The p21CIP1-CDK4-DREAM axis is a master regulator of genotoxic stress-induced cellular senescence.

Cellular senescence, a major driver of aging, can be stimulated by DNA damage, and is counteracted by the DNA repair machinery. Here we show that in p16INK4a-deficient cells, senescence induction by the environmental genotoxin B[a]P or ionizing radiation (IR) completely depends on p21CIP1. Immunoprecipitation-based mass spectrometry interactomics data revealed that during senescence induction and maintenance, p21CIP1 specifically inhibits CDK4 and thereby activates the DREAM complex. Genome-wide transcriptomics revealed striking similarities in the response induced by B[a]P and IR. Among the top 100 repressed genes 78 were identical between B[a]P and IR and 76 were DREAM targets. The DREAM complex transcriptionally silences the main proliferation-associated transcription factors E2F1, FOXM1 and B-Myb as well as multiple DNA repair factors. Knockdown of p21CIP1, E2F4 or E2F5 diminished both, repression of these factors and senescence. The transcriptional profiles evoked by B[a]P and IR largely overlapped with the profile induced by pharmacological CDK4 inhibition, further illustrating the role of CDK4 inhibition in genotoxic stress-induced senescence. Moreover, data obtained by live-cell time-lapse microscopy suggest the inhibition of CDK4 by p21CIP1 is especially important for arresting cells which slip through mitosis. Overall, we identified the p21CIP1/CDK4/DREAM axis as a master regulator of genotoxic stress-induced senescence.

Activation and Purification of ß-Glucocerebrosidase by Exploiting its Transporter LIMP-2 - Implications for Novel Treatment Strategies in Gaucher's and Parkinson's Disease.

Genetic variants of GBA1 can cause the lysosomal storage disorder Gaucher disease and are among the highest genetic risk factors for Parkinson's disease (PD). GBA1 encodes the lysosomal enzyme beta-glucocerebrosidase (GCase), which orchestrates the degradation of glucosylceramide (GluCer) in the lysosome. Recent studies have shown that GluCer accelerates α-synuclein aggregation, exposing GCase deficiency as a major risk factor in PD pathology and as a promising target for treatment. This study investigates the interaction of GCase and three disease-associated variants (p.E326K, p.N370S, p.L444P) with their transporter, the lysosomal integral membrane protein 2 (LIMP-2). Overexpression of LIMP-2 in HEK 293T cells boosts lysosomal abundance of wt, E326K, and N370S GCase and increases/rescues enzymatic activity of the wt and E326K variant. Using a novel purification approach, co-purification of untagged wt, E326K, and N370S GCase in complex with His-tagged LIMP-2 from cell supernatant of HEK 293F cells is achieved, confirming functional binding and trafficking for these variants. Furthermore, a single helix in the LIMP-2 ectodomain is exploited to design a lysosome-targeted peptide that enhances lysosomal GCase activity in PD patient-derived and control fibroblasts. These findings reveal LIMP-2 as an allosteric activator of GCase, suggesting a possible therapeutic potential of targeting this interaction.

Three-in-One Peptide Prodrug with Targeting, Assembly and Release Properties for Overcoming Bacterium-Induced Drug Resistance and Potentiating Anti-Cancer Immune Response.

The presence of bacteria in tumor results in chemotherapeutic drug resistance and weakens the immune response in colorectal cancer. To overcome bacterium-induced chemotherapeutic drug resistance and potentiate antitumor immunity, herein a novel molecule Biotin-Lys(SA-Cip-OH)-Lys(SA-CPT)-Phe-Phe-Nap (Biotin-Cip-CPT-Nap) is rationally designed containing four functional motifs (i.e., a biotin motif for targeting, Phe-Phe(-Nap) motif for self-assembly, ciprofloxacin derivative (Cip-OH) motif for antibacterial effect, and camptothecin (CPT) motif for chemotherapy). Using the designed molecule, a novel strategy of intracellular enzymatic nanofiber formation and synergistic antibacterium-enhanced chemotherapy and immunotherapy is achieved. Under endocytosis mediated by highly expressed biotin receptor in colorectal cancer cell membrane and the catalysis of highly expressed carboxylesterase in the cytoplasm, this novel molecule can be transformed into Biotin-Nap, which self-assembled into nanofibers. Meanwhile, antibiotic Cip-OH and chemotherapeutic drug CPT are released, overcoming bacterium-induced drug resistance and enhancing the therapeutic efficacy of immunotherapy towards colorectal cancer. This work offers a feasible strategy for the design of novel multifunctional prodrugs to improve the efficiency of colorectal cancer treatment.

