Dissecting B/Plasma Cells in Periodontitis at Single-Cell/Bulk Resolution

In recent decades, our understanding of periodontitis has evolved from that based on a gross/histologic level to one on a cellular/molecular level. Previous landscape studies have explored molecular subtyping, diagnosis, and gingival tissue cell decomposition in periodontitis, and meaningful results have been obtained at a transcriptomic level. However, current periodontitis transcriptomic studies lack a finer dissection of the intercommunication between immune cells and the biological processes of specific immune cell subtypes. In this study, we classified 15 immune cell types in periodontitis at a single-cell level and conducted a cell communication analysis based on a multicenter integrated single-cell transcriptome profile, in which plasma cell-generated macrophage migration inhibitory factor can communicate with most other immune cells in periodontitis. A pseudotime analysis focusing on B/plasma cell infiltration in periodontitis revealed 2 distinct cell fates (CFs) for B/plasma cells. In addition, at a bulk tissue level, a single-sample gene set enrichment analysis showed a similar immune cell infiltration trend, and a weighted gene coexpression network analysis identified an immune-related gene module. Combined with the above findings, we used machine learning methods to further narrow down potential gene candidates for developing and validating molecular diagnostic models of periodontitis. Multivariable logistic regression of a large public cohort (68 healthy vs. 235 periodontitis) and an independent validation cohort (12 healthy vs. 7 periodontitis) showed the CF1 signature provides a good discrimination and calibration performance with clinical benefits at a proper threshold probability. Furthermore, quantitative real-time polymerase chain reaction validation of the gene candidates was performed in both snap-frozen gingival tissues and gingival crevicular fluids. Our transcriptomic landscape analysis at both single-cell and bulk tissue resolutions thereby illustrates the B/plasma cell infiltration process in periodontitis and reveals a gene signature that may assist in molecular diagnosis of the disease.

Preoperative MRI of breast squamous cell carcinoma: diagnostic value of distinguishing between two subtypes

AIM

To retrospectively analyse the clinical and MRI data of primary squamous cell carcinoma (SCC), particularly pure squamous cell carcinoma (PSCC) and mixed squamous cell carcinoma (MSCC).

MATERIALS AND METHODS

The MRI data and clinicopathological characteristics of 20 patients with histopathologically confirmed SCC of the breast, including eight PSCC patients and 12 MSCC patients, from multiple centres between January 2013 and December 2020 were analysed retrospectively.

RESULTS

Nine of 12 patients in the MSCC group showed hyperintensity on T1-weighted imaging (WI), while this feature was not observed in the PSCC group (p=0.001). Most of the PSCC group showed rim enhancement, whereas most of the MSCC group showed heterogeneous enhancement (p=0.007). In addition, there was no significant difference in the thickness of the rim enhancement and the percentage of necrotic components in the tumours between the two types of SCCs of the breast (p=0.545 and p=0.662, respectively). Four patients (4/12) in the MSCC group had sentinel lymph node metastasis, while only one patient (1/8) in the PSCC group showed lymph node metastasis (p=0.603). Metastatic disease occurred in 25% of patients with PSCC and in approximately 41.7% of patients with MSCC.

CONCLUSION

The signal on T1WI and internal enhancement characteristics were the key features for differentiating PSCC and MSCC. Therefore, MRI phenotypes may provide additional information for the pathological classification of breast SCC.

Caloric restriction and Roux-en-Y Gastric Bypass promote white adipose tissue browning in mice

PURPOSE

Caloric restriction (CR) and Roux-en-Y Gastric Bypass (RYGB) are considered effective means of body weight control, but the mechanism by which CR and RYGB protect against high-fat diet (HFD)-induced obesity remains elusive. The browning of white adipose tissue (WAT) is a potential approach to combat obesity. Here we assess whether browning of WAT is involved in CR- and RYGB-treatment.

METHODS

The average size of adipocytes was determined by histological analysis. Expression of thermogenic genes in both human subjects and mice were measured by quantitative real-time PCR and immunohistochemical staining.

RESULTS

The average size of adipocytes was bigger, while the expression of thermogenic genes such as uncoupling protein 1 (UCP1), nuclear factor erythroid-2 like 1 (NRF1) and PPARγ coactivator-1 α (PGC1α) were lower in the WAT of obese subjects when compared to lean controls. Both CR and RYGB promoted weight and fat loss. Increment of the average adipocytes size and down-regulation of thermogenic genes were significantly reversed by both CR and RYGB in the WAT of obese mice.

CONCLUSIONS

Our findings showed that CR and RYGB significantly improved high-fat diet-induced lipid accumulation by promoting the browning of WAT.

Optical coherence tomography

Optical coherence tomography (OCT) is a non-contact method for imaging the topological and internal microstructure of samples in three dimensions. OCT can be configured as a conventional microscope, as an ophthalmic scanner, or using endoscopes and small diameter catheters for accessing internal biological organs. In this Primer, we describe the principles underpinning the different instrument configurations that are tailored to distinct imaging applications and explain the origin of signal, based on light scattering and propagation. Although OCT has been used for imaging inanimate objects, we focus our discussion on biological and medical imaging. We examine the signal processing methods and algorithms that make OCT exquisitely sensitive to reflections as weak as just a few photons and that reveal functional information in addition to structure. Image processing, display and interpretation, which are all critical for effective biomedical imaging, are discussed in the context of specific applications. Finally, we consider image artifacts and limitations that commonly arise and reflect on future advances and opportunities.

