Autophagy and Apoptosis: Current Challenges of Treatment and Drug Resistance in Multiple Myeloma.

Over the past two decades, the natural history of multiple myeloma (MM) has evolved dramatically, owing primarily to novel agents targeting MM in the bone marrow microenvironment (BMM) pathways. However, the mechanisms of resistance acquisition remain a mystery and are poorly understood. Autophagy and apoptosis are tightly controlled processes and play a critical role in the cell growth, development, and survival of MM. Genetic instability and abnormalities are two hallmarks of MM. During MM progression, plasma malignant cells become genetically unstable and activate various signaling pathways, resulting in the overexpression of abnormal proteins that disrupt autophagy and apoptosis biological processes. Thus, achieving a better understanding of the autophagy and apoptosis processes and the proteins that crosslinked both pathways, could provide new insights for the MM treatment and improve the development of novel therapeutic strategies to overcome resistance. This review presents a sufficient overview of the roles of autophagy and apoptosis and how they crosslink and control MM progression and drug resistance. Potential combination targeting of both pathways for improving outcomes in MM patients also has been addressed.

Hedgehog signaling promotes lipolysis in adipose tissue through directly regulating Bmm/ATGL lipase.

Hedgehog (Hh) signaling has been shown to regulate multiple developmental processes, however, it is unclear how it regulates lipid metabolism. Here, we demonstrate that Hh signaling exhibits potent activity in Drosophila fat body, which is induced by both locally expressed and midgut-derived Hh proteins. Inactivation of Hh signaling increases, whereas activation of Hh signaling decreases lipid accumulation. The major lipase Brummer (Bmm) acts downstream of Smoothened (Smo) in Hh signaling to promote lipolysis, therefore, the breakdown of triacylglycerol (TAG). We identify a critical Ci binding site in bmm promoter that is responsible to mediate Bmm expression induced by Hh signaling. Genomic mutation of the Ci binding site significantly reduces the expression of Bmm and dramatically decreases the responsiveness to Ci overexpression. Together, our findings provide a model for lipolysis to be regulated by Hh signaling, raising the possibility for Hh signaling to be involved in lipid metabolic and/or lipid storage diseases.

The involvement of Kav001 in inhibition of LPS/P. gingivalis-induced.

TNF-a is an important cytokine mediator of inflammation which suggests that inhibition of TNF activity may provide potential for clinical application. Recent data indicated that treatment of both human and mouse cells with Kavain significantly modulates P. gingivalis- and LPS-induced TNF-α expression. In order to obtain a selective analog with optimized biological activity and structural physico-chemical properties of Kavain, Kavain analogs were designed and synthesized and found one Kavain analogue (named Kav001) that is similar to Kavain but soluble and does not induce a significant toxicity. Both studies in vitro and in vivo treatment by Kav001 showed stronger biological function as compared to Kavain. Furthermore, most mouse bone marrow macrophages up-regulated Bcl-6 while down-regulating LITAF expression after treatment with Kav001 for 36 h. Consequently, this led to an extension of macrophage pseudopods due to its immune response to P.g. infection/LPS stimulation.

Glycoprotein non-metastatic melanoma protein b (Gpnmb) is highly expressed in macrophages of acute injured kidney and promotes M2 macrophages polarization.

Acute kidney injury (AKI) is an increasingly common disorder that is strongly linked to short- and long-term morbidity and mortality. During AKI process, macrophages, one of the important immune response cells, can polarize into M1 and M2 subtype from M0 subtype. It is well-known that M1 macrophages play a pro inflammatory role while M2 macrophages play an anti-inflammatory role. Glycoprotein non-metastatic melanoma protein b (Gpnmb) is a glycosylated transmembrane protein highly expressed in numerous cells, including osteoblasts, dendritic cells and macrophages. Gpnmb serves as a negative regulator of inflammation in macrophages and has a protective effect on injuries. In acute kidney injury, the macrophage has been shown diverse roles depending on different phenotype. This study provided gene expression and protein expression evidence that Gpnmb was highly expressed in M2 macrophages in the damaged areas of kidney after ischemia-reperfusion injury. Then, we successful isolated and culture mouse bone marrow-derived macrophages (BMMφ) and found that Gpnmb showed different expression levels in M0, M1 and M2 BMMφ: lowest in M1, highest in M2. After knocking down Gpnmb with si-Gpnmb, BMMφ M2 polarization and secretion of anti-inflammatory cytokines IL-10 and TGF-ß were inhibited, while M1 polarization and secretion of proinflammatory cytokines IL-1ß and TNF-α were promoted. Moreover, IL-4-STAT6 pathway was involved in the promotion of M2 polarization by Gpnmb. Taken together, Gpnmb may serve as a potential biomarker of AKI and play a protective role against the AKI by modulating the polarization of macrophage.

