CircVMP1 promotes glycolysis and disease progression by upregulating HKDC1 in colorectal cancer.

BACKGROUND: Circular RNAs (circRNAs) have been reported to play important roles in cancers. Here, we characterized circVMP1 (hsa_circ_0006508), an important circRNA which promoted glycolysis and disease progression in colorectal cancer (CRC). In this study, we aimed to explore the mechanism by which circVMP1 regulated tumor glycolysis and its related pathways in promoting CRC cell proliferation and metastasis. METHODS: The expression level of circVMP1 in CRC tissues and adjacent normal tissues was detected using quantitative PCR. In vitro and in vivo functional experiments were used to evaluate the effects of circVMP1 in the regulation of CRC cell proliferation and migration. Mitochondrial stress tests and glycolysis stress tests were conducted to detect the effect of circVMP1 on oxidative phosphorylation and glycolysis. Dual-luciferase reporter and RNA immunoprecipitation assays were used to evaluate the interaction between circVMP1, miR-3167, and HKDC1. RESULTS: We demonstrated that the level of circVMP1 was significantly upregulated in CRC tissues compared with normal tissues. In HCT116 and SW480 cells, overexpression of circVMP1 promoted proliferation, metastasis, and glycolysis. In vivo analysis indicated that circVMP1 accelerated the proliferation of xenograft tumors. As for the mechanism, overexpression of circVMP1 increased the levels of hexokinase domain component 1 (HKDC1) through competitive binding with miR-3167. CONCLUSION: Our study reported that circVMP1 was one of the tumor driver genes that promoted CRC malignant progression and glycolysis by upregulating HKDC1. CircVMP1/miR-3167/HKDC1 was a signaling axis that might be a target for CRC therapy.

Methods for Engineering Binders to Multi-Pass Membrane Proteins.

Numerous potential drug targets, including G-protein-coupled receptors and ion channel proteins, reside on the cell surface as multi-pass membrane proteins. Unfortunately, despite advances in engineering technologies, engineering biologics against multi-pass membrane proteins remains a formidable task. In this review, we focus on the different methods used to prepare/present multi-pass transmembrane proteins for engineering target-specific biologics such as antibodies, nanobodies and synthetic scaffold proteins. The engineered biologics exhibit high specificity and affinity, and have broad applications as therapeutics, probes for cell staining and chaperones for promoting protein crystallization. We primarily cover publications on this topic from the past 10 years, with a focus on the different formats of multi-pass transmembrane proteins. Finally, the remaining challenges facing this field and new technologies developed to overcome a number of obstacles are discussed.

Relationship between serum uric acid levels and osteoporosis.

Osteoporosis (OP) is a systemic bone disease in which bone density and quality decrease and bone fragility increases due to a variety of causes, making it prone to fractures. The development of OP is closely related to oxidative stress. Uric acid (UA) is the end product of purine metabolism in the human body. Extracellular UA has antioxidant properties and is thought to have a protective effect on bone metabolism. However, the process of UA degradation can lead to intracellular oxidative stress, which together with UA-induced inflammatory factors, leads to increased bone destruction. In addition, UA can inhibit vitamin D production, resulting in secondary hyperparathyroidism and further exacerbating UA-associated bone loss. This review summarizes the relationship between serum UA levels and bone mineral density, bone turnover markers, and so on, in the hope of providing new insights into the pathogenesis and treatment of OP.

Click display: a rapid and efficient in vitro protein display method for directed evolution.

We describe a novel method for in vitro protein display-click display-that does not depend on maintaining RNA integrity during biopanning and yields covalently linked protein-cDNA complexes from double-stranded input DNA within 2 h. The display is achieved in a one-pot format encompassing transcription, translation and reverse transcription reactions in series. Stable linkage between proteins and the encoding cDNA is mediated by a modified DNA linker-ML-generated via a click chemistry reaction between a puromycin-containing oligo and a cDNA synthesis primer. Biopanning of a click-displayed mock library coupled with next-generation sequencing analysis revealed >600-fold enrichment of target binders within a single round of panning. A synthetic library of Designed Ankyrin Repeat Proteins (DARPins) with ∼1012 individual members was generated using click display in a 25-µl reaction and six rounds of library panning against a model protein yielded a panel of nanomolar binders. This study establishes click display as a powerful tool for protein binder discovery/engineering and provides a convenient platform for in vitro biopanning selection even in RNase-rich environments such as on whole cells.

