Heat Shock Protein Research Articles

BiP Proteins from Symbiodiniaceae: A “Shocking” Story

More than four decades ago, the discovery of a companion protein of immunoglobulins in myeloma cells and soon after, of their ability to associate with heavy chains, made the term immunoglobulin binding protein (BiP) emerge, prompting a tremendous amount of effort to understand their versatile cellular functions. BiPs belong to the heat shock protein (Hsp) 70 family and are crucial for protein folding and cellular stress responses. While extensively studied in model organisms such as Chlamydomonas, their roles in dinoflagellates, especially in photosynthetic Symbiodiniaceae, remain largely underexplored. Given the importance of Symbiodiniaceae-cnidarian symbiosis, critical for the sustaining of coral reef ecosystems, understanding the contribution of Hsps to stress resilience is essential; however, most studies have focused on Hsps in general but none on BiPs. Moreover, despite the critical role of light in the physiology of these organisms, research on light effects on BiPs from Symbiodiniaceae has also been limited. This review synthesizes the current knowledge from the literature and sequence data, which reveals a high degree of BiP conservation at the gene, protein, and structural levels in Symbiodiniaceae and other dinoflagellates. Additionally, we show the existence of a potential link between circadian clocks and BiP regulation, which would add another level of regulatory complexity. The evolutionary relationship among dinoflagellates overall suggests conserved functions and regulatory mechanisms, albeit expecting confirmation by experimental validation. Finally, our analysis also highlights the significant knowledge gap and underscores the need for further studies focusing on gene and protein regulation, promoter architecture, and structural conservation of Symbiodiniaceae and dinoglagellate BiPs in general. These will deepen our understanding of the role of BiPs in the Symbiodiniaceae-cnidarian interactions and dinoflagellate physiology.

Trichophyton indotineae Erg1Ala448Thr Strain Expressed Constitutively High Levels of Sterol 14-α Demethylase Erg11B mRNA, While Transporter MDR3 and Erg11A mRNA Expression Was Induced After Addition of Short Chain Azoles

Trichophyton indotineae is an emerging pathogen causing recalcitrant skin infections and exhibiting multiple resistances to azoles and allylamines. Squalene epoxidase erg1Ala448Thr mutants often show association with azole resistance. RT-PCR gene expression analysis helps to elucidate the connection between ergosterol biosynthesis regulation and efflux control through the activation of multidrug resistance (MDR) and major facilitator superfamily (MFS1) transporters as well as heat shock proteins (HSP). Several T. indotineae isolates demonstrated a heat-dependent increase of Erg11B transcripts combined with downregulation of Erg1, suggesting a protective role for Erg11B. They also showed persistent upregulation of MFS1. The addition of fluconazole or voriconazole induced the expression of Erg11A, MDR3 and, to a lesser extent, Erg11B and Erg1. The azole-resistant erg1Ala448Thr mutant UKJ 476/21 exhibited exceptionally high transcript levels of sterol 14-αdemethylase Erg11B, combined with the inability of HSP60 and HSP90 to respond to increasing growth temperatures. Itraconazole demonstrated similar effects in a few T. indotineae isolates, but terbinafine did not enhance Erg1 transcription at all. Overexpression of Erg11B may explain the multiple azole resistance phenotype, whereas Erg11B point mutations are not associated with resistance to azoles used for medical treatment.

Small heat shock protein B8: from cell functions to its involvement in diseases and potential therapeutic applications.

Heat shock protein family B (small) member 8 (HSPB8) is a 22 kDa ubiquitously expressed protein belonging to the family of small heat shock proteins. HSPB8 is involved in various cellular mechanisms mainly related to proteotoxic stress response and in other processes such as inflammation, cell division, and migration. HSPB8 binds misfolded clients to prevent their aggregation by assisting protein refolding or degradation through chaperone-assisted selective autophagy. In line with this function, the pro-degradative activity of HSPB8 has been found protective in several neurodegenerative and neuromuscular diseases characterized by protein misfolding and aggregation. In cancer, HSPB8 has a dual role being capable of exerting either a pro-or an anti-tumoral activity depending on the pathways and factors expressed by the model of cancer under investigation. Moreover, HSPB8 exerts a protective function in different diseases by modulating the inflammatory response, which characterizes not only neurodegenerative diseases, but also other chronic or acute conditions affecting the nervous system, such as multiple sclerosis and intracerebellar hemorrhage. Of note, HSPB8 modulation may represent a therapeutic approach in other neurological conditions that develop as a secondary consequence of other diseases. This is the case of cognitive impairment related to diabetes mellitus, in which HSPB8 exerts a protective activity by assuring mitochondrial homeostasis.This review aims to summarize the diverse and multiple functions of HSPB8 in different pathological conditions, focusing on the beneficial effects of its modulation. Drug-based and alternative therapeutic approaches targeting HSPB8 and its regulated pathways will be discussed, emphasizing how new strategies for cell and tissue-specific delivery represent an avenue to advance in disease treatments.

