Piperlongumine Acts as an Immunosuppressant by Exerting Prooxidative Effects in Human T Cells Resulting in Diminished TH17 but Enhanced Treg Differentiation

Alkaloids in Cancer therapy: Targeting the tumor microenvironment and metastasis signaling pathways

The use of phytomedicine in cancer therapy is a growing field of research that takes use of the medicinal properties of plant-derived compounds. Under the domain of cancer therapy and management, alkaloids, a prominent group of natural compounds, have showed significant potential. Alkaloids often affect a wide range of essential cellular mechanisms involved in cancer progression. These multi-targeting capabilities, can give significant advantages to alkaloids in overcoming resistance mechanisms. For example, berberine, an alkaloid found in Berberis species, is widely reported to induce apoptosis by activating caspases and regulating apoptotic pathways. Notably, alkaloids like as quinine have showed promise in inhibiting the formation of new blood vessels required for tumor growth. In addition, alkaloids have shown anti-proliferative and anticancer properties mostly via modulating key signaling pathways involved in metastasis, including those regulating epithelial-mesenchymal transition. This work provides a comprehensive overview of naturally occurring alkaloids that exhibit anticancer properties, with a specific emphasis on their underlying molecular mechanisms of action. Furthermore, many methods to modify previously reported difficult physicochemical properties using nanocarriers in order to enhance its systemic bioavailability have been discussed as well. This study also includes information on newly discovered alkaloids that are now being studied in clinical trials for their potential use in cancer treatment. Further, we have also briefly mentioned on the application of high-throughput screening and molecular dynamics simulation for acceleration on the identification of potent alkaloids based compounds to target and treat cancer.

Pan-cancer analysis of T-cell proliferation regulatory genes as potential immunotherapeutic targets

T cells are the key to killing tumor cells. However, the exact mechanism of their role in cancer is not fully understood. Therefore, a comprehensive understanding of the role of T-cell proliferation regulatory genes in tumors is needed. In our study, we investigated the expression levels of genes controlling T-cell proliferation, their impact on prognosis, and their genetic variations. Additionally, we explored their associations with TMB, MSI, ESTIMATEScore, ImmuneScore, StromalScore, and immune cell infiltration. We examined the role of these genes in cancer-related pathways using GSEA. Furthermore, we calculated their activity levels across various types of cancer. Drug analysis was also conducted targeting these genes. Single-cell analysis, LASSO Cox model construction, and prognosis analysis were performed. We observed distinct expression patterns of T-cell proliferation regulatory genes across different malignant tumors. Their abnormal expression may be caused by CNA and DNA methylation. In certain cancers, they also showed complex associations with TMB and MSI. Moreover, in many tumors, they exhibited significant positive correlations with ESTIMATEScores, ImmuneScore, and StromalScore. Additionally, in most tumors, their GSVA scores were significantly positively correlated with various T-cell subtypes. GSEA analysis revealed their involvement in multiple immune pathways. Furthermore, we found that model scores were associated with patient prognosis and related to tumor malignancy progression. T-cell proliferation regulatory genes are closely associated with the tumor immune microenvironment (TIM), especially T cells. Targeting them may be an essential approach for cancer immunotherapy.

Piperlongumine regulates genes involved in the skin barrier in epidermal keratinocyte HaCaT cells

Given that the skin is the largest tissue in the human body, performing external barrier functions with innate and adaptive immunity and undergoing substantial changes during aging, it is under investigation as a major target of various bioactive molecules. In the present study, we examined the biological activity of the senolytic piperlongumine by analyzing alterations in mRNA expression of notable skin genes using transformed aneuploid immortal epidermal keratinocytes, HaCaT cells. We observed that piperlongumine increased the mRNA expression of genes playing critical roles in skin barrier function. In addition, piperlongumine increased expression enzymes involved in the synthesis of ceramide, a major component of intercellular lipids. Furthermore, we measured the protein levels of various cytokines secreted by epidermal keratinocytes and found changes in the release of GRO-αβγ, CCL5, and MCP1. Additionally, we observed that piperlongumine treatment modulated the expression of keratinocyte-specific aging markers and influenced telomerase activity. Based on these findings, piperlongumine could regulate the physiological activity of epidermal keratinocytes to induce beneficial effects in human skin by regulating important skin-related genes.

