Understanding Emergent Complexity from a Single-Molecule Perspective.

Molecules, with structural, scaling, and interaction diversities, are crucial for the emergence of complex behaviors. Interactions are essential prerequisites for complex systems to exhibit emergent properties that surpass the sum of individual component characteristics. Tracing the origin of complex molecular behaviors from interactions is critical to understanding ensemble emergence, and requires insights at the single-molecule level. Electrical signals from single-molecule junctions enable the observation of individual molecular behaviors, as well as intramolecular and intermolecular interactions. This technique provides a foundation for bottom-up explorations of emergent complexity. This Perspective highlights investigations of various interactions via single-molecule junctions, including intramolecular orbital and weak intermolecular interactions and interactions in chemical reactions. It also provides potential directions for future single-molecule junctions in complex system research.

HECW1 restrains cervical cancer cell growth by promoting DVL1 ubiquitination and downregulating the activation of Wnt/ß-catenin signaling.

HECW1 belongs to ubiquitin ligase (E3) HECT family, and is found to be involved in tumorigenesis and tumor progression. However, the function of HECW1 in cervical cancer (CC) remains unknown. Clinical analysis showed that HECW1 is significantly decreased in CC tumor tissues. Ectopic expression of HECW1 suppressed cell growth, promoting cell cycle arrest and apoptosis in CC cells, while downregulation of HECW1 reversed these trends, impeded proliferation and accelerated cell cycle progression of CC cells. Overexpressing of HECW1 reduced mitochondrial membrane potential and the protein expression of voltage-dependent anion channel 1 (VDAC1). In addition, upregulation of HECW1 inhibited nuclear ß-catenin accumulation, downregulated ß-catenin/TCF/LEF-mediated transcriptional activity and the expression of downstream gene c-Myc, whereas inhibition of HECW1 received opposite results. Further results confirmed HECW1 affects the protein expression of dishevelled-1 (DVL1), a potent activator of Wnt/ß-catenin, and inhibition of HECW1 inhibited the ubiquitination of DVL1, upregulating its expression. Inhibition of DVL1 restrained the promotion effect of HECW1 suppression on cell proliferation. In vivo experiments also verified that HECW1 suppression promoted the tumor formation of CC cells. Summary, we demonstrated that HECW1 inhibits CC cell proliferation and tumor formation by downregulating DVL1 induced Wnt/ß-catenin signaling pathway activation.

Breaks for Precision Medicine in Cancer: Development and Prospects of Spatiotemporal Transcriptomics.

With the development of the social economy and the deepening understanding of cancer, cancer has become a significant cause of death, threatening human health. Although researchers have made rapid progress in cancer treatment strategies in recent years, the overall survival of cancer patients is still not optimistic. Therefore, it is essential to reveal the spatial pattern of gene expression, spatial heterogeneity of cell populations, microenvironment interactions, and other aspects of cancer. Spatiotemporal transcriptomics can help analyze the mechanism of cancer occurrence and development, greatly help precise cancer treatment, and improve clinical prognosis. Here, we review the integration strategies of single-cell RNA sequencing and spatial transcriptomics data, summarize the recent advances in spatiotemporal transcriptomics in cancer studies, and discuss the combined application of spatial multiomics, which provides new directions and strategies for the precise treatment and clinical prognosis of cancer.

Effect of Fragment 1 on the Binding of Epigallocatechin Gallate to the PD-L1 Dimer Explored by Molecular Dynamics.

Blocking the interaction between programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) by directly targeting the PD-L1 dimer has emerged as a hot topic in the field of cancer immunotherapy. Epigallocatechin gallate (EGCG), a natural product, has been demonstrated binding to the PD-L1 dimer in our previous study, but has a weaker binding capacity, moreover, EGCG is located at the end of the binding pocket of the PD-L1 dimer. The inhibitor fragment 1 (FRA) lies at the other end. So, we proposed that the introduction of FRA might be able to improve the binding ability. To illuminate this issue, molecular dynamics (MD) simulation was performed in the present study. Binding free energy calculations show that the binding affinity is significantly increased by 17 kcal/mol upon the introduction of FRA. It may be due to the energy contributions of emerging key residues ATyr56, AMet115, BTyr123, AIle54 and the enhanced contributions of initial key residues ATyr123 and BVal68. Binding mode and non-bonded interaction results indicate that FRA_EGCG (EGCG in combination with FRA) binds to the C-, F- and G-sheet of the PD-L1 dimer. Importantly, the introduction of FRA mainly strengthened the nonpolar interactions. The free energy landscape and secondary structure results further show that FRA_EGCG can interact with the PD-L1 dimer more stably. These data demonstrated here provide the theoretical basis for screening two or more natural products with additive inhibitory effect on this pathway and therefore exerting more effective anticancer immunity.

