FASEB bioAdvances最新文献

Training of doctoral students as part of the next generation of the biomedical workforce is essential for sustaining the scientific enterprise in the United States. Training primarily occurs at institutions of higher education, and these trainees comprise an important part of the workforce at these institutions. Federal investment in the support of doctoral students in the biological and biomedical sciences is distributed differently than the distribution of students across different types of institutions, for example, public vs private. Institutions in states that historically receive less federal support for research also receive less support for doctoral student training. Doctorates at different types of institution exhibit little difference in research productivity, with the exception of citations, and subsequent receipt of additional NIH awards. Thus, training outcomes, which are related to the quality of the student and training environment, are similar across different institutions. Research productivity of doctoral students does not correlate with the number of F31s awarded to an institution. Factors that correlate with F31 funding include R01 funding levels and program size. The findings suggest strategies for institutions to increase success at securing F31s and modification of policy to promote more equitable distribution of F31s across institutions.

This erratum corrects the following:

Yasom, S., Watcharanurak, P., Bhummaphan, N., Thongsroy, J., Puttipanyalears, C., Settayanon, S., Chalertpet, K., Khumsri, W., Kongkaew, A., Patchsung, M., Siriwattanakankul, C., Pongpanich, M., Pin-on, P., Jindatip, D., Wanotayan, R., Odton, M., Supasai, S., Oo, T. T., Arunsak, B., Pratchayasakul, W., Chattipakorn, N., Chattipakorn, S., Mutirangura, A. (First published March 9, 2022) The roles of HMGB1-produced DNA gaps in DNA protection and aging biomarker reversal. FASEB BioAdvances. 2022;4:408–434. doi: 10.1096/fba.2021-00131

The authors report that inadvertent errors were made in assembling two of the figures submitted for publication. In both Figures 8 and 9, the left-hand row labels “Liver 1” to “Liver 4” are misleading and should not have been inserted. In Figure 8, the images in the 7m PC column should be the same as those shown in the 7m PC column in Figure 9, as the same group of rats is represented in both figures. In Figure 9, a different view of the image in row two of the 30m PC column was inadvertently placed in row four of the 30m PC column. The authors apologize for these oversights and for any confusion caused by the errors. These errors do not affect the results and conclusions reported in the article.

The correct versions of Figures 8 and 9 are as follows:

Acidification of the cellular lysosome is an important factor in infection of mammalian cells by SARS-CoV-2. Therefore, raising the pH of the lysosome would theoretically be beneficial in prevention or treatment of SARS-CoV-2 infection. Sodium bicarbonate, carbicarb, and THAM are buffers that can be used clinically to provide base to patients. To examine whether these bases could raise lysosomal pH and therefore be a primary or adjunctive treatment of SARS-CoV-2 infection, we measured lysosomal and intracellular pH of mammalian cells after exposure to each of these bases. Mammalian HEK293 cells expressing RpH-LAMP1-3xFLAG, a ratiometric sensor of lysosomal luminal pH, were first exposed to Hepes which was then switched to sodium bicarbonate, carbicarb, or THAM and lysosomal pH measured. In bicarbonate buffer the mean lysosomal pH was 4.3 ± 0.1 (n = 20); p = NS versus Hepes (n = 20). The mean lysosomal pH in bicarbonate/carbonate was 4.3 ± 0.1 (n = 21) versus Hepes (n = 21), p = NS. In THAM buffer the mean lysosomal pH was 4.7 ± 0.07 (n = 20) versus Hepes (4.6 ± 0.1, n = 20), p = NS. In addition, there was no statistical difference between pH_i in bicarbonate, carbicarb or THAM solutions. Using the membrane permeable base NH₄Cl (5 mM), lysosomal pH increased significantly to 5.9 ± 0.1 (n = 21) compared to Hepes (4.5 ± 0.07, n = 21); p < 0.0001. Similarly, exposure to 1 mM hydroxychloroquine significantly increased the lysosomal pH to (5.9 ± 0.06, n = 20) versus Hepes (4.3 ± 0.1, n = 20), p < 0.0001. Separately steady-state pHi was measured in HEK293 cells bathed in various buffers. In bicarbonate pH_i was 7.29 ± 0.02 (n = 12) versus Hepes (7.45 ± 0.03, [n = 12]), p < 0.001. In cells bathed in carbicarb pH_i was 7.27 ± 0.02 (n = 5) versus Hepes (7.43 ± 0.04, [n = 5]), p < 0.01. Cells bathed in THAM had a pH_i of 7.25 ± 0.03 (n = 12) versus Hepes (7.44 ± 0.03 [n = 12]), p < 0.001. In addition, there was no statistical difference in pH_i in bicarbonate, carbicarb or THAM solutions. The results of these studies indicate that none of the buffers designed to provide base to patients alters lysosomal pH at the concentrations used in this study and therefore would be predicted to be of no value in the treatment of SARS-CoV-2 infection. If the goal is to raise lysosomal pH to decrease the infectivity of SARS-CoV-2, utilizing lysosomal permeable buffers at the appropriate dose that is non-toxic appears to be a useful approach to explore.

