Poly (ADP-ribose) polymerase-1 binds to BCL2 major breakpoint region and regulates BCL2 expression

Perillaldehyde targeting PARP1 to inhibit TRPM2-CaMKII/CaN signal transduction in diabetic cardiomyopathy

BACKGROUND

Diabetic cardiomyopathy (DC) is a serious complication of diabetes, characterized by myocardial fibrosis, hypertrophy, oxidative stress, and inflammation. Perillaldehyde (PAE), a natural monoterpene, has shown potential in mitigating cardiac damage.

PURPOSE

This study aims to elucidate the molecular mechanism of the protective effect of PAE on the DC and the interaction between DC pathogenesis.

METHODS

Network pharmacology and molecular docking were used to identify PARP1 as a core target for PAE in DC. Animal experiments involved intervening DC mice with PAE and assessing cardiac function, oxidative stress, and apoptosis. In vitro, high glucose-induced H9c2 cells were used to validate PAE's effects on cell viability and protein expression.

RESULTS

The results showed that PAE improved the general condition of DC mice, reduced cardiac injury and cardiac insufficiency, decreased myocardial mitochondrial damage, and reduced apoptosis. In addition, PAE upregulated the expression of Bcl-2, downregulated Bax protein expression, inhibited Caspase-3 activity, and inhibited the expression of PARP1, TRPM2, CaN, and CaMKII proteins in DC mice and high glucose-induced H9c2 cells.

CONCLUSION

Mechanically, this study clarified that PAE's inhibition of the PARP1-TRPM2-CaMKII/CaN pathway reduces calcium-activated mitochondrial damage, apoptosis, and oxidative stress in diabetic cardiomyopathy. This discovery provides an innovative therapeutic strategy for DC and an experimental foundation for PAE's drug development, with significant practical implications.

Restoring Homeostasis: Treating Amyotrophic Lateral Sclerosis by Resolving Dynamic Regulatory Instability

Amyotrophic lateral sclerosis (ALS) has an interactive, multifactorial etiology that makes treatment success elusive. This study evaluates how regulatory dynamics impact disease progression and treatment. Computational models of wild-type (WT) and transgenic SOD1-G93A mouse physiology dynamics were built using the first-principles-based first-order feedback framework of dynamic meta-analysis with parameter optimization. Two in silico models were developed: a WT mouse model to simulate normal homeostasis and a SOD1-G93A ALS model to simulate ALS pathology dynamics and their response to in silico treatments. The model simulates functional molecular mechanisms for apoptosis, metal chelation, energetics, excitotoxicity, inflammation, oxidative stress, and proteomics using curated data from published SOD1-G93A mouse experiments. Temporal disease progression measures (rotarod, grip strength, body weight) were used for validation. Results illustrate that untreated SOD1-G93A ALS dynamics cannot maintain homeostasis due to a mathematical oscillating instability as determined by eigenvalue analysis. The onset and magnitude of homeostatic instability corresponded to disease onset and progression. Oscillations were associated with high feedback gain due to hypervigilant regulation. Multiple combination treatments stabilized the SOD1-G93A ALS mouse dynamics to near-normal WT homeostasis. However, treatment timing and effect size were critical to stabilization corresponding to therapeutic success. The dynamics-based approach redefines therapeutic strategies by emphasizing the restoration of homeostasis through precisely timed and stabilizing combination therapies, presenting a promising framework for application to other multifactorial neurodegenerative diseases.

Upregulated osterix promotes invasion and bone metastasis and predicts for a poor prognosis in breast cancer

Approximately 70% of patients with advanced breast cancer develop bone metastases, accompanied by complications, such as bone pain, fracture, and hypercalcemia. However, our understanding of the molecular mechanisms that govern this process remains fragmentary. Osterix (Osx) is a zinc finger-containing transcription factor essential for osteoblast differentiation and bone formation. Here, we identified the functional roles of Osx in facilitating breast cancer invasion and bone metastasis. Osx upregulation was associated with lymph node metastasis and was negatively prognostic for overall survival. Knockdown of Osx inhibited invasion of breast cancer and osteolytic metastasis by downregulating MMP9, MMP13, VEGF, IL-8, and PTHrP, which are involved in invasion, angiogenesis, and osteolysis; overexpression of Osx had the opposite effect. Moreover, MMP9 was a direct target of Osx and mediated the Osx-driven invasion of breast cancer cells. Together, our data showed that Osx facilitates bone metastasis of breast cancer by upregulating the expression of a cohort of genes that contribute to steps in the metastatic cascade. These findings suggest that Osx is an attractive target for the control of bone metastasis of breast cancers.