Downregulation of heat shock protein 47 caused lysosomal dysfunction leading to excessive chondrocyte apoptosis

Heat shock protein 47 (HSP47) is a collagen-specific chaperone present in several regions of the endoplasmic reticulum and cytoplasm. Elevated HSP47 expression in cells causes various cancers and fibrotic disorders. However, the consequences of HSP47 downregulation leading to chondrocyte death, as well as the underlying pathways, remain largely unclear. This study presents the first experimental evidence of the localization of HSP47 on lysosomes. Additionally, it successfully designed and generated shRNA HSP47 target sequences to suppress the expression of HSP47 in ATDC5 chondrocytes using lentiviral vectors. By employing a chondrocyte model that has undergone stable downregulation of HSP47, we observed that HSP47 downregulation in chondrocytes, disturbs the acidic homeostatic environment of chondrocyte lysosomes, causes hydrolytic enzyme activity dysregulation, impairs the lysosome-mediated autophagy-lysosome pathway, and causes abnormal expression of lysosomal morphology, number, and functional effector proteins. This implies the significance of the presence of HSP47 in maintaining proper lysosomal function. Significantly, the inhibitor CA-074 Me, which can restore the dysfunction of lysosomes, successfully reversed the negative effects of HSP47 on the autophagy-lysosomal pathway and partially reduced the occurrence of excessive cell death in chondrocytes. This suggests that maintaining proper lysosomal function is crucial for preventing HSP47-induced apoptosis in chondrocytes. The existence of HSP47 is crucial for preserving optimal lysosomal function and autophagic flux, while also inhibiting excessive apoptosis in ATDC5 chondrocytes.

DTALE approach demonstrates that induction of common bean OVATE Family Protein 7 (PvOFP7) promotes resistance to common bacterial blight

Abstract Common bacterial blight of bean (CBB) is a devastating seed-transmitted disease caused by Xanthomonas phaseoli pv. phaseoli and Xanthomonas citri pv. fuscans on common bean (Phaseolus vulgaris L.). The genes responsible for CBB resistance are largely unknown. Moreover, the lack of a reproducible and universal transformation protocol limits the study of genetic traits in common bean. We produced X. phaseoli pv. phaseoli strains expressing artificially-designed Transcription-Activator Like Effectors (dTALEs) to target 14 candidate genes for resistance to CBB based on previous transcriptomic data. In planta assays in a susceptible common bean genotype showed that induction of PvOFP7, PvAP2-ERF71 or PvExpansinA17 expression by dTALEs resulted in CBB symptom reduction. After PvOFP7 induction, in planta bacterial growth was reduced at early colonisation stages and RNA-Seq analysis revealed up-regulation of cell wall formation and primary metabolism, together with major down-regulation of Heat Shock Proteins. Our results demonstrate that PvOFP7 contributes to CBB resistance, and underline the usefulness of dTALEs for functional validation of genes whose induction impacts Xanthomonas-plant interaction.

HIP is involved in NaCl and endoplasmic reticulum stress resistance in Arabidopsis

Heat shock protein 70 (HSP70)-interacting proteins (HIPs) have been studied in animals. HIPs perform diverse cellular functions, ranging from alleviating stress to suppressing the formation of insoluble protein, but how their orthologs function in plants is less known. This study shows that Arabidopsis HIP is a cytosolic and nuclear protein associated with HSP70. The hip mutants showed compromised tolerance to NaCl and endoplasmic reticulum (ER) stress, although they grew normally under standard growth conditions. Furthermore, hip mutants presented a decreased HSP70 level compared with the wild type under NaCl and ER stress conditions. These findings suggest the involvement of HIP in NaCl and ER stress tolerance.

AtZAT10/STZ1 improves drought tolerance and increases fiber yield in cotton.

