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Although tankyrases (TNKSs) were originally described as enzymes safeguarding genome integrity, TNKSs are also associated with metabolism and are involved in the differentiation of multiple cell lineages including adipocytes. Here we aimed to understand the role of TNKSs specifically in adipocyte differentiation. We found that the deletion of TNKS1 or TNKS2 decreased the rate of adipocyte differentiation. Furthermore, the loss of TNKs induced a multi‐pronged cellular adaptation characterized by changes in cellular proteostasis centered around the inhibition of autophagy, AMPK activation and the suppression of mTORC1 activity. Deleting TNKSs also induced mitochondrial oxidative phosphorylation and glycolytic flux. Interestingly, the fraction of oligomycin‐resistant respiration decreased, suggesting more coupled OXPHOS. However, the lower differentiation rate of TNKS2 knockout cells was salvaged by pharmacological activation of autophagy (by NV‐5138) and the pharmacological inhibition of LKB1 (by HY‐10371), an upstream suppressor of the mTOR system. Finally, TNKS2 can ADP‐ribosylate LKB1, rendering it susceptible for ubiquitinylation that appears to be a key step towards committing adipocytes to differentiation. Together this data validates the use of TNK inhibitors for managing metabolic diseases and raises the possibility that TNK inhibition can influence tumor or immunometabolism and amplify the effects of other treatments.

Mitochondrial topoisomerase 1 (TOP1MT) regulates mitochondrial DNA (mtDNA) topology during transcription and replication. Perturbed mtDNA maintenance and RNA metabolism have been implicated in neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). Here we show that the common TOP1MT variant rs2293925 (R525W) has enhancer-like activity and is associated with increased mitochondrial R-loops (RNA : DNA hybrids). Tissue-dependent expression, quantitative trait locus analysis, chromatin-state annotation, reporter assays, and allele-specific DNA-protein binding assays support a transcriptional regulatory role for rs2293925. In isogenic cell models, rs2293925 increased TOP1MT mRNA and protein abundance, and this was accompanied by increased mitochondrial R-loop signal. TOP1MT trapping with lamellarin D supported increased TOP1MT-R525W occupancy at mitochondrial control region sites together with enhanced R-loops, consistent with altered TOP1MT-mtDNA interaction and/or increased TOP1MT abundance. Elevated mitochondrial R-loop signal was also detected in a pilot cohort of sporadic ALS samples carrying rs2293925 and in neural stem cells derived from C9orf72-positive ALS patients. These data support a dual-effect model in which rs2293925 increases TOP1MT expression and is associated with altered mitochondrial R-loop dynamics, linking common genetic variation to mitochondrial nucleic acid stress in disease-relevant contexts.

Although platinum-based complexes are pivotal in chemotherapy, their clinical use is limited by toxicity and resistance. Previously, we identified a set of osmium, ruthenium, and iridium half-sandwich complexes of 1-N-(β-d-glucopyranosyl)-4-hetaryl-1,2,3-triazole-type N,N-chelators with potent and selective activity against a large set of diverse neoplasia cell models and multiresistant Gram-positive bacteria (methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE)). Our aim in this study was to assess how the configuration of the C1 carbon in the glucose moiety affects the biological activity of the complexes. Thus, 1-N-(α-d-glucopyranosyl)-4-hetaryl-1,2,3-triazoles were synthesized and used as N,N-bidentate ligands to result in half-sandwich type complexes analogous to the earlier reported ones. Overall, the newly prepared complexes with the α-anomeric carbohydrate moiety had similar biological properties to the complexes with the β-anomeric carbohydrate unit in terms of their biological activity on cancer cells or primary human cells. Importantly, the bacteriostatic property of the complexes with an α-anomeric sugar moiety was inferior to that of the complexes containing the β-anomer.

