Broad-Spectrum Inhibitors for Conserved Unique Phosphoethanolamine Methyltransferases in Parasitic Nematodes Possess Anthelmintic Efficacy.

In humans, nematode infections are prevalent in developing countries, causing long-term ill health, particularly in children. Worldwide, nematode infections are prevalent in livestock and pets, affecting productivity and health. Anthelmintic drugs are the primary means of controlling nematodes, but there is now high prevalence of anthelmintic resistance, requiring urgent identification of new molecular targets for anthelmintics with novel mechanisms of action. Here, we identified orthologous genes for phosphoethanolamine methyltransferases (PMTs) in nematodes within the families Trichostrongylidae, Dictyocaulidae, Chabertiidae, Ancylostomatoidea, and Ascarididae. We characterized these putative PMTs and found that they possess bona fide PMT catalytic activities. By complementing a mutant yeast strain lacking the ability to synthesize phosphatidylcholine, the PMTs were validated to catalyze the biosynthesis of phosphatidylcholine. Using an in vitro phosphoethanolamine methyltransferase assay with PMTs as enzymes, we identified compounds with cross-inhibitory effects against the PMTs. Corroboratively, treatment of PMT-complemented yeast with the PMT inhibitors blocked growth of the yeast, underscoring the essential role of the PMTs in phosphatidylcholine synthesis. Fifteen of the inhibitors with the highest activity against complemented yeast were tested against Haemonchus contortus using larval development and motility assays. Among them, four were found to possess potent anthelmintic activity against both multiple drug-resistant and susceptible isolates of H. contortus, with IC50 values (95% confidence interval) of 4.30 µM (2.15-8.28), 4.46 µM (3.22-6.16), 28.7 µM (17.3-49.5), and 0.65 µM (0.21-1.88). Taken together, we have validated a molecular target conserved in a broad range of nematodes and identified its inhibitors that possess potent in vitro anthelmintic activity.

Nobiletin protects retinal ganglion cells in models of ocular hypertension in vivo and hypoxia in vitro.

Glaucoma, a common cause of blindness, is characterized by the progressive loss of retinal ganglion cells (RGCs). Growing evidence suggests that nobiletin (NOB) is a promising neuroprotective drug; however, its effects on glaucomatous neurodegeneration remain unknown. Using rat models of microbead occlusion in vivo and primary RGCs model of hypoxia in vitro, we first demonstrate that NOB reduces RGC apoptosis by a TUNEL assay, Hoechst 33342 staining and FluoroGold (FG) retrograde labeling. This effect does not depend on intraocular pressure (IOP) lowering. Additionally, NOB partially restored the functional and structural damage of inner retinas, attenuated Müller glial activation and oxidative stress caused by ocular hypertension. At 2 weeks after IOP elevation, NOB further enhanced Nrf2/HO-1 pathway in RGCs to withstand the cumulative damage of ocular hypertension. With the administration of HO-1 inhibitor tin-protoporphyrin IX (SnPP), the protective effect of NOB was attenuated. Overall, these results indicate that NOB exerts an outstanding neuroprotective effect on RGCs of glaucomatous neurodegeneration. Besides, interventions to enhance activation of Nrf2/HO-1 pathway can slow the loss of RGCs and are viable therapies for glaucoma.

Novel lactate dehydrogenase inhibitors with in vivo efficacy against Cryptosporidium parvum.

Cryptosporidium parvum is a highly prevalent zoonotic and anthroponotic protozoan parasite that causes a diarrheal syndrome in children and neonatal livestock, culminating in growth retardation and mortalities. Despite the high prevalence of C. parvum, there are no fully effective and safe drugs for treating infections, and there is no vaccine. We have previously reported that the bacterial-like C. parvum lactate dehydrogenase (CpLDH) enzyme is essential for survival, virulence and growth of C. parvum in vitro and in vivo. In the present study, we screened compound libraries and identified inhibitors against the enzymatic activity of recombinant CpLDH protein in vitro. We tested the inhibitors for anti-Cryptosporidium effect using in vitro infection assays of HCT-8 cells monolayers and identified compounds NSC158011 and NSC10447 that inhibited the proliferation of intracellular C. parvum in vitro, with IC50 values of 14.88 and 72.65 µM, respectively. At doses tolerable in mice, we found that both NSC158011 and NSC10447 consistently significantly reduced the shedding of C. parvum oocysts in infected immunocompromised mice's feces, and prevented intestinal villous atrophy as well as mucosal erosion due to C. parvum. Together, our findings have unveiled promising anti-Cryptosporidium drug candidates that can be explored further for the development of the much needed novel therapeutic agents against C. parvum infections.