SGLT-2 Inhibitors for Non-Alcoholic Fatty Liver Disease: A Review.

Non-alcoholic fatty liver disease (NAFLD) is a group of metabolic liver illnesses that lead to accumulation of liver fat mainly due to excessive nutrition. It is closely related to insulin resistance, obesity, type 2 diabetes, and cardiovascular disease, and has become one of the main causes of chronic liver disease worldwide. At present, there is no specific drug for the treatment of NAFLD; lifestyle interventions including dietary control and exercise are recommended as routine treatments. As a drug for the treatment of type 2 diabetes, sodium-glucose co-transporter type 2 (SGLT-2) inhibitors may also play a beneficial role in the treatment of NAFLD. This article reviews the mechanism of SGLT-2 inhibitors in the treatment of NAFLD.

AGConv: Adaptive Graph Convolution on 3D Point Clouds.

Convolution on 3D point clouds is widely researched yet far from perfect in geometric deep learning. The traditional wisdom of convolution characterises feature correspondences indistinguishably among 3D points, arising an intrinsic limitation of poor distinctive feature learning. In this article, we propose Adaptive Graph Convolution (AGConv) for wide applications of point cloud analysis. AGConv generates adaptive kernels for points according to their dynamically learned features. Compared with the solution of using fixed/isotropic kernels, AGConv improves the flexibility of point cloud convolutions, effectively and precisely capturing the diverse relations between points from different semantic parts. Unlike the popular attentional weight schemes, AGConv implements the adaptiveness inside the convolution operation instead of simply assigning different weights to the neighboring points. Extensive evaluations clearly show that our method outperforms state-of-the-arts of point cloud classification and segmentation on various benchmark datasets. Meanwhile, AGConv can flexibly serve more point cloud analysis approaches to boost their performance. To validate its flexibility and effectiveness, we explore AGConv-based paradigms of completion, denoising, upsampling, registration and circle extraction, which are comparable or even superior to their competitors.

TOX promotes follicular helper T cell differentiation in patients with primary Sjögren's syndrome.

OBJECTIVES: Whether naive CD4+ T cells are dysregulated and associated with the overactivation of CD4+ T cells in primary SS (pSS) remains unclear. We aimed to explore the role and underlying mechanism of naive CD4+ T cells in pSS. METHODS: We examined the activation, proliferation and differentiation of naive CD4+ T cells from pSS patients and healthy controls. Differentially expressed genes were identified using RNA sequencing, and were overexpressed or silenced to determine the gene regulating follicular helper T (Tfh) cells. Assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) with chromatin immunoprecipitation with high-throughput sequencing (ChIP-seq) was performed to explore the epigenetic mechanism. Naive CD4+ T cells were treated with pSS-related cytokines to explore the upstream signalling pathway. RESULTS: pSS naive CD4+ T cells had higher potentials of activation, proliferation and differentiation towards Tfh cells. Thymocyte selection-associated high mobility group box protein (TOX) was upregulated in pSS naive CD4+ T cells and promoted T cell activation and Tfh cell polarization. TOX silencing in pSS naive CD4+ T cells downregulated B cell lymphoma 6 (BCL6) expression and altered levels of multiple Tfh-associated genes. ChIP-seq analysis implied that TOX bound to the BCL6 locus, where there were accessible regions found by ATAC-seq. IFN-α induced TOX overexpression, which was attenuated by Janus kinase (JAK) and signal transducer and activator of transcription 1 (STAT1) inhibitors. CONCLUSION: Our data suggest that TOX in pSS naive CD4+ T cells is upregulated, which facilitates Tfh cell differentiation. Mechanistically, IFN-α induces TOX overexpression in naive CD4+ T cells through JAK-STAT1 signalling and TOX regulates BCL6 expression. Therefore, IFN-α-JAK-STAT1 signalling and TOX might be potential therapeutic targets in pSS.

A potent and broad neutralization of SARS-CoV-2 variants of concern by DARPins.