Genetic Analyses of Flower Main Traits from Two Pitayas and Their Progenies: A Cactus Plant.

Elucidation of the genetic foundation governing crucial traits in pitaya flowers is imperative for enhancing both the ornamental and economic values. In this study, the dynamic variation in flower genetics, segregation variation patterns, and a mixed inheritance model of the major and multigene flower traits of 'Dahong' and 'Honghuaqinglong' pitayas and their progenies were explored. The results showed that the main traits of flowers exhibited varying degrees of variation among the reciprocal F1 hybrids, with the data exhibiting the characteristics of quantitative traits. The betalain content, petal number, and stigma number exhibited values below the median values of the parents, suggesting a genetic inclination towards lower values. Perianth width, calyx tube width, petal number, and stigma number had the same genetic effects and significant correlation. Stigma-related traits had a clear maternal inheritance tendency. The heritability of flower length, stigma relative to anther distance, and petal betalain content was governed by two pairs of additive-dominant major genes. Perianth width, calyx tube width, petal number, and stigma number all conformed to the model of two pairs of equal-additive-dominant major genes. This study provides valuable information for parental selection, cross-breeding, and the enhancement of pitaya varieties to meet market preferences and environmental conditions.

The Proteomic Composition and Organization of Constitutive Heterochromatin in Mouse Tissues.

Pericentric heterochromatin (PCH) forms spatio-temporarily distinct compartments and affects chromosome organization and stability. Albeit some of its components are known, an elucidation of its proteome and how it differs between tissues in vivo is lacking. Here, we find that PCH compartments are dynamically organized in a tissue-specific manner, possibly reflecting compositional differences. As the mouse brain and liver exhibit very different PCH architecture, we isolated native PCH fractions from these tissues, analyzed their protein compositions using quantitative mass spectrometry, and compared them to identify common and tissue-specific PCH proteins. In addition to heterochromatin-enriched proteins, the PCH proteome includes RNA/transcription and membrane-related proteins, which showed lower abundance than PCH-enriched proteins. Thus, we applied a cut-off of PCH-unspecific candidates based on their abundance and validated PCH-enriched proteins. Amongst the hits, MeCP2 was classified into brain PCH-enriched proteins, while linker histone H1 was not. We found that H1 and MeCP2 compete to bind to PCH and regulate PCH organization in opposite ways. Altogether, our workflow of unbiased PCH isolation, quantitative mass spectrometry, and validation-based analysis allowed the identification of proteins that are common and tissue-specifically enriched at PCH. Further investigation of selected hits revealed their opposing role in heterochromatin higher-order architecture in vivo.

Protein-based nanoparticles for therapeutic nucleic acid delivery.

To realize the full potential of emerging nucleic acid therapies, there is a need for effective delivery agents to transport cargo to cells of interest. Protein materials exhibit several unique properties, including biodegradability, biocompatibility, ease of functionalization via recombinant and chemical modifications, among other features, which establish a promising basis for therapeutic nucleic acid delivery systems. In this review, we highlight progress made in the use of non-viral protein-based nanoparticles for nucleic acid delivery in vitro and in vivo, while elaborating on key physicochemical properties that have enabled the use of these materials for nanoparticle formulation and drug delivery. To conclude, we comment on the prospects and unresolved challenges associated with the translation of protein-based nucleic acid delivery systems for therapeutic applications.

Higher BST2 Expression Promotes the Anti-HBV Effect of IFN-α and BST2 Genetic Variant Predicts PegIFNα Treatment Response of HBeAg-Positive Chronic Hepatitis B Patients.