Particle trapping and beaming using a 3D nanotip excited with a plasmonic vortex.

Recent advances in nanotechnology have prompted the need for tools to accurately and noninvasively manipulate individual nano-objects. Among the possible strategies, optical forces have been widely used to enable nano-optical tweezers capable of trapping or moving a specimen with unprecedented accuracy. Here, we propose an architecture consisting of a nanotip excited with a plasmonic vortex enabling effective dynamic control of nanoparticles in three dimensions. The structure illuminated by a beam with angular momentum can generate an optical field that can be used to manipulate single dielectric nanoparticles. We demonstrate that it is possible to stably trap or push the particle from specific points, thus enabling a new, to the best of our knowledge, platform for nanoparticle manipulation.

Neuroprotective effects of DAAO are mediated via the ERK1/2 signaling pathway in a glaucomatous animal model.

Neuronal excitotoxicity caused by over activation of N -Methyl-D-Aspartate (NMDA) receptors is an important risk factor for the retinal ganglion cells (RGCs) death in glaucoma. D-serine played a role as a key co-agonist for NMDA receptor activity and neurotoxicity. Our previous studies have demonstrated that increased D-serine and serine racemase (SR) expression in the retina of the chronic intraocular hypertension (COH) model were detected. D-amino acid oxidase (DAAO) treatment significantly increased RGCs survival in the glaucomatous eyes. However, the molecular mechanism remains unclear. In the present study, we investigated the extracellular signal-regulated protein kinase1/2 (ERK1/2) signaling pathway involved in DAAO neuroprotective effects on RGC survival and explore the effect of inhibited ERK1/2 phosphorylation on RGC survival and Müller cell activation in a COH rat model. We found that ERK1/2 phosphorylation and p38 kinase (p38) phosphorylation increased in the COH model, while c-Jun N-terminal kinase (JNK) phosphorylation didn't change. DAAO treatment induced ERK-1/2 MAP kinase phosphorylation and its upstream regulator, p-MEK increased in the COH model. The increased p-ERK was mainly located in retinal Müller cells. In contrast, p-JNK and p-p38 protein expression was not significantly different under these conditions. Quantitative analysis of RGC survival by fluorescent labeling and TdT-mediated dUTP nick-end labeling (TUNEL) assays confirmed that p-ERK1/2 inhibition by PD98059 attenuates DAAO-mediated reductions in RGC apoptosis. Additionally, p-ERK1/2 inhibition induced elevated glial fibrillary acidic protein (GFAP) expression in Müller cells in the COH model. Together, these results suggest that the ERK1/2 signaling pathway is involved in DAAO's neuroprotective effects on RGC survival.

Small GTPase Immunity-Associated Proteins Mediate Resistance to Toxoplasma gondii Infection in Lewis Rat.

Rats vary in their susceptibilities to Toxoplasma gondii infection depending on the rat strain. Compared to the T. gondii-susceptible Brown Norway (BN) rat, the Lewis (LEW) rat is extremely resistant to T. gondii Thus, these two rat strains are ideal models for elucidating host mechanisms that are important for host resistance to T. gondii infection. Therefore, in our efforts to unravel molecular factors directing the protective early innate immune response in the LEW rat, we performed RNA sequencing analysis of the LEW versus BN rat with or without T. gondii infection. We identified three candidate small GTPase immunity-associated proteins (GIMAPs) that were upregulated (false discovery rate, 0.05) in the LEW rat in response to T. gondii infection. Subsequently, we engineered T. gondii-susceptible NR8383 rat macrophage cells for overexpression of LEW rat-derived candidate GIMAP 4, 5, and 6. By immunofluorescence analysis we observed that GIMAP 4, 5, and 6 in T. gondii-infected NR8383 cells each colocalized with GRA5, a parasite parasitophorous vacuole membrane (PVM) marker protein, suggesting their translocation to the PVM. Interestingly, overexpression of each candidate GIMAP in T. gondii-infected NR8383 cells induced translocation of LAMP1, a lysosome marker protein, to the T. gondii surface membrane. Importantly, overexpression of GIMAP 4, 5, or 6 individually inhibited intracellular T. gondii growth, with GIMAP 4 having the highest inhibitory effect. Together, our findings indicate that upregulation of GIMAP 4, 5, and 6 contributes to the robust refractoriness of the LEW rat to T. gondii through induction of lysosomal fusion to the otherwise nonfusogenic PVM.

