Erratum: "Air Pollution Particulate Matter Exposure and Chronic Cerebral Hypoperfusion and Measures of White Matter Injury in a Murine Model"

Abstract

Due to lack of clear and adequate labeling of the original images, we are not able to determine with confidence which protein each of the strips and condition each lane in this figure and the original blots represent. [...]we have removed the western blot analysis (Figure 4A and the accompanying graphs Figure 4B-E) from the article. In the "Methods" section, in the "Study Design" subsection, the fifth sentence of the third paragraph was changed from "However, multiple markers of white matter injury [KB, dMBP, T2 weighted magnetic resonance imaging (MRI)], inflammation (Iba-1, GFAP, C5, C5oc, CD88, TLR4), and oxidative stress (8-OHdG, nitrate, nitrite) were measured in separate experimental cohorts (Table SI)." to "However, multiple markers of white matter injury [KB, dMBP, T2 weighted magnetic resonance imaging (MRI)], inflammation (Iba-1, GFAP, C5, C5oc, CD88), and oxidative stress (8-OHdG, nitrate, nitrite) were measured in separate experimental cohorts (Table SI)." Additionally, four representative images from Figure 3A (Iba-1) and C (GFAP) (FA and nPM from each panel) were inadvertently duplicated from a previously published study from our laboratory.1 Importantly, the two studies were performed under the same exposure conditions with distinct mouse cohorts. [...]Figure 3A and C have been modified to include the correct representative images.

The published article contained an error in the western blot image in Figure 4A. The C5 and C5oc strips were duplicate images of the same blot. Due to lack of clear and adequate labeling of the original images, we are not able to determine with confidence which protein each of the strips and condition each lane in this figure and the original blots represent. Therefore, we have removed the western blot analysis (Figure 4A and the accompanying graphs Figure 4B-E) from the article.

In addition, the description of the western blot was removed from the "Methods" section and the Figure 4 caption.

In the "Methods" section, in the "Study Design" subsection, the fifth sentence of the third paragraph was changed from "However, multiple markers of white matter injury [KB, dMBP, T2 weighted magnetic resonance imaging (MRI)], inflammation (Iba-1, GFAP, C5, C5oc, CD88, TLR4), and oxidative stress (8-OHdG, nitrate, nitrite) were measured in separate experimental cohorts (Table SI)." to "However, multiple markers of white matter injury [KB, dMBP, T2 weighted magnetic resonance imaging (MRI)], inflammation (Iba-1, GFAP, C5, C5oc, CD88), and oxidative stress (8-OHdG, nitrate, nitrite) were measured in separate experimental cohorts (Table SI)."

The second to last sentence of the "Animals" subsection was removed: "For western blot, mice were transcardially perfused with PBS with heparin (without a fixative solution) and brains were fresh frozen with liquid nitrogen and preserved at -80°C."

In Table 1, the entire rows with headings "Inflammation (whole brain)," "TLR4," "C5," "C5oc," and "CD88" have been removed. In the Table Note, the sentence "NOR testing, White matter injury (Kluver-Barrera, dMBP), glial activation (Iba-1, GFAP), inflammation (TLR4, C5, C5oc, CD88), oxidative stress (Nitrate, Nitrite, 8-OHdG) and MRI volumes were analyzed using a general linear model with main effects for nPM, BCAS and the nPM + BCAS interaction." has been changed to "NOR testing, White matter injury (Kluver-Barrera, dMBP), glial activation (Iba-1, GFAP), inflammation (C5, C5oc, CD88), oxidative stress (Nitrate, Nitrite, 8-OHdG) and MRI volumes were analyzed using a general linear model with main effects for nPM, BCAS and the nPM + BCAS interaction." The sentence "Inflammatory markers in the whole brain (TLR4, C5, C5oc, CD88) were assessed with western blots." has been removed. The phrase "inflammation in the whole brain (TLR4, C5, C5oc, CD88)" has been removed from the "Units" list. The expansion "TLR4, Toll-like receptor 4" has been removed the abbreviation expansion list.

The entire "Protein Analysis by Western Blot" subsection has been removed.

The fifth sentence of the "Statistical Analyses" subsection, "Histochemistry, western blot, MRI, and NOR were analyzed using a general linear model with main effects for nPM, BCAS, and the nPM + BCAS interaction (testing for synergy)." has been changed to "Histochemistry, MRI, and NOR were analyzed using a general linear model with main effects for nPM, BCAS, and the nPM + BCAS interaction (testing for synergy)."

In the "Results" section, the subsection heading "Inflammation in the Brain and Corpus Collosum" has been changed to "Inflammation in the Corpus Collosum" and the entire first paragraph has been removed.

The first sentence of the fifth paragraph of the "Discussion" section has been changed from "Western blot (whole brain) and histo-chemical analyses (corpus callosum) demonstrated that nPM + BCAS exposure resulted in higher degrees of inflammation in the whole brain and corpus callosum, with synergistic effects on C5 deposition in the corpus callosum." to "Histochemical analyses (corpus callosum) demonstrated that nPM + BCAS exposure resulted in higher degrees of inflammation in the whole brain and corpus callosum, with synergistic effects on C5 deposition in the corpus callosum."

The second sentence of that same paragraph has been removed: "Higher levels of TLR4 protein was also noted in the whole brain tissue of the joint nPM + BCAS group."

The Supplementary Material was corrected to remove Table S2, which provided details for the antibodies used for the western blot. Naming of and callouts for Tables S3-S12 were updated accordingly (to Tables S2-S11). Exclusion of the referenced panels do not have substantial impact on the conclusions of the paper.

Additionally, four representative images from Figure 3A (Iba-1) and C (GFAP) (FA and nPM from each panel) were inadvertently duplicated from a previously published study from our laboratory.1 Importantly, the two studies were performed under the same exposure conditions with distinct mouse cohorts. Therefore, Figure 3A and C have been modified to include the correct representative images. This was an error in uploading the figures only; it did not affect any analyses, data, results, or conclusions.

The authors regret the errors.

References

References

1. Babadjouni R, Patel A, Liu Q, Shkirkova K, Lamorie-Foote K, Connor M, et al. 2018. Nanoparticulate matter exposure results in neuroinflammatory changes in the corpus callosum. PLoS One 13(11):e0206934, PMID: 30395590, https://doi.org/10.1371/journal.pone.0206934.