Exosome-delivered circRNA circSYT15 contributes to cisplatin resistance in cervical cancer cells through the miR-503-5p/RSF1 axis.

The development of chemotherapy resistance is a major obstacle for cervical cancer (CC) patients. Exosome-mediated transfer of circular RNAs (circRNAs) was found to have relevance to the CC. This study is designed to explore the role and mechanism of exosomal circRNA synaptotagmin 15 (circSYT15) on cisplatin (DDP) resistance in CC. Cell proliferation ability and apoptosis rate were detected by Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), colony formation, and flow cytometry assays. CircSYT15, microRNA-503-5p (miR-503-5p), Remodeling spacing factor 1 (RSF1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Exosomes were analyzed by a transmission electron microscope and nanoparticle tracking analysis. CD63, CD81, TSC101, Bcl-2, Bax, C-caspase 3, and RSF1 protein levels were examined by western blot assay. The binding between miR-503-5p and circSYT15 or RSF1 was predicted by circBank or Starbase and then verified by a dual-luciferase reporter and RNA Immunoprecipitation (RIP). The biological role of exosomal circSYT15 in DDP resistance of CC in vivo. CircSYT15 was upregulated in the DDP-resistant CC cells and exosomes isolated from DDP-resistant CC cells. CircSYT15 knockdown repressed the proliferation and drug resistance of CC and induced apoptosis in CC cells. Exosomes shuttled circSYT15 act as a sponge to affect RSF1 expression, thereby promoting proliferation and drug resistance and repressing apoptosis of sensitive CC cells. Exosomal circSYT15 boost DDP resistance of cervical cancer in vivo. Exosome-mediated transfer of circSYT15 enhanced DDP resistance in CC partly by targeting the miR-503-5p/RSF1 axis, providing a foundation for future clinical applications of CC drug resistance.

Base editing of the HBG promoter induces potent fetal hemoglobin expression with no detectable off-target mutations in human HSCs.

Reactivating silenced γ-globin expression through the disruption of repressive regulatory domains offers a therapeutic strategy for treating ß-hemoglobinopathies. Here, we used transformer base editor (tBE), a recently developed cytosine base editor with no detectable off-target mutations, to disrupt transcription-factor-binding motifs in hematopoietic stem cells. By performing functional screening of six motifs with tBE, we found that directly disrupting the BCL11A-binding motif in HBG1/2 promoters triggered the highest γ-globin expression. Via a side-by-side comparison with other clinical and preclinical strategies using Cas9 nuclease or conventional BEs (ABE8e and hA3A-BE3), we found that tBE-mediated disruption of the BCL11A-binding motif at the HBG1/2 promoters triggered the highest fetal hemoglobin in healthy and ß-thalassemia patient hematopoietic stem/progenitor cells while exhibiting no detectable DNA or RNA off-target mutations. Durable therapeutic editing by tBE persisted in repopulating hematopoietic stem cells, demonstrating that tBE-mediated editing in HBG1/2 promoters is a safe and effective strategy for treating ß-hemoglobinopathies.

Translatomics to explore dynamic differences in immunocytes in the tumor microenvironment.

Protein is an essential component of all living organisms and is primarily responsible for life activities; furthermore, its synthesis depends on a highly complex and accurate translation system. For proteins, the regulation at the translation level exceeds the sum of that during transcription, mRNA degradation, and protein degradation. Therefore, it is necessary to study regulation at the translation level. Imbalance in the translation process may change the cellular landscape, which not only leads to the occurrence, maintenance, progression, invasion, and metastasis of cancer but also affects the function of immune cells and changes the tumor microenvironment. Detailed analysis of transcriptional and protein atlases is needed to better understand how gene translation occurs. However, a more rigorous direct correlation between mRNA and protein levels is needed, which somewhat limits further studies. Translatomics is a technique for capturing and sequencing ribosome-related mRNAs that can effectively identify translation changes caused by ribosome stagnation and local translation abnormalities during cancer occurrence to further understand the changes in the translation landscape of cancer cells themselves and immune cells in the tumor microenvironment, which can provide new strategies and directions for tumor treatment.