Quasi-phase-matched second harmonic generation of long-range surface plasmon polaritons.

In this paper, we experimentally demonstrate the second harmonic generation of long-range surface plasmon polaritons via quasi-phase matching in lithium niobate. After depositing a 9/13 nm thick Au film on periodically poled lithium niobate, TiO2 of about 2.3 µm in thickness is evaporated on the sample as a refractive-index-matching material. This dielectric (periodically poled lithium niobate)-metal(Au)-dielectric(TiO2) sandwich structure can support the transmission of long-range surface plasmon polaritons through it. By designing a moderate ferroelectric domain period of periodically poled lithium niobate, the phase mismatch between the fundamental wave and second harmonic wave of the long-range surface plasmon polaritons can be compensated and a second harmonic wave can be generated effectively. This can be used to provide integrated plasmonic devices with attractive applications in quantum and classic information processing.

Inherent Oxidative Stress in the Lewis Rat Is Associated with Resistance to Toxoplasmosis.

The course of Toxoplasma gondii infection in rats closely resembles that in humans. However, compared to the Brown Norway (BN) rat, the Lewis (LEW) rat is extremely resistant to T. gondii infection. Thus, we performed RNA sequencing analysis of the LEW rat versus the BN rat, with or without T. gondii infection, in order to unravel molecular factors directing robust and rapid early T. gondii-killing mechanisms in the LEW rat. We found that compared to the uninfected BN rat, the uninfected LEW rat has inherently higher transcript levels of cytochrome enzymes (Cyp2d3, Cyp2d5, and Cybrd1, which catalyze generation of reactive oxygen species [ROS]), with concomitant higher levels of ROS. Interestingly, despite having higher levels of ROS, the LEW rat had lower transcript levels for antioxidant enzymes (lactoperoxidase, microsomal glutathione S-transferase 2 and 3, glutathione S-transferase peroxidase kappa 1, and glutathione peroxidase) than the BN rat, suggesting that the LEW rat maintains cellular oxidative stress that it tolerates. Corroboratively, we found that scavenging of superoxide anion by Mn(III) tetrakis (4-benzoic acid) porphyrin (MnTBAP) decreased the refractoriness of LEW rat peritoneal cells to T. gondii infection, resulting in proliferation of parasites in LEW rat peritoneal cells which, in turn, led to augmented cell death in the infected cells. Together, our results indicate that the LEW rat maintains inherent cellular oxidative stress that contributes to resistance to invading T. gondii, and they thus unveil new avenues for developing therapeutic agents targeting induction of host cell oxidative stress as a mechanism for killing T. gondii.

Comparative transcriptome analysis reveals differentially expressed genes associated with sex expression in garden asparagus (Asparagus officinalis).

BACKGROUND: Garden asparagus (Asparagus officinalis) is a highly valuable vegetable crop of commercial and nutritional interest. It is also commonly used to investigate the mechanisms of sex determination and differentiation in plants. However, the sex expression mechanisms in asparagus remain poorly understood. RESULTS: De novo transcriptome sequencing via Illumina paired-end sequencing revealed more than 26 billion bases of high-quality sequence data from male and female asparagus flower buds. A total of 72,626 unigenes with an average length of 979 bp were assembled. In comparative transcriptome analysis, 4876 differentially expressed genes (DEGs) were identified in the possible sex-determining stage of female and male/supermale flower buds. Of these DEGs, 433, including 285 male/supermale-biased and 149 female-biased genes, were annotated as flower related. Of the male/supermale-biased flower-related genes, 102 were probably involved in anther development. In addition, 43 DEGs implicated in hormone response and biosynthesis putatively associated with sex expression and reproduction were discovered. Moreover, 128 transcription factor (TF)-related genes belonging to various families were found to be differentially expressed, and this finding implied the essential roles of TF in sex determination or differentiation in asparagus. Correlation analysis indicated that miRNA-DEG pairs were also implicated in asparagus sexual development. CONCLUSIONS: Our study identified a large number of DEGs involved in the sex expression and reproduction of asparagus, including known genes participating in plant reproduction, plant hormone signaling, TF encoding, and genes with unclear functions. We also found that miRNAs might be involved in the sex differentiation process. Our study could provide a valuable basis for further investigations on the regulatory networks of sex determination and differentiation in asparagus and facilitate further genetic and genomic studies on this dioecious species.

