-induced rheumatoid arthritis by the inhibition of glycogen synthase kinase-3ß / Supresión del estrés nitrosativo e inflamación de la sinovial de la articulación de la rodilla en la artritis reumatoide inducida por colágeno tipo ii mediante la inhibición de la glucógeno sintasa quinasa-3 ß

SUMMARY: Rheumatoid arthritis (RA), an inflammatory autoimmune disease that causes cartilage degradation and tissue destruction, can affect synovial joints such as the knee joint. The link between the nitrosative stress enzyme inducible nitric oxide synthase (iNOS) and the cytokine interleukin-1 (IL-1β) in RA-induced knee joint synovial membrane damage with and without the incorporation of the GSK3β inhibitor TDZD-8 has never been studied. As a result, we used active immunization method with collagen type II (COII) for twenty one days to induce RA in rats. TDZD-8 (1 mg/kg; i.p.) was given daily into matched immunized rats for three weeks after day 21 (COII+TDZD-8). Blood and tissue samples were taken 42 days after immunization. A dramatic increase in rheumatoid factor (RF) blood levels, as well as considerable synovial tissue damage and inflammatory cell infiltration of the synovial membrane, were used to validate the onset of RA following COII immunization. COII immunization increased tissue levels of iNOS protein and IL- 1β mRNA and protein expression, which TDZD-8 suppressed considerably (p<0.0001). Furthermore, there was a significantly (p<0.001) positive correlation between iNOS, inflammatory biomarkers, and RF. We concluded that TDZD-8 reduced RA-induced IL-1β -iNOS axis-mediated arthritis in the rat knee joint synovium.

RESUMEN: La artritis reumatoide (AR), es una enfermedad autoinmune inflamatoria que causa la degradación del cartílago y la destrucción del tejido, pudiendo afectar las articulaciones sinoviales, como la articulación de la rodilla. No se ha estudiado el vínculo entre la óxido nítrico sintasa inducible por la enzima del estrés nitrosativo (iNOS) y la citocina interleucina-1 (IL-1β) en el daño de la membrana sinovial de la articulación de la rodilla provocado por AR con y sin la incorporación del inhibidor de GSK3β TDZD-8. Utilizamos el método de inmunización activa con colágeno tipo II (COII) durante veintiún días para inducir AR en ratas. Se administró TDZD-8 (1 mg/kg; i.p.) diariamente a ratas inmunizadas emparejadas durante tres semanas después del día 21 (COII+TDZD- 8). Se tomaron muestras de sangre y tejido 42 días después de la inmunización. Se observó un gran aumento de los niveles sanguíneos del factor reumatoideo (FR), así como un daño considerable del tejido sinovial e infiltración de células inflamatorias en la membrana sinovial, para validar la aparición de la AR después de la inmunización con COII. La inmunización con COII aumentó los niveles tisulares de la proteína iNOS y la expresión de proteína y ARNm de IL-1β, que TDZD-8 suprimió considerablemente (p<0,0001). Además, hubo una correlación positiva significativa (p<0,001) entre iNOS, biomarcadores inflamatorios y FR. Concluimos que TDZD- 8 redujo la artritis mediada por el eje IL-1β-iNOS inducida por la AR en la sinovial de la articulación de la rodilla de rata.

Inhibition of glycogen synthase kinase-3ß protects against collagen type II-induced arthritis associated with the inhibition of miR155/24 and inflammation and upregulation of apoptosis in rats.