We report the engineering and selection of two synthetic proteins-FSR16m and FSR22-for the possible treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. FSR16m and FSR22 are trimeric proteins composed of DARPin SR16m or SR22 fused with a T4 foldon. Despite selection by a spike protein from a now historical SARS-CoV-2 strain, FSR16m and FSR22 exhibit broad-spectrum neutralization of SARS-CoV-2 strains, inhibiting authentic B.1.351, B.1.617.2 and BA.1.1 viruses, with respective IC50 values of 3.4, 2.2 and 7.4 ng ml-1 for FSR16m. Cryo-EM structures revealed that these DARPins recognize a region of the receptor-binding domain (residues 456, 475, 486, 487 and 489) overlapping a critical portion of the angiotensin-converting enzyme 2 (ACE2)-binding surface. K18-hACE2 transgenic mice inoculated with B.1.617.2 and receiving intranasally administered FSR16m showed less weight loss and 10-100-fold lower viral burden in upper and lower respiratory tracts. The strong and broad neutralization potency makes FSR16m and FSR22 promising candidates for the prevention and treatment of infection by SARS-CoV-2.

A PCR-free rapid protocol for one-pot construction of highly diverse genetic libraries.

In vitro protein display methods can access extensive libraries (e.g., 1012-1014) and play an increasingly important role in protein engineering. However, the preparation of large libraries remains a laborious and time-consuming process. Here we report an efficient one-pot ligation & elongation (L&E) method for sizeable synthetic library preparation free of PCR amplification or any purification steps. As a proof of concept, we constructed an ankyrin repeat protein templated synthetic library with 1011 variants in 150 µL volume. The entire process from the oligos to DNA template ready for transcription is linearly scalable and took merely 90 minutes. We believe this L&E method can significantly simplify the preparation of synthetic libraries and accelerate in vitro protein display experiments.

A Multi-Specific DARPin Potently Neutralizes Shiga Toxin 2 via Simultaneous Modulation of Both Toxin Subunits.

Shiga toxin-producing E. coli (STEC) is a common cause of bloody diarrhea. The pathology of STEC infection derives from two exotoxins-Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2)-that are secreted by STEC in the gut, from where they are systemically absorbed, causing severe kidney damage leading to hemolytic uremic syndrome (HUS). Currently, there is no effective treatment for HUS, and only supportive care is recommended. We report the engineering of a panel of designed ankyrin repeat proteins (DARPin) with potent neutralization activity against Stx2a, the major subtype associated with HUS. The best dimeric DARPin, SD5, created via a combination of directed evolution and rational design, neutralizes Stx2a with a half maximal effective concentration (EC50) of 0.61 nM in vitro. The two monomeric DARPin constituents of SD5 exhibit complementary functions-SHT targets the enzymatic A subunit of Stx2a and inhibits the toxin's catalytic activity, while DARPin #3 binds the B subunit, based on the cryo-EM study, and induces a novel conformational change in the B subunit that distorts its five-fold symmetry and presumably interferes with toxin attachment to target cells. SD5 was fused to an albumin-binding DARPin, and the resulting trimeric DARPin DA1-SD5 efficiently protects mice in a toxin challenge model, pointing to a high potential of this DARPin as a therapeutic for STEC infection. Finally, the unprecedented toxin conformational change induced by DARPin #3 represents a novel mode of action for neutralizing Stx2 toxicity and reveals new targets for future drug development.

Chicken-derived CD20 antibodies with potent B-cell depletion activity.

We report four novel anti-human CD20 (hCD20) monoclonal antibodies (mAbs) discovered from a phylogenetically distant species-chickens. The chicken-human chimaeric antibodies exhibit at least 10-fold enhanced antibody-dependent cellular cytotoxicity (ADCC) and 4-8-fold stronger complement-dependent cytotoxicity (CDC) relative to the clinically used mouse-human chimaeric anti-hCD20 antibody rituximab (RTX). Thus, to our knowledge these mAbs are the first to significantly outperform RTX in both Fc-mediated mechanisms of action. The antibodies show 20-100-fold superior depletion of B cells in whole blood from healthy humans relative to RTX and retain efficacy in vivo. One of the mAbs, AC1, can bind mouse CD20, indicating specificity for a novel hCD20 epitope inaccessible to current (mouse-derived) anti-hCD20 mAbs. A humanized version of one antibody, hAC11-10, was created by complementarity-determining region (CDR) grafting into a human variable region framework and this molecule retained the ADCC, in vitro human whole-blood B-cell depletion, and in vivo lymphoma cell depletion activities of the parent. These mAbs represent promising monotherapy candidates for improving upon current less-than-ideal clinical outcomes in lymphoid malignancies and provide an arsenal of biologically relevant molecules for the development of next-generation CD20-mediated immunotherapies including bispecific T-cell engagers (BiTE), antibody-drug conjugates (ADC) and chimaeric antigen receptor-engineered T (CAR-T) cells.