Innate immune escape and adaptive immune evasion of African swine fever virus: A review.

African swine fever virus (ASFV) causes hemorrhagic fever in domestic and wild pigs. The continued spread of the virus in Africa, Europe and Asia threatens the global pig industry. The lack of an effective vaccine limits disease control. ASFV has evolved a variety of encoded immune escape proteins and can evade host adaptive immunity, inducing cellular inflammation, autophagy, or apoptosis in host cells. Frequent persistent infections hinder the development of a viral vaccine and impose technical barriers. Currently, knowledge of the virulence-related genes, main pathogenic genes and immunoregulatory mechanism of ASFV is not comprehensive. We explain that ASFV invades the host to regulate its inflammatory response, interferon production, antigen presentation and cellular immunity. Furthermore, we propose potential ideas for ASFV vaccine target design, such as knocking out high-virulence genes in ASFV and performing data mining to identify the main genes that induce antiviral responses. To support a rational strategy for vaccine development, a better understanding of how ASFV interacts with the host and regulates the host's response to infection is needed. We review the current knowledge about ASFV targeting of host innate and adaptive immunity and the mechanisms by which the affected immune pathways are suppressed.

Evaluation of therapeutic mechanism of Hedyotis diffusa Willd (HDW)‒Scutellaria barbata (SB) in clear cell renal cell carcinoma via single-cell RNA sequencing and network pharmacology.

OBJECTIVE: The present study aimed to investigate the therapeutic mechanism of Hedyotis diffusa Willd (HDW) and Scutellaria barbata (SB) in ccRCC using a combination of single-cell RNA sequencing (scRNA-seq) and network pharmacology. METHODS: The active ingredients and potential molecular targets of HDW-SB were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. Gene expression data (GSE53757) were obtained from the Gene Expression Omnibus database. The hub genes of HDW-SB against ccRCC were identified via the protein-protein interaction network, and further analyzed by molecular complex detection. The roles of these genes in the diagnosis and immune infiltration of ccRCC were analyzed. The clinical significance of hub genes was verified using scRNA-seq data (GSE121638) and molecular docking. RESULTS: Following the PPI network analysis, 29 hub genes of HDW-SB against ccRCC were identified. All hub genes, except for CENPE, had significantly different expressions in tumor tissue and a more accurate diagnosis of ccRCC. Fifteen cell clusters were defined based on the scRNA-seq dataset, and the clusters were annotated as six cell types using marker genes. TYMS and KIAA0101 from hub genes were highly expressed in NK cells. Three active compounds, quercetin, luteolin, and baicalein, were found to target TYMS and KIAA0101 from the compound-target interaction network. CONCLUSION: 29 hub genes of HDW-SB against ccRCC were identified and showed good performance in terms of diagnosis and prognosis. Moreover, among these hub genes docking with the main ingredients of HDW-SB, TYMS and KIAA0101 exerted anti-ccRCC effects through NK cells.

Lymph node metastasis-related gene signature shows good performance in predicting prognosis and immune infiltration in cervical cancer.

Aims: This study aimed to construct a lymph node metastasis-related gene signature to predict prognosis and immune infiltration in patients with cervical cancer. Methods: Clinical and RNA sequencing data of 193 patients with cervical cancer, which were divided into lymph node metastasis (N1) and non-lymph node metastasis (N0) groups, were acquired from TCGA. Differentially expressed genes (DEGs) between the N1 and N0 groups were detected, and protein-protein interaction combined with LASSO analysis was conducted to further screen lymph node metastasis-related genes. Univariate and multivariate Cox regression analyses were performed to establish a predictive signature. The genetic features, potential biological behavior, and immune infiltration characteristics of the predictive signature were explored. Furthermore, the sensitivity of patients to chemotherapy drugs was estimated based on the predictive signature and the expression of TEKT2 and RPGR was investigated in the cervical cancer tissue samples. Results: A total of 271 lymph node metastasis-related DEGs, including 100 upregulated and 171 downregulated genes, were identified. Two genes, TEKT2 and RPGR, were associated with lymph node metastasis and prognosis in cervical cancer, and were used to construct a lymph node metastasis-related predictive signature. Based on the predictive signature, patients with cervical cancer were divided into high- and low-risk groups. The high-risk group, characterized by a higher tumor mutation burden and somatic mutation rate, indicated a poor overall survival. The activation of immune infiltration and increased expression of checkpoint genes were observed in the high-risk group, indicating that they might benefit from immunotherapy. Cytarabine, FH535, and procaspase-activating compound-1 were estimated as reasonable chemotherapy options for patients in the high-risk group, whereas two taxanes and five tyrosine kinase inhibitors, including etoposide and vinorelbine, had therapeutic significance for patients in the low-risk group. The expression of TEKT2 and RPGR was significantly downregulated in cervical cancer tissues, especially in metastatic lymph node tissues. Discussion: The lymph node metastasis-related predictive signature based on TEKT2 and RPGR showed good performance in predicting the survival outcomes of patients with cervical cancer. The risk score of the predictive signature was related to genetic variation and immune infiltration, which could guide immunotherapy and chemotherapy strategies.

