Iron-sulfur Research Articles

Inherited myogenic abilities in muscle precursor cells defined by the mitochondrial complex I-encoding protein

Skeletal muscle comprises different muscle fibers, including slow- and fast-type muscles, and satellite cells (SCs), which exist in individual muscle fibers and possess different myogenic properties. Previously, we reported that myoblasts (MBs) from slow-type enriched soleus (SOL) had a high potential to self-renew compared with cells derived from fast-type enriched tibialis anterior (TA). However, whether the functionality of myogenic cells in adult muscles is attributed to the muscle fiber in which they reside and whether the characteristics of myogenic cells derived from slow- and fast-type fibers can be distinguished at the genetic level remain unknown. Global gene expression analysis revealed that the myogenic potential of MBs was independent of the muscle fiber type they reside in but dependent on the region of muscles they are derived from. Thus, in this study, proteomic analysis was conducted to clarify the molecular differences between MBs derived from TA and SOL. NADH dehydrogenase (ubiquinone) iron-sulfur protein 8 (Ndufs8), a subunit of NADH dehydrogenase in mitochondrial complex I, significantly increased in SOL-derived MBs compared with that in TA-derived cells. Moreover, the expression level of Ndufs8 in MBs significantly decreased with age. Gain- and loss-of-function experiments revealed that Ndufs8 expression in MBs promoted differentiation, self-renewal, and apoptosis resistance. In particular, Ndufs8 suppression in MBs increased p53 acetylation, followed by a decline in NAD/NADH ratio. Nicotinamide mononucleotide treatment, which restores the intracellular NAD+ level, could decrease p53 acetylation and increase myogenic cell self-renewal ability in vivo. These results suggested that the functional differences in MBs derived from SOL and TA governed by the mitochondrial complex I-encoding gene reflect the magnitude of the decline in SC number observed with aging, indicating that the replenishment of NAD+ is a possible approach for improving impaired cellular functions caused by aging or diseases.

Paramagnetic NMR to study iron sulfur proteins: 13C detected experiments illuminate the vicinity of the metal center.

The robustness of NMR coherence transfer in proximity of a paramagnetic center depends on the relaxation properties of the nuclei involved. In the case of Iron-Sulfur Proteins, different pulse schemes or different parameter sets often provide complementary results. Tailored versions of HCACO and CACO experiments significantly increase the number of observed Cα/C' connectivities in highly paramagnetic systems, by recovering many resonances that were lost due to paramagnetic relaxation. Optimized 13C direct detected experiments can significantly extend the available assignments, improving the overall knowledge of these systems. The different relaxation properties of Cα and C' nuclei are exploited in CACO vs COCA experiments and the complementarity of the two experiments is used to obtain structural information. The two [Fe2S2]+ clusters containing NEET protein CISD3 and the one [Fe4S4]2+ cluster containing HiPIP protein PioC have been taken as model systems. We show that tailored experiments contribute to decrease the blind sphere around the cluster, to extend resonance assignment of cluster bound cysteine residues and to retrieve details on the topology of the iron-bound ligand residues.

FDX1 Is Required for the Biogenesis of Mitochondrial Cytochrome c Oxidase in Mammalian Cells

Ferredoxins (FDXs) are evolutionarily conserved iron-sulfur (Fe-S) proteins that function as electron transfer proteins in diverse metabolic pathways. Mammalian mitochondria contain two ferredoxins, FDX1 and FDX2, which share a high degree of structural similarity but exhibit different functionalities. Previous studies have established the unique role of FDX2 in the biogenesis of Fe-S clusters; however, FDX1 seems to have multiple targets in vivo, some of which are only recently emerging. Using CRISPR-Cas9-based loss-of-function studies in rat cardiomyocyte cell line, we demonstrate an essential requirement of FDX1 in mitochondrial respiration and energy production. We attribute reduced mitochondrial respiration to a specific decrease in the abundance and assembly of cytochrome c oxidase (CcO), a mitochondrial heme-copper oxidase and the terminal enzyme of the mitochondrial respiratory chain. FDX1 knockout cells have reduced levels of copper and heme a/a3, factors that are essential for the maturation of the CcO enzyme complex. Copper supplementation failed to rescue CcO biogenesis, but overexpression of heme a synthase, COX15, partially rescued COX1 abundance in FDX1 knockout cells. This finding links FDX1 function to heme a biosynthesis, and places it upstream of COX15 in CcO biogenesis like its ancestral yeast homolog. Taken together, our work has identified FDX1 as a critical CcO biogenesis factor in mammalian cells.