We previously reported that an interferon (IFN)-inducible protein, BST2, was regulated by the JAK-STAT pathway activated by CD40, and subsequently suppressing hepatitis B virus (HBV) repliaction and transcription. The current research attempted to assess the impact of BST2 on the IFN-treated anti-HBV effect, and explore BST2 variants for predicting pegylated IFN alpha (PegIFNα) therapy response of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB). Using an HBV-transfected cell model, the function of BST2 on HBV DNA replication and transcription driven by IFN was studied. The potentially functional BST2 variants were selected through a strategy of gene-wide screening. The associations of BST2 variants and polygenic score (PGS) model, which was used to quantify the combined influence of several genetic variants, with treatment response were examined in 2 separate PegIFNα-treated cohorts of 238 and 707 patients with CHB, respectively. We found that overexpression of BST2 improved the anti-HBV activity triggered by IFN-α. Among PegIFNα-treated patients with CHB, BST2_rs9576 was screened out to be significantly correlated with combined response (CR; i.e., HBeAg seroconversion along with HBV DNA level <3.3log10 IU/mL, P = 7.12 × 10-5 ). Additionally, there was a strong correlation between the PGS incorporating BST2_rs9576 and other 5 genetic variations (previously described predictors of therapy response to PegIFNα) and CR (P = 1.81 × 10-13 ), hepatitis B surface antigen (HBsAg) level (P = 0.004), as well as HBsAg decline (P = 0.017). In conclusion, higher BST2 expression responded better to IFN-α treatment. BST2_rs9576 is an effective indicator to forecast therapy response of PegIFNα-treated patients with CHB. The PGS possesses the potential to boost the ability of PegIFNα therapy response.

Ubiquiton-An inducible, linkage-specific polyubiquitylation tool.

The posttranslational modifier ubiquitin regulates most cellular processes. Its ability to form polymeric chains of distinct linkages is key to its diverse functionality. Yet, we still lack the experimental tools to induce linkage-specific polyubiquitylation of a protein of interest in cells. Here, we introduce a set of engineered ubiquitin protein ligases and matching ubiquitin acceptor tags for the rapid, inducible linear (M1-), K48-, or K63-linked polyubiquitylation of proteins in yeast and mammalian cells. By applying the so-called "Ubiquiton" system to proteasomal targeting and the endocytic pathway, we validate this tool for soluble cytoplasmic and nuclear as well as chromatin-associated and integral membrane proteins and demonstrate how it can be used to control the localization and stability of its targets. We expect that the Ubiquiton system will serve as a versatile, broadly applicable research tool to explore the signaling functions of polyubiquitin chains in many biological contexts.

The Characterization of Laser-Induced Particles Generated from Aluminum Alloy in High Power Laser Facility.

Aerosol particle contamination in high-power laser facilities has become a major cause of internal optical component damage resistance and service life reduction. In general, contaminating particles primarily originate from stray light; therefore, it is crucial to investigate the mechanism and dynamics of the dynamic contaminating particle generation to control the cleanliness level. In this study, corresponding research was conducted on experiments and theory. We investigated the particle generation and surface composition modification under the action of a laser. We employed various surface analytical methods to identify the possible variations in the aluminum alloy surface during laser irradiations. A theoretical model for particle ejection from aluminum alloy surfaces was established by taking the adhesion force and laser cleaning force (due to thermal expansion) into account. The results show that the threshold energies for contamination particle generation and damage are around 0.1 and 0.2 J/cm2, respectively. Subsurface impurities are the primary source of particles, and particle adhesion density is related to surface roughness. Pollution particle generation and splashing processes include temperature increases, phase changes, impact diffusion, and adhesion. The results provide a reference for the normal operation of high-energy laser systems. The results also suggest that the laser irradiation pretreatment of aluminum alloy surfaces is essential to improve the cleanliness level.

SOX2 promotes vasculogenic mimicry by accelerating glycolysis via the lncRNA AC005392.2-GLUT1 axis in colorectal cancer.

Vasculogenic mimicry (VM), a new model of angiogenesis, fulfills the metabolic demands of solid tumors and contributes to tumor aggressiveness. Our previous study demonstrated the effect of SOX2 in promoting VM in colorectal cancer (CRC). However, the underlying mechanisms behind this effect remain elusive. Here, we show that SOX2 overexpression enhanced glycolysis and sustained VM formation via the transcriptional activation of lncRNA AC005392.2. Suppression of either glycolysis or AC005392.2 expression curbed SOX2-driven VM formation in vivo and in vitro. Mechanistically, SOX2 combined with the promoter of AC005392.2, which decreased H3K27me3 enrichment and thus increased its transcriptional activity. Overexpression of AC005392.2 increased the stability of GLUT1 protein by enhancing its SUMOylation, leading to a decrease in the ubiquitination and degradation of GLUT1. Accumulation of GLUT1 contributed to SOX2-mediated glycolysis and VM. Additionally, clinical analyses showed that increased levels of AC005392.2, GLUT1, and EPHA2 expression were positively correlated with SOX2 and were also associated with poor prognoses in patients with CRC. Our study conclusively demonstrates that the SOX2-lncRNA AC005392.2-GLUT1 signaling axis regulates VM formation in CRC, offering a foundation for the development of new antiangiogenic drugs or new drug combination regimens.

