Identification of COQ2 as a regulator of proliferation and lipid peroxidation through genome-scale CRISPR-Cas9 screening in myeloma cells.

Multiple myeloma (MM) is the second most common malignant haematological disease with a poor prognosis. The limit therapeutic progress has been made in MM patients with cancer relapse, necessitating deeper research into the molecular mechanisms underlying its occurrence and development. A genome-wide CRISPR-Cas9 loss-of-function screening was utilized to identify potential therapeutic targets in our research. We revealed that COQ2 plays a crucial role in regulating MM cell proliferation and lipid peroxidation (LPO). Knockout of COQ2 inhibited cell proliferation, induced cell cycle arrest and reduced tumour growth in vivo. Mechanistically, COQ2 promoted the activation of the MEK/ERK cascade, which in turn stabilized and activated MYC protein. Moreover, we found that COQ2-deficient MM cells increased sensitivity to the LPO activator, RSL3. Using an inhibitor targeting COQ2 by 4-CBA enhanced the sensitivity to RSL3 in primary CD138+ myeloma cells and in a xenograft mouse model. Nevertheless, co-treatment of 4-CBA and RSL3 induced cell death in bortezomib-resistant MM cells. Together, our findings suggest that COQ2 promotes cell proliferation and tumour growth through the activation of the MEK/ERK/MYC axis and targeting COQ2 could enhance the sensitivity to ferroptosis in MM cells, which may be a promising therapeutic strategy for the treatment of MM patients.

miR-34a/TAN1/CREB Axis Engages in Alleviating Oligodendrocyte Trophic Factor-Induced Myelin Repair Function and Astrocyte-Dependent Neuroinflammation in the Early Stages of Alzheimer's Disease: The Anti-Neurodegenerative Effect of Treadmill Exercise.

Reduced myelin stability observed in the early stages of Alzheimer's disease leads to spatial learning and memory impairment. Exercise has been shown to protect nerves, reduce the risk of Alzheimer's disease, and strengthen synaptic connectivity. However, the underlying mechanisms of how exercise can promote myelin repair and coordinate inflammation and proliferation are still uncertain. In this study, we conducted histological and biochemical assays of cortical lysates after behavioral testing to detect pathological changes, myelin sheath thickness, and mRNA and protein levels. It is notable that D-galactose model mice exhibited elevated miRNA-34a levels, overactive astrocytes, decreased myelin staining scores, increased apoptosis, and decreased synaptic plasticity in the brain. Significantly, after eight weeks of exercise, we observed improvements in LFB scores, NeuN( +) neuron counts, and myelin basic protein (MBP) expression. Additionally, exercise promoted the expression of oligodendrocyte markers Olig2 and PDFGR-α associated with brain proliferation, and improved spatial cognitive function. Furthermore, it decreased the inflammation caused by astrocyte secretions (TNF-α, Cox-2, CXCL2). Interestingly, we also observed downregulation of miR-34a and activation of the TAN1/PI3K/CREB signaling pathway. Our data shed light on a previously unsuspected mechanism by which exercise reduces miR-34a levels and protects neuronal function and survival by preventing excessive demyelination and inflammatory infiltration in the CNS.

[Effect on Danggui Shaoyao Powder on mitophagy in rat model of Alzheimer's disease based on PINK1-Parkin pathway].

This study investigated the mechanism of Danggui Shaoyao Powder(DSP) against mitophagy in rat model of Alzheimer's disease(AD) induced by streptozotocin(STZ) based on PTEN induced putative kinase 1(PINK1)-Parkin signaling pathway. The AD rat model was established by injecting STZ into the lateral ventricle, and the rats were divided into normal group, model group, DSP low-dose group(12 g·kg~(-1)·d~(-1)), DSP medium-dose group(24 g·kg~(-1)·d~(-1)), and DSP high-dose group(36 g·kg~(-1)·d~(-1)). Morris water maze test was used to detect the learning and memory function of the rats, and transmission electron microscopy and immunofluorescence were employed to detect mitophagy. The protein expression levels of PINK1, Parkin, LC3BⅠ/LC3BⅡ, and p62 were assayed by Western blot. Compared with the normal group, the model group showed a significant decrease in the learning and memory function(P<0.01), reduced protein expression of PINK1 and Parkin(P<0.05), increased protein expression of LC3BⅠ/LC3BⅡ and p62(P<0.05), and decreased occurrence of mitophagy(P<0.01). Compared with the model group, the DSP medium-and high-dose groups notably improved the learning and memory ability of AD rats, which mainly manifested as shortened escape latency, leng-thened time in target quadrants and elevated number of crossing the platform(P<0.05 or P<0.01), remarkably activated mitophagy(P<0.05), up-regulated the protein expression of PINK1 and Parkin, and down-regulated the protein expression of LC3BⅠ/LC3BⅡ and p62(P<0.05 or P<0.01). These results demonstrated that DSP might promote mitophagy mediated by PINK1-Parkin pathway to remove damaged mitochondria and improve mitochondrial function, thereby exerting a neuroprotective effect.