MicroRNAs have been implicated in the pathogenesis of rheumatoid arthritis (RA) and their syntheses are modulated by glycogen synthase kinase-3ß (GSK-3ß). Therefore, we hypothesised that the GSK-3ß inhibitor, TDZD-8 can protect against collagen-induced arthritis (CIA) via downregulating miR155 and miR-24 expression. Rats were randomly allocated into four groups (n = 6) as follows: Control, Control + TDZD-8 (1 mg/kg), CIA, and CIA + TDZD-8. Rats were sacrificed after 6 weeks. We observed in the model group (CIA) significant (p<.05) increase in arthritis score and serum levels of RA biomarkers, which were significantly (p < .05) inhibited by TDZD-8. TDZD-8 also significantly (p<.05) inhibited CIA-induced synovial tissue levels of miR155, miR-24, and inflammation. In addition, a significant (p<.05) modulation of biomarkers of survival (Bcl-2) and apoptosis (cleaved caspase-3) by TDZD-8 was observed. Thus, TDZD-8 protects against CIA in rats for a period of 6 weeks, which is associated with the inhibition of miR155/24 and inflammation, and apoptosis augmentation.

Effects of GSK3β/eEF2K signaling pathway on pulmonary fibrosis in mice / 中国应用生理学杂志

Objective: To investigate the effects of glycogen synthase kinase-3β (GSK3β)/eukaryotic extension factor kinase 2 (eEF2K) signaling pathway on the process of pulmonary fibrosis through in vivo experiments, and find new ideas for clinical treatment of pulmonary fibrosis. Methods: The pulmonary fibrosis model of C57BL/6 male mice was induced by bleomycin with intratracheal injection at the dose of 2 mg/kg. After 14 days of modeling, animals were divided into model group, negative inhibition group and inhibition group (n=5 for each group), and control group was not processed. The inhibition group was treated with TDZD-8 (4 mg/kg) after modeling, the negative inhibition group was given DMSO solution after modeling, and the samples were collected after 28 days. Hematoxylin-eosin staining method was used to detect lung fibrosis in mice and scored according to Ashcroft scale. Expression levels of GSK3β, p-GSK3β, eEF2K, p-eEF2K (Ser70, Ser392, Ser470), precursor protein of matrix metalloproteinase-2 (pro-MMP-2), matrix metalloproteinase-2 (MMP-2), collagen I (Col I), collagen Ⅲ (Col Ⅲ) and α-smooth muscle actin (α-SMA) were detected by Western blot. Results: Compared with control group, the fibrosis score was up-regulated, the expression levels of GSK3β, p-GSK3β, p-eEF2K (Ser70, Ser392, Ser470), pro-MMP-2, MMP-2, Col I, Col Ⅲ and α-SMA were increased, while that of eEF2K was decreased in model group (P＜0.05). Compared with model group, the fibrosis score, expression levels of GSK3β, p-GSK3β, p-eEF2K (Ser70, Ser392, Ser470), pro-MMP-2, MMP-2, Col I, Col Ⅲ and α-SMA were decreased, but the expression level of eEF2K was increased in inhibition group (P＜0.05). Conclusion: GSK3β can activate eEF2K by phosphorylation at the sites of Ser70, Ser392 and Ser470, increase the contents of fibrosis indicators, promote the formation of pulmonary fibrosis, and aggravate lung tissue lesions.

TDZD-8 suppresses rheumatoid arthritis induced by collagen type II in rats: potential role of apoptosis and inflammation / TDZD-8 suprime la artritis reumatoide inducida por colágeno tipo II en ratas: papel potencial de la apoptosis y la inflamación