K6-linked ubiquitylation marks formaldehyde-induced RNA-protein crosslinks for resolution.

Reactive aldehydes are produced by normal cellular metabolism or after alcohol consumption, and they accumulate in human tissues if aldehyde clearance mechanisms are impaired. Their toxicity has been attributed to the damage they cause to genomic DNA and the subsequent inhibition of transcription and replication. However, whether interference with other cellular processes contributes to aldehyde toxicity has not been investigated. We demonstrate that formaldehyde induces RNA-protein crosslinks (RPCs) that stall the ribosome and inhibit translation in human cells. RPCs in the messenger RNA (mRNA) are recognized by the translating ribosomes, marked by atypical K6-linked ubiquitylation catalyzed by the RING-in-between-RING (RBR) E3 ligase RNF14, and subsequently resolved by the ubiquitin- and ATP-dependent unfoldase VCP. Our findings uncover an evolutionary conserved formaldehyde-induced stress response pathway that protects cells against RPC accumulation in the cytoplasm, and they suggest that RPCs contribute to the cellular and tissue toxicity of reactive aldehydes.

Designing photoaffinity tool compounds for the investigation of the DENV NS2B-NS3 protease allosteric binding pocket.

Dengue virus (DENV) infection still lacks specific antiviral therapy, making the NS2B-NS3 protease an attractive target for drug development. However, allosteric inhibitors that bind to a site other than the active site still need to be better understood. In this study, we designed and synthesised tool compounds for photoaffinity labelling (PAL) to investigate the binding site of allosteric inhibitors on the DENV protease. These tool compounds contained an affinity moiety, a photoreactive group, and a reporter tag for detection. Upon irradiation, the photoreactive group formed a covalent bond with the protease, allowing for binding site identification. SDS-PAGE-based assays confirmed the qualitative binding of the designed inhibitors to the allosteric pocket, and pull-down experiments validated the interaction. Tryptic protein digestion following liquid chromatography/mass spectrometry analysis further supported the binding of the inhibitor to the proposed pocket revealing photo-attachment to an NS3 loop close to the C-terminus. These results enhance our understanding of allosteric inhibitors and their mechanism of action against the DENV protease. The developed tool compounds and PAL are potent tools for future drug discovery efforts and investigations targeting the DENV protease.

Resolvin D1 promotes the resolution of inflammation in the ACLF rat model by increasing the proportion of Treg cells.

OBJECTIVE: Acute-on-chronic liver failure (ACLF) causes organ system failures in patients and increases the risk of mortality. One of the main predictors of ACLF development in patients is the severity of systemic inflammation. The purpose of this study was to explore the effects of resolvin D1 (RvD1) on the rat model of ACLF. METHODS: The ACLF rats were induced by first intraperitoneally (ip) injecting CCl4 and porcine serum for 6 weeks to establish the chronic liver injury, followed by once administration (ip) of lipopolysaccharide and d-galactose d-GalN to cause acute liver injury (ALI). An hour before the ALI-induced treatment, rats were administrated (ip) with 0.9% saline or different doses of RvD1 (0.3 or 1 µg/kg). Afterward, the control and treated rats were killed and samples were collected. Biochemical analysis, hematoxylin-eosin and Sirius red staining, flow cytometry assay, and real-time polymerase chain reaction were used to assess the rat liver histopathological injury, the percentage of Treg cells in the spleen, and the messenger RNA (mRNA) levels of transcription factors and immunologic cytokines in liver. RESULTS: The necroinflammatory scores and the serum levels of transaminase significantly increased in ACLF rats compared with those in control rats. These impaired changes observed in ACLF rats could be attenuated by the administration of a low dose of RvD1 before the induction of ALI, which was associated with the increased proportion of regulatory T cells (Treg) in the spleen together with the increased gene expression ratio of Foxp3/RORγt and decreased mRNA level of Il-17a and Il-6 in the liver. CONCLUSION: A low dose of RvD1 can promote the resolution of inflammation in ACLF rats by increasing the proportion of Treg cells. RvD1, therefore, may be used as a potential drug for the treatment of patients with ACLF.

Pitaya Nutrition, Biology, and Biotechnology: A Review.