Drought poses a significant challenge to global crop productivity, necessitating innovative approaches to bolster plant resilience. Leveraging transgenic technology to bolster drought tolerance in crops emerges as a promising strategy for addressing the demands of a rapidly growing global populace. AtZAT10/STZ1, a C2H2-type zinc finger protein transcription factor has shown to significantly improve Arabidopsis' tolerance to various abiotic stresses. In this study, we reports that AtSTZ1 confers notable drought resistance in upland cotton (Gossypium hirsutum), amplifying cotton fiber yield under varying conditions, including irrigated and water-limited environments, in field trials. Notably, AtSTZ1-overexpressing transgenic cotton showcases enhanced drought resilience across critical growth stages, including seed germination, seedling establishment, and reproductive phases. Morphological analysis reveals an expanded root system characterized by an elongated taproot system, increased lateral roots, augmented root biomass, and enlarged cell dimensions from transgenic cotton plants. Additionally, higher contents of proline, chlorophyll, soluble sugars, and enhanced ROS-scavenging enzyme activities are observed in leaves of transgenic plants subjected to drought, underscoring improved physiological adaptations. Furthermore, transgenic lines exhibit heightened photosynthetic rate, increased water use efficiency, and larger stomatal and epidermal cell sizes, coupled with a decline in leaf stomatal conductance and density, as well as diminished transpiration rates compared to the wild type counterparts. Transcriptome profiling unveils 106 differentially expressed genes in transgenic cotton leaves post-drought treatment, including protein kinases, transcription factors, aquaporins, and heat shock proteins, indicative of an orchestrated stress response. Collectively, these findings underscore the capacity of AtSTZ1 to augment the expression of abiotic stress-related genes in cotton following drought conditions, thus presenting a compelling candidate for genetic manipulation aimed at enhancing crop resilience.

Asparagine614 Determines the Transport and Function of the Murine Anti-Aging Protein Klotho.

Klotho is an anti-aging protein whose deletion significantly reduces lifespan in mice, while its over-expression increases lifespan. Klotho is a type-I transmembrane protein that is N-glycosylated at eight positions within its ectodomain. Our study demonstrates that N-glycosylation or mutation at position N614, but not at N161, N285, or N346 in mouse Klotho, is critically involved in the transport of Klotho out of the endoplasmic reticulum (ER). Consequently, while wild-type Klotho-EGFP as well as the N-glycosylation mutants N161Q, N285Q, and N346Q were present at the plasma membrane (PM), only small amounts of the N614Q Klotho-EGFP were present at the PM, with most of the protein accumulating in the ER. Protein interactome analysis of Klotho-EGFP N614Q revealed increased interactions with proteasome-related proteins and proteins involved in ER protein processing, like heat shock proteins and protein disulfide isomerases, indicative of impaired protein folding. Co-immunoprecipitation experiments confirmed the interaction of Klotho-EGFP N614Q with ER chaperons. Interestingly, despite the low amounts of Klotho-EGFP N614Q at the PM, it efficiently induced FGF receptor-mediated ERK activation in the presence of FGF23, highlighting its efficacy in triggering downstream signaling, even in limited quantities at the PM.

Hidden pathogen risk in mature compost: Low optimal growth temperature confers pathogen survival and activity during manure composting

Livestock manure is a major reservoir for pathogens, posing significant environmental risks if used untreated. The efficacy of composting in fully inactivating pathogens remains controversial, particularly regarding the influence of their optimal growth temperature (OGT). This study investigated the composition and dynamic changes of pathogen communities and virulence factors (VFs) during the composting of chicken, bovine, ovine, and swine manure. We identified 134 pathogens across 16 composting piles, with ten pathogens exhibited increased abundance and transcriptional activity in curing phase. They included high-risk VFs-carrying pathogens, such as Mycolicibacterium thermoresistibile and Mycolicibacterium phlei, indicating the hidden pathogen risk in mature compost. Community-scale analyses revealed a linkage of these pathogens’ survival with their low OGT and an increased number of heat shock proteins (HSPs), enabling them to tolerate high temperatures and regrow. Integrating our data with prior composting studies, we found that the surviving pathogens express 42 VFs and their persistence in mature compost was a widespread issue, highlighting a greater risk of pathogen spread than previously thought. Finally, we compiled the 134 pathogens and 1009 VFs into a comprehensive Environmental Risk of Compost Pathogens (ERCP) catalog, providing a valuable resource for routine pathogen surveillance.

