stf-083010 and Disease-Models--Animal

Accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) leads to ER stress, which is characteristic of cells with high level of secretory activity and implicated in a variety of disease conditions. In response to ER stress, the cell elicits an adaptive process called the unfolded protein response (UPR) to support cellular homeostasis and survival. However, prolonged and unsolvable ER stress also induces apoptosis. As the most conserved signaling branch of the UPR, the IRE1α-XBP1 pathway plays important roles in both physiological and pathological settings and its activity has profound effects on disease progression and prognosis. Recently, modulating this pathway with small molecule compounds has been demonstrated as a promising approach for disease therapy. In this review, we summarize a list of current investigational compounds targeting this pathway and their therapeutic features for treating human diseases.

Topics: Aldehydes; Animals; Apoptosis; Cell Survival; Coumarins; Disease Models, Animal; Disease Progression; DNA-Binding Proteins; Drug Design; Drug Discovery; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Endoribonucleases; Homeostasis; Humans; Mice; Neoplasms; Neurodegenerative Diseases; Prognosis; Protein Folding; Protein Serine-Threonine Kinases; Quercetin; Regulatory Factor X Transcription Factors; Signal Transduction; Sulfonamides; Thiophenes; Toyocamycin; Transcription Factors; Unfolded Protein Response; X-Box Binding Protein 1

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

B lymphocyte hyperactivity plays a pathogenic role in systemic lupus erythematosus (SLE), and spliced X box-binding protein 1 (XBP1s) has been implicated in B cell maturation and differentiation. We hypothesized that blockade of the XBP1s pathway inhibits the B cell hyperactivity underlying SLE and lupus nephritis (LN) development. In the present study, we systematically evaluated the changes in B cell activation induced by the Xbp1 splicing inhibitor STF083010 in a pristane-induced lupus mouse model. The lupus mouse model was successfully established, as indicated by the presence of LN with markedly increased urine protein levels, renal deposition of Ig, and mesangial cell proliferation. In lupus mice, B cell hyperactivity was confirmed by increased CD40 and B cell-activating factor levels. B cell activation and plasma cell overproduction were determined by increases in CD40-positive and CD138-positive cells in the spleens of lupus mice by flow cytometry and further confirmed by CD45R and Ig light chain staining in the splenic tissues of lupus mice. mRNA and protein expression of XBP1s in B cells was assessed by real-time PCR, Western blot analysis, and immunofluorescence analysis and was increased in lupus mice. In addition, almost all changes were reversed by STF083010 treatment. However, the expression of XBP1s in the kidneys did not change when mice were exposed to pristane and STF083010. Taken together, these findings suggest that expression of XBP1s in B cells plays key roles in SLE and LN development. Blockade of the XBP1s pathway may be a potential strategy for SLE and LN treatment.

Topics: Animals; Autoantibodies; B-Lymphocytes; Cell Proliferation; Disease Models, Animal; Female; Immunoglobulin G; Kidney; Lupus Erythematosus, Systemic; Lupus Nephritis; Lymphocyte Activation; Mice, Inbred BALB C; Signal Transduction; Spleen; Sulfonamides; Terpenes; Thiophenes; X-Box Binding Protein 1

Inhibition of inositol-requiring enzyme-1 alpha (IRE1α), one of the sensor signaling proteins associated with endoplasmic reticulum (ER) stress, has been shown to alleviate brain injury and improve neurological behavior in a neonatal hypoxic-ischemic encephalopathy (HIE) rat model. However, there is no information about the role of IRE1α inhibitor as well as its molecular mechanisms in preventing neuronal pyroptosis induced by NLRP1 (NOD-, LRR- and pyrin domain-containing 1) inflammasome. In the present study, we hypothesized that IRE1α can degrade microRNA-125-b-2-3p (miR-125-b-2-3p) and activate NLRP1/caspased-1 pathway, and subsequently promote neuronal pyroptosis in HIE rat model.. Ten-day old unsexed rat pups were subjected to hypoxia-ischemia (HI) injury, and the inhibitor of IRE1α, STF083010, was administered intranasally at 1 h after HI induction. AntimiR-125 or NLRP1 activation CRISPR was administered by intracerebroventricular (i.c.v) injection at 24 h before HI induction. Immunofluorescence staining, western blot analysis, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), brain infarct volume measurement, neurological function tests, and Fluoro-Jade C staining were performed.. Endogenous phosphorylated IRE1α (p-IRE1α), NLRP1, cleaved caspase-1, interleukin-1β (IL-1β), and interleukin-18 (IL-18) were increased and miR-125-b-2-3p was decreased in HIE rat model. STF083010 administration significantly upregulated the expression of miR-125-b-2-3p, reduced the infarct volume, improved neurobehavioral outcomes and downregulated the protein expression of NLRP1, cleaved caspase-1, IL-1β and IL-18. The protective effects of STF083010 were reversed by antimiR-125 or NLRP1 activation CRISPR.. IRE1α inhibitor, STF083010, reduced neuronal pyroptosis at least in part via miR-125/NLRP1/caspase-1 signaling pathway after HI.