Simultaneous RNA-seq based transcriptional profiling of intracellular Brucella abortus and B. abortus-infected murine macrophages.

Brucella is a zoonotic pathogen that survives within macrophages; however the replicative mechanisms involved are not fully understood. We describe the isolation of sufficient Brucella abortus RNA from primary host cell environment using modified reported methods for RNA-seq analysis, and simultaneously characterize the transcriptional profiles of intracellular B. abortus and bone marrow-derived macrophages (BMM) from BALB/c mice at 24 h (replicative phase) post-infection. Our results revealed that 25.12% (801/3190) and 16.16% (515/3190) of the total B. abortus genes were up-regulated and down-regulated at >2-fold, respectively as compared to the free-living B. abortus. Among >5-fold differentially expressed genes, the up-regulated genes are mostly involved in DNA, RNA manipulations as well as protein biosynthesis and secretion while the down-regulated genes are mainly involved in energy production and metabolism. On the other hand, the host responses during B. abortus infection revealed that 14.01% (6071/43,346) of BMM genes were reproducibly transcribed at >5-fold during infection. Transcription of cytokines, chemokines and transcriptional factors, such as tumor necrosis factor (Tnf), interleukin-1α (Il1α), interleukin-1ß (Il1ß), interleukin-6 (Il6), interleukin-12 (Il12), chemokine C-X-C motif (CXCL) family, nuclear factor kappa B (Nf-κb), signal transducer and activator of transcription 1 (Stat1), that may contribute to host defense were markedly induced while transcription of various genes involved in cell proliferation and metabolism were suppressed upon B. abortus infection. In conclusion, these data suggest that Brucella modulates gene expression in hostile intracellular environment while simultaneously alters the host pathways that may lead to the pathogen's intracellular survival and infection.

IL-4 blocks TH1-polarizing/inflammatory cytokine gene expression during monocyte-derived dendritic cell differentiation through histone hypoacetylation.

BACKGROUND: Whereas recent research has characterized the mechanism by which dendritic cells (DCs) induce T(H)1/T(H)17 responses, the functional specialization enabling DCs to polarize T(H)2 responses remains undefined. Because IL-4 is essential during T(H)2 responses not only by acting on CD4(+) T cells through the activation of GATA-3 but also by regulating IgE class-switching, epithelial cell permeability, and muscle contractility, we hypothesized that IL-4 could also have a role in the conditioning of DCs during T(H)2 responses. OBJECTIVE: We sought to analyze whether IL-4 exerts an immunomodulatory function on DCs during their differentiation, leading to their functional specialization for the induction of T(H)2 responses. METHODS: Monocyte-derived DCs (moDCs) conditioned by IL-4 during their differentiation (IL-4-conditioned moDCs [IL-4-moDCs]) were analyzed for T(H)1-polarizing/inflammatory cytokine production in response to Toll-like receptor stimulation. The acetylation level of the promoters of the genes encoding these cytokines was analyzed by using chromatin immunoprecipitation. Gene expression profiling of IL-4-moDCs was defined by using mouse genome microarrays. IL-4-moDCs were tested for their capacity to induce house dust mite-mediated allergic reactions. RESULTS: Our data suggest that IL-4 inhibits T(H)1-polarizing/inflammatory cytokine gene expression on IL-4-moDCs through the deacetylation of the promoters of these genes, leading to their transcriptional repression. Microarray analyses confirmed that IL-4 upregulated T(H)2-related genes as eosinophil-associated ribonucleases, eosinophil/basophil chemokines, and M2 genes. IL-4 licensed moDCs for the induction of T(H)2 responses, causing house dust mite-mediated allergic airway inflammation. CONCLUSION: This study describes a new role for IL-4 by demonstrating that moDCs are conditioned by IL-4 for the induction of T(H)2 responses by blocking T(H)1-polarizing/inflammatory cytokine production through histone hypoacetylation and upregulating T(H)2-related genes.

BubR1 controls starvation-induced lipolysis via IMD signaling pathway in Drosophila.

Lipolysis, the key process releasing fat acids to generate energy in adipose tissues, correlates with starvation resistance. Nevertheless, its detail mechanisms remain elusive. BubR1, an essential mitotic regulator, ensures proper chromosome alignment and segregation during mitosis, but its physiological functions are largely unknown. Here, we use Drosophila adult fat body, the major lipid storage organ, to study the functions of BubR1 in lipolysis. We show that both whole body- and fat body-specific BubR1 depletions increase lipid degradation and shorten the lifespan under fasting but not feeding. Relish, the conserved regulator of IMD signaling pathway, acts as the downstream target of BubR1 to control the expression level of Bmm and modulate the lipolysis upon fasting. Thus, our study reveals new functions of BubR1 in starvation-induced lipolysis and provides new insights into the molecular mechanisms of lipolysis mediated by IMD signaling pathway.