Pitaya (Hylocereus spp.) is a member of the cactus family that is native to Central and South America but is now cultivated throughout the sub-tropical and tropical regions of the world. It is of great importance due to its nutritional, ornamental, coloring, medicinal, industrial, and high consumption values. In order to effectively utilize and develop the available genetic resources, it is necessary to appreciate and understand studies pertaining to the usage, origin, nutrition, diversity, evaluation, characterization, conservation, taxonomy, and systematics of the genus Hylocereus. Additionally, to gain a basic understanding of the biology of the plant, this review has also discussed how biotechnological tools, such as cell and tissue culture, micropropagation (i.e., somatic embryogenesis, organogenesis, somaclonal variation, mutagenesis, androgenesis, gynogenesis, and altered ploidy), virus-induced gene silencing, and molecular marker technology, have been used to enhance pitaya germplasm.

Hg2+-triggered cascade strand displacement assisted CRISPR-Cas12a for Hg2+ quantitative detection using a portable glucose meter.

CRISPR-Cas12a is a powerful and programmable tool that has revolutionized the field of biosensing. However, the construction of a CRISPR-Cas12a-mediated portable system for on-site and quantitative detection of mercury ion (Hg2+) has yet to be explored. By integrating a target-triggered cascade toehold-mediated strand displacement reaction (TSDR) and CRISPR-Cas12a, we herein construct a portable on-site biosensor for the quantitative, sensitive, and selective detection of Hg2+ with a glucose meter. The Hg2+ initiates two cascade TSDRs through the T-Hg2+-T interaction to produce multiple double-stranded DNAs that can activate Cas12a's trans-cleavage activity. The Cas12a cleaves the sucrase-modified DNA on the electrode, resulting in the liberation of sucrase into the solution. The freed sucrase can catalyze sucrose to generate glucose, which can be quantitatively monitored by a glucometer. The developed portable biosensor provides a dynamic range of 5 orders of magnitude with a detection limit of 40 fM. This biosensor also displays excellent selectivity and stability for detecting Hg2+. Moreover, environmental water samples are utilized to further verify the robustness and effectiveness of the developed biosensor, highlighting its potential application in environmental monitoring and food safety analysis.

hUC-MSC transplantation therapy effects on lupus-prone MRL/lpr mice at early disease stages.

BACKGROUND: The efficacy of human umbilical cord mesenchymal stem cell (hUC-MSC) transplantation in treating systemic lupus erythematosus (SLE) has been confirmed by small-scale clinical trials. However, these trials focused on severe or refractory SLE, while few studies focused on mild SLE. Therefore, this study focused on the therapeutic effects of hUC-MSC transplantation in early-stage or mild MRL/lpr lupus model mice. METHODS: Commercially available hUC-MSCs were transplanted into 8-week-old MRL/lpr mice by tail vein injection. Flow cytometry was used to analyze B cells and their subsets in the peripheral blood. Further, plasma inflammatory factors, autoantibodies, and plasma biochemical indices were detected using protein chip technology and ELISA kits. In addition, pathological staining and immunofluorescence were performed to detect kidney injury in mice. RESULTS: hUC-MSC transplantation did not affect the mice's body weight, and both middle and high dose hUC-MSC transplantation (MD and HD group) actually reduced spleen weight. hUC-MSC transplantation significantly decreased the proportion of plasmablasts (PB), IgG1- PB, IgG1+ PB, IgG1+ memory B (MB) cells, IgG1+ DN MB, and IgG1+ SP MB cells. The hUC-MSC transplantation had significantly reduced plasma levels of inflammatory factors, such as TNF-α, IFN-γ, IL-6, and IL-13. Pathological staining showed that the infiltration of glomerular inflammatory cells was significantly reduced and that the level of glomerular fibrosis was significantly alleviated in hUC-MSC-transplanted mice. Immunofluorescence assays showed that the deposition of IgG and IgM antibodies in the kidneys of hUC-MSC-transplanted mice was significantly lower than in the control. CONCLUSION: hUC-MSC transplantation could inhibit the proliferation and differentiation of peripheral blood B cells in the early-stage of MRL/lpr mice, thereby alleviating the plasma inflammatory environment in mice, leading to kidney injury remission. The study provides a new and feasible strategy for SLE treatment.

Proteome changes of fibroblasts and endothelial cells upon incubation with human cytomegalovirus subviral Dense Bodies.

Human cytomegalovirus (HCMV) is a pathogen of high medical relevance. Subviral Dense Bodies (DB) were developed as a vaccine candidate to ameliorate the severe consequences of HCMV infection. Development of such a candidate vaccine for human application requires detailed knowledge of its interaction with the host. A comprehensive mass spectrometry (MS)- based analysis was performed regarding the changes in the proteome of cell culture cells, exposed to DB.