Topics: Animals; Animals, Newborn; Disease Models, Animal; Endoribonucleases; Hypoxia-Ischemia, Brain; Inflammasomes; MicroRNAs; Multienzyme Complexes; Nerve Tissue Proteins; Neurons; Protein Serine-Threonine Kinases; Pyroptosis; Rats; Rats, Sprague-Dawley; Signal Transduction; Sulfonamides; Thiophenes

The nod-like receptor protein-3 (NLRP3)-mediated pyroptosis is involved in kidney diseases. Thioredoxin interacting protein (TXNIP) directly interacts with NLRP3. This study aimed to probe the mechanism of TXNIP and NLRP3 pathway in diabetic nephropathy (DN). Marker detection and histological staining indicated that in DN rats, the renal function was destroyed, and the TXNIP/NLRP3 axis was activated to induce inflammatory generation and pyroptosis. The protein levels of TXNIP, NLRP3 inflammatory components and endoplasmic reticulum stress (ERS)-related factors (ATF4, CHOP and IRE1α) were measured. DN rats were injected with LV-TXNIP-shRNA or IRE1α RNase specific inhibitor (STF-083010) to examine ERS- and pyroptosis-related proteins, and renal injury. Silencing TXNIP inhibited the NLRP3 axis and reduced renal damage in DN rats. ERS was activated in DN rats, and miR-200a expression was degraded by IRE1α. miR-200a bound to TXNIP. NRK-52E cells were induced by high glucose (HG) to simulate DN in vitro. The damage and pyroptosis of NRK-52E cells were analyzed. After inhibiting IRE1α, miR-200a expression increased and TXNIP expression decreased. miR-200a inhibition in HG-induced NRK-52E cells partially reversed the reduced pyroptosis by STF-083010. Overall, IRE1α upregulates miR-200a degradation in DN rats, and stimulates the TXINP/NLRP3 pathway-mediated pyroptosis and renal damage.

Topics: Animals; Cell Cycle Proteins; Cell Line; Diabetic Nephropathies; Disease Models, Animal; Down-Regulation; Endoplasmic Reticulum Stress; Endoribonucleases; Glucose; Kidney Tubules; Male; MicroRNAs; Models, Biological; Multienzyme Complexes; NLR Family, Pyrin Domain-Containing 3 Protein; Protein Serine-Threonine Kinases; Pyroptosis; Rats, Sprague-Dawley; Sulfonamides; Thiophenes; Up-Regulation

Our previous studies have shown evidence of endoplasmic reticulum (ER) stress-induced apoptosis in the hippocampus and mPFC in an animal model of post- traumatic stress disorder (PTSD). Inositol-requiring enzyme 1α (IRE1α) and its downstream molecule X-box binding protein 1 (XBP1) play key roles in the ER-related apoptosis pathway. Dysregulation of the locus coeruleus (LC) has been reported to contribute to cognitive and/or arousal impairments associated with PTSD. The aim of the present study was to explore the role of IRE1α pathway in neuronal apoptosis in the LC of rat models of PTSD. We used an acute exposure to prolonged stress (single prolonged stress, SPS) to model PTSD in rats and examined the effects related to the IRE1α pathway. Neuronal apoptosis in LC was detected by transmission electron microscopy and TUNEL staining. The results showed that the level of LC neuronal apoptosis was markedly increased after SPS. SPS exposure triggered IRE1α pathway, as evidenced by the increased activity of IRE1α, specific splicing of XBP1, and up-regulated expression of binding immunoglobulin protein/78kDa glucose-regulated protein (BiP/GRP78), and C/EBP-homologous protein (CHOP). Treatment with STF-083010, an IRE1α RNase-specific inhibitor, successfully attenuated the above changes. These results indicate that excessive activation of the ER stress-associated IRE1α pathway is involved in LC neuronal apoptosis induced by SPS exposure; this may be a crucial mechanism of the pathogenesis of PTSD.

Topics: Animals; Apoptosis; Disease Models, Animal; Endoplasmic Reticulum Stress; Endoribonucleases; Enzyme Inhibitors; Heat-Shock Proteins; Locus Coeruleus; Male; Multienzyme Complexes; Neurons; Protein Serine-Threonine Kinases; Random Allocation; Rats, Wistar; Signal Transduction; Stress Disorders, Post-Traumatic; Sulfonamides; Thiophenes; Transcription Factor CHOP; X-Box Binding Protein 1