EZH2 Promotes T Follicular Helper Cell Differentiation Through Enhancing STAT3 Phosphorylation in Patients With Primary Sjögren's Syndrome.

Objectives: Enhancer of zeste homolog 2 (EZH2) is an epigenetic regulator that plays an essential role in immune system development and autoimmune diseases. This study aimed to characterize the role of EZH2 in the pathogenesis of primary Sjögren's syndrome (pSS). Methods: We analyzed EZH2 expression in two transcriptomic datasets of peripheral blood mononuclear cells (PBMCs) from pSS patients and healthy controls. We measured EZH2 expression in CD4+ T cells, CD8+ T cells, and CD19+ B cells from pSS patients and healthy controls and correlated EZH2 expression with clinical parameters. We also examined the activation, proliferation, and T-cell differentiation of CD4+ T cells using the EZH2 inhibitor GSK126, EZH2 siRNA, and EZH2-expressing vector. We further examined the STAT3 signaling pathway after EZH2 inhibition and detected Tfh differentiation in EZH2-overexpressed CD4+ T cells with STAT3 knocked down. Results: EZH2 was upregulated in GSE164885 and GSE48378. EZH2 expression was higher in pSS CD4+ and CD8+ T cells, and EZH2 expression in circulating pSS CD4+ T cells was positively correlated with IgG, IgA, ESR, RF, and the circulating Tfh population. EZH2 inhibition and silencing EZH2 suppressed activation, proliferation, and Tfh differentiation. Furthermore, overexpressing EZH2 promoted activation, proliferation, and Tfh differentiation in CD4+ T cells. EZH2 inhibition attenuated STAT3 phosphorylation in CD4+ T cells. STAT3 knockdown abrogated EZH2-promoted Tfh differentiation. Conclusions: EZH2 expression was abnormally elevated in pSS CD4+ T cells, which facilitated Tfh differentiation of CD4+ T cells by enhancing STAT3 phosphorylation. EZH2 promotes Tfh differentiation and might be implicated in pSS pathogenesis.

Methylprednisolone pulse therapy promotes the differentiation of regulatory T cells by inducing the apoptosis of CD4+ T cells in patients with systemic lupus erythematosus.

OBJECTIVES: To investigate the differentiation of regulatory T cells (Tregs) induced by methylprednisolone (MP) pulse therapy in patients with Systemic Lupus Erythematosus (SLE). METHODS: We enrolled 30 patients with SLE and analyzed peripheral blood mononuclear cells (PBMCs) before and after MP pulse therapy. Peripheral Tregs, apoptosis of PBMCs subsets, and TGFß production by monocytes was quantified by flow cytometry. Proliferation and IFN-γ production of CD4+ T cells were measured. Furthermore, TGFß1 production by human monocyte-derived macrophages (HMDM) stimulated with MP-treated CD4+ T cells were quantified by ELISA. RESULTS: Peripheral Tregs was significantly increased after MP pulse therapy (6.76 ± 1.46% vs. 3.82 ± 1.02%, p < 0.01), with an expansion of Nrp1- induced Tregs (4.54 ± 0.46% vs. 1.75 ± 0.38%, p < 0.01). Proliferation and IFN-γ production of CD4+ T cells were significantly decreased after MP pulse therapy. MP pulse therapy induced CD4+ T cell apoptosis (early apoptosis, 26.34 ± 3.54% vs. 14.81 ± 2.89%, p < 0.01) and TGFß expression on monocytes (6.02% vs. 2.45%, p < 0.01). Furthermore, MP induced CD4+ T cell apoptosis in vitro, which stimulated HMDM to produce TGFß. Moreover, elevated TGFß level in supernatant from HMDM stimulated with MP-treated CD4+ T cells promoted Tregs differentiation. CONCLUSIONS: MP pulse therapy induces CD4+ T cell apoptosis, which promotes monocytes to produce TGFß and further facilitates Tregs differentiation. Newly-differentiated Tregs suppress proliferation and IFN-γ production of CD4+ T cells and contribute to immunoregulatory milieu after MP pulse therapy.

Potent and pan-neutralization of SARS-CoV-2 variants of concern by DARPins.