Alternative splicing analysis showed the splicing factor polypyrimidine tract-binding protein 1 as a potential target in acute myeloid leukemia therapy.

Alternative splicing (AS) is a universal post-transcriptional regulation process in cells, and increasing evidences have validated its crucial role in tumors. We collected AS event, gene expression, and clinical data of 178 AML patients from The Cancer Genome Atlas (TCGA) project. More than 1,000 AS events were found associated with overall survival (OS), and alternate promoter (AP) events were the most significant. The expression of the KIAA0930 transcript was the most significantly different AS event selected from AP events and significantly correlated with the expression of the splicing factor (SF) polypyrimidine tract-binding protein 1 (PTBP1). Then, the roles of PTBP1 on AS of the KIAA0930 and the proliferation of AML cells were confirmed. KIAA0930 variant 1 (KIAA0930-1) was upregulated and variant 2 (KIAA0930-2) downregulated with knockdown PTBP1 expression of AML cells by specific shRNA. A low level of PTBP1 can decrease the proliferation ability of AML cells. In conclusion, the results showed that PTBP1 might be a potential target for AML therapy.

[Protective Effects of Akkermansia muciniphila and Amuc_1100 Protein on Rats on High-Fat Diet Combined with Streptozotocin Injection].

OBJECTIVE: To explore the protective effects of live or pasteurized Akkermansia muciniphila and Amuc_1100 protein on a rat model of diabetes mellitus induced by high-fat diet (HFD) combined with streptozotocin (STZ). METHODS: A total of 96 Sprague-Dawley (SD) rats were randomly assigned to 8 groups, including 6 experimental groups and 2 control groups, with 12 rats in each group. HFD combined with STZ injection was given to the rats to create a simulated model of the progression of diabetes mellitus type 2. In addition, the rats were treated with different doses of live or pasteurized Akkermansia muciniphila or Amuc_1100 protein by way of gavage for 8 weeks simultaneously. Plasma samples were collected to determine the level of parameters related to lipid and glucose metabolism, and inflammation mediators. Colon tissue specimens were collected for HE staining. Stool samples of the rats were collected for 16S rRNA gene sequencing. RESULTS: Compared with the HFD control group, rats in the group treated with Akkermansia muciniphila exhibited significantly lower body mass gain ( P<0.01) and lower plasma TNF-α level ( P<0.05). Administration of Akkermansia muciniphila or Amuc_1100 protein increased the number of goblet cells and mucin secretion. The ß diversity analysis of the samples showed no overall difference in the intervention groups. CONCLUSION: Oral administration of Akkermansia muciniphila can effectively ameliorate HFD-induced metabolic disorders, including body mass gain and systemic inflammation. Akkermansia muciniphila and Amuc_1100, to a certain degree, improved the gut barrier function. After eight weeks of intervention, there was no significant impact on the structure of the gut microbiota.

Comprehensive Analysis of Key mRNAs and lncRNAs in Osteosarcoma Response to Preoperative Chemotherapy with Prognostic Values.

OBJECTIVE: Osteosarcoma is one of the most common types of bone sarcoma with a poor prognosis. However, identifying the predictive factors that contribute to the response to neoadjuvant chemotherapy remains a significant challenge. METHODS: A public data series (GSE87437) was downloaded to identify differentially expressed genes (DEGs) and differentially expressed lncRNAs (DElncRNAs) between osteosarcoma patients that do and do not respond to preoperative chemotherapy. Subsequently, functional analysis of the transcriptome expression profile, regulatory networks of DEGs and DElncRNAs, competing endogenous RNAs (ceRNA) and protein-protein interaction networks were performed. Furthermore, the function, pathway, and survival analysis of hub genes was performed and drug and disease relationship prediction of DElncRNA was carried out. RESULTS: A total of 626 DEGs, 26 DElncRNAs, and 18 hub genes were identified. However, only one gene and two lncRNAs were found to be suitable as candidate gene and lncRNAs respectively. CONCLUSION: The DEGs, hub genes, candidate gene, and candidate lncRNAs screened out in this context were considered as potential biomarkers for the response to neoadjuvant chemotherapy of osteosarcoma.

