Optimization of cancer immunotherapy on the basis of programmed death ligand-1 distribution and function

Programmed cell death protein-1 (PD-1)/programmed death ligand-1 (PD-L1) immune checkpoint blockade as a breakthrough in cancer immunotherapy has shown unprecedented positive outcomes in the clinic. However, the overall effectiveness of PD-L1 antibody is less than expected. An increasing number of studies have demonstrated that PD-L1 is widely distributed and expressed not only on the cell membrane but also on the inside of the cells as well as on the extracellular vesicles secreted by tumour cells. Both endogenous and exogenous PD-L1 play significant roles in influencing the therapeutic effect of anti-tumour immunity. Herein, we mainly focused on the distribution and function of PD-L1 and further summarized the potential targeted therapeutic strategies. More importantly, in addition to taking the overall expression abundance of PD-L1 as a predictive indicator for selecting corresponding PD-1/PD-L1 monoclonal antibodies (mAbs), we also proposed that personalized combination therapies based on the different distribution of PD-L1 are worth attention to achieve more efficient and effective therapeutic outcomes in cancer patients. LINKED ARTICLES: This article is part of a themed issue on Cancer Microenvironment and Pharmacological Interventions. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.2/issuetoc.

Impact of Pharmacological and Non-Pharmacological Modulators on Dendritic Spines Structure and Functions in Brain

Dendritic spines are small, thin, hair-like protrusions found on the dendritic processes of neurons. They serve as independent compartments providing large amplitudes of Ca²⁺ signals to achieve synaptic plasticity, provide sites for newer synapses, facilitate learning and memory. One of the common and severe complication of neurodegenerative disease is cognitive impairment, which is said to be closely associated with spine pathologies viz., decreased in spine density, spine length, spine volume, spine size etc. Many treatments targeting neurological diseases have shown to improve the spine structure and distribution. However, concise data on the various modulators of dendritic spines are imperative and a need of the hour. Hence, in this review we made an attempt to consolidate the effects of various pharmacological (cholinergic, glutamatergic, GABAergic, serotonergic, adrenergic, and dopaminergic agents) and non-pharmacological modulators (dietary interventions, enriched environment, yoga and meditation) on dendritic spines structure and functions. These data suggest that both the pharmacological and non-pharmacological modulators produced significant improvement in dendritic spine structure and functions and in turn reversing the pathologies underlying neurodegeneration. Intriguingly, the non-pharmacological approaches have shown to improve intellectual performances both in preclinical and clinical platforms, but still more technology-based evidence needs to be studied. Thus, we conclude that a combination of pharmacological and non-pharmacological intervention may restore cognitive performance synergistically via improving dendritic spine number and functions in various neurological disorders.

Pharmacological Modulators of Small GTPases of Rho Family in Neurodegenerative Diseases

Classical Rho GTPases, including RhoA, Rac1, and Cdc42, are members of the Ras small GTPase superfamily and play essential roles in a variety of cellular functions. Rho GTPase signaling can be turned on and off by specific GEFs and GAPs, respectively. These features empower Rho GTPases and their upstream and downstream modulators as targets for scientific research and therapeutic intervention. Specifically, significant therapeutic potential exists for targeting Rho GTPases in neurodegenerative diseases due to their widespread cellular activity and alterations in neural tissues. This study will explore the roles of Rho GTPases in neurodegenerative diseases with focus on the applications of pharmacological modulators in recent discoveries. There have been exciting developments of small molecules, nonsteroidal anti-inflammatory drugs (NSAIDs), and natural products and toxins for each classical Rho GTPase category. A brief overview of each category followed by examples in their applications will be provided. The literature on their roles in various diseases [e.g., Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS), Frontotemporal dementia (FTD), and Multiple sclerosis (MS)] highlights the unique and broad implications targeting Rho GTPases for potential therapeutic intervention. Clearly, there is increasing knowledge of therapeutic promise from the discovery of pharmacological modulators of Rho GTPases for managing and treating these conditions. The progress is also accompanied by the recognition of complex Rho GTPase modulation where targeting its signaling can improve some aspects of pathogenesis while exacerbating others in the same disease model. Future directions should emphasize the importance of elucidating how different Rho GTPases work in concert and how they produce such widespread yet different cellular responses during neurodegenerative disease progression.

