Gasdermin D Mediated Mitochondrial Metabolism Orchestrate Neurogenesis Through LDHA During Embryonic Development.

Regulatory cell death is an important way to eliminate the DNA damage that accompanies the rapid proliferation of neural stem cells during cortical development, including pyroptosis, apoptosis, and so on. Here, the study reports that the absence of GSDMD-mediated pyroptosis results in defective DNA damage sensor pathways accompanied by aberrant neurogenesis and autism-like behaviors in adult mice. Furthermore, GSDMD is involved in organizing the mitochondrial electron transport chain by regulating the AMPK/PGC-1α pathway to target Aifm3. This process promotes a switch from oxidative phosphorylation to glycolysis. The perturbation of metabolic homeostasis in neural progenitor cells increases lactate production which acts as a signaling molecule to regulate the p38MAPK pathway. And activates NF-𝜿B transcription to disrupt cortex development. This abnormal proliferation of neural progenitor cells can be rescued by inhibiting glycolysis and lactate production. Taken together, the study proposes a metabolic axis regulated by GSDMD that links pyroptosis with metabolic reprogramming. It provides a flexible perspective for the treatment of neurological disorders caused by genotoxic stress and neurodevelopmental disorders such as autism.

Structural diversification of bioactive bibenzyls through modular co-culture leading to the discovery of a novel neuroprotective agent.

Bibenzyls, a kind of important plant polyphenols, have attracted growing attention for their broad and remarkable pharmacological activities. However, due to the low abundance in nature, uncontrollable and environmentally unfriendly chemical synthesis processes, these compounds are not readily accessible. Herein, one high-yield bibenzyl backbone-producing Escherichia coli strain was constructed by using a highly active and substrate-promiscuous bibenzyl synthase identified from Dendrobium officinale in combination with starter and extender biosynthetic enzymes. Three types of efficiently post-modifying modular strains were engineered by employing methyltransferases, prenyltransferase, and glycosyltransferase with high activity and substrate tolerance together with their corresponding donor biosynthetic modules. Structurally different bibenzyl derivatives were tandemly and/or divergently synthesized by co-culture engineering in various combination modes. Especially, a prenylated bibenzyl derivative (12) was found to be an antioxidant that exhibited potent neuroprotective activity in the cellular and rat models of ischemia stroke. RNA-seq, quantitative RT-PCR, and Western-blot analysis demonstrated that 12 could up-regulate the expression level of an apoptosis-inducing factor, mitochondria associated 3 (Aifm3), suggesting that Aifm3 might be a new target in ischemic stroke therapy. This study provides a flexible plug-and-play strategy for the easy-to-implement synthesis of structurally diverse bibenzyls through a modular co-culture engineering pipeline for drug discovery.

Bioinformatic Prediction of Novel Signaling Pathways of Apoptosis-inducing Factor, Mitochondrion-associated 3 (AIFM3) and Their Roles in Metastasis of Cholangiocarcinoma Cells.

BACKGROUND/AIM: We previously demonstrated that a mitochondrial protein, apoptosis-inducing factor, mitochondrion-associated 3 (AIFM3) is over-expressed in cholangiocarcinoma (CCA) and its serum levels can be a prognostic biomarker for CCA. To elucidate the functional roles of AIFM3 in CCA progression, we aimed to determine the signaling pathways of AIFM3 in CCA. MATERIALS AND METHODS: AIFM3 gene in CCA cells was silenced and AIFM3-related proteins were identified using mass spectrometry and bioinformatics tools. The relationships between AIFM3 and 441 related proteins were explored. To validate the functions of AIFM3, transwell migration/invasion assays were used. RESULTS: Bioinformatic analyses predicted that AIFM3 interacts with formin-like protein 3 (FMNL3) and is involved in tumor cell motilities. Online database analysis revealed higher AIFM3 mRNA expression levels in CCA, particularly with lymph node metastasis. After AIFM3 gene silencing, CCA cell migration/invasion was significantly decreased (p<0.001). Furthermore, AIFM3 expression levels were significantly associated with lymph node metastasis (p=0.0009) and shorter survival time (p=0.020). CONCLUSION: The AIFM3 signaling pathway is mediated via FMNL3 and involved in metastasis, suggesting that AIFM3 might be a molecular target to prevent CCA metastasis.

CRKL, AIFM3, AIF, BCL2, and UBASH3A during Human Kidney Development.

We aimed to investigate the spatio-temporal expression of possible CAKUT candidate genes CRKL, AIFM3, and UBASH3A, as well as AIF and BCL2 during human kidney development. Human fetal kidney tissue was stained with antibodies and analyzed by fluorescence microscopy and RT-PCR. Quantification of positive cells was assessed by calculation of area percentage and counting cells in nephron structures. Results showed statistically significant differences in the temporal expression patterns of the examined markers, depending on the investigated developmental stage. Limited but strong expression of CRKL was seen in developing kidneys, with increasing expression up to the period where the majority of nephrons are formed. Results also lead us to conclude that AIFM3 and AIF are important for promoting cell survival, but only AIFM3 is considered a CAKUT candidate gene due to the lack of AIF in nephron developmental structures. Our findings imply great importance of AIFM3 in energy production in nephrogenesis and tubular maturation. UBASH3A raw scores showed greater immunoreactivity in developing structures than mature ones which would point to a meaningful role in nephrogenesis. The fact that mRNA and proteins of CRKL, UBASH3A, and AIFM3 were detected in all phases of kidney development implies their role as renal development control genes.