Diethylhexyl phthalate induces immune dysregulation and is an environmental immune disruptor

Diethylhexyl phthalate (DEHP) is the most abundant phthalate compound in the environment, and has been linked with multiple human diseases. The immune system is closely associated with the occurrence and progression of various diseases. However, minimal research has addressed the impact of DEHP on the immune system. In this study, single-cell RNA sequencing was performed using spleen tissue of mice to comprehensively determine alterations of the immune system in response to DEHP. The results showed that DEHP exposure reduced the absolute number of peripheral white blood cells (WBCs), including lymphocytes, monocytes, eosinophils, basophils, and neutrophils in mice. In addition, scRNA-seq analyses showed that inflammatory signaling and the expression of heat shock proteins (HSPs) were reduced in all peripheral immune cell populations. Furthermore, we established a mice cecal ligation and puncture (CLP) model, and showed that DEHP exacerbated sepsis-induced immunosuppression and organ damage. These results suggest that DEHP is an environmental immune disruptor that undermines the immune system, exacerbating acute infections and organ damage. Our findings offer a novel perspective on the hazards of DEHP to human health.

Heat shock protein 70 promotes the progression of type 2 diabetic nephropathy by inhibiting T-cell immunoglobulin and mucin domain-3 and thereby promoting Th17/Treg imbalance.

Diabetic nephropathy (DN) is the most common complication of diabetes mellitus. We aimed to investigate the role of regulatory T cells (Tregs) and helper T cells 17 (Th17) in the development and progression of DN. A mouse type 2 diabetic nephropathy (T2DN) model was established. Immunohistochemistry was used to detect the expression of HSP70 and Tim-3 in mouse kidney tissues, and western blotting was used to detect the expression levels of HSP70 and Tim-3. PAS staining and Masson's trichrome staining were used to detect the degree of kidney injury. Flow cytometry was used to detect the number of Th17 and Treg cells in blood and kidney tissues. The expression levels of interleukin 17 (IL-17) and interleukin 10 (IL-10) in the serum were measured via ELISA. The expression of HSP70 was significantly increased while the expression of Tim-3 was significantly decreased in the kidneys of mice in the T2DN group compared with those in the control (NC) group. Additionally, the inhibition of HSP70 upregulated the expression of Tim-3 in T2DN mice. The Th17/Treg ratio was significantly greater in the blood and kidneys of the mice in the T2DN group than in those of the NC group, the expression of serum IL-17 was increased, and the expression of IL-10 was decreased. Increased HSP70 inhibits Tim-3 expression in T2DN mouse kidney tissues, and subsequently causes a Th17/Treg imbalance and an inflammatory response, ultimately leading to kidney injury. The inhibition of HSP70 may alleviate the progression of T2DN.

Biogenic silver nanoparticles synthesized using bracken fern inhibits cell proliferation in HCT-15 cells through induction of apoptosis pathway and overexpression of heat shock proteins

BackgroundIn recent years, biosynthesized nanoparticles has shown a promise as alternative avenue for improving the effectiveness of conventional chemotherapy. Despite, there is a significant gap in existing literature concerning the comprehensive study of biogenic silver nanoparticles derived from terrestrial fern species and their potential effects on cancer cells. This study is aiming to investigate effects of biogenic silver nanoparticles synthesized using aqueous extract of bracken fern Pteridium revolutum on inhibiting cell proliferation and inducing apoptosis in HCT-15 cells. MethodsBiogenic silver nanoparticles synthesized using aqueous extract of Pteridum revolutum followed by their characterization (UV–Visible spectroscopy, TEM, XRD and FTIR). The impact on cell proliferation of HCT-15 cells was assessed by MTT assay while induction of apoptosis was demonstrated via DNA fragmentation, caspase-3 assay, cell cycle arrest, FITC V- Annexin assay and evaluation of expression of apoptotic genes using real time PCR and western blotting techniques. ResultsResults of UV–Vis spectrum of colloidal solution of CW-AgNPs showed surface plasmon resonance peak at 430 nm. TEM and XRD results confirmed synthesis of spherical shaped, 20–40 nm sized nanoparticles. The results elucidate cytotoxic effect of PR-AgNPs against HCT-15 cells in time and dose dependent manner with IC50 observed at 5.79 ± 0.58 µg /mL after 24 h of exposure. Furthermore, PR-AgNPs induce significant alterations in cellular morphology, elevate DNA DNA fragmentation and enhance expression of p53 and caspase-3 in HCT10 cells. ConclusionThe findings from this study address the noteworthy antiproliferative effects of PR-AgNPs in cancer cells primarily mediated through activation of intrinsic apoptosis pathway by inducing p53 and caspase-3 genes.

