Bolin Chen

Intervertebral disc degeneration (IDD) has been considered as the primary pathological mechanism that underlies low back pain. Understanding the molecular mechanisms underlying human IDD is imperative for making strategies to treat IDD-related diseases. Herein, we report the molecular programs, lineage progression patterns, and paths of cellular communications during the progression of IDD using single-cell RNA sequencing (scRNA-seq) on nucleus pulposus (NP) cells from patients with different grades of IDD undergoing discectomy. New subtypes of cells and cell-type-specific gene signatures of the metabolic homeostatic NP cells (Met NPC), adhesive NP cells (Adh NPC), inflammatory response NP cells (IR NPC), endoplasmic reticulum stress NP cells (ERS NPC), fibrocartilaginous NP cells (Fc NPC), and CD70 and CD82 + progenitor NP cells (Pro NPC) were identified. In the late stage of IDD, the IR NPC and Fc NPC account for a large proportion of NPC. Importantly, immune cells including macrophages, T cells, myeloid progenitors, and neutrophils were also identified, and further analysis showed that significant intercellular interaction between macrophages and Pro NPC occurred via MIF (macrophage migration inhibitory factor) and NF-kB signaling pathways during the progression of IDD. In addition, dynamic polarization of macrophage M1 and M2 cell subtypes was found in the progression of IDD, and gene set functional enrichment analysis suggested a significant role of the macrophage polarization in regulating cell metabolism, especially the Pro NPC. Finally, we found that the NP cells in the late degenerative stage were mainly composed of the cell types related to inflammatory and endoplasmic reticulum (ER) response, and fibrocartilaginous activity. Our results provided new insights into the identification of NP cell populations at single-cell resolution and at the relatively whole-transcriptome scale, accompanied by cellular communications between immune cells and NP cells, and discriminative markers in relation to specific cell subsets. These new findings present clues for effective and functional manipulation of human IDD-related bioremediation and healthcare.

Ischemia/reperfusion (I/R) injury is a common cause of injury to target organs such as brain, heart, and kidneys. Renal injury from I/R, which may occur in renal transplantation, surgery, trauma, or sepsis, is known to be an important cause of acute kidney injury. The detailed molecular mechanism of renal I/R injury is still not fully clear. Here, we investigate the role of AMP-activated protein kinase (AMPK)-evoked autophagy in the renal proximal tubular cell death in an in vitro I/R injury model. To mimic in vivo renal I/R injury, LLC-PK1 cells, a renal tubular cell line derived from pig kidney, were treated with antimycin A and 2-deoxyglucose to mimic ischemia injury followed by reperfusion with growth medium. This I/R injury model markedly induced apoptosis and autophagy in LLC-PK1 cells in a time-dependent manner. Autophagy inhibitor 3-methyladenine (3MA) significantly enhanced I/R injury-induced apoptosis. I/R could also up-regulate the phosphorylation of AMPK and down-regulate the phosphorylation of mammalian target of rapamycin (mTOR). Cells transfected with small hairpin RNA (shRNA) for AMPK significantly increased the phosphorylation of mTOR as well as decreased the induction of autophagy followed by enhancing cell apoptosis during I/R. Moreover, the mTOR inhibitor RAD001 significantly enhanced autophagy and attenuated cell apoptosis during I/R. Taken together, these findings suggest that autophagy induction protects renal tubular cell injury via an AMPK-regulated mTOR pathway in an in vitro I/R injury model. AMPK-evoked autophagy may be as a potential target for therapeutic intervention in I/R renal injury.

Background: Selecting patients that potentially benefit from immune checkpoint inhibitors (ICIs) is critical. Programmed death ligand-1 (PD-L1) protein immunohistochemical expression on cancer cells or immune cells and Next generation sequencing based tumor mutational burden (TMB) are the hot spots in studies on ICIs, but there is still confusion in the testing methods. Due to blood samples are much easier for clinical application, many potential peripheral biomarkers have been proposed. This study identify blood parameters that associated with outcome of non-small cell lung cancer (NSCLC) patients with ICIs monotherapy. Materials and Methods: Data of 76 NSCLC patients were analyzed retrospectively. To assess the connection between survival and peripheral blood markers measured before and after treatment, we utilized COX regression model survival analysis and receiver operating characteristic (ROC) curve to assess the markers. Results: In the nivolumab cohort, the optimal cutoff for predicting 11 month overall survival (OS) were 168.13 and 43g/L in Platelet-to-lymphocyte ratio (PLR) and albumin, respectively. When patients are grouped with PLR and albumin the cut-offs, a significant difference in SD-PR vursus PD rate were found between high and low groups, separately. which was not found when grouped by PD-L1 expression. Patients with high PLR (>168.13) or low albumin (168.13) after the fourth cycle of ICIs was also an prognostic biomarker, which significantly correlated with shorter OS in both Nivolumab (P=0.046) and durvalumab cohort (P=0.028) . Conclusions: PLR and albumin may help the stratification of high progression and death risk group in advanced NSCLC patients treated with nivolumab and durvalumab monotherapy.