SUMMARY: Rheumatoid arthritis (RA) is considered an autoimmune disease distinguished by chronic synovial membrane inflammation, degraded cartilage, as well as bone destruction, which lead to joints pain and stiffness. The pathogenesis of RA involved at least two mechanisms: Cellular proliferation and activation of glycogen synthase kinase-3β (GSK3β) enzyme. Thus, we tested the hypothesis that the GSK3binhibitor, TDZD-8, can treat the synovial tissue toward collagen type II (COII)-mediated RA linked to apoptosis induction and biomarker suppression of inflammation. Wistar rats were immunized with COII (the model group) for 21 days. Matched immunized rats were daily injected with TDZD-8 (1 mg/kg; i.p) for three additional weeks (COII+TDZD- 8).After 42 days of post-immunization, blood and tissues were collected. Histology (H&E) and immunohistochemistry (CD45; leukocyte common antigen) images showed that COII induced RA was demonstrated by profound damage to the synovial tissue and infiltration of the inflammatory cells, which were substantially ameliorated with TDZD-8. In addition, COII immunization caused the induction of rheumatoid factor (RF), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin 1 beta (IL-1β) that were substantially (p<0.05) suppressed by TDZD-8. Whereas, TDZD-8 augmented the apoptotic biomarker, Bcl-2-associated X protein (Bax), which was significantly (p<0.05) ameliorated by RA. We also showed a substantial relationship (p<0.001) between the blood levels of RF and the synovial tissue levels of TNF-α (r = 0.759), IL-1b (r = 0.969), IL-6 (r = 0.749), and Bax (r = - 0.914). These results indicate effective treatment of the injured synovial tissue by TDZD-8 against COII-induced RA in rats, which also decreases inflammatory biomarkers and augmentation of apoptosis.

RESUMEN: La artritis reumatoide (AR) es una enfermedad autoinmune que se distingue por la inflamación crónica de la membrana sinovial, el cartílago degradado y la destrucción de los huesos, lo que provoca dolor y rigidez en las articulaciones. La patogenia de la AR involucra al menos dos mecanismos: la proliferación celular y la activación de la enzima glucógeno sintasa quinasa-3b (GSK3β) Por lo tanto, probamos la hipótesis de que el inhibidor de GSK3β, TDZD-8, puede tratar el tejido sinovial hacia el colágeno tipo II (COII) - AR mediada por inducción de apoptosis y supresión de biomarcadores de inflamación. Se inmunizaron ratas Wistar con COII (el grupo modelo) durante 21 días. Se inyectaron diariamente ratas emparejadas inmunizadas con TDZD-8 (1 mg / kg; i.p) durante tres semanas adicionales (COII + TDZD-8). Después de 42 días de post-inmunización, se recolectó sangre y tejidos. Las imágenes de histología (H&E) e inmunohistoquímica (CD45; antígeno común de leucocitos) mostraron que la AR inducida por COII presentaba un daño profundo en el tejido sinovial e infiltración de las células inflamatorias, las que mejoraron con TDZD-8. Además, la inmunización con COII provocó la inducción de factor reumatoide (FR), factor de necrosis tumoral alfa (TNF-α), interleucina-6 (IL-6) e interleucina 1 beta (IL-1β) que fueron suprimidos por TDZD-8 de manera significativa (p < 0.05). Considerando que TDZD-8 aumentó el biomarcador apoptótico, la proteína X asociada a Bcl-2 (Bax), que fue mejorado (p <0,05) por RA. También se observó una relación sustancial (p <0,001) entre los niveles sanguíneos de RF y los niveles de tejido sinovial de TNF-α (r = 0,759), IL-1β (r = 0,969), IL-6 (r = 0,749), y Bax (r = -0,914). Estos resultados indicaron un tratamiento eficaz del tejido sinovial lesionado por TDZD-8 contra la AR inducida por COII en ratas, que también disminuye los biomarcadores inflamatorios y el aumento de la apoptosis.

Glycogen Synthase Kinase-3 Signaling in Acute Kidney Injury.

Acute kidney injury (AKI) is a common clinical syndrome that involves renal tubular epithelial cell death and leads to acute decline in renal function. Improper tubular regeneration following AKI often leads to CKD. We discuss the role of a serine/threonine protein kinase called glycogen synthase kinase-3 (GSK3) in renal tubular injury and renal fibrosis. We also highlight the importance of GSK3 as a potential drug target in AKI patients and molecular mechanisms promoting tissue regeneration.

Inhibition of GSK3ß protects against collagen type II-induced arthritis associated with a decrease in synovial leukocyte infiltration and inhibition of endoplasmic reticulum stress and autophagy biomarkers.