Anhydro-aldose oximes were employed to generate in situ nitrile oxides via a halogenation/base-induced elimination sequence in the presence of NCS and Et₃N, which were then used in 1,3-dipolar cycloadditions with alkenes and alkynes to afford 5-substituted 3-(β-d-glycopyranosyl)isoxazole and -isoxazoline derivatives exclusively. These newly synthesized glycomimetics were evaluated for their potential to act as antagonists of A2780 ovarian cancer cells and as inhibitors of glycogen phosphorylase; however, they exhibited no significant activity.

Numerous secreted bacterial metabolites were identified with bioactivity in various neoplasias, including ovarian cancer. One such metabolite is ursodeoxycholic acid (UDCA), a secondary bile acid that has widespread beneficial effects in neoplasias. Hereby, we assessed the bioactivity of UDCA in cell models of ovarian cancer, by applying UDCA in concentrations corresponding to the serum reference concentrations of UDCA (300 nM). UDCA induced epithelial-to-mesenchymal transition (EMT), increased the flux of glycolysis and reduced the naturally occurring oxidative stress in ovarian cancer cells. These changes were dependent on the activation of NRF2. The tumoral overexpression of UDCA-induced genes in humans correlated with worse survival. These results point out that bacterial metabolites may have opposite effects in different neoplasias and raise the possibility that UDCA-containing remedies on the long run may support cancer progression in ovarian cancer patients.

Alveolar macrophages (AMs) act as gatekeepers of the lung’s immune responses, serving essential roles in recognizing and eliminating pathogens. The transcription factor (TF) early growth response 2 (EGR2) has been recently described as required for mature AMs in mice; however, its mechanisms of action have not been explored. Here, we identified EGR2 as an epigenomic regulator and likely direct proximal transcriptional activator in AMs using epigenomic approaches (RNA sequencing, ATAC sequencing, and CUT&RUN). The predicted direct proximal targets of EGR2 included a subset of AM identity genes and ones related to pathogen recognition, phagosome maturation, and adhesion, such as Clec7a , Atp6v0d2 , Itgb2 , Rhoc , and Tmsb10 . We provided evidence that EGR2 deficiency led to impaired zymosan internalization and reduced the capacity to respond to Aspergillus fumigatus . Mechanistically, the lack of EGR2 altered the transcriptional response, secreted cytokines (i.e., CXCL11), and inflammation-resolving lipid mediators (i.e., RvE1) of AMs during in vivo zymosan-induced inflammation, which manifested in impaired resolution. Our findings demonstrated that EGR2 is a key proximal transcriptional activator and epigenomic bookmark in AMs responsible for select, distinct components of cell identity and a protective transcriptional and epigenomic program against fungi.

Oxidative stress and poly(ADP-ribosyl)ation (PARylation) leads to tissue damage and inflammation in multiple lung diseases, likely in COVID-19. In a previous study we evidenced PARylation in multiple pulmonary cell types in patients who died of COVID-19, but not in patients who died of non-COVID-19 causes. We extended these observations in this retrospective immunohistochemical study by enlarging and stratifying the study population. We showed that pulmonary PARylation and oxidative stress peaked in the exudative and then decreased in the proliferative phase. Pulmonary oxidative stress and PARylation correlated with the serum markers of liver and kidney damage, oxygen transport, tissue hypoxia, lymphocytopenia, blood clotting and disseminated intravascular coagulation. Most correlations between PARylation and serum chemistry readouts were identified in the exudative phase. PARylation correlated with viral load and with the oxidative stress in the tissues, however, correlation between viral load and oxidative stress was marginal suggesting that oxidative stress and the presence of SARS-CoV-2 can independently induce PARylation. In males the time of hospitalization (time to death) was inversely correlated with pulmonary PARylation. Furthermore, males, died of COVID-19, were ∼15 years younger than females, however, there was no difference in pulmonary oxidative stress and PARylation between genders at death. Taken together, pulmonary PARylation and oxidative stress manifests early, in the exudative phase of COVID-19 and PARylation contributes to worse clinical outcome for males. These results suggest repurposing pharmacological PARP inhibitors for acute COVID-19 to counteract tissue damage.