The Effectiveness of Cognitive Behavioral Therapy for Depression Among Individuals with Diabetes: a Systematic Review and Meta-Analysis.

PURPOSE OF REVIEW: Depression is prevalent and common among individuals living with diabetes. The aim of this review is to systematically assess and meta-analyze the treatment effect of cognitive-behavioral therapy for depression (and other affective outcomes) among patients with diabetes. RECENT FINDINGS: Earlier investigations found both psychosocial and pharmacological interventions, including cognitive-behavioral therapy, were promising in managing depression in patients with diabetes, though these findings remain inclusive due to poor study designs and a small number of trials included, which calls for a comprehensive systematic review and meta-analysis. A total of 33 studies (89 effect sizes) reported a moderate and statistically significant treatment effect of cognitive-behavioral therapy for depressive symptoms among individuals with diabetes (d = 0.301, 95% CI 0.115-0.487, p < 0.001). On average, cognitive-behavioral therapy was effective for psychological stress/distress outcomes but not for anxiety or physiological outcomes. The findings of the study confirmed CBT as an effective treatment option for depression among diabetes patients and identified important areas for future research.

Cargo-selective and adaptive delivery of nucleic acid therapeutics by bola-amphiphilic dendrimers.

Nucleic acid therapeutics are becoming an important drug modality, offering the unique opportunity to address "undruggable" targets, respond rapidly to evolving pathogens, and treat diseases at the gene level for precision medicine. However, nucleic acid therapeutics have poor bioavailability and are chemolabile and enzymolabile, imposing the need for delivery vectors. Dendrimers, by virtue of their well-defined structure and cooperative multivalence, represent precision delivery systems. We synthesized and studied bola-amphiphilic dendrimers for cargo-selective and on-demand delivery of DNA and small interfering RNA (siRNA), both important nucleic acid therapeutics. Remarkably, superior performances were achieved for siRNA delivery with the second-generation dendrimer, yet for DNA delivery with the third generation. We systematically studied these dendrimers with regard to cargo binding, cellular uptake, endosomal release, and in vivo delivery. Differences in size both of the dendrimers and their nucleic acid cargos impacted the cooperative multivalent interactions for cargo binding and release, leading to cargo-adaptive and selective delivery. Moreover, both dendrimers harnessed the advantages of lipid and polymer vectors, while offering nanotechnology-based tumor targeting and redox-responsive cargo release. Notably, they allowed tumor- and cancer cell-specific delivery of siRNA and DNA therapeutics for effective treatment in different cancer models, including aggressive and metastatic malignancies, outperforming the currently available vectors. This study provides avenues to engineer tailor-made vectors for nucleic acid delivery and precision medicine.

Identification of HuSPL family and key role of HuSPL12 in regulation of betalain biosynthesis in pitaya.

The SQUAMOSA promoter binding protein-like (SPL) gene family is a unique family of plant-specific transcription factors (TFs), which plays vital roles in a variety of plant biological processes. Its role in betalain biosynthesis in Hylocereus undantus; however, is still unclear. Here, we report a total of 16 HuSPL genes from the pitaya genome, which were unevenly distributed among nine chromosomes. The HuSPL genes were clustered into seven groups, and most HuSPLs within the same group shared similar exon-intron structures and conserved motifs. Eight segment replication events in the HuSPL gene family were the main driving force behind the gene family expansion. Nine of the HuSPL genes had potential target sites for Hmo-miR156/157b. Hmo-miR156/157b-targeted HuSPLs exhibited differential expression patterns compared with constitutive expression patterns of most Hmo-miR156/157b-nontargeted HuSPLs. The expression of Hmo-miR156/157b gradually increased during fruit maturation, while the expression of Hmo-miR156/157b-targeted HuSPL5/11/14 gradually decreased. In addition, the lowest expression level of Hmo-miR156/157b-targeted HuSPL12 was detected 23rd day after flowering, when the middle pulps started to turn red. HuSPL5, HuSPL11, HuSPL12, and HuSPL14 were nucleus-localized proteins. HuSPL12 could inhibit the expression of HuWRKY40 by binding to its promoter. Results from yeast two-hybrid and bimolecular fluorescence complementation assays showed that HuSPL12 could interact with HuMYB1, HuMYB132, or HuWRKY42 TFs responsible for betalain biosynthesis. The results of the present study provide an essential basis for future regulation of betalain accumulation in pitaya.