We sought to determine whether TDZD-8, the inhibitor of the glycogen synthase kinase-3ß (GSK3ß), can protect the synovial membrane of the knee joint against injuries induced by collagen type II immunization (CIA) possibly via the downregulation of synovial leukocyte infiltration, endoplasmic reticulum stress (ERS), and autophagy. The model group of rats (CIA) were immunized over a period of 3 weeks with collagen type II, whereas the treated group of rats (CIA + TDZD-8) were treated with TDZD-8 (1 mg/kg) for 21 days after the completion of the immunization regimen. All rats were then killed at week 6. Harvested synovial tissues were prepared for immunohistochemistry staining, and synovial homogenates were assayed for biomarkers of ERS, autophagy, apoptosis, and cell survival and proliferation. In addition, blood samples were assayed for biomarkers of arthritis. Synovial tissue images showed that CIA enhanced leukocyte recruitment as demonstrated by an increased CD45+ (leukocyte common antigen) immunostaining, which was markedly decreased by TDZD-8. TDZD-8 also significantly (P < .05) inhibited collagen-induced autophagy biomarkers Beclin-1 and LC3II, the ERS biomarkers GRP-78, IRE1-α, XBPIs, and eIF2a, and the survival protein Bcl-2. Whereas, the collagen-induced proliferative biomarkers Akt and mTOR were not inhibited by TDZD-8, and CIA inhibited the apoptotic proteins CHOP and cleaved caspase-3, which were augmented by TDZD-8. We further demonstrated a significant (P < .05) correlation between autoantibodies generated during the course of arthritis and biomarkers of ERS and autophagy. We conclude that TDZD-8 inhibits CIA and decreases synovial leukocyte infiltration, ERS, and autophagy, which is independent of Akt/mTOR signalling.

TDZD-8 alleviates delayed neurological sequelae following acute carbon monoxide poisoning involving tau protein phosphorylation.

Objective: Acute carbon monoxide （CO）poisoning can cause delayed neurological sequelae (DNS). Glycogen synthase kinase 3ß (GSK-3ß) /Tau protein pathway is reported to play a key role in neurological abnormalities. In the present study, we aimed to determine the role of GSK-3ß/Tau in DNS following acute CO poisoning.Methods: 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8), a specific non-competitive inhibitor of GSK-3ß, was used to inhibit GSK-3ß. Twenty-four male Sprague-Dawley rats were randomly assigned to the three groups: Control group, CO group and CO-TDZD-8 group. Rats breathed 1000 ppm CO for 40 minutes and then 3000 ppm for up to 20 minutes until they lost consciousness. TDZD-8 (1 mg/kg) was administered intravenously three times after the end of CO exposure at 0, 24, 48 hours late. Learning and memory abilities were observed using the Morris Water Maze (MWM). Brain histological changes were evaluated by hematoxylin-eosin staining. Moreover, the expression levels of Tau and GSK-3ß were detected after acute carbon monoxide poisoning.Results: TDZD-8 significantly attenuated the learning and memory dysfunction induced by acute CO poisoning, ameliorated the histology structure of damaged neural cells in cortex and hippocampus CA1 area. TDZD-8 clearly decreased p-Tau expression, reversed the reduction of p-GSK-3ß induced by acute CO poisoning.Conclusions: The therapeutic effect of TDZD-8 in alleviating DNS caused by acute CO poisoning is related to the inactivation of Tau by intensifying the level of GSK-3ß phosphorylation.

The GSK3ß inhibitor, TDZD-8, rescues cognition in a zebrafish model of okadaic acid-induced Alzheimer's disease.