Integrated Nanozymes with Nanoscale Proximity for in Vivo Neurochemical Monitoring in Living Brains.

Nanozymes, the nanostructures with enzymatic activities, have attracted considerable attention because, in comparison with natural enzymes, they offer the possibility of lowered cost, improved stability, and excellent recyclability. However, the specificity and catalytic activity of current nanozymes are still far lower than that of their natural counterparts, which in turn has limited their use such as in bioanalysis. To address these challenges, herein we report the design and development of integrated nanozymes (INAzymes) by simultaneously embedding two cascade catalysts (i.e., a molecular catalyst hemin and a natural enzyme glucose oxidase, GOx) inside zeolitic imidazolate framework (ZIF-8) nanostructures. Such integrated design endowed the INAzymes with major advantage in improved catalytic efficiency as the first enzymatic reaction occurred in close (nanoscale) proximity to the second enzyme, so products of the first reaction can be used immediately as substrates for the second reaction, thus overcoming the problems of diffusion-limited kinetics and product instability. The considerable high catalytic activity and stability enabled the INAzymes to efficiently draw a colorimetric detection of glucose with good sensitivity and selectivity. When facilitated with in vivo microdialysis, the INAzyme was successfully used for facile colorimetric visualization of cerebral glucose in the brain of living rats. Moreover, when further combined with microfluidic technology, an integrative INAzyme-based online in vivo analytical platform was constructed. The promising application of the platform was successfully illustrated by continuously monitoring the dynamic changes of striatum glucose in living rats' brain following ischemia/reperfusion. This study developed a useful approach to not only functional nanomaterial design but also advanced platforms developments for diverse targets monitoring.

Polarization-independent broadband plasmonic absorber based on a silicon-nanowire array decorated by gold nanoparticles at the optical regime.

We present a design for a plasmonic absorber that is composed of a hexagonal-packed silicon nanowires (SiNWs) array with gold nanoparticles (AuNPs) decoration. Simulations and experiments demonstrated that the proposed absorber achieves a broadband absorption. Its bandwidth over an absorption of 80% ranges from 400 nm to 1000 nm at 0 degree to 30 degrees incidence. It was also demonstrated that the plasmonic absorber is polarization-insensitive. Analyzing the field distributions in the structure, we find that the wideband absorption is ascribed to the formation of cavity modes in the SiNWs and surface plasmon polaritons on the AuNPs. Such a designed plasmonic structure with high-efficiency absorption can be served as a good optical absorber.

Genes encoding Δ(8)-sphingolipid desaturase from various plants: identification, biochemical functions, and evolution.

∆(8)-sphingolipid desaturase catalyzes the C8 desaturation of a long chain base, which is the characteristic structure of various complex sphingolipids. The genes of 20 ∆(8)-sphingolipid desaturases from 12 plants were identified and functionally detected by using Saccharomyces cerevisiae system to elucidate the relationship between the biochemical function and evolution of this enzyme. Results showed that the 20 genes all can encode a functional ∆(8)-sphingolipid desaturase, which catalyzes different ratios of two products, namely, 8(Z) and 8(E)-C18-phytosphingenine. The coded enzymes could be divided into two groups on the basis of biochemical functions: ∆(8)-sphingolipid desaturase with a preference for an E-isomer product and ∆(8)-sphingolipid desaturase with a preference for a Z-isomer product. The conversion rate of the latter was generally lower than that of the former. Phylogenetic analysis revealed that the 20 desaturases could also be clustered into two groups, and this grouping is consistent with that of the biochemical functions. Thus, the biochemical function of ∆(8)-sphingolipid desaturase is correlated with its evolution. The two groups of ∆(8)-sphingolipid desaturases could arise from distinct ancestors in higher plants. However, they might have initially evolved from ∆(8)-sphingolipid desaturases in lower organisms, such as yeasts, which can produce E-isomer products only. Furthermore, almost all of the transgenic yeasts harboring ∆(8)-sphingolipid desaturase genes exhibit an improvement in aluminum tolerance. Our study provided new insights into the biochemical function and evolution of ∆(8)-sphingolipid desaturases in plants.