Piperlongumine: the amazing amide alkaloid from Piper in the treatment of breast cancer

Piperlongumine (PL), an alkaloid found primarily in the fruits and roots of the plant Piper longum L. (Piperaceae), is a natural compound that exhibits potent activity against various cancer cell proliferation. The most frequently caused malignancy in women globally, breast cancer (BC), has been demonstrated to be significantly inhibited by PL. Apoptosis, cell cycle arrest, increased ROS generation, and changes in the signalling protein's expression are all caused by the numerous signalling pathways that PL impacts. Since BC cells resist conventional chemotherapeutic drugs (doxorubicin, docetaxel etc.), researchers have shown that the drugs in combination with PL can exhibit a synergistic effect, greater than the effects of the drug or PL alone. Recently, techniques for drug packaging based on nanotechnology have been employed to improve PL release. The review has presented an outline of the chemistry of PL, its molecular basis in BC, its bioavailability, toxicity, and nanotechnological applications. An attempt to understand the future prospects and direction of research about the compound has also been discussed.

Computational identification of natural senotherapeutic compounds that mimic dasatinib based on gene expression data

The major risk factor for chronic disease is chronological age, and age-related chronic diseases account for the majority of deaths worldwide. Targeting senescent cells that accumulate in disease-related tissues presents a strategy to reduce disease burden and to increase healthspan. The senolytic combination of the tyrosine-kinase inhibitor dasatinib and the flavonol quercetin is frequently used in clinical trials aiming to eliminate senescent cells. Here, our goal was to computationally identify natural senotherapeutic repurposing candidates that may substitute dasatinib based on their similarity in gene expression effects. The natural senolytic piperlongumine (a compound found in long pepper), and the natural senomorphics parthenolide, phloretin and curcumin (found in various edible plants) were identified as potential substitutes of dasatinib. The gene expression changes underlying the repositioning highlight apoptosis-related genes and pathways. The four compounds, and in particular the top-runner piperlongumine, may be combined with quercetin to obtain natural formulas emulating the dasatinib + quercetin formula.

Piperlongumine based nanomedicine impairs glycolytic metabolism in triple negative breast cancer stem cells through modulation of GAPDH & FBP1

BACKGROUND

Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and exhibits high rate of chemoresistance, metastasis, and relapse. This can be attributed to the failure of conventional therapeutics to target a sub-population of slow cycling or quiescent cells called as cancer stem cells (CSCs). Therefore, elimination of CSCs is essential for effective TNBC treatment.

PURPOSE

Research suggests that breast CSCs exhibit elevated glycolytic metabolism which directly contributes in maintenance of stemness, self-renewability and chemoresistance as well as in tumor progression. Therefore, this study aimed to target rewired metabolism which can serve as Achilles heel for CSCs population and have far reaching effect in TNBC treatment.

METHODS

We used two preclinical models, zebrafish and nude mice to evaluate the fate of nanoparticles as well as the therapeutic efficacy of both piperlongumine (PL) and its nanomedicine (PL-NPs).

RESULTS

In this context, we explored a phytochemical piperlongumine (PL) which has potent anti-cancer properties but poor pharmacokinetics impedes its clinical translation. So, we developed PLGA based nanomedicine for PL (PL-NPs), and demonstrated that it overcomes the pharmacokinetic limitations of PL, along with imparting advantages of selective tumor targeting through Enhanced Permeability and Retention (EPR) effect in zebrafish xenograft model. Further, we demonstrated that PL-NPs efficiently inhibit glycolysis in CSCs through inhibition of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by modulating glutathione S-transferase pi 1 (GSTP1) and upregulation of fructose-1,6-bisphosphatase 1 (FBP1), a rate-limiting enzyme in gluconeogenesis. We also illustrated that inhibition of glycolysis results in overall tumor regression in two preclinical models.