Currently, no treatments exist that are able to directly treat against Alzheimer's disease (AD), and we are facing an inevitable increase in the near future of the amount of patients who will suffer from AD. Most animal models of AD are limited by not being able to recapitulate the entire pathology of AD. Recently an AD model in zebrafish was established by using the protein phosphatase 2A inhibitor, okadaic acid (OKA). Administering OKA to zebrafish was able to recapitulate most of the neuropathology associated with AD. Therefore, providing a drug discovery model for AD that is also time and cost efficient. This study was designed to investigate the effects of GSK3ß inhibition by 4-benzyl-2-methyl-1, 2, 4-thiadiazolidine-3, 5-dione (TDZD-8) on this newly developed AD model. Fish were divided into 4 groups and each group received a different treatment. The fish were divided into a control group, a group treated with 1 µM TDZD-8 only, a group treated with 1 µM TDZD-8 + 100 nM OKA, and a group treated with 100 nM OKA only. Administering the GSK3ß inhibitor to zebrafish concomitantly with OKA proved to be protective. TDZD-8 treatment reduced the mortality rate, the ratio of active: inactive GSK3ß, pTau (Ser199), and restored PP2A activity. This further corroborates the use of GSKß inhibitors in the treatment against AD and bolsters the use of the OKA-induced AD-like zebrafish model for drug discovery.

Experimental study on the mechanism of glycogen synthase kinase-3β inhibitor on acute kidney injury of acute necrotizing pancreatitis in rats / 中华危重病急救医学

Objective To explore the protective mechanism of glycogen synthase kinase-3β(GSK-3β) inhibitor TDZD-8 on acute necrotizing pancreatitis (ANP) associated kidney injury in rats. Methods SPF male Wistar rats were randomly divided into four groups (n = 20): sham operation group (Sham group), ANP model group, TDZD-8 intervention group and TDZD-8 control group. The rat ANP model was prepared by retrograde injection of 5% sodium taurocholate into the bile duct; the same volume of normal saline was injected into the pancreatic duct of the Sham group. The TDZD-8 intervention group and the TDZD-8 control group were injected with GSK-3β inhibitor TDZD-8 (1 mL/kg) via the femoral vein 30 minutes before the model or sham operation; the ANP model group and the Sham group were injected equal volume of 10% dimethyl sulfoxide (DMSO). Rats in each group were sacrificed at 12 hours after operation to measure the serum amylase (AMY), blood lipase (LIPA), serum creatinine (SCr) and blood urea nitrogen (BUN) levels and to observe the pathological changes of pancreatic tissues and kidney tissues. Ultrastructural change of renal cells was analyzed by transmission electron microscopy. Serum interleukin-1β (IL-1β) and interleukin-6 (IL-6) levels were evaluated by enzyme linked immunosorbent assay (ELISA). The activation of nuclear factor-κB p65 (NF-κB p65) was evaluated by immunohistochemistry assay. The protein expressions of GSK-3β, phospho-GSK-3β (Ser 9), tumor necrosis factor -α (TNF-α), inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1) and interleukin-10 (IL-10) in the kidney were determined by Western Blot. Results Compared with the Sham group, the serum and inflammatory factors levels of the ANP model group were significantly increased, the pathological damage of the pancreas and kidney tissues were severe, the histopathological score was significantly increased, the expression of NF-κB p65 was enhanced in the nucleus of the kidney tissue, and the expressions of GSK-3β, TNF-α, ICAM-1 and iNOS were significantly enhanced, and the expressions of p-GSK-3β(Ser 9) and IL-10 were significantly attenuated. Compared with the ANP model group, TDZD-8 pretreatment significantly reduced serum and inflammatory factor levels in the ANP model group [AMY (kU/L): 5.60±0.30 vs. 10.07±0.34, LIPA (U/L): 1 111.0±110.8 vs. 2 375.0±51.1, SCr (μmol/L): 47.38±1.48 vs. 72.50±2.43, BUN (mmol/L): 17.6±1.0 vs. 26.0±1.0, IL-1β (ng/L):195.90±5.50 vs. 332.40±38.29, IL-6 (ng/L): 246.10±26.74 vs. 385.30±32.19, all P < 0.01]; pathological damage of pancreas and kidney tissue (histopathological score: 7.1±0.4 vs. 12.1±0.3, 301.2±7.5 vs. 433.5±13.8, both P < 0.01) and ultrastructural damage of renal cells were alleviated; the expression of NF-κB p65 in the nucleus was significantly decreased; the expression of p-GSK-3β(Ser 9) was significantly increased, and blocking GSK-3β activity could inhibit the expressions of TNF-α, ICAM-1, iNOS and increase the expression of IL-10, while the expression of GSK-3β in renal tissues was not statistically significant. There were no significant differences between the TDZD-8 control group and the Sham group. Conclusions Blockade of GSK-3βactivity by TDZD-8 exerts the protective effect against kidney injury by inhibiting the inflammation signaling pathway in ANP. It can alleviate histopathological and ultrastructural changes in kidney injury, which protection mechanism is mediated by NF-κB and its related inflammatory mediators.

