Tracking the therapeutic efficacy of a ketone mono ester and β-hydroxybutyrate for ulcerative colitis in rats: New perspectives

Ulcerative colitis (UC) is an inflammatory condition that affects the colon's lining and increases the risk of colon cancer. Despite ongoing research, there is no identified cure for UC. The recognition of NLRP3 inflammasome activation in the pathogenesis of UC has gained widespread acceptance. Notably, the ketone body β-hydroxybutyrate inhibits NLRP3 demonstrating its anti-inflammatory properties. Additionally, BD-AcAc 2 is ketone mono ester that increases β-hydroxybutyrate blood levels. It has the potential to address the constraints associated with exogenous β-hydroxybutyrate as a therapeutic agent, including issues related to stability and short duration of action. However, the effects of β-hydroxybutyrate and BD-AcAc 2 on colitis have not been fully investigated. This study found that while both exogenous β-hydroxybutyrate and BD-AcAc 2 produced the same levels of plasma β-hydroxybutyrate, BD-AcAc 2 demonstrated superior effectiveness in mitigating dextran sodium sulfate-induced UC in rats. The mechanism of action involves modulating the NF-κB signaling, inhibiting the NLRP3 inflammasome, regulating antioxidant capacity, controlling tight junction protein expression and a potential to inhibit apoptosis and pyroptosis. Certainly, BD-AcAc 2's anti-inflammatory effects require more than just increasing plasma β-hydroxybutyrate levels and other factors contribute to its efficacy. Local ketone concentrations in the gastrointestinal tract, as well as the combined effect of specific ketone bodies, are likely to have contributed to the stronger protective effect observed with ketone mono ester ingestion in our experiment. As a result, further investigations are necessary to fully understand the mechanisms of BD-AcAc 2 and optimize its use.

Linagliptin, a DPP-4 inhibitor, activates AMPK/FOXO3a and suppresses NFκB to mitigate the debilitating effects of diethylnitrosamine exposure in rat liver: Novel mechanistic insights

Accumulating evidence suggests that dysregulation of FOXO3a plays a significant role in the progression of various malignancies, including hepatocellular carcinoma (HCC). FOXO3a inactivation, driven by oncogenic stimuli, can lead to abnormal cell growth, suppression of apoptosis, and resistance to anticancer drugs. Therefore, FOXO3a emerges as a potential molecular target for the development of innovative treatments in the era of oncology. Linagliptin (LNGTN), a DPP-4 inhibitor known for its safe profile, has exhibited noteworthy anti-inflammatory and anti-oxidative properties in previous in vivo studies. Several potential molecular mechanisms have been proposed to explain these effects. However, the capacity of LNGTN to activate FOXO3a through AMPK activation has not been investigated. In our investigation, we examined the potential repurposing of LNGTN as a hepatoprotective agent against diethylnitrosamine (DENA) intoxication. Additionally, we assessed LNGTN's impact on apoptosis and autophagy. Following a 10-week administration of DENA, the liver underwent damage marked by inflammation and early neoplastic alterations. Our study presents the first experimental evidence demonstrating that LNGTN can reinstate the aberrantly regulated FOXO3a activity by elevating the nuclear fraction of FOXO3a in comparison to the cytosolic fraction, subsequent to AMPK activation. Moreover, noteworthy inactivation of NFκB induced by LNGTN was observed. These effects culminated in the initiation of apoptosis, the activation of autophagy, and the manifestation of anti-inflammatory, antiproliferative, and antiangiogenic outcomes. These effects were concomitant with improved liver function and microstructure. In conclusion, our findings open new avenues for the development of novel therapeutic strategies targeting the AMPK/FOXO3a signaling pathway in the management of chronic liver damage.

Alvespimycin Exhibits Potential Anti-TGF-β Signaling in the Setting of a Proteasome Activator in Rats with Bleomycin-Induced Pulmonary Fibrosis: A Promising Novel Approach

Idiopathic pulmonary fibrosis (IPF) is an irreversible and life-threatening lung disease of unknown etiology presenting only a few treatment options. TGF-β signaling orchestrates a cascade of events driving pulmonary fibrosis (PF). Notably, recent research has affirmed the augmentation of TGF-β receptor (TβR) signaling via HSP90 activation. HSP90, a molecular chaperone, adeptly stabilizes and folds TβRs, thus intricately regulating TGF-β1 signaling. Our investigation illuminated the impact of alvespimycin, an HSP90 inhibitor, on TGF-β-mediated transcriptional responses by inducing destabilization of TβRs. This outcome stems from the explicit interaction of TβR subtypes I and II with HSP90, where they are clients of this cellular chaperone. It is worth noting that regulation of proteasome-dependent degradation of TβRs is a critical standpoint in the termination of TGF-β signal transduction. Oleuropein, the principal bioactive compound found in Olea europaea, is acknowledged for its role as a proteasome activator. In this study, our aim was to explore the efficacy of a combined therapy involving oleuropein and alvespimycin for the treatment of PF. We employed a PF rat model that was induced by intratracheal bleomycin infusion. The application of this dual therapy yielded a noteworthy impediment to the undesired activation of TGF-β/mothers against decapentaplegic homologs 2 and 3 (SMAD2/3) signaling. Consequently, this novel combination showcased improvements in both lung tissue structure and function while also effectively restraining key fibrosis markers such as PDGF-BB, TIMP-1, ACTA2, col1a1, and hydroxyproline. On a mechanistic level, our findings unveiled that the antifibrotic impact of this combination therapy likely stemmed from the enhanced degradation of both TβRI and TβRII. In conclusion, the utilization of proteasomal activators in conjunction with HSP90 inhibitors ushers in a promising frontier for the management of PF.