Cuproptosis as the new kryptonite of cancer: a copper-dependent novel cell death mechanism with promising implications for the treatment of hepatocellular carcinoma.

Copper is an essential element for critical cellular functions such as mitochondrial respiration, cholesterol biosynthesis and immune response. Altered copper homeostasis has been associated with various disorders, including cancer. The copper overload is known to contribute to tumorigenesis, angiogenesis and metastasis, and recently it has been suggested that the elevated level of this element may also create vulnerability to a novel cell death mechanism, named cuproptosis. Excessive amount of copper in mitochondria binds to lipoylated enzymes of the TCA cycle and forms insoluble oligomers. The aggregation of these oligomers and subsequent iron-sulfur cluster protein loss results in proteotoxic stress and eventual cell death. Hepatocellular carcinoma is a common malignancy with a low survival rate, despite the available treatment options. The discovery of cuproptosis led many researchers to explore its potential use in hepatocellular cancer therapy due to the rich mitochondria content of hepatic cells. In this regard, a number of genomic studies were conducted to discover several cuproptosis-related genes and explored their association with prognosis, survival and immunotherapy response. This review brings together the available data on the relationship between cuproptosis and hepatocellular cancer for the first time, and highlights some of the potential biomarkers or target molecules that may be useful in the treatment.

Nitrogen removal performance of aerobic denitrifying bacteria enhanced by an iron-anode pulsed electric field.

Pulsed electric field (PEF) technology has attracted considerable attention because it can efficiently treat pollutants that are difficult to degrade. In this study, a PEF system using iron as the electrode was constructed to investigate the effect of PEF-Fe on the growth and metabolism of aerobic denitrifying bacteria and the effectiveness of wastewater nitrogen removal. The chemical oxygen demand, NO3--N and nitrate removal rates were 98.93%, 97.60% and 24.40 mg·L-1·h-1, respectively, under optimal conditions. As confirmed in this study, PEF-Fe could improve the key enzyme activities of W207-14. Scanning electron microscopy revealed that the surface of PEF-Fe-treated W207-14 was intact and smooth without any irreversible deformation. Flow cytometry combined with fluorescence staining analysis also confirmed reversible electroporation on the cell membrane surface of PEF-Fe-treated W207-14. Differentially expressed gene enrichment analysis showed that PEF-Fe activated the transmembrane transport function of ATP-binding cassette transporte (ABC) transport proteins and enhanced the cell membrane permeability of aerobic denitrifying bacteria. The significant differential expression of iron-sulphur cluster proteins facilitated the regulation of electron transport and maintenance of the dynamic balance of iron ions within the PEF-Fe system.

A concerted ATPase cycle of the protein transporter AAA-ATPase Bcs1

Bcs1, a homo-heptameric transmembrane AAA-ATPase, facilitates folded Rieske iron-sulfur protein translocation across the inner mitochondrial membrane. Structures in different nucleotide states (ATPγS, ADP, apo) provided conformational snapshots, but the kinetics and structural transitions of the ATPase cycle remain elusive. Here, using high-speed atomic force microscopy (HS-AFM) and line scanning (HS-AFM-LS), we characterized single-molecule Bcs1 ATPase cycling. While the ATP conformation had ~5600 ms lifetime, independent of the ATP-concentration, the ADP/apo conformation lifetime was ATP-concentration dependent and reached ~320 ms at saturating ATP-concentration, giving a maximum turnover rate of 0.17 s−1. Importantly, Bcs1 ATPase cycle conformational changes occurred in concert. Furthermore, we propose that the transport mechanism involves opening the IMS gate through energetically costly straightening of the transmembrane helices, potentially driving rapid gate resealing. Overall, our results establish a concerted ATPase cycle mechanism in Bcs1, distinct from other AAA-ATPases that use a hand-over-hand mechanism.