[Correlation of preoperative reconstruction of foramen ovale parameters and intraluminal balloon pressure during percutaneous balloon compression for trigeminal neuralgia]

Objective: To explore the relationship between the anatomic parameters of foramen ovale and intraluminal pressure during percutaneous balloon compression (PBC) in the treatment of primary trigeminal neuralgia. Methods: Twenty patients diagnosed with primary trigeminal neuralgia in the Department of Pain Medicine of the Third Xiangya Hospital, Central South University between November 2020 and April 2021 were enrolled. Three-dimensional (3D) high-resolution CT reconstruction of skull base was performed preoperatively to evaluate the parameters of foramen ovale. The intraluminal balloon pressure was continuously recorded during the PBC procedure. Correlation analysis was conducted between intraluminal pressure and foramen ovale parameters. Results: Eighteen patients had complete pain relief, 1 had obvious relief, and 1 had partial relief after PBC. The maximum cross-sectional length of the foramen ovale was (7.8±1.7) mm. The peak intraluminal pressure (P_M) during PBC was (194±27) kPa. The intraluminal pressure was (164±28) kPa at initial compression (P₀), and (135±20) kPa after compression for 120 seconds respectively. Correlation analysis showed that the P₀ was positively and significantly correlated with the length of foramen ovale (r=0.56, P<0.05), but not with the width of foramen ovale (r=0.24, P>0.05), the area of foramen ovale (r=0.36, P>0.05) and the degree of balloon filling (r=-0.09, P>0.05). Similarly, P₁₂₀ was significantly correlated with the length of foramen ovale (r=0.54, P<0.05). No significant correlation was observed between P₁₂₀ and the width of the foramen ovale (r=0.18, P>0.05), the area of the foramen ovale (r=0.28, P>0.05) or the width of balloon filling (r=-0.13, P>0.05). Conclusions: The length of foramen ovale correlates with the intraluminal pressure during PBC procedure in trigeminal neuralgia patients. Parameters of foramen ovale obtained via preoperative high-resolution CT reconstruction of skull base may provide reference for predicting targeted intraluminal balloon pressure during PBC.

Overcoming Acquired Epigenetic Resistance to BTK Inhibitors

The use of Bruton tyrosine kinase (BTK) inhibitors to block B-cell receptor (BCR)-dependent NF-κB activation in lymphoid malignancies has been a major clinical advance, yet acquired therapeutic resistance is a recurring problem. We modeled the development of resistance to the BTK inhibitor ibrutinib in the activated B-cell (ABC) subtype of diffuse large B-cell lymphoma, which relies on chronic active BCR signaling for survival. The primary mode of resistance was epigenetic, driven in part by the transcription factor TCF4. The resultant phenotypic shift altered BCR signaling such that the GTPase RAC2 substituted for BTK in the activation of phospholipase Cγ2, thereby sustaining NF-κB activity. The interaction of RAC2 with phospholipase Cγ2 was also increased in chronic lymphocytic leukemia cells from patients with persistent or progressive disease on BTK inhibitor treatment. We identified clinically available drugs that can treat epigenetic ibrutinib resistance, suggesting combination therapeutic strategies.

Significance

In diffuse large B-cell lymphoma, we show that primary resistance to BTK inhibitors is due to epigenetic rather than genetic changes that circumvent the BTK blockade. We also observed this resistance mechanism in chronic lymphocytic leukemia, suggesting that epigenetic alterations may contribute more to BTK inhibitor resistance than currently thought.See related commentary by Pasqualucci, p. 555. This article is highlighted in the In This Issue feature, p. 549.

[A novel attention fusion network-based multiple instance learning framework to automate diagnosis of chronic gastritis with multiple indicators]

Objective: To explore the performance of the attention-multiple instance learning (MIL) framework, an attention fusion network-based MIL, in the automated diagnosis of chronic gastritis with multiple indicators. Methods: A total of 1 015 biopsy cases of gastritis diagnosed in Fudan University Cancer Hospital, Shanghai, China and 115 biopsy cases of gastritis diagnosed in Shanghai Pudong Hospital, Shanghai, China were collected from January 1st to December 31st in 2018. All pathological sections were digitally converted into whole slide imaging (WSI). The WSI label was based on the corresponding pathological report, including "activity" "atrophy" and "intestinal metaplasia". The WSI were divided into a training set, a single test set, a mixed test set and an independent test set. The accuracy of automated diagnosis for the Attention-MIL model was validated in three test sets. Results: The area under receive-operator curve (AUC) values of Attention-MIL model in single test sets of 240 WSI were: activity 0.98, atrophy 0.89, and intestinal metaplasia 0.98; the average accuracy of the three indicators was 94.2%. The AUC values in mixed test sets of 117 WSI were: activity 0.95, atrophy 0.86, and intestinal metaplasia 0.94; the average accuracy of the three indicators was 88.3%. The AUC values in independent test sets of 115 WSI were: activity 0.93, atrophy 0.84, and intestinal metaplasia 0.90; the average accuracy of the three indicators was 85.5%. Conclusions: To assist in pathological diagnosis of chronic gastritis, the diagnostic accuracy of Attention-MIL model is very close to that of pathologists. Thus, it is suitable for practical application of artificial intelligence technology.