Mixed galactolipid anomers accentuate apoptosis of multiple myeloma cells by inducing DNA damage.

This study describes an interesting observation that the mixture of anomeric galactolipids has synergistic effects on the growth inhibition of human multiple myeloma (MM) cells. We determine that the equivalent mixture of a pair of α- and ß-galactolipids with a 14-carbon lipid chain can cause stronger poly ADP-ribose polymerase cleavage and DNA damage, producing more late apoptotic MM cells, than either anomer alone.

Protein kinase A rescues microtubule affinity-regulating kinase 2-induced microtubule instability and neurite disruption by phosphorylating serine 409.

Microtubule affinity-regulating kinase 2 (MARK2)/PAR-1b and protein kinase A (PKA) are both involved in the regulation of microtubule stability and neurite outgrowth, but whether a direct cross-talk exists between them remains unclear. Here, we found the disruption of microtubule and neurite outgrowth induced by MARK2 overexpression was blocked by active PKA. The interaction between PKA and MARK2 was confirmed by coimmunoprecipitation and immunocytochemistry both in vitro and in vivo. PKA was found to inhibit MARK2 kinase activity by phosphorylating a novel site, serine 409. PKA could not reverse the microtubule disruption effect induced by a serine 409 to alanine (Ala) mutant of MARK2 (MARK2 S409A). In contrast, mutation of MARK2 serine 409 to glutamic acid (Glu) (MARK2 S409E) did not affect microtubule stability and neurite outgrowth. We propose that PKA functions as an upstream inhibitor of MARK2 in regulating microtubule stability and neurite outgrowth by directly interacting and phosphorylating MARK2.

Capturing intercellular sugar-mediated ligand-receptor recognitions via a simple yet highly biospecific interfacial system.

Intercellular ligand-receptor recognitions are crucial natural interactions that initiate a number of biological and pathological events. We present here the simple construction of a unique class of biomimetic interfaces based on a graphene-mediated self-assembly of glycosyl anthraquinones to a screen-printed electrode for the detection of transmembrane glycoprotein receptors expressed on a hepatoma cell line. We show that an electroactive interface confined with densely clustered galactosyl ligands is able to ingeniously recognize the asialoglycoprotein receptors on live Hep-G2 cells employing simple electrochemical techniques. The only facility used is a personal laptop in connection with a cheap and portable electrochemical workstation.

5'-AMP-activated protein kinase (AMPK) regulates progesterone receptor transcriptional activity in breast cancer cells.

The steroid hormone progesterone is an essential regulator of the cellular processes that are required for the development and maintenance of reproductive function. The diverse effects of progesterone are mediated by the progesterone receptor (PR). The functions of the PR are regulated not only by ligands but also by modulators of various cell signaling pathways. However, it is not clear which energy state regulates PR activity. AMP-activated protein kinase (AMPK), a serine/threonine protein kinase, is a key modulator of energy homeostasis. Once activated by an increasing cellular AMP:ATP ratio, AMPK switches off ATP-consuming processes and switches on ATP-producing processes. We found that both 5-aminoimidazole-4-carboxamide 1-ß-d-ribofuranoside (AICAR) and metformin, traditional pharmacological activators of AMPK, inhibited the PR pathway, as evidenced by progesterone response element (PRE)-driven luciferase activity and PR target gene expression. Compound C, an inhibitor of AMPK, partly but significantly reversed the anti-PR effects of AICAR and metformin. The downregulation of endogenous AMPK by small interfering RNAs (siRNAs) stimulated PR activity. AMPK activation by AICAR decreased the progesterone-induced phosphorylation of PR at serine 294 and inhibited the recruitment of PR to an endogenous PRE. Taken together, our data suggest that AMPK, an energy sensor, is involved in the regulation of PR signaling.