NARFL deficiency caused mitochondrial dysfunction in lung cancer cells by HIF-1α–DNMT1 axis

NARFL was reported to be a component of cytosolic iron–sulfur cluster assembly pathway and a causative gene of the diffused pulmonary arteriovenous malformations (dPAVMs). NARFL knockout dramatically impaired mitochondrial integrity in mice, which might promote mitochondrial dysfunction and lead to worse survival rate of lung cancer. However, the underlying molecular mechanism of NARFL deficiency in non-small cell lung cancer (NSCLC) is unknown. Knockdown assay was performed in A549 and H1299 cells. The protein levels of HIF-1α and DNMT1 were measured, and then Complex I activity, mtDNA copy numbers and mRNA levels of mtND genes were determined. Cisplatin resistance and cell proliferation were conducted using CCK8 assay. Cell migration and invasion were detected using wound heal assay and transwell assay. Survival analysis of lung cancer patients and KM plotter database were used for evaluating the potential value of NARFL deficiency. NARFL protein was expressed in two cell lines and knockdown assay significantly reduced its levels. Knockdown NARFL increased the protein levels of HIF-1α and DNMT1, and downregulated the mRNA levels of ND genes, mitochondrial Complex I activity, mtDNA copy number, and ATP levels. The mitochondrial dysfunction caused by NARFL deficiency were ameliorated by siHIF-1α and DNMT1 inhibitor. Knockdown NARFL increased the drug resistance and cell migration, and siHIF-1α reversed this effect. Moreover, NSCLC patients with NARFL deficiency had a poor survival rate using a tissue array and KM plotter database, and it would be a target for cancer prognosis and treatment. NARFL deficiency caused dysregulation of energy metabolism in lung cancer cells via HIF-1α–DNMT1 axis, which promoted drug resistance and cell migration. It provided a potential target for treatment and prognosis of lung cancer.

THU083 Disulfiram Mediated Anti-tumor Effect In Pituitary Neuroendocrine Tumors By Inducing Cuproptosis

Abstract Disclosure: N. Huang: None. Y. Zhang: None. Y. Liu: None. Y. Feng: None. L. Xue: None. Z. Wu: None. Pituitary neuroendocrine tumors (PitNETs) are common intracranial tumors. Dopamine agonists and somatostatin analogues are the first-line drugs for PRL and GH-secreting PitNETs clinically. However, there is no effective drug for other subtypes and drug-resistant PitNETs. Thus, it’s impending to discover new therapeutic targets and medicine. Cuproptosis is a copper-dependent form of cell death driven by lipoylated protein aggregation, loss of Fe-S cluster-containing proteins, and induction of HSP70. However, the role of cuproptosis in PitNETs is not clear. In this study, a total of 17 primary samples of PitNETs were collected to perform high-throughput drug screening, an anti-abuse drug disulfiram (DSF) was identified that can induce cell death effectively. We found that disulfiram also has a strong inhibitory effect on pituitary tumor cell lines MMQ, Att20 and GH3 (-87.1%, -62.5%, -92.7%, p<0.001), but the inhibitory effect was eliminated by copper chelator TTM/BCS. This indicated that DSF played the anti-tumor effect requiring the participation of copper ions. To explore the underlying mechanism that DSF induces the cell death of PitNETs, we detected the hallmark of cuproptosis and found that DSF leads to a decrease in the acylation level of proteins related to the tricarboxylic acid cycle, limiting the function of the protein. On the one hand, DSF leads to the downregulation of iron-sulfur cluster-associated proteins, and the oligomerization of dihydrolipoamide S-acetyltransferase (DLAT), which is eventually accompanied by an increase in the protein level of heat shock protein 70 (HSP70) at protein and mRNA level, causing proteotoxic stress leading to cell death. Finally, DSF treatment inhibited the tumor growth in MMQ cell transplanted mouse model and destructed the morphology of the pituitary tumor 3D sphere similarly demonstrating the inhibition effect. In conclusion, we find that the anti-abuse drug disulfiram can induce coproptosis in pituitary tumor cells in a copper-dependent manner and is a potential drug for the treatment of PitNETs. Presentation: Thursday, June 15, 2023