Evaluation the injectability of injectable microparticle delivery systems on the basis of injection force and discharged rate.

BACKGROUND: Subcutaneous injection of biopharmaceutical agents or microparticles is challenging due to issues with low injection efficiency and high residual amounts. OBJECTIVE: This study aimed to determine the important factors affecting the injectability of microparticle delivery systems, establish a suitable injection system with lower injection force and higher discharge rate, and eventually develop a reliable injectability evaluation system for injectable microparticle delivery systems in vitro and in vivo. METHODS: The effects of various parameters, including particle size, injection speed, concentration of microspheres suspension, vehicle viscosity, needle length and gauge were evaluated by measuring the injection force and discharge rate. The characteristics of microparticles and rheological measurement of the suspension systems were studied. A design of experiment approach was utilized to evaluate the interaction between the microsphere suspension, vehicle viscosity and needle gauges. Both in vitro sieve tests and in vivo tests in rats were conducted to evaluate injectability. RESULTS: The in vitro test results showed that the vehicle viscosity and injection speed have varying effects on discharge rate and injection force, respectively. Particle size and needle gauge have substantial influence on injectability, larger particle size and smaller needle gauges resulting in poor injectability, while the needle gauge was found to have the greatest influence on injectability. Levonorgestrel (LNG) microsphere and glass bead were relatively uniform spherical, the glass bead had extremely smooth surface; while mesoporous silica had irregular shape. The settling rate of glass bead was the fastest, which was about 18 times faster than the LNG microsphere. The CMC-Na had a poor interaction with the LNG microspheres, glass bead and mesoporous silica and showed basically Newtonian behavior in the shear rate range of 0.1 s-1-100 s-1. When shear rate increased to more than 100 s-1, no obvious shear thinning behavior was observed. CMC-Na formed a nodule structure with whether LNG microspheres or the glass beads, which were much lower than that with the mesoporous silica in static state, among which the glass beads were the weakest. The viscosity of the suspension increased with the rising of the volume fraction of particles. Fundamentals of hydrodynamics in capillaries were referenced, such as Navier-Stokes Law equation, Krieger-Dougherty (K-D) equation, Hagen-Poiseuille equation. The best results achieved was using a suspension concentration of 120-240 mg /mL and a viscosity of 60 cP at 20 °C with 23-gauge needles. The optimized conditions were verified in vivo tests. It was proven that the LNG microsphere suspension had a good injectability when injected into subcutaneous tissue of rats. CONCLUSION: The injection system of injectable microparticle delivery system with lower injection force and higher discharge rate was established and the evaluation method was suitable for the injectability evaluation both in vivo and in vitro. Improved injectability would promote the clinical translation of microparticle delivery systems.

Effects of soy protein and its hydrolysates on the formation of heterocyclic aromatic amines in roasted pork.

This study investigated the influence mechanism of soy protein and its hydrolysates (under three different degree of hydrolysis) on formation of heterocyclic aromatic amines (HAAs) formation in roasted pork. The results showed that 7S and its hydrolysates significantly inhibited the formation of quinoxaline HAAs, and the maximum inhibitory rate of MeIQx, 4,8-MeIQx, and IQx was 69%, 79%, and 100%, respectively. However, soy protein and its hydrolysates could promote the formation of pyridine HAAs (PhIP, and DMIP), its content increased significantly with the increase in the degree of hydrolysis of the protein. The content of PhIP increased 41, 54, and 165 times with the addition of SPI, 7S, and 11S at 11% degree of hydrolysis, respectively. In addition, they promoted the formation of ß-carboline HAAs (Norharman and Harman), in a manner similar with that of PhIP, especially the 11S group. The inhibitory effect on quinoxaline HAAs was probably correlated with DPPH radical scavenging capacity. Nevertheless, the promotive effect on other HAAs might be related to the high levels of free amino acids and reactive carbonyls. This research may provide recommendation for the application of soy protein in high-temperature meat products.