Kidney fibrosis is the common final pathway of chronic kidney disease (CKD), and it is distinguished by inflammation, mesenchymal transition with myofibroblast formation, and epithelial-to-mesenchymal transition (EMT). Macrophages are protuberant inflammatory cells in the kidney, and their roles are dependent on their phenotypes. However, it remains unclear whether tubular epithelial cells (TECs) undergoing EMT can influence the phenotypes of macrophages and the underlying mechanisms during the development of kidney fibrosis. Here, we investigated the characteristics of TECs and macrophages during kidney fibrosis with a focus on EMT and inflammation. We found that the coculture of exosomes from transforming growth factor-beta (TGF-β)-induced TECs with macrophages induced macrophage M1 polarization, while exosomes from TECs without TGF-β stimulation or stimulation with TGF-β alone did not induce an increase in M1 macrophage-related markers. Notably, TECs induced to undergo EMT by TGF-β treatment released more exosomes than the other groups. Furthermore, it is noteworthy that when we injected exosomes from TECs undergoing EMT into mice, in addition to the high level of inflammatory response and the activation of M1 macrophages, the indicators of EMT and renal fibrosis in mouse kidney tissue were correspondingly elevated. In summary, exosomes from TECs undergoing EMT by TGF-β treatment induced M1 polarization and led to a positive feedback effect for further EMT and the development of renal fibrosis. Therefore, the obstacle to the release of such exosomes may be a novel therapeutic strategy for CKD.

CK2β is the non-catalytic modulating part of the S/T-protein kinase CK2. However, the overall function of CK2β is poorly understood. Here, we report on the identification of 38 new interaction partners of the human CK2β from lysates of DU145 prostate cancer cells using photo-crosslinking and mass spectrometry, whereby HSP70-1 was identified with high abundance. The K_D value of its interaction with CK2β was determined as 0.57 μM by microscale thermophoresis, this being the first time, to our knowledge, that a K_D value of CK2β with another protein than CK2α or CK2α′ was quantified. Phosphorylation studies excluded HSP70-1 as a substrate or activity modulator of CK2, suggesting a CK2 activity independent interaction of HSP70-1 with CK2β. Co-immunoprecipitation experiments in three different cancer cell lines confirmed the interaction of HSP70-1 with CK2β in vivo. A second identified CK2β interaction partner was Rho guanin nucleotide exchange factor 12, indicating an involvement of CK2β in the Rho-GTPase signal pathway, described here for the first time to our knowledge. This points to a role of CK2β in the interaction network affecting the organization of the cytoskeleton.

The NF-κB family of transcription factors plays an important role in skeletal development and bone homeostasis. In osteoblast cells, NF-κB signaling has been shown to suppress survival, proliferation, and differentiation. Furthermore, pharmacological suppression of NF-κB enhances osteoblast differentiation and bone formation. Thus, NF-κB antagonists are promising candidates as anabolic agents for enhancing bone mass. In this study, we describe the mechanism by which nobiletin, an inhibitor of NF-κB activity, regulates osteoblast differentiation and mineralization. We found that in MC3T3-E1 osteoblast cells, nobiletin inhibited a TNF-α responsive NF-κB luciferase reporter and also decreased the induction of classical NF-κB target genes by TNF-α. Consistent with this, nobiletin prevented TNF-α -mediated suppression of osteogenesis and potently enhanced the differentiation and mineralization of MC3T3-E1 cells. Likewise, in an in vivo BMP2-induced ectopic bone formation assay, nobiletin markedly enhanced ossicle bone volume. Western blotting and SMAD-responsive luciferase assays also demonstrated that NF-κB suppression of BMP signaling could be inhibited by nobiletin. Thus, our data suggest that mechanistically, nobiletin prevents the endogenous repression of BMP signaling by TNF-α, thereby enhancing osteoblast activity. In conclusion, nobiletin is a novel NF-κB antagonist that may be a useful anabolic agent for bone formation.