Therapeutic implications of circadian clocks in neurodegenerative diseases

Circadian clocks, endogenous oscillators generating daily biological rhythms, have important roles in the nervous system to control diverse cellular processes-not only in the suprachiasmatic nucleus (SCN), where the master clocks reside to synchronize all circadian clocks in the body but also in other non-SCN areas. Accumulating evidence has shown relationships between circadian abnormalities (e.g., sleep disturbances and abnormal rest-activity rhythms) and disease progressions in various neurodegenerative diseases, including Alzheimer's (AD) and Parkinson's (PD) disease. Although circadian abnormalities were frequently considered as consequences of disease onsets, recent studies suggest altered circadian clocks as risk factors to develop neurodegenerative diseases via altered production or clearance rates of toxic metabolites like amyloid β. In this review, we will summarize circadian clock-related pathologies in the most common neurodegenerative diseases in the central nervous system, AD and PD. Then, we will introduce the current clinical trials to rescue circadian abnormalities in AD and PD patients. Finally, a discussion about how to improve targeting circadian clocks to increase treatment efficiencies and specificities will be followed. This discussion will provide insight into circadian clocks as potential therapeutic targets to attenuate onsets and progressions of neurodegenerative diseases.

Dichotomous Sirtuins: Implications for Drug Discovery in Neurodegenerative and Cardiometabolic Diseases

Sirtuins (SIRT1-7), a class of NAD⁺-dependent deacylases, are central regulators of metabolic homeostasis and stress responses. While numerous salutary effects associated with sirtuin activation, especially SIRT1, are well documented, other reports show health benefits resulting from sirtuin inhibition. Furthermore, conflicting findings have been obtained regarding the pathophysiological role of specific sirtuin isoforms, suggesting that sirtuins act as 'double-edged swords'. Here, we provide an integrated overview of the different findings on the role of mammalian sirtuins in neurodegenerative and cardiometabolic disorders and attempt to dissect the reasons behind these different effects. Finally, we discuss how addressing these obstacles may provide a better understanding of the complex sirtuin biology and improve the likelihood of identifying effective and selective drug targets for a variety of human disorders.

Autophagy in Metabolic Age-Related Human Diseases

Autophagy is a highly conserved homeostatic cellular mechanism that mediates the degradation of damaged organelles, protein aggregates, and invading pathogens through a lysosome-dependent pathway. Over the last few years, specific functions of autophagy have been discovered in many tissues and organs; however, abnormal upregulation or downregulation of autophagy has been depicted as an attribute of a variety of pathologic conditions. In this review, we will describe the current knowledge on the role of autophagy, from its regulation to its physiological influence, in metabolic age-related disorders. Finally, we propose to discuss the therapeutic potential of pharmacological and nutritional modulators of autophagy to treat metabolic diseases.

The current status and perspectives regarding the clinical implication of intracellular calcium in breast cancer

Calcium ions (Ca²⁺ ) act as second messengers in intracellular signaling. Ca²⁺ pumps, channels, sensors, and calcium binding proteins, regulate the concentrations of intracellular Ca²⁺ as a key regulator of important cellular processes such as gene expression, proliferation, differentiation, DNA repair, apoptosis, metastasis, and hormone secretion. Intracellular Ca²⁺ also influences the functions of several organelles, that include: the endoplasmic reticulum, mitochondria, the Golgi, and cell membrane both in normal and breast cancer cells. In breast cancer, the disruption of intracellular: Ca²⁺ homeostasis may cause tumor progression by affecting key factors/pathways including phospholipase C (PLC), inositol 1,4,5-trisphosphate (IP3), calmodulin (CaM), nuclear factor of activated T-cells (NFAT), calpain, calmodulin-dependent protein kinase II (CaMKII), mitogen-activated protein kinase (MAPK), epithelial-mesenchymal transition (EMT), vascular endothelial growth factor (VEGF), poly (ADP-Ribose) polymerase-1 (PARP1), estrogen, and estrogen receptor. Because the foregoing molecules play crucial roles in breast cancer, the factors/pathways influencing intracellular Ca²⁺ concentrations are putative targets for cancer treatment, using drugs such as Mephebrindole, Tilapia piscidin 4, Nifetepimine, Paricalcitol, and Prednisolone. We have explored the factors/pathways which are related to breast cancer and Ca²⁺ homeostasis and signaling in this review, and also discussed their potential as biomarkers for breast cancer staging, prognosis, and therapy.