Aspartyl-tRNA synthetase 2 orchestrates iron-sulfur metabolism in hematopoietic stem cells via fine-tuning alternative RNA splicing

Aspartyl-tRNA synthetase 2 (Dars2) is involved in the regulation of mitochondrial protein synthesis and tissue-specific mitochondrial unfolded protein response (UPRmt). The role of Dars2 in the self-renewal and differentiation of hematopoietic stem cells (HSCs) is unknown. Here, we show that knockout (KO) of Dars2 significantly impairs the maintenance of hematopoietic stem and progenitor cells (HSPCs) without involving its tRNA synthetase activity. Dars2 KO results in significantly reduced expression of Srsf2/3/6 and impairs multiple events of mRNA alternative splicing (AS). Dars2 directly localizes to Srsf3-labeled spliceosomes in HSPCs and regulates the stability of Srsf3. Dars2-deficient HSPCs exhibit aberrant AS of mTOR and Slc22a17. Dars2 KO greatly suppresses the levels of labile ferrous iron and iron-sulfur cluster-containing proteins, which dampens mitochondrial metabolic activity and DNA damage repair pathways in HSPCs. Our study reveals that Dars2 plays a crucial role in the iron-sulfur metabolism and maintenance of HSPCs by modulating RNA splicing.

Interaction between Cfd1 and Nbp35 proteins involved in cytosolic Fe[sbnd]S cluster assembly machinery deciphers a stable complexation in Leishmania donovani

Leishmania donovani is the causative unicellular parasite for visceral leishmaniasis (VL); and FeS proteins are likely to be very essential for their survival and viability. Cytosolic FeS cluster assembly (CIA) machinery is one of the four systems for the biosynthesis and transfer of FeS clusters among eukaryotes; Cfd1 and Nbp35 are the scaffold components for cytosolic FeS cluster biogenesis. We investigated the role of CIA machinery components and purified Cfd1 and Nbp35 proteins of L. donovani. We also investigated the interactive nature between LdCfd1 and LdNbp35 proteins by in silico analysis, in vitro co-purification, pull down assays along with in vivo immuno-precipitation; which inferred that both LdCfd1 and LdNbp35 proteins are interacting with each other. Thus, our collective data revealed the interaction between these two proteins which forms a stable complex that can be attributed to the cellular process of FeS clusters biogenesis, and transfer to target apo-proteins of L. donovani. The expression of Cfd1 and Nbp35 proteins in Amp B resistant parasites is up-regulated leading to increased amount of FeS proteins. Hence, it favors increased tolerance towards ROS level, which helps parasites survival under drug pressure contributing in Amphotericin B resistance.

Aging-Related Mitochondrial Dysfunction Is Associated With Fibrosis in Benign Prostatic Hyperplasia.

Age is the greatest risk factor for lower urinary tract symptoms attributed to benign prostatic hyperplasia (LUTS/BPH). Although LUTS/BPH can be managed with pharmacotherapy, treatment failure has been putatively attributed to numerous pathological features of BPH (eg, prostatic fibrosis, inflammation). Mitochondrial dysfunction is a hallmark of aging; however, its impact on the pathological features of BPH remains unknown. Publicly available gene array data were analyzed. Immunohistochemistry examined mitochondrial proteins in the human prostate. The effect of complex I inhibition (rotenone) on a prostatic cell line was examined using quantitative polymerase chain reaction, immunocytochemistry, and Seahorse assays. Oleic acid (OA) was tested as a bypass of complex I inhibition. Aged mice were treated with OA to examine its effects on urinary dysfunction. Voiding was assessed longitudinally, and a critical complex I protein measured. Mitochondrial function and fibrosis genes were altered in BPH. Essential mitochondrial proteins (ie, voltage-dependent anion channels 1 and 2, PTEN-induced kinase 1, and NADH dehydrogenase [ubiquinone] iron-sulfur protein 3, mitochondrial [NDUFS3]) were significantly (p < .05) decreased in BPH. Complex I inhibition in cultured cells resulted in decreased respiration, altered NDUFS3 expression, increased collagen deposition, and gene expression. OA ameliorated these effects. OA-treated aged mice had significantly (p < .05) improved voiding function and higher prostatic NDUFS3 expression. Complex I dysfunction is a potential contributor to fibrosis and lower urinary tract dysfunction in aged mice. OA partially bypasses complex I inhibition and therefore should be further investigated as a mitochondrial modulator for treatment of LUTS/BPH. Hypotheses generated in this investigation offer a heretofore unexplored cellular target of interest for the management of LUTS/BPH.