Brain-Defective Insulin Signaling Is Associated to Late Cognitive Impairment in Post-Septic Mice.

Sepsis survivors frequently develop late cognitive impairment. Because little is known on the mechanisms of post-septic memory deficits, there are no current effective approaches to prevent or treat such symptoms. Here, we subjected mice to severe sepsis induced by cecal ligation and puncture (CLP) and evaluated the sepsis-surviving animals in the open field, novel object recognition (NOR), and step-down inhibitory avoidance (IA) task at different times after surgery. Post-septic mice (30 days post-surgery) failed in the NOR and IA tests but exhibited normal performance when re-evaluated 45 days after surgery. Cognitive impairment in post-septic mice was accompanied by reduced hippocampal levels of proteins involved in synaptic plasticity, including synaptophysin, cAMP response element-binding protein (CREB), CREB phosphorylated at serine residue 133 (CREBpSer133), and GluA1 phosphorylated at serine residue 845 (GluA1pSer845). Expression of tumor necrosis factor α (TNF-α) was increased and brain insulin signaling was disrupted, as indicated by increased hippocampal IRS-1 phosphorylation at serine 636 (IRS-1pSer636) and decreased phosphorylation of IRS-1 at tyrosine 465 (IRS-1pTyr465), in the hippocampus 30 days after CLP. Phosphorylation of Akt at serine 473 (AktpSer473) and of GSK3 at serine 9 (GSK3ßpSer9) were also decreased in hippocampi of post-septic animals, further indicating that brain insulin signaling is disrupted by sepsis. We then treated post-septic mice with liraglutide, a GLP-1 receptor agonist with insulinotropic activity, or TDZD-8, a GSK3ß inhibitor, which rescued NOR memory. In conclusion, these results establish that hippocampal inflammation and disrupted insulin signaling are induced by sepsis and are linked to late memory impairment in sepsis survivors.

The effects of different GSK-3β inhibitors and dose-response relationship in severe acute pancreatitis associated kidney injury in rats / 中华急诊医学杂志