Comprehensive review of solid tumor bone marrow metastasis.

Bone marrow metastasis (BMM) of solid tumors refers to a group of diseases that originate from non-hematopoietic malignant tumor cells invading the bone marrow (BM) through complex metastatic patterns. If BMM identification is delayed, the disease will rapidly develop into disseminated carcinogenesis of the BM, which manifests as a series of hematological disorders and microangiopathic hemolytic anemia, leading to serious life-threatening conditions. Although the study of solid tumor BMM is receiving increasing attention, study remains limited, and most descriptions are derived from case reports. Currently, clinicians have insufficient understanding of BMM, and BMM occurrence is often not recognized early or treated effectively, resulting in high mortality rates. In this article, we review the epidemiology, molecular mechanisms, clinical diagnosis, treatment, and prognosis of solid tumor BMM.

Excessive glucocorticoids combined with RANKL promote the differentiation of bone marrow macrophages (BMM) into osteoclasts and accelerate the progression of osteoporosis by activating the SYK/SHP2/NF-κB signaling pathway.

The primary objective of this study was to explore the extensive implications and complex molecular interactions arising from the confluence of excessive glucocorticoids and RANKL on the differentiation process of BMM into osteoclasts, profoundly impacting osteoporosis development. The methodology encompassed X-ray analysis and HE staining for evaluating bone loss in mice, while immunohistochemical staining was utilized to observe phosphorylated SHP2 (p-SHP2) expression. The assessment of several phosphorylated and total protein expression levels, including NF-κB, SHP2, SYK, JAK2, TAK1, NFATC1, c-fos, and Cathepsin K, was conducted via Western blotting. Additional experiments, involving CCK8 and monoclonal proliferation assays, were undertaken to determine BMM proliferation capacity. Immunofluorescence staining facilitated the quantification of TRAP fluorescence intensity. In vivo analysis revealed that glucocorticoid surplus triggers SHP2 signaling pathway activation, accelerating osteoporosis progression. Western blot results demonstrated that SHP2 inhibition could decrease the expression of specific proteins such as p-NF-κB and p-SHP2, with minimal effects on p-SYK levels. In vitro findings indicated that glucocorticoid and RANKL interaction activates the SHP2 pathway through NF-κB and SYK pathways, enhancing expressions of p-JAK2, p-TAK1, NFATC1, c-fos, and Cathepsin K, thereby promoting BMM to osteoclast transformation. Conclusion: Excessive glucocorticoids and RANKL interaction advance osteoclast differentiation from BMM by activating the SYK/SHP2/NF-κB signaling pathway, expediting osteoporosis progression.

Dihydroartemisinin alleviates erosive bone destruction by modifying local Treg cells in inflamed joints: A novel role in the treatment of rheumatoid arthritis.

Treg cell-based therapy has exhibited promising efficacy in combatting rheumatoid arthritis (RA). Dihydroartemisinin (DHA) exerts broad immunomodulatory effects across various diseases, with its recent spotlight on T-cell regulation in autoimmune conditions. The modulation of DHA on Treg cells and its therapeutic role in RA has yet to be fully elucidated. This study seeks to unveil the influence of DHA on Treg cells in RA and furnish innovative substantiation for the potential of DHA to ameliorate RA. To this end, we initially scrutinized the impact of DHA-modulated Treg cells on osteoclast (OC) formation in vitro using Treg cell-bone marrow-derived monocyte (BMM) coculture systems. Subsequently, employing the collagen-induced arthritis (CIA) rat model, we validated the efficacy of DHA and probed its influence on Treg cells in the spleen and popliteal lymph nodes (PLN). Finally, leveraging deep proteomic analysis with data-independent acquisition (DIA) and parallel accumulation-serial fragmentation (PASEF) technology, we found the alterations in the Treg cell proteome in PLN by proteomic analysis. Our findings indicate that DHA augmented suppressive Treg cells, thereby impeding OC formation in vitro. Consistently, DHA mitigated erosive joint destruction and osteoclastogenesis by replenishing splenic and joint-draining lymph node Treg cells in CIA rats. Notably, DHA induced alterations in the Treg cell proteome in PLN, manifesting distinct upregulation of alloantigen Col2a1 (Type II collagen alfa 1 chain) and CD8a (T-cell surface glycoprotein CD8 alpha chain) in Treg cells, signifying DHA's targeted modulation of Treg cells, rendering them more adept at sustaining immune tolerance and impeding bone erosion. These results unveil a novel facet of DHA in the treatment of RA.