Lead Discovery of Type II BRAF V600E Inhibitors Targeting the Structurally Validated DFG-Out Conformation Based upon Selected Fragments.

The success of the first approved kinase inhibitor imatinib has spurred great interest in the development of type II inhibitors targeting the inactive DFG-out conformation, wherein the Phe of the DFG motif at the start of the activation loop points into the ATP binding site. Nevertheless, kinase inhibitors launched so far are heavily biased toward type I inhibitors targeting the active DFG-in conformation, wherein the Phe of the DFG motif flips by approximately 180° relative to the inactive conformation, resulting in Phe and Asp swapping their positions. Data recently obtained with structurally validated type II inhibitors supported the conclusion that type II inhibitors are more selective than type I inhibitors. In our type II BRAF V600E inhibitor lead discovery effort, we identified phenylaminopyrimidine (PAP) and unsymmetrically disubstituted urea as two fragments that are frequently presented in FDA-approved protein kinase inhibitors. We therefore defined PAP and unsymmetrically disubstituted urea as privileged fragments for kinase drug discovery. A pharmacophore for type II inhibitors, 4-phenylaminopyrimidine urea (4-PAPU), was assembled based upon these privileged fragments. Lead compound SI-046 with BRAF V600E inhibitory activity comparable to the template compound sorafenib was in turn obtained through preliminary structure-activity relationship (SAR) study. Molecular docking suggested that SI-046 is a bona fide type II kinase inhibitor binding to the structurally validated "classical DFG-out" conformation of BRAF V600E. Our privileged fragments-based approach was shown to efficiently deliver a bona fide type II kinase inhibitor lead. In essence, the theme of this article is to showcase the strategy and rationale of our approach.

Intermolecular Sulfur···Oxygen Interactions: Theoretical and Statistical Investigations.

Intermolecular S···O interactions are very common and are important in biological systems, but until recently, the presence of these contacts in protein-ligand systems largely depended on serendipitous discovery instead of rational design. Here we provide insight into the phenomenon of intermolecular S···O contacts by focusing on three sulfur-containing aromatic rings. Quantum mechanics is employed to characterize the strength and directionality of the S···O interactions and to determine their energy dependence on their geometric parameters. Protein Data Bank mining is performed to systematically determine the occurrence and geometry of intermolecular S···O interactions, and several representative examples are discussed. Three typical cases are investigated using a combined quantum mechanics/molecular mechanics approach to demonstrate the potential of these interactions in improving binding affinities and physiochemical properties. Overall, our work elucidates the structures and energy features of intermolecular S···O interactions and addresses their use in molecular design.

Current insights into computer-aided immunotherapeutic design strategies.

Drug designing costs as well as design of immunotherapeutic agents could be nearly halved through the involvement of computer-aided drug designing methods in discovery and research. The inter-disciplinary, time-, and money-consuming process of drug discovery is amended by the development of drug designing, the technique of creating or finding a molecule that can render stimulatory or inhibitory activity upon various biological organisms. Meanwhile, the advancements made within this scientific domain in the last couple of decades have significantly modified and affected the way new bioactive molecules have been produced by the pharmaceutical industry. In this regard, improvements made in hardware solutions and computational techniques along with their efficient integration with biological processes have revolutionized the in silico methods in speeding up the lead identification and optimization processes. In this review, we will discuss various methods of recent computer-aided drug designing techniques that forms the basis of modern day drug discovery projects.

[Lymphoplasmacytic lymphoma/Waldenström macroglobulinemia with P53 deletion and TCR-delta rearrangement in a case].