Objective To observe the dose-response relationship of the GSK-3β inhibitor TDZD-8 in severe acute pancreatitis (SAP) associated kidney injury in rats. In order to identify the most effective class of GSK-3β inhibitor and its effective and reasonable safe dose in SAP associated kidney injury model in rats by comparing three kinds of frequently-used GSK-3β inhibitor TDZD-8, lithium chloride (LiCL), SB216763 in this model. Methods Totally 96 SPF male Wistar rats were randomly(random number) divided into 8 groups (n=12): sham operation group (SO group), severe acute pancreatitis group (SAP group), TDZD-8 pretreatment groups (TD group, marked TD1, TD2, TD3 and TD4 group, respectively) at different dosage (0.25, 0.5, 1.0 and 2.0 mg/kg), LiCL pretreatment groups (L group, 40 mg/kg), and SB216763 pretreatment group (SB group, 1 mg/kg). SAP model was induced by retrograde infusion of 5％ sodium taurocholate into the biliopancreatic duct. Rats in each group were sacrificed at 12 h after operation. Then the mortality, quantity of ascites, serum AMY, Cr, BUN and ALT were recorded, and the pathological changes of pancreatic tissues and kidney tissues were observed. Results Compared with the SO group, the levels of ascites, serum AMY, Cr, BUN, ALT and pancreatic and renal pathologic score in the SAP group were all significantly increased (P<0.05). Compared with the TD1 group, quantity of ascites, serum AMY, Cr, BUN,ALT and pancreatic tissue pathological grading were reduced in different degrees in the TD2, TD3 and TD4 groups with statistically significant difference (P<0.05); ALT values were reduce in different degrees in the TD2 and TD3 groups as compared with the SAP group (P<0.05), while ALT value in the TD4 group was similar to that in the SAP group; compared with the TD2 group, all the indexes in the TD3 group were significant better (P<0.05); Compared with TD3 group (the best group in TD group), the levels of ascites and serum ALT in the L group and SB group had no significant difference (P>0.05), but the levels of AMY, Cr, BUN, ALT, pancreatic and renal pathologic score were significantly reduced in the TD3 group than those in the L and SB groups (P<0.05); compared with the SB group, the values of Cr, BUN, pancreatic and renal pathologic score in the L group were lower (P<0.05). GSK-3βprotein expression in all groups showed no obvious difference (P>0.05), while p-GSK-3β ser9 protein expression in the SAP group was lower than that in the SO group (P<0.05), and p-GSK-3β ser9 protein expression in the TD3, L and SB groups were stronger than that in the SAP group. Among them, p-GSK-3βser9 protein expression was highest in the TD3 group, followed by the L group, finally the SB group, and the differences were statistically significant (P<0.05). Conclusions Among the three different GSK-3βinhibitors, TDZD-8 is the most effective GSK-3β inhibitor for SAP associated with kidney injury in rats. The GSK-3β inhibitor TDZD-81 mg/kg administered intravenously is safe, effective and optimal dosage for attenuating the severity of severe acute pancreatitis associated with kidney injury.

Activation of Nrf2/HO-1 Pathway by Glycogen Synthase Kinase-3ß Inhibition Attenuates Renal Ischemia/Reperfusion Injury in Diabetic Rats.

BACKGROUND/AIMS: Diabetes mellitus can exacerbate renal ischemia-reperfusion (I/R) injury (RI/RI). The aim of the present study was to evaluate the protective effect of GSK-3ß inhibition (TDZD-8) on I/R-induced renal injury through the Nrf2/HO-1 pathway in a streptozocin (STZ)-induced diabetic rat model. METHODS: STZ-induced diabetic rats preconditioned with TDZD-8 and ZnPP were subjected to renal I/R. The extent of renal morphologic lesions. Renal function was assessed from blood urea nitrogen (BUN) and serum creatinine (Scr), as determined utlizing commercial kits. Oxidative stress and inflammatory activity in the kidney tissue was estimated from levels of malondialdehyde (MDA), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), and nitric oxide (NO), as well as the activities of superoxide dismutase (SOD) and glutathione (GSH) using qRT-PCR and ELISA. The expressions of Nrf2, HO-1, Bcl-2 and NF-κB in the renal tissue were measured by qRT-PCR and western blotting. RESULTS: I/R-induced renal inflammation was reduced significantly by TDZD-8 pretreatment. Preconditioning with TDZD-8 suppressed NF-κB expression and enhanced Bcl-2 expression in the renal tissue. The upregulated level of malondialdehyde (MDA), and reduced activities of superoxide dismutase (SOD) and glutathione (GSH) in I/R-shocked rats were markedly restored by TDZD-8 pretreatment. Furthermore, pretreatment with TDZD-8 enhanced activation of the Nrf2/HO-1 pathway in the renal tissue of diabetic RI/RI rats. CONCLUSION: These findings suggest that preconditioning with TDZD-8 may protect the kidney from I/R-induced damage via the activation of the Nrf2/HO-1 pathway in STZ-induced diabetic rats. Further detailed studies are needed to further clarify the underlying mechanisms.