Proteomic response to phosphorus deficiency and aluminum stress of three aluminum-tolerant phosphobacteria isolated from acidic soils

Aluminum (Al)-tolerant phosphobacteria enhance plant growth in acidic soils by improving Al complexing and phosphorus (P)availability. However, the impact of Al stress and P deficiency on bacterial biochemistry and physiology remains unclear. We investigated the single and mutual effects of Al stress (10mM) and P deficiency (0.05mM) on the proteome of three aluminum-tolerant phosphobacteria: Enterobacter sp. 198, Enterobacter sp. RJAL6, and Klebsiella sp. RCJ4. Cultivated under varying conditions, P deficiency upregulated P metabolism proteins while Al exposure downregulated iron-sulfur and heme-containing proteins and upregulated iron acquisition proteins. This demonstrated that Al influence on iron homeostasis and bacterial central metabolism. This study offers crucial insights into bacterial behavior in acidic soils, benefiting the development of bioinoculants for crops facing Al toxicity and P deficiency. This investigation marks the first proteomic study on the interaction between high Al and P deficiency in acid soils-adapted bacteria.

The minimal SUF system is not required for Fe–S cluster biogenesis in the methanogenic archaeon Methanosarcina acetivorans

Iron–sulfur (Fe–S) proteins are essential for the ability of methanogens to carry out methanogenesis and biological nitrogen fixation (diazotrophy). Nonetheless, the factors involved in Fe–S cluster biogenesis in methanogens remain largely unknown. The minimal SUF Fe–S cluster biogenesis system (i.e., SufBC) is postulated to serve as the primary system in methanogens. Here, the role of SufBC in Methanosarcina acetivorans, which contains two sufCB gene clusters, was investigated. The CRISPRi-dCas9 and CRISPR-Cas9 systems were utilized to repress or delete sufC1B1 and sufC2B2, respectively. Neither the dual repression of sufC1B1 and sufC2B2 nor the deletion of both sufC1B1 and sufC2B2 affected the growth of M. acetivorans under any conditions tested, including diazotrophy. Interestingly, deletion of only sufC1B1 led to a delayed-growth phenotype under all growth conditions, suggesting that the deletion of sufC2B2 acts as a suppressor mutation in the absence of sufC1B1. In addition, the deletion of sufC1B1 and/or sufC2B2 did not affect the total Fe–S cluster content in M. acetivorans cells. Overall, these results reveal that the minimal SUF system is not required for Fe–S cluster biogenesis in M. acetivorans and challenge the universal role of SufBC in Fe–S cluster biogenesis in methanogens.

Cardiac iron metabolism during aging – Role of inflammation and proteolysis

Iron is the most abundant trace element in the human body. Since iron can switch between its 2-valent and 3-valent form it is essential in various physiological processes such as energy production, proliferation or DNA synthesis. Especially high metabolic organs such as the heart rely on iron-associated iron-sulfur and heme proteins. However, due to switches in iron oxidation state, iron overload exhibits high toxicity through formation of reactive oxygen species, underlining the importance of balanced iron levels. Growing evidence demonstrates disturbance of this balance during aging. While age-associated cardiovascular diseases are often related to iron deficiency, in physiological aging cardiac iron accumulates. To understand these changes, we focused on inflammation and proteolysis, two hallmarks of aging, and their role in iron metabolism. Via the IL-6-hepcidin axis, inflammation and iron status are strongly connected often resulting in anemia accompanied by infiltration of macrophages. This tight connection between anemia and inflammation highlights the importance of the macrophage iron metabolism during inflammation. Age-related decrease in proteolytic activity additionally affects iron balance due to impaired degradation of iron metabolism proteins. Therefore, this review accentuates alterations in iron metabolism during aging with regards to inflammation and proteolysis to draw attention to their implications and associations.