STA9090 as a Potential Therapeutic Agent for Liver Fibrosis by Modulating the HSP90/TβRII/Proteasome Interplay: Novel Insights from In Vitro and In Vivo Investigations

Liver fibrosis is a progressive condition characterized by the build-up of fibrous tissue resulting from long-term liver injury. Although there have been advancements in research and treatment, there is still a need for effective antifibrotic medication. HSP90 plays a crucial role in the development of fibrosis. It acts as a molecular chaperone that assists in the proper folding and stability of TβRII, potentially regulating the signaling of TGF-β1. It has been established that TβRII can be degraded through the proteasome degradation system, either via ubiquitination-dependent or -independent pathways. In the present study, STA9090 demonstrated promising effects in both in vitro and in vivo models. It reduced LDH leakage, prolonged the survival rate of hepatocytes in rats with liver fibrosis, and improved liver function. Importantly, STA9090 exerted pleiotropic effects by targeting proteins involved in limiting collagen production, which resulted in improved microscopic features of the rat livers. Our findings suggest that STA9090-induced inhibition of HSP90 leads to the degradation of TβRII, a fibrogenic client protein of HSP90, through the activation of the 20S proteasomal degradation system. We also revealed that this degradation mechanism is not dependent on the autophagy-lysosomal pathway. Additionally, STA9090 was found to destabilize HIF-1α and facilitate its degradation, leading to the reduced transcription of VEGF. Moreover, STA9090's ability to deactivate the NFκB signaling pathway highlights its potential as an anti-inflammatory and antifibrotic agent. However, further research is necessary to fully elucidate the underlying mechanisms and fully capitalize on the therapeutic benefits of targeting HSP90 and associated pathways.

(R,R)-BD-AcAc2 Mitigates Chronic Colitis in Rats: A Promising Multi-Pronged Approach Modulating Inflammasome Activity, Autophagy, and Pyroptosis

Ulcerative colitis is a chronic and incurable form of inflammatory bowel disease that can increase the risk of colitis-associated cancer and mortality. Limited treatment options are available for this condition, and the existing ones often come with non-tolerable adverse effects. This study is the first to examine the potential benefits of consuming (R,R)-BD-AcAc2, a type of ketone ester (KE), and intermittent fasting in treating chronic colitis induced by dextran sodium sulfate (DSS) in rats. We selected both protocols to enhance the levels of β-hydroxybutyrate, mimicking a state of nutritional ketosis and early ketosis, respectively. Our findings revealed that only the former protocol, consuming the KE, improved disease activity and the macroscopic and microscopic features of the colon while reducing inflammation scores. Additionally, the KE counteracted the DSS-induced decrease in the percentage of weight change, reduced the colonic weight-to-length ratio, and increased the survival rate of DSS-insulted rats. KE also showed potential antioxidant activities and improved the gut microbiome composition. Moreover, consuming KE increased the levels of tight junction proteins that protect against leaky gut and exhibited anti-inflammatory properties by reducing proinflammatory cytokine production. These effects were attributed to inhibiting NFκB and NLRP3 inflammasome activation and restraining pyroptosis and apoptosis while enhancing autophagy as revealed by reduced p62 and increased BECN1. Furthermore, the KE may have a positive impact on maintaining a healthy microbiome. To conclude, the potential clinical implications of our findings are promising, as (R,R)-BD-AcAc2 has a greater safety profile and can be easily translated to human subjects.

Vorinostat induces G2/M cell cycle arrest in breast cancer cells via upregulation of PTEN

OBJECTIVE

Breast cancer (BC) is the most common type of cancer in females worldwide. Various approaches were proposed to treat the disease, with no sole agent proved efficient. Thus, understanding the molecular mechanisms of different drugs became mandatory. The present study aimed at evaluating the role of erlotinib (ERL) and vorinostat (SAHA) in inducing apoptosis in breast cancer cells. The role of these drugs was assessed also on the expression profile of some cancer-related genes; PTEN, P21, TGF, and CDH1.

MATERIALS AND METHODS

In the present study, breast cancer cells (MCF-7) and MDA-MB-231 along with human amniotic cells (WISH) were treated with two concentrations (50, and 100 µM) of erlotinib (ERL) and vorinostat (as known as SAHA) for 24 h. Cells were harvested for downstream analysis. DNA content and apoptosis were analyzed by flow cytometer, and qPCR was performed to assess the expression of different cancer-related genes.

RESULTS

The results indicated that ERL and SAHA arrested both breast cancer cells at the G2/M phase after 24 h compared to normal cells and control. For apoptosis, BC cells showed an elevated level of total apoptosis (early and late) increasing the concentrations of the two applied drugs, with the most effective concentration of ERL at 100 µM in the 24-h treatment. In the control cells, SAHA was proved to be the most effective drug at a concentration of 100 µM with a percentage of apoptosis ranging from 1.7-12% in the 24-h treatment. Necrosis also was dose-dependent in the two breast cancer cell lines used. We further evaluated the expression profiles of PTEN, P21, TGF-β, and CDH1. In MCF-7, data indicated that for TGF-β, PTEN, and P21, the most effective treatment was SAHA at a concentration of 100 µM, while for CDH1, the most effective concentration was ERL at 100 µM. A similar profile was observed in MDA-MB-232, where for TGF-β, PTEN, and P21, the most effective treatment was SAHA at a concentration of 100 µM, while for CDH1, the most effective concentration was SAHA at 50 µM.

CONCLUSIONS

Our results shed some light on the role of ERL and SAHA in regulating the expression of cancer-related genes, though these data need further investigation.