Comprehensive Assessment of Copy Number Alterations Uncovers Recurrent AIFM3 and DLK1 Copy Gain in Medullary Thyroid Carcinoma.

Medullary thyroid carcinoma (MTC) is a malignant tumor originating from thyroid C-cells that can occur either in sporadic (70-80%) or hereditary (20-30%) form. In this study we aimed to identify recurrent copy number alterations (CNA) that might be related to the pathogenesis or progression of MTC. We used Affymetrix SNP array 6.0 on MTC and paired-blood samples to identify CNA using PennCNV and Genotyping Console software. The algorithms identified recurrent copy number gains in chromosomes 15q, 10q, 14q and 22q in MTC, whereas 4q cumulated losses. Coding genes were identified within CNA regions. The quantitative PCR analysis performed in an independent series of MTCs (n = 51) confirmed focal recurrent copy number gains encompassing the DLK1 (14q32.2) and AIFM3 (22q11.21) genes. Immunohistochemistry confirmed AIFM3 and DLK1 expression in MTC cases, while no expression was found in normal thyroid tissues and few MTC samples were found with normal copy numbers. The functional relevance of CNA was also assessed by in silico analysis. CNA status correlated with protein expression (DLK1, p = 0.01), tumor size (DLK1, p = 0.04) and AJCC staging (AIFM3p = 0.01 and DLK1p = 0.05). These data provide a novel insight into MTC biology, and suggest a common CNA landscape, regardless of if it is sporadic or hereditary MTC.

Apoptosis-Inducing Factor, Mitochondrion-Associated 3 (AIFM3) Protein Level in the Sera as a Prognostic Marker of Cholangiocarcinoma Patients.

Prognosis of cholangiocarcinoma (CCA) patients is absolutely poor. Since improvement of prognosis and/or response to treatment by personalized and precision treatments requires earlier and precise diagnostic markers, discovery of prognostic markers attracts more attention. Apoptosis-inducing factor, mitochondrion-associated 3 (AIFM3) is highly expressed in several cancers including CCA. The present study investigated whether the serum AIFM3 level can be used as a potential marker for CCA prognosis. For this purpose, we first determined secretory protein nature of AIFM3 using bioinformatic tools. The results show that although AIFM3 lacks signal peptide, it can be secreted into plasma/serum via an unconventional pathway. Then, the AIFM3 levels in the sera of 141 CCA patients and 70 healthy controls (HC) were measured using a semi-quantitative dot blot assay. The results show that the AIFM3 level in the sera of CCA group was significantly higher than that of HC. When correlation between serum AIFM3 levels and the clinicopathological parameters of CCA patients were examined, serum AIFM3 levels correlated significantly with lymph node metastasis, age, and the patients' overall survival (OS). Higher AIFM3 levels were significantly associated with shorter OS, and only AIFM3 was an independent prognostic marker for CCA. In conclusion, AIFM3 can be used as a prognostic marker for CCA.

Clinical implications of a novel prognostic factor AIFM3 in breast cancer patients.

BACKGROUND: In a time of increasing concerns over personalized and precision treatment in breast cancer (BC), filtering prognostic factors attracts more attention. Apoptosis-Inducing Factor Mitochondrion-associated 3 (AIFM3) is widely expressed in various tissues and aberrantly expressed in several cancers. However, clinical implication of AIFM3 has not been reported in BC. The aim of the study is to investigate the crystal structure, clinical and prognostic implications of AIFM3 in BC. METHODS: AIFM3 expression in 151 BC samples were assessed by immunohistochemistry (IHC). The Cancer Genome Atlas (TCGA) and Kaplan-Meier survival analysis were used to demonstrate expression and survival of AIFM3 signature. Gene Set Enrichment Analysis (GSEA) was performed to investigate the mechanisms related to AIFM3 expression in BC. RESULTS: AIFM3 was significantly more expressed in breast cancer tissues than in normal tissues. AIFM3 expression had a significant association with tumor size, lymph node metastasis, TNM stage and molecular typing. Higher AIFM3 expression was related to a shorter overall survival (OS) and disease-free survival (DFS). Lymph node metastasis and TNM stage were independent factors of AIFM3 expression. The study presented the crystal structure of AIFM3 successfully and predicted several binding sites when AIFM3 bonded to PTPN12 by Molecular Operating Environment software (MOE). CONCLUSIONS: AIFM3 might be a potential biomarker for predicting prognosis in BC, adding to growing evidence that AIFM3 might interact with PTPN12.