Understanding the expected efficacy and safety of a new regenerative therapy requires analysis of the fate of the transplanted cell graft. We have shown that transplantation of autologous cultured nasal epithelial cell sheets onto the middle ear mucosa can improve middle ear aeration and hearing. However, it remains unknown whether cultured nasal epithelial cell sheets have the potential to gain mucociliary function in the environment of the middle ear because sampling cell sheets after transplantation is challenging. The present study re-cultured cultured nasal epithelial cell sheets in different culture media and evaluated whether the sheets have the potential to differentiate into airway epithelium. Before re-cultivation, cultured nasal epithelial cell sheets fabricated in keratinocyte culture medium (KCM) contained no FOXJ1-positive and acetyl-α-tubulin-positive multiciliated cells or MUC5AC-positive mucus cells. Interestingly, multiciliated cells and mucus cells were observed when the cultured nasal epithelial cell sheets were re-cultured in conditions that promote differentiation of airway epithelium. However, multiciliated cells, mucus cells and CK1-positive keratinized cells were not observed when cultured nasal epithelial cell sheets were re-cultured in conditions that promote epithelial keratinization. These findings support the suggestion that cultured nasal epithelial cell sheets have the ability to differentiate and gain mucociliary function in response to an appropriate environment (possibly including the environment found in the middle ear) but are unable to develop into an epithelial type that differs from its origins.

Excitability and contraction of cardiac muscle from brain-dead donors critically influence the success of heart transplantation. Membrane physiology, Ca²⁺-handling, and force production of cardiac muscle and the contractile properties of coronary arteries were studied in hearts of brain-dead pigs. Cardiac muscle and vascular function after 12 h brain death (decapitation between C2 and C3) were compared with properties of fresh tissue. In both isolated cardiomyocytes (whole-cell patch clamp) and trabecular muscle (conventional microelectrodes), action potential duration was shorter in brain dead, compared to controls. Cellular shortening and Ca²⁺ transients were attenuated in the brain dead, and linked to lower mRNA expression of L-type calcium channels and a slightly lower I_Ca,_L, current, as well as to a lower expression of phospholamban. The current–voltage relationship and the current above the equilibrium potential of the inward K⁺ (I_K1) channel were altered in the brain-dead group, associated with lower mRNA expression of the Kir2.2 channel. Delayed K⁺ currents were detected (I_Kr, I_Ks) and were not different between groups. The transient outward K⁺ current (I_to) was not observed in the pig heart. Coronary arteries exhibited increased contractility and sensitivity to the thromboxane analogue (U46619), and unaltered endothelial relaxation. In conclusion, brain death involves changes in cardiac cellular excitation which might lower contractility after transplantation. Changes in the inward rectifier K⁺ channel can be associated with an increased risk for arrhythmia. Increased reactivity of coronary arteries may lead to increased risk of vascular spasm, although endothelial relaxant function was well preserved.

Xeroderma pigmentosum (XP) is a hereditary disorder characterized by photosensitivity, predisposition to skin cancers, and neurological abnormalities including microcephaly and progressive neurodegeneration. A lack of nucleotide excision repair (NER) in patients with XP can cause hypersensitivity to the sun, leading to skin cancer, whereas the etiology of the neuronal symptoms of XP remains ambiguous. There are various neurological disorders that perturb neuronal migration, causing mislocalization and disorganization of the cortical lamination. Here, we investigated the role of the XP group-A (Xpa) gene in directed cell migration. First, we adopted an in utero electroporation method to transduce shRNA vectors into the murine embryonic cerebral cortex for the in vivo knockdown of Xpa. Xpa-knockdown neurons in the embryonic cerebral cortex showed abnormal cell migration, cell cycle exit, and differentiation. The genotype–phenotype relationship between the lack of XPA and cell migration abnormalities was confirmed using both a scratch assay and time-lapse microscopy in XP-A patient-derived fibroblasts. Unlike healthy cells, these cells showed impairment in overall mobility and the direction of motility. Therefore, abnormal cell migration may explain neural tissue abnormalities in patients with XP-A.

5-Fluorouracil (5-FU) is a cornerstone drug used to treat colorectal cancer (CRC). However, the prolonged exposure of CRC cells to 5-FU results in acquired resistance. We have previously demonstrated that levels of the 5-fluorodeoxyuridylate (FdUMP) covalent complex with thymidylate synthase (FdUMP-TS) and free-TS (native enzyme) are higher in 5-FU-resistant CRC cells than in the parental cell line (HCT116). Accordingly, resistant cells may have an efficient system for trapping and removing FdUMP-TS, thus imparting resistance. In this study, using a model of 5-FU-resistant CRC cells generated by repeated exposure, the role of autophagy in the elimination of FdUMP-TS in resistant cells was investigated. The resistant cells showed greater sensitivity to autophagy inhibitors than that of parental cells. Autophagy inhibition increased 5-FU cytotoxicity more substantially in resistant cells than in parental cells. Furthermore, autophagy inhibition increased FdUMP-TS protein accumulation in resistant cells. Our findings suggest that resistance to 5-FU is mediated by autophagy as a system to eliminate FdUMP-TS and may guide the use and optimization of combination therapies involving autophagy inhibitors.