OBJECTIVE To study the morphology, immunology, cyto- and molecular genetics of a patient with lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM), deletion of P53 gene and rearrangement of clonal T cell receptors-delta (TCR-delta) gene. METHODS The cell morphology and immunocytochemistry were analyzed by bone marrow testing and biopsy. Cellular immunology was analyzed by flow cytometry. Genetic analysis was carried out by chromosome karyotyping, fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR). Immunoglobulin M (IgM) in serum and urine was assayed by immunofixation electrophoresis. And the effect of chlorambucil therapy was evaluated. RESULTS Bone marrow biopsy suggested that the patient was of B lymphocyte type and had abnormal increase of lymphocytoid plasma cells, which were CD38 and CD138 positive. The patient had a normal male karyotype. FISH and PCR analysis of peripheral blood samples suggested deletion of P53 gene and rearrangement of TCR-delta gene. Immunofixation electrophoresis has detected IgM-kappa in both serum and urine. The patient showed partial response to chlorambucil. CONCLUSION In addition to typical clinical features, bone marrow examination, flow cytometry, histochemistry and immunophenotyping, testing for P53 gene deletion and lymphocyte gene rearrangement can facilitate the diagnosis and treatment of LPL/WM.

Asymmetric transmission and optical rotation of a quasi-3D asymmetric metallic structure.

Three-dimensional (3D) asymmetric plasmonic structures possessing asymmetric optical transmission properties have been widely studied. However, these structures have limitations for application due to fabrication techniques. Here, a quasi-3D asymmetric structure built up by a metallic rod-shaped particles layer and a metallic L-shaped holes layer was fabricated by the sputtering and the focused ion beam (FIB) milling. A broadband (1000-1600 nm) asymmetric transmission and optical rotation have been demonstrated experimentally. Numerical calculations show that the coupling between the cavity and particle plasmonic resonances contributes to this effect.

Amplified spontaneous emission via the coupling between Fabry-Perot cavity and surface plasmon polariton modes.

We demonstrated amplified spontaneous emission by embedding dye molecules within a dielectric layer of a metal-dielectric-metal subwavelength structure. It was reinforced when a strong coupling occurred between the Fabry-Perot mode supported by the dielectric layer and the surface plasmon polariton mode supported by the adjacent metallic grating. Here, we adjust the two mode interaction via tuning the depth of the metallic grating grooves. The stronger the interaction, the smaller the full width at half-maximum of the emission spectra and the lower the threshold of the amplified spontaneous emission.

Ordered Ag/Si nanowires array: wide-range surface-enhanced Raman spectroscopy for reproducible biomolecule detection.

Surface-enhanced Raman scattering (SERS) systems utilizing the interparticle nanogaps as hot spots have demonstrated ultrasensitive single-molecule detection with excellent selectivity yet the electric fields are too confined in the small nanogaps to enable reproducible biomolecule detections. Here, guided by finite-difference-time-domain simulation, we report hexagonal-packed silver-coated silicon nanowire (Ag/SiNW) arrays as a nanogap-free SERS system with wide-range electric fields and controlled interwire separation. Significantly, the system achieves a SERS detection of long double-strand DNA of 25-50 nm in length with a relative standard deviation (RSD) of 14% for measurements of above 4000 spots over an area of 200 × 200 µm(2). The high reproducibility in the SERS detection is attributed to (1) the large interwire spacing of 150 nm that allows access and excitation of large biomolecules; and (2) 600 nm wide-range electric field generated by propagating surface plasmons along the surface of continuous Ag coating on a SiNW. Moreover, a reproducible multiplex SERS measurement is also demonstrated with RSDs of 7-16% with an enhancement factor of ~10(6). The above results show that the ordered Ag/SiNW array system may serve as an excellent SERS platform for practical chemical and biological detection.

A review on the calculation and application of lignin Hansen solubility parameters.

Hansen solubility parameters (HSPs) play a critical role in the majority of processes involving lignin depolymerization, separation, fractionation, and polymer blending, which are directly related to dissolution properties. However, the calculation of lignin HSPs is highly complicated due to the diversity of sources and the complexity of lignin structures. Despite their important role, lignin HSPs have been undervalued, attracting insufficient attention. This review summarizes the calculation methods for lignin HSPs and proposes a straightforward method based on lignin subunits. Furthermore, it highlights the crucial applications of lignin HSPs, such as identifying ideal solvents for lignin dissolution, selecting suitable solvents for lignin depolymerization and extraction, designing green solvents for lignin fractionation, and guiding the preparation of lignin-based composites. For instance, leveraging HSPs to design a series of solvents could potentially achieve sequential controllable lignin fractionation, addressing issues of low value-added applications of lignin resulting from poor homogeneity. Notably, HSPs serve as valuable tools for understanding the dissolution behavior of lignin. Consequently, we expect this review to be of great interest to researchers specializing in lignin and other macromolecules.