PARP-1 involvement in neurodegeneration: A focus on Alzheimer's and Parkinson's diseases

DNA damage is the prime activator of the enzyme poly(ADP-ribose)polymerase1 (PARP-1) whose overactivation has been proven to be associated with the pathogenesis of numerous central nervous system disorders, such as ischemia, neuroinflammation, and neurodegenerative diseases. Under oxidative stress conditions PARP-1 activity increases, leading to an accumulation of ADP-ribose polymers and NAD(+) depletion, that induces energy crisis and finally cell death. This review aims to explain the contribution of PARP-1 in neurodegenerative diseases, focusing on Alzheimer's and Parkinson's disease, to stimulate further studies on this issue and thereby engage a new perspective regarding the design of possible therapeutic agents or the identification of biomarkers.

PARP-1 modulates amyloid beta peptide-induced neuronal damage

Amyloid beta peptide (Aβ) causes neurodegeneration by several mechanisms including oxidative stress, which is known to induce DNA damage with the consequent activation of poly (ADP-ribose) polymerase (PARP-1). To elucidate the role of PARP-1 in the neurodegenerative process, SH-SY5Y neuroblastoma cells were treated with Aβ_25–35 fragment in the presence or absence of MC2050, a new PARP-1 inhibitor. Aβ_25–35 induces an enhancement of PARP activity which is prevented by cell pre-treatment with MC2050. These data were confirmed by measuring PARP-1 activity in CHO cells transfected with amylod precursor protein and in vivo in brains specimens of TgCRND8 transgenic mice overproducing the amyloid peptide. Following Aβ_25–35 exposure a significant increase in intracellular ROS was observed. These data were supported by the finding that Aβ_25–35 induces DNA damage which in turn activates PARP-1. Challenge with Aβ_25–35 is also able to activate NF-kB via PARP-1, as demonstrated by NF-kB impairment upon MC2050 treatment. Moreover, Aβ_25–35via PARP-1 induces a significant increase in the p53 protein level and a parallel decrease in the anti-apoptotic Bcl-2 protein. These overall data support the hypothesis of PARP-1 involvment in cellular responses induced by Aβ and hence a possible rationale for the implication of PARP-1 in neurodegeneration is discussed.

Cleavage of poly (ADP-ribose) polymerase-1 is involved in the process of porcine ovarian follicular atresia

Ovarian follicle atresia is a common phenomenon in vertebrate ovaries and this process is characterized by follicular wall degeneration. The molecular mechanism underlying follicle atresia is apoptotic granulusa cell death; however, the exact signaling pathway is still unclear. PARP-1, the founding member of the poly (ADP-ribose) polymerase (PARP) family, plays an important role in a large variety of physiological processes. Although its cleavage has recently been implicated in a variety of physiological and pathological processes, its role in the process of follicular atresia is not yet completely defined. We identified the cleavage of PARP-1 involved in the process of follicle degeneration, which is known as "follicular atresia", both from in vivo models and cell culture data. The results from immunohistochemistry (IHC) showed that cleaved PARP-1 was mainly located in apoptotic granulosa cells (GCs); and the expression of PARP-1 and caspase-3 were decreased in apoptotic granulosa cells (GCs). The results from western blotting showed that PARP-1 expression was significantly decreased in atretic follicles compared with healthy (H) follicles, and the cleavage of caspase-3 (17kDa) significantly increased in atretic follicles. Along with the cleavage of caspase-3, the expression of cleaved PARP-1 (24kDa) product was significantly increased, which confirmed caspase-3 activation. Serum starvation led to a reduction in PARP-1 and an increase in cleaved PARP-1 (24kDa) and caspase-3 (17kDa), suggesting that caspase-3 was activated under the stress of withdrawal of growth factors, in accordance with the in vivo study. In the present study, the concentrations of estradiol (E2) and progesterone (P4) as well as the P4/E2 (P/E) ratio were combined with morphological features to determine follicular classification. In summary, the present study demonstrated that cleavage of PARP-1 by caspase-3 was involved in the process of granulosa cell apoptosis. PARP-1 may through its cleavage act as a critical regulator in the process of porcine follicular atresia. Our results identified that cleavage of PARP-1 by activated (cleaved) caspase-3 may serve a key role in controlling follicular atresia through granulosa cell degeneration. These findings should prove helpful in understanding the regulatory mechanisms controlling follicular development and atresia.