Real-time monitoring of reaction stereochemistry through single-molecule observations of chirality-induced spin selectivity.

Stereochemistry has an essential role in organic synthesis, biological catalysis and physical processes. In situ chirality identification and asymmetric synthesis are non-trivial tasks, especially for single-molecule systems. However, going beyond the chiral characterization of a large number of molecules (which inevitably leads to ensemble averaging) is crucial for elucidating the different properties induced by the chiral nature of the molecules. Here we report direct monitoring of chirality variations during a Michael addition followed by proton transfer and keto-enol tautomerism in a single molecule. Taking advantage of the chirality-induced spin selectivity effect, continuous current measurements through a single-molecule junction revealed in situ chirality variations during the reaction. Chirality identification at a high sensitivity level provides a promising tool for the study of symmetry-breaking reactions and sheds light on the origin of the chirality-induced spin selectivity effect itself.

Graphene-molecule-graphene single-molecule junctions to detect electronic reactions at the molecular scale.

The ability to measure the behavior of a single molecule during a reaction implies the detection of inherent dynamic and static disordered states, which may not be represented when measuring ensemble averages. Here, we describe the building of devices with graphene-molecule-graphene single-molecule junctions integrated into an electrical circuit. These devices are simple to build and are stable, showing tolerance to mechanical changes, solution environment and voltage stimulation. The design of a conductive channel based on a single molecule enables single-molecule detection and is sensitive to variations in physical properties and chemical structures of the detected molecules. The on-chip setup of single-molecule junctions further offers complementary metal-oxide-semiconductor (CMOS) compatibility, enabling logic functions in circuit elements, as well as deciphering of reaction intermediates. We detail the experimental procedure to prepare graphene transistor arrays as a basis for single-molecule junctions and the preparation of nanogapped carboxyl-terminal graphene electrodes by using electron-beam lithography and oxygen plasma etching. We describe the basic design of a molecular bridge with desired functions and terminals to form covalent bonds with electrode arrays, via a chemical reaction, to construct stably integrated single-molecule devices with a yield of 30-50% per chip. The immobilization of the single molecules is then characterized by using inelastic electron tunneling spectra, single-molecule imaging and fluorescent spectra. The whole protocol can be implemented within 2 weeks and requires users trained in using ultra-clean laboratory facilities and the aforementioned instrumentation.

Tunable Interferometric Effects between Single-Molecule Suzuki-Miyaura Cross-Couplings.

Parallel two molecular bridges loaded with a palladium catalyst were integrated into separate pairs of graphene electrodes in the same device. Based on the complete description of the one-palladium catalytic pathway by single-molecule electrical spectroscopy, this setup enables the mapping of the cross-correlation between different catalysts and demonstrates the emergent complexity in the extrapolation from single molecule to ensemble. The anticorrelation behaviors at the time scale of two individual catalysts in sufficiently close proximity were revealed in the Suzuki-Miyaura cross-coupling. Further experimental evidence demonstrates that the long-range electric dipole-dipole interaction induced by solvent leads to the destructive interferometric effect of two catalysts. In contrast, the cooperative coupling of the elementary step between two catalysts affords a local acceleration. This new form of reaction dynamics measurement via focusing on multiple molecules with single-event resolution holds great promise to build a bridge between single molecule and ensemble.

Distinguishing between monozygotic twins' blood samples through immune repertoire sequencing.

Monozygotic (MZ) twins with highly similar genomic DNA sequences can not be distinguished by conventional forensic DNA testing. The immune repertoire (IR) reflects an individual's immune history, which is unique between individuals, has been applied to individualized treatment in precision medicine. However, the application of IR in forensic genetics has not been reported to date. In this study, the diversity in the complementary determining region 3 (CDR3) of both the T-cell receptor ß chain (TCRß) and B-cell receptor heavy chain (also known as immunoglobulin heavy chain, IGH) in four pairs of MZ twins were analyzed. The results showed that the amino acid sequences length distribution frequency of TCRß CDR3 had 4-10 differences, and the nucleic acid sequences length distribution frequency of TCRß CDR3 had 2-7 differences between MZ twins. The shared difference of four pairs of MZ twins focused on the length distribution frequency of 34 bp nucleotide sequences in TCRß. By analyzing the usage frequency of V and J genes in TCRß and IGH CDR3 DNA sequence rearrangements, we also found that there were biases between each pair of MZ twins, and the usage frequency of TRBJ2-3 showed common differences between each pair of MZ twins. Furthermore, each pair of MZ twins had its own unique V-J genes combination mode in TCRß and IGH CDR3 DNA sequences. This study, for the first time, suggested that IR can be used as a potential biological marker to distinguish MZ twins.

