Response to Oxidative Burst-Induced Hypoxia Is Associated With Macrophage Inflammatory Profiles as Revealed by Cellular Genome-Wide Association

Harnessing Macrophages in Cancer Therapy: from Immune Modulators to Therapeutic Targets

Macrophages, as the predominant phagocytes, play an essential role in pathogens defense and tissue homeostasis maintenance. In the context of cancer, tumor-associated macrophages (TAMs) have evolved into cunning actors involved in angiogenesis, cancer cell proliferation and metastasis, as well as the construction of immunosuppressive microenvironment. Once properly activated, macrophages can kill tumor cells directly through phagocytosis or attack tumor cells indirectly by stimulating innate and adaptive immunity. Thus, the prospect of targeting TAMs has sparked significant interest and emerged as a promising strategy in immunotherapy. In this review, we summarize the diverse roles and underlying mechanisms of TAMs in cancer development and immunity and highlight the TAM-based therapeutic strategies such as inhibiting macrophage recruitment, inhibiting the differentiation reprogramming of TAMs, blocking phagocytotic checkpoints, inducing trained macrophages, as well as the potential of engineered CAR-armed macrophages in cancer therapy.

Ferroptosis and its relationship with cancer

Marked by iron buildup and lipid peroxidation, ferroptosis is a relatively new regulatory cell death (RCD) pathway. Many diseases like cancer, myocardial ischemia-reperfusion injury (MIRI), neurological disorders and acute renal failure (AKI) are corelated with ferroptosis. The main molecular processes of ferroptosis discovered yet will be presented here, along with the approaches in which it interacts with tumour-associated signaling pathways and its uses in systemic therapy, radiation therapy, and immunotherapy managing tumors.

Deletion of CD38 mitigates the severity of NEC in experimental settings by modulating macrophage-mediated inflammation

Necrotizing enterocolitis (NEC) is a form of potentially lethal gastrointestinal inflammation that primarily affects preterm neonates. It is crucial to recognize that, while the disease carries significant risks, timely and effective medical intervention can greatly enhance the chances of survival. Additionally, NEC is closely linked to the activation of macrophages, highlighting the complex interplay between the immune response and disease progression. CD38, acting as an ectoenzyme, catalyzes the hydrolysis of NAD+ to produce cyclic ADP-ribose (cADPR), a reaction critical for modulating cellular redox balance and energy homeostasis. This enzymatic activity is particularly pertinent in the context of necrotizing enterocolitis (NEC). In this research, we investigated whether CD38 deletion can elevate NAD+ levels to reduce macrophage-mediated inflammation and improve NEC severity. We show that NEC patients was associated with the increased CD38 expression in intestine and blood. These results were also observed in NEC mice, and CD38 deletion ameliorated NEC intestinal injury. Mechanistically, CD38 deletion elevated NAD+ levels that reduced oxidative stress and intestinal inflammation. Furthermore, CD38 deletion promoted M2 macrophage polarization, inhibited macrophage activation and phagocytosis ability. Thus, our results reveal a critical role for CD38 as an intracellular immune regulator for regulating macrophage activation and intestinal inflammation in NEC. Targeting CD38 and NAD+ signal maybe a promising strategy for treatment of NEC.

Genetic influence on vascular smooth muscle cell apoptosis

Vascular smooth muscle cell (VSMC) proliferation, migration, and apoptosis play important roles in many physiological processes and pathological conditions. To identify genetic influences on VSMC behavior, we measured these traits and undertook genome-wide association studies in primary umbilical artery-derived VSMCs from >2000 individuals. Although there were no genome-wide significant associations for VSMC proliferation or migration, genetic variants at two genomic loci (7p15.3 and 7q32.3) showed highly significant associations with VSMC apoptosis (P = 1.95 × 10-13 and P = 7.47 × 10-9, respectively). The lead variant at the 7p51.3 locus was associated with increased expression of the GSDME and PALS2 genes in VSMCs. Knockdown of GSDME or PALS2 in VSMCs attenuated apoptotic cell death. A protein co-immunoprecipitation assay indicated that GSDME complexed with PALS2. PALS2 knockdown attenuated activated caspase-3 and GSDME fragmentation, whilst GSDME knockdown also reduced activated caspase-3. These findings provide new insights into the genetic regulation of VSMC apoptosis, with potential utility for therapeutic development.

Non-apoptotic regulated cell death mediates reprogramming of the tumour immune microenvironment by macrophages

Tumour immune microenvironment (TIME) plays an indispensable role in tumour progression, and tumour-associated macrophages (TAMs) are the most abundant immune cells in TIME. Non-apoptotic regulated cell death (RCD) can avoid the influence of tumour apoptosis resistance on anti-tumour immune response. Specifically, autophagy, ferroptosis, pyroptosis and necroptosis mediate the crosstalk between TAMs and tumour cells in TIME, thus reprogram TIME and affect the progress of tumour. In addition, although some achievements have been made in immune checkpoint inhibitors (ICIs), there is still defect that ICIs are only effective for some people because non-apoptotic RCD can bypass the apoptosis resistance of tumour. As a result, ICIs combined with targeting non-apoptotic RCD may be a promising solution. In this paper, the basic molecular mechanism of non-apoptotic RCD, the way in which non-apoptotic RCD mediates crosstalk between TAMs and tumour cells to reprogram TIME, and the latest research progress in targeting non-apoptotic RCD and ICIs are reviewed.