CONCLUSION

This study discusses novel mechanism of action by which PL acts on CSCSs. Taken together our study provides insight into development of PL based nanomedicine which could be exploited in clinics to achieve complete eradication of TNBC by targeting CSCs.

Targeting abnormal lipid metabolism of T cells for systemic lupus erythematosus treatment

Systemic lupus erythematosus (SLE) is an autoimmune disease in which the immune system attacks its own tissues and organs. However, the causes of SLE remain unknown. Dyslipidemia is a common symptom observed in SLE patients and animal models and is closely correlated to disease activity. Lipid metabolic reprogramming has been considered as a hallmark of the dysfunction of T cells in patients with SLE, therefore, manipulating lipid metabolism provides a potential therapeutic target for treating SLE. A better understanding of the underlying mechanisms for the metabolic events of immune cells under pathological conditions is crucial for tuning immunometabolism to manage autoimmune diseases such as SLE. In this review, we aim to summarize the cross-link between lipid metabolism and the function of T cells as well as the underlying mechanisms, and provide light on the novel therapeutic strategies of active compounds from herbals for the treatment of SLE by targeting lipid metabolism in immune cells.

Cholesterol suppresses human iTreg differentiation and nTreg function through mitochondria-related mechanisms

BACKGROUND

Both the crystalline and soluble forms of cholesterol increase macrophage secretion of interleukin 1β (IL-1β), aggravating the inflammatory response in atherosclerosis (AS). However, the link between cholesterol and regulatory T cells (Tregs) remains unclear. This study aimed to investigate the effect of cholesterol treatment on Tregs.

METHODS

Differentiation of induced Tregs (iTregs) was analyzed using flow cytometry. The expression of hypoxia-inducible factor-1a (HIF-1a) and its target genes was measured by western blotting and/or RT-qPCR. Two reporter jurkat cell lines were constructed by lentiviral transfection. Mitochondrial function and the structure of natural Tregs (nTregs) were determined by tetramethylrhodamine (TMRM) and mitoSOX staining, Seahorse assay, and electron microscopy. The immunoregulatory function of nTregs was determined by nTreg-macrophage co-culture assay and ELISA.

RESULTS

Cholesterol treatment suppressed iTreg differentiation and impaired nTreg function. Mechanistically, cholesterol induced the production of mitochondrial reactive oxygen species (mtROS) in naïve T cells, inhibiting the degradation of HIF-1α and unleashing its inhibitory effects on iTreg differentiation. Furthermore, cholesterol-induced mitochondrial oxidative damage impaired the immunosuppressive function of nTregs. Mixed lymphocyte reaction and nTreg-macrophage co-culture assays revealed that cholesterol treatment compromised the ability of nTregs to inhibit pro-inflammatory conventional T cell proliferation and promote the anti-inflammatory functions of macrophages. Finally, mitoTEMPO (MT), a specific mtROS scavenger, restored iTreg differentiation and protected nTreg from further deterioration.

CONCLUSION

Our findings suggest that cholesterol may aggravate inflammation within AS plaques by acting on both iTregs and nTregs, and that MT may be a promising anti-atherogenic drug.

Resveratrol as an Adjunctive Therapy for Excessive Oxidative Stress in Aging COVID-19 Patients

The coronavirus disease 2019 (COVID-19) pandemic continues to burden healthcare systems worldwide. COVID-19 symptoms are highly heterogeneous, and the patient may be asymptomatic or may present with mild to severe or fatal symptoms. Factors, such as age, sex, and comorbidities, are key determinants of illness severity and progression. Aging is accompanied by multiple deficiencies in interferon production by dendritic cells or macrophages in response to viral infections, resulting in dysregulation of inflammatory immune responses and excess oxidative stress. Age-related dysregulation of immune function may cause a more obvious pathophysiological response to SARS-CoV-2 infection in elderly patients and may accelerate the risk of biological aging, even after recovery. For more favorable treatment outcomes, inhibiting viral replication and dampening inflammatory and oxidative responses before induction of an overt cytokine storm is crucial. Resveratrol is a potent antioxidant with antiviral activity. Herein, we describe the reasons for impaired interferon production, owing to aging, and the impact of aging on innate and adaptive immune responses to infection, which leads to inflammation distress and immunosuppression, thereby causing fulminant disease. Additionally, the molecular mechanism by which resveratrol could reverse a state of excessive basal inflammatory and oxidative stress and low antiviral immunity is discussed.