We report the engineering and selection of two synthetic proteins - FSR16m and FSR22 - for possible treatment of SARS-CoV-2 infection. FSR16m and FSR22 are trimeric proteins composed of DARPin SR16m or SR22 fused with a T4 foldon and exhibit broad spectrum neutralization of SARS-Cov-2 strains. The IC 50 values of FSR16m against authentic B.1.351, B.1.617.2 and BA.1.1 variants are 3.4 ng/mL, 2.2 ng/mL and 7.4 ng/mL, respectively, comparable to currently used therapeutic antibodies. Despite the use of the spike protein from a now historical wild-type virus for design, FSR16m and FSR22 both exhibit increased neutralization against newly-emerged variants of concern (39- to 296-fold) in pseudovirus assays. Cryo-EM structures revealed that these DARPins recognize a region of the receptor binding domain (RBD, residues 455-456, 486-489) overlapping a critical portion of the ACE2-binding surface. K18-hACE2 transgenic mice inoculated with a B.1.617.2 variant and receiving intranasally-administered FSR16m were protected as judged by less weight loss and 10-100-fold reductions in viral burden in the upper and lower respiratory tracts. The strong and broad neutralization potency make FSR16m and FSR22 promising candidates for prevention and treatment of infection by current and potential future strains of SARS-CoV-2.

Structural dynamics of receptor recognition and pH-induced dissociation of full-length Clostridioides difficile Toxin B.

Clostridioides difficile secretes Toxin B (TcdB) as one of its major virulence factors, which binds to intestinal epithelial and subepithelial receptors, including frizzled proteins and chondroitin sulfate proteoglycan 4 (CSPG4). Here, we present cryo-EM structures of full-length TcdB in complex with the CSPG4 domain 1 fragment (D1401-560) at cytosolic pH and the cysteine-rich domain of frizzled-2 (CRD2) at both cytosolic and acidic pHs. CSPG4 specifically binds to the autoprocessing and delivery domains of TcdB via networks of salt bridges, hydrophobic and aromatic/proline interactions, which are disrupted upon acidification eventually leading to CSPG4 drastically dissociating from TcdB. In contrast, FZD2 moderately dissociates from TcdB under acidic pH, most likely due to its partial unfolding. These results reveal structural dynamics of TcdB during its preentry step upon endosomal acidification, which provide a basis for developing therapeutics against C. difficile infections.

Downregulation of Programmed Death-1 Pathway Promoting CD8 + T Cell Cytotoxicity in Primary Biliary Cholangitis.

BACKGROUND: Primary biliary cholangitis (PBC) is an autoimmune disease. CD8 + T cell (CTLs) cytotoxicity played a crucial rule in of PBC with unclear detailed pathogenesis. AIMS: The role of the programmed death-1 (PD-1) pathway in CD8 + T cell cytotoxicity in patients with PBC was determined. METHODS: We recruited 69 patients with PBC and 57 healthy controls (HCs). PD-1 pathway in peripheral CD8 + T cells and related cytokines were detected, and gene expression levels were detected. Immunofluorescence staining of PD-1/PD-L1 was performed on liver tissue. PD-1 ± CTLs were cocultured with human intrahepatic biliary epithelial cells (HiBECs) to measure CTL cytotoxicity, proliferation and cytokine levels and HiBEC apoptosis. The upstream signaling pathway of PD-1 was detected. RESULTS: PBC patients exhibited Tbet gene upregulation and PD-1 downregulation in CTLs, with PD-1 expression reduced in CTLs and PD-L1 reduced in the liver portal region relative to HCs. Higher plasma IL-10, interferon-γ and transforming growth factor-ß concentrations were observed in the PBC group than the HC group. In CTL and HiBEC coculture experiment, compared with PD-1- CTLs, PD-1 + CTLs exhibited weaker cytotoxicity, less proliferation and lower cytokine production. When the system was blocked by anti-PD-1 antibodies, these effects were antagonized. CONCLUSIONS: PD-1 expression in CD8 + T cells decreased, and PD-1 pathway-related cytokines changed in patients with PBC. PD-1/PD-L1 pathway silencing increased CD8 + T cell proliferation, related cytokine production and CTL cytotoxic effects on HiBECs in coculture experiment. The PD-1/PD-L1 pathway might represent an important pathway in the immunological mechanism underlying PBC.

Protease-stable DARPins as promising oral therapeutics.