Structure of a putative immature form of a Rieske-type iron-sulfur protein in complex with zinc chloride

Iron-sulfur clusters are prosthetic groups of proteins involved in various biological processes. However, details of the immature state of the iron-sulfur cluster into proteins have not yet been elucidated. We report here the first structural analysis of the Zn-containing form of a Rieske-type iron-sulfur protein, PetA, from Thermochromatium tepidum (TtPetA) by X-ray crystallography and small-angle X-ray scattering analysis. The Zn-containing form of TtPetA was indicated to be a dimer in solution. The zinc ion adopts a regular tetra-coordination with two chloride ions and two cysteine residues. Only a histidine residue in the cluster-binding site exhibited a conformational difference from the [2Fe-2S] containing form. The Zn-containing structure indicates that the conformation of the cluster binding site is already constructed and stabilized before insertion of [2Fe-2S]. The binding mode of ZnCl2, similar to the [2Fe-2S] cluster, suggests that the zinc ions might be involved in the insertion of the [2Fe-2S] cluster.

Why Is Iron Deficiency/Anemia Linked to Alzheimer's Disease and Its Comorbidities, and How Is It Prevented?

Impaired iron metabolism has been increasingly observed in many diseases, but a deeper, mechanistic understanding of the cellular impact of altered iron metabolism is still lacking. In addition, deficits in neuronal energy metabolism due to reduced glucose import were described for Alzheimer's disease (AD) and its comorbidities like obesity, depression, cardiovascular disease, and type 2 diabetes mellitus. The aim of this review is to present the molecular link between both observations. Insufficient cellular glucose uptake triggers increased ferritin expression, leading to depletion of the cellular free iron pool and stabilization of the hypoxia-induced factor (HIF) 1α. This transcription factor induces the expression of the glucose transporters (Glut) 1 and 3 and shifts the cellular metabolism towards glycolysis. If this first line of defense is not adequate for sufficient glucose supply, further reduction of the intracellular iron pool affects the enzymes of the mitochondrial electron transport chain and activates the AMP-activated kinase (AMPK). This enzyme triggers the translocation of Glut4 to the plasma membrane as well as the autophagic recycling of cell components in order to mobilize energy resources. Moreover, AMPK activates the autophagic process of ferritinophagy, which provides free iron urgently needed as a cofactor for the synthesis of heme- and iron-sulfur proteins. Excessive activation of this pathway ends in ferroptosis, a special iron-dependent form of cell death, while hampered AMPK activation steadily reduces the iron pools, leading to hypoferremia with iron sequestration in the spleen and liver. Long-lasting iron depletion affects erythropoiesis and results in anemia of chronic disease, a common condition in patients with AD and its comorbidities. Instead of iron supplementation, drugs, diet, or phytochemicals that improve energy supply and cellular glucose uptake should be administered to counteract hypoferremia and anemia of chronic disease.

Impact of weak radiofrequency and static magnetic fields on key signaling molecules, intracellular pH, membrane potential, and cell growth in HT-1080 fibrosarcoma cells

There are substantial concerns that extended exposures to weak radiofrequency (RF) fields can lead to adverse health effects. In this study, HT-1080 fibrosarcoma cells were simultaneously exposed to a static magnetic flux density between 10 mathrm{mu T} and 300 mathrm{mu T} and RF magnetic fields with amplitudes ranging from 1 nT to 1.5 μT in the frequency range from 1.8 to 7.2 MHz for four days. Cell growth rates, intracellular pH, hydrogen peroxide, peroxynitrite, membrane potential and mitochondrial calcium were measured. Results were dependent on carrier frequency and the magnitude of the RF magnetic field, modulation frequencies and the background static magnetic field (SMF). Iron sulphur (Fe-S) clusters are essential for the generation of reactive oxygen species and reactive nitrogen species (ROS and RNS). We believe the observed changes are associated with hyperfine couplings between the chemically active electrons and nuclear spins. Controlling external magnetic fields may have important clinical implications on aging, cancer, arthritis, and Alzheimer’s.

PINK1 and Parkin regulate IP3R-mediated ER calcium release.