A Tunable Single-Molecule Light-Emitting Diode with Single-Photon Precision.

A robust single-molecule light-emitting diode (SM-LED) with high color purity, linear polarization, and efficiency tunability is prepared by covalently integrating one fluorescent molecule into nanogapped graphene electrodes. Furthermore, single-molecule Förster resonance energy transfer from the electroluminescent center to different accepters is achieved through rational molecular engineering, enabling construction of a multicolor SM-LED. All these characterizations are accomplished in the photoelectrical integration system with high temporal/spatial/energy resolution, demonstrating the capability of the single-photon emission of SM-LEDs. The success in developing high-performance SM-LEDs inspires the development of the next generation of commercial display devices and promises a single-photon emitter for use in quantum computation and quantum communication.

LncRNA CARMN inhibits cervical cancer cell growth via the miR-92a-3p/BTG2/Wnt/ß-catenin axis.

Long noncoding RNA (lncRNA) cardiac mesoderm enhancer-associated noncoding RNA (CARMN) is a newly discovered tumor-suppressor lncRNA in cancers. However, its role in cervical cancer (CC) remains elusive. This study was conducted to analyze the molecular mechanism of CARMN in CC cell growth and provide a novel theoretical basis for CC treatment. RT-qPCR and clinical analysis revealed that CARMN and B-cell translocation gene 2 (BTG2) were downregulated, whereas miR-92a-3p was upregulated in CC tissues and cells and their expressions were correlated with clinicopathological characteristics and prognosis. MTT assay, flow cytometry, and Transwell assays revealed that CARMN overexpression reduced proliferation, migration, and invasion and increased apoptosis rate in CC cells. Mechanically, CARMN repressed miR-92a-3p to promote BTG2 transcription. Functional rescue assays revealed that miR-92a-3p overexpression or BTG2 downregulation reversed the inhibitory role of CARMN overexpression in CC cell growth. Western blot analysis elicited that Wnt3a and ß-catenin were elevated in CC cells and CARMN blocked the Wnt/ß-catenin signaling pathway via the miR-92a-3p/BTG2 axis. Overall, our findings demonstrated that CARMN repressed miR-92a-3p to upregulate BTG2 transcription and then blocked the Wnt/ß-catenin signaling pathway, thereby suppressing CC cell growth.

Highly sensitive curvature sensor based on a sandwich multimode fiber Mach-Zehnder interferometer.

A highly sensitive optical fiber Mach-Zehnder interference curvature sensor based on MMF-GIMMF-MMF, which was made by sandwiching the graded-index multimode fiber (GIMMF) between two pieces of very short stepped-index multimode fibers (SIMMFs) spliced with input-single-mode fiber (SMF) and output-SMF, respectively, was proposed. The core diameter of the SIMMFs and GIMMF was 105 µm and 50 µm, respectively, and cladding diameter of them were both 125 µm. The sensing principle of the MMF-GIMMF- MMF sensors and the influences of structure parameters on the interference spectrum characteristics were theoretically analyzed in detail. Experimental results showed that when the length of the GIMMF was short enough (usually ≤ 10 mm), interference spectrum was induced by the interaction between the core modes and the low-order cladding modes due to the special structure of the designed Mach-Zehnder interferometer. Intensity of the interference valleys was highly sensitive to the applied bending but nearly independent of the surrounding temperature, on the contrary, the dip wavelength showed negligible sensitivity to the applied bending but relatively high temperature sensitivity. Thus, a temperature- independent curvature sensor could be realized by tracing the intensity variation of interference valley. In addition, different interference valley exhibited different intensity-based curvature sensitivity, providing more options for curvature sensing applications. Especially, total length of the sensor could be as short as 3 mm with length of GIMMF and SIMMFs only 1mm, the maximum curvature sensitivity could reach up to -78.75 dB/m-1 in the small curvature range of 0-2.36 m-1. Owing to its compact size, easy fabrication, good reproducibility and low cost, the proposed sensor is promising for bending-related high-precision engineering applications.