GSK-3ß inhibitor TDZD-8 reduces neonatal hypoxic-ischemic brain injury in mice.

AIMS: Glycogen synthase kinase 3ß (GSK-3ß) is activated following hypoxic-ischemic (HI) brain injury. TDZD-8 is a specific GSK-3ß inhibitor. Currently, the impact of inhibiting GSK-3ß in neonatal HI injury is unknown. We aimed to investigate the effect of TDZD-8 following neonatal HI brain injury. METHODS: Unilateral common carotid artery ligation followed by hypoxia was used to induce HI injury in postnatal day 7 mouse pups pretreated with TDZD-8 or vehicle. The infarct volume, whole-brain imaging, Nissl staining, and behavioral tests were used to evaluate the protective effect of TDZD-8 on the neonatal brain and assess functional recovery after injury. Western blot was used to evaluate protein levels of phosphorylated protein kinase B (Akt), GSK-3ß, and cleaved caspase-3. Protein levels of cleaved caspase-3, neuronal marker, and glial fibrillary acidic protein were detected through immunohistochemistry. RESULTS: Pretreatment with TDZD-8 significantly reduced brain damage and improved neurobehavioral outcomes following HI injury. TDZD-8 reversed the reduction of phosphorylated Akt and GSK-3ß, and the activation of caspase-3 induced by hypoxia-ischemia. In addition, TDZD-8 suppressed apoptotic cell death and reduced reactive astrogliosis. CONCLUSION: TDZD-8 has the therapeutic potential for hypoxic-ischemic brain injury in neonates. The neuroprotective effect of TDZD-8 appears to be mediated through its antiapoptotic activity and by reducing astrogliosis.

Learning ability is a key outcome determinant of GSK-3 inhibition on visuospatial memory in rats.

Learning aptitude has never been a focus of visuospatial performance studies, particularly on memory consolidation and reconsolidation. The aim of this study was to determine the consequences of learning ability on memory consolidation/reconsolidation following inhibition of glucose synthase kinase-3 (GSK-3) by 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8). The anxiety-like nature of rats was characterized in the elevated plus maze. The rats were then trained for four days in the Morris water maze (MWM) and classified as 'superior', 'intermediate' or 'inferior' learners. There were no major differences between superior, intermediate or inferior learners with respect to anxiety which might have influenced learning. After training (day-5), TDZD-8 (2.0 mg/kg) was administered and half of the cohort were exposed to a MWM retrieval trial. Ten days later, animals were subjected to repeated MWM learning. TDZD-8 without a retrieval trial impaired subsequent reconsolidation in inferior learners, but enhanced it in superior learners. There was no modification of performance in intermediate learners. In TDZD-8-treated subjects exposed to retrieval, the pattern of outcomes was identical whereby impairment of reconsolidation occurred in inferior learners, enhancement occurred in superior learners but there was no modification of performance in intermediate learners. Thus, learning ability was a key determinant of the qualitative outcome from GSK-3 inhibition on visuospatial memory.

Glycogen synthase kinase-3ß inhibitor ameliorates imbalance of connexin 43 in an acute kidney injury model.

This study was designed to evaluate whether glycogen synthase kinase-3ß (GSK-3ß) inhibitor, 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8) induced the the expression of connexin 43 (Cx43) to protect against renal ischemia-reperfusion (I/R) injury (RI/RI) in rats. Rats were subjected to 45 min ischemia followed 2 h reperfusion with TDZD-8 (1 mg/kg) for 5 min prior to reperfusion. The results indicated that TDZD-8 improved the recovery of renal function, reduced oxidative stress and inflammation injury, and upregulated the expression of (Cx43) as compared to I/R group. Therefore, our study demonstrated that TDZD-8 provided a protection to the kidney against I/R injury in rats through inducing the expression of (Cx43).