Overview of piperlongumine analogues and their therapeutic potential

Natural products have long been an important source for discovery of new drugs to treat human diseases. Piperlongumine (PL) is an amide alkaloid isolated from Piper longum L. (long piper) and other piper plants and has received widespread attention because of its diverse biological activities. A large number of PL derivatives have been designed, synthesized and assessed in many pharmacological functions, including antiplatelet aggregation, neuroprotective activities, anti-diabetic activities, anti-inflammatory activities, anti-senolytic activities, immune activities, and antitumor activities. Among them, the anti-tumor effects and application of PL and its derivatives are most extensively studied. We herein summarize the development of PL derivatives, the structure and activity relationships (SARs), and their therapeutic potential on the treatments of various diseases, especially against cancer. We also discussed the challenges and future directions associated with PL and its derivatives in these indications.

Nitric Oxide and Electrophilic Cyclopentenone Prostaglandins in Redox signaling, Regulation of Cytoskeleton Dynamics and Intercellular Communication

Nitric oxide (NO) and electrophilic cyclopentenone prostaglandins (CyPG) are local mediators that modulate cellular response to oxidative stress in different pathophysiological processes. In particular, there is increasing evidence about their functional role during inflammation and immune responses. Although the mechanistic details about their relationship and functional interactions are still far from resolved, NO and CyPG share the ability to promote redox-based post-translational modification (PTM) of proteins that play key roles in cellular homeostasis, signal transduction and transcription. NO-induced S-nitrosylation and S-glutathionylation as well as cyclopentenone-mediated adduct formation, are a few of the main PTMs by which intra- and inter-cellular signaling are regulated. There is a growing body of evidence indicating that actin and actin-binding proteins are susceptible to covalent PTM by these agents. It is well known that the actin cytoskeleton is key for the establishment of interactions among leukocytes, endothelial and muscle cells, enabling cellular activation and migration. In this review we analyze the current knowledge about the actions exerted by NO and CyPG electrophilic lipids on the regulation of actin dynamics and cytoskeleton organization, and discuss some open questions regarding their functional relevance in the regulation of intercellular communication.

Devilishly radical NETwork in COVID-19: Oxidative stress, neutrophil extracellular traps (NETs), and T cell suppression

Pandemic coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and poses an unprecedented challenge to healthcare systems due to the lack of a vaccine and specific treatment options. Accordingly, there is an urgent need to understand precisely the pathogenic mechanisms underlying this multifaceted disease. There is increasing evidence that the immune system reacts insufficiently to SARS-CoV-2 and thus contributes to organ damage and to lethality. In this review, we suggest that the overwhelming production of reactive oxygen species (ROS) resulting in oxidative stress is a major cause of local or systemic tissue damage that leads to severe COVID-19. It increases the formation of neutrophil extracellular traps (NETs) and suppresses the adaptive arm of the immune system, i.e. T cells that are necessary to kill virus-infected cells. This creates a vicious cycle that prevents a specific immune response against SARS-CoV-2. The key role of oxidative stress in the pathogenesis of severe COVID-19 implies that therapeutic counterbalancing of ROS by antioxidants such as vitamin C or NAC and/or by antagonizing ROS production by cells of the mononuclear phagocyte system (MPS) and neutrophil granulocytes and/or by blocking of TNF-α can prevent COVID-19 from becoming severe. Controlled clinical trials and preclinical models of COVID-19 are needed to evaluate this hypothesis.