Clostridioides difficile is an enteric bacterium whose exotoxins, TcdA and TcdB, inactivate small GTPases within the host cells, leading to bloody diarrhea. In prior work, our group engineered a panel of potent TcdB-neutralizing designed ankyrin repeat proteins (DARPin) as oral therapeutics against C. difficile infection. However, all these DARPins are highly susceptible to digestion by gut-resident proteases, i.e. trypsin and chymotrypsin. Close evaluation of the protein sequence revealed a large abundance of positively charged and aromatic residues in the DARPin scaffold. In this study, we significantly improved the protease stability of one of the DARPins, 1.4E, via protein engineering. Unlike 1.4E, whose anti-TcdB EC50 increased >83-fold after 1-hour incubation with trypsin (1 mg/ml) or chymotrypsin (0.5 mg/ml), the best progenies-T10-2 and T10b-exhibit similar anti-TcdB potency as their parent in PBS regardless of protease treatment. The superior protease stability of T10-2 and T10b is attributed to the removal of nearly all positively charged and aromatic residues except those directly engaged in target binding. Furthermore, T10-2 was found to retain significant toxin-neutralization ability in ex vivo cecum fluid and can be easily detected in mouse fecal samples upon oral administration. Both T10-2 and T10b enjoy a high thermo- and chemo-stability and can be expressed very efficiently in Escherichia coli (>100 mg/l in shaker flasks). We believe that, in additional to their potential as oral therapeutics against C. difficile infection, T10-2 and T10b can also serve as a new generation DARPin scaffold with superior protease stability.

The myristoylated alanine-rich C-kinase substrates (MARCKS): A membrane-anchored mediator of the cell function.

The myristoylated alanine-rich C-kinase substrate (MARCKS) and the MARCKS-related protein (MARCKSL1) are ubiquitous, highly conserved membrane-associated proteins involved in the structural modulation of the actin cytoskeleton, chemotaxis, motility, cell adhesion, phagocytosis, and exocytosis. MARCKS includes an N-terminal myristoylated domain for membrane binding, a highly conserved MARCKS Homology 2 (MH2) domain, and an effector domain (which is the phosphorylation site). MARCKS can sequester phosphatidylinositol-4, 5-diphosphate (PIP2) at lipid rafts in the plasma membrane of quiescent cells, an action reversed by protein kinase C (PKC), ultimately modulating the immune function. Being expressed mostly in innate immune cells, MARCKS promotes the inflammation-driven migration and adhesion of cells and the secretion of cytokines such as tumor necrosis factor (TNF). From a clinical point of view, MARCKS is overexpressed in patients with schizophrenia and bipolar disorders, while the brain level of MARCKS phosphorylation is associated with Alzheimer's disease. Furthermore, MARCKS is associated with the development and progression of numerous types of cancers. Data in autoimmune diseases are limited to rheumatoid arthritis models in which a connection between MARCKS and the JAK-STAT pathway is mediated by miRNAs. We provide a comprehensive overview of the structure of MARCKS, its molecular characteristics and functions from a biological and pathogenetic standpoint, and will discuss the clinical implications of this pathway.

Long Non-coding RNA Regulation of Mesenchymal Stem Cell Homeostasis and Differentiation: Advances, Challenges, and Perspectives.

Given the self-renewal, multi-differentiation, immunoregulatory, and tissue maintenance properties, mesenchymal stem cells (MSCs) are promising candidates for stem cell-based therapies. Breakthroughs have been made in uncovering MSCs as key contributors to homeostasis and the regenerative repair of tissues and organs derived from three germ layers. MSC differentiation into specialized cell types is sophisticatedly regulated, and accumulating evidence suggests long non-coding RNAs (lncRNAs) as the master regulators of various biological processes including the maintenance of homeostasis and multi-differentiation functions through epigenetic, transcriptional, and post-translational mechanisms. LncRNAs are ubiquitous and generally referred to as non-coding transcripts longer than 200 bp. Most lncRNAs are evolutionary conserved and species-specific; however, the weak conservation of their sequences across species does not affect their diverse biological functions. Although numerous lncRNAs have been annotated and studied, they are nevertheless only the tip of the iceberg; the rest remain to be discovered. In this review, we characterize MSC functions in homeostasis and highlight recent advances on the functions and mechanisms of lncRNAs in regulating MSC homeostasis and differentiation. We also discuss the current challenges and perspectives for understanding the roles of lncRNAs in MSC functions in homeostasis, which could help develop promising targets for MSC-based therapies.