Although defects in intracellular calcium homeostasis are known to play a role in the pathogenesis of Parkinson's disease (PD), the underlying molecular mechanisms remain unclear. Here, we show that loss of PTEN-induced kinase 1 (PINK1) and Parkin leads to dysregulation of inositol 1,4,5-trisphosphate receptor (IP3R) activity, robustly increasing ER calcium release. In addition, we identify that CDGSH iron sulfur domain 1 (CISD1, also known as mitoNEET) functions downstream of Parkin to directly control IP3R. Both genetic and pharmacologic suppression of CISD1 and its Drosophila homolog CISD (also known as Dosmit) restore the increased ER calcium release in PINK1 and Parkin null mammalian cells and flies, respectively, demonstrating the evolutionarily conserved regulatory mechanism of intracellular calcium homeostasis by the PINK1-Parkin pathway. More importantly, suppression of CISD in PINK1 and Parkin null flies rescues PD-related phenotypes including defective locomotor activity and dopaminergic neuronal degeneration. Based on these data, we propose that the regulation of ER calcium release by PINK1 and Parkin through CISD1 and IP3R is a feasible target for treating PD pathogenesis.

CISD2 transcriptional activated by transcription factor E2F7 promotes the malignant progression of cervical cancer.

Cervical cancer (CC) is the second most common type of cancer in women, and presents a serious threat to public health. We aimed to investigate the regulatory impacts of CDGSH iron-sulfur domain-containing protein 2 (CISD2) in CC and to discuss its relationship with E2F transcription factor 7 (E2F7). With the employment of real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) and western blot, the expression of CISD2 and E2F7 in SiHa cells before or after transfection was estimated. Cell counting kit-8 (CCK-8) assay, Terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) assay, wound healing and transwell were used to detect the proliferation, apoptosis, migration and invasion of SiHa cells. The activity of CISD2 was detected using luciferase report assay and chromatin immunoprecipitation (ChIP) assay was used to confirm the binding of E2F7 and CISD2 promoter. The contents of proliferation- and apoptosis-related proteins were detected using western blot. Results revealed that CISD2 expression was greatly enhanced in CC cell lines. CISD2 depletion inhibited the proliferation, migration and invasion of SiHa cells but promoted the cell apoptosis. It was also found that E2F7 was remarkably elevated in SiHa cells. According to JASPAR database, the binding sites of E2F7 and CISD2 were predicted and ChIP confirmed the binding of E2F7 and CISD2 promoter. Results obtained from luciferase report assay indicated that E2F7 overexpression increased the activity of CISD2 promoter region. Furthermore, further functional experiments demonstrated that the impacts of E2F7 interference on the proliferation, migration, invasion and apoptosis of SiHa cells were reversed by CISD2 overexpression. In summary, CISD2 silence could alleviate the malignant progression of CC and could be transcribed by E2F7.

Identification of Male Sex-Related Genes Regulated by SDHB in Macrobrachium nipponense Based on Transcriptome Analysis after an RNAi Knockdown.

The oriental river prawn (Macrobrachium nipponense) is a commercially important species in Asia. A previous study showed that the succinate dehydrogenase complex iron sulfur subunit B (SDHB) gene participates in testes development in this species through its effect on the expression of the insulin-like androgenic gland hormone gene. This study knocked-down the Mn-SDHB genes in M. nipponense using RNAi. A transcriptome analysis of the androgenic gland and testes was then performed to discover the male sex-related genes regulated by SDHB and investigate the mechanism of male sexual development in this species. More than 16,623 unigenes were discovered in each sample generated. In the androgenic gland, most of the differentially expressed genes were enriched in the hypertrophic cardiomyopathy pathway, while in the testes, they were enriched in the citrate cycle pathway. In addition, after Mn-SDHB knockdown, five genes were found to be downregulated in the androgenic gland in a series of biological processes associated with phosphorylated carbohydrate synthesis and transformations in the glycolysis/gluconeogenesis pathway. Moreover, a total of nine male sex-related genes were identified including Pro-resilin, insulin-like androgenic gland hormone, Protein mono-ADP-ribosyltransferase PAPR11, DNAJC2, C-type Lectin-1, Tyrosine-protein kinase Yes, Vigilin, and Sperm motility kinase Y-like, demonstrating the regulatory effects of Mn-SDHB, and providing a reference for the further study of the mechanisms of male development in M. nipponense.