Alleviating rheumatoid arthritis with a photo-pharmacotherapeutic glycan-integrated nanogel complex for advanced percutaneous delivery

The prospective of percutaneous drug delivery (PDD) mechanisms to address the limitations of oral and injectable treatment for rheumatoid arthritis (RA) is increasing. These limitations encompass inadequate compliance among patients and acute gastrointestinal side effects. However, the skin’s intrinsic layer can frequently hinder the percutaneous dispersion of RA medications, thus mitigating the efficiency of drug delivery. To circumvent this constraint, we developed a strontium ranelate (SrR)-loaded alginate (ALG) phototherapeutic hydrogel to assess its effectiveness in combating RA. Our studies revealed that this SrR-loaded ALG hydrogel incorporating photoelectrically responsive molybdenum disulfide nanoflowers (MoS2 NFs) and photothermally responsive polypyrrole nanoparticles (Ppy NPs) to form ALG@SrR-MoS2 NFs-Ppy NPs demonstrated substantial mechanical strength, potentially enabling delivery of hydrophilic therapeutic agents into the skin and significantly impeding the progression of RA. Comprehensive biochemical, histological, behavioral, and radiographic analyses in an animal model of zymosan-induced RA demonstrated that the application of these phototherapeutic ALG@SrR-MoS2 NFs-Ppy NPs effectively reduced inflammation, increased the presence of heat shock proteins, regulatory cluster of differentiation M2 macrophages, and alleviated joint degeneration associated with RA. As demonstrated by our findings, treating RA and possibly other autoimmune disorders with this phototherapeutic hydrogel system offers a distinctive, highly compliant, and therapeutically efficient method.

Unveiling the secrets of lotus seed longevity: insights into adaptive strategies for extended storage.

Seed longevity is crucial for long-term storage, but prolonged unfavorable conditions can lead to viability loss. This study integrated theoretical and experimental techniques to elucidate the inherent mechanisms underlying the unique ability of lotus seed capacity to maintain stable viability even after enduring years. Transcriptome analysis and microscopy revealed the sturdy structure of the lotus seed pericarp, which predominantly expressed cellulose synthase genes involved in cell wall biogenesis. The cotyledon serves as a nutrient source for seeds during long-term storage. Additionally, the inactivation of chlorophyll degradation pathways may allow for the retention of chlorophyll in the lotus seed plumule, potentially enhancing the environmental adaptability of lotus seedlings. While the reduced abundance of transcripts corresponding to heat shock protein genes could impact protein processing and consequently diminish the vitality of aging lotus seeds. Moreover, an expansion in the number of seed maturation and defense response genes was observed in the lotus genome compared to other 11 species, which might represent an adaptive strategy against long-term adverse storage conditions. Overall, these findings are crucial for understanding the mechanisms underlying lotus seed longevity and may inform future improvements in the extended storage periods of seed crops.

Geldanamycins: Potent Hsp90 Inhibitors with Significant Potential in Cancer Therapy.

Geldanamycin, an ansa-macrolide composed of a rigid benzoquinone ring and an aliphatic ansa-bridge, was isolated from Streptomyces hygroscopicus. Geldanamycin is a potent heat shock protein inhibitor with remarkable antiproliferative activity. However, it shows pronounced hepatotoxicity in animal models and unfavorable pharmacokinetic properties. Four geldanamycin analogs have progressed through various phases of clinical trials, but none have yet completed clinical evaluation or received FDA approval. To enhance the efficacy of these Hsp90 inhibitors, strategies such as prodrug approaches or nanocarrier delivery systems could be employed to minimize systemic and organ toxicity. Furthermore, exploring new drug combinations may help overcome resistance, potentially improving therapeutic outcomes. This review discusses the mechanism of action of geldanamycin, its pharmacokinetic properties, and the various approaches employed to alleviate its toxicity and maximize its clinical efficacy. The main focus is on those derivatives that have progressed to clinical trials or that have shown important in vivo activity in preclinical models.

Downregulation of the GhROD1 Gene Improves Cotton Fiber Fineness by Decreasing Acyl Pool Saturation, Stimulating Small Heat Shock Proteins (sHSPs), and Reducing H2O2 Production.

Cotton fiber is one of the most important natural fiber sources in the world, and lipid metabolism plays a critical role in its development. However, the specific role of lipid molecules in fiber development and the impact of fatty acid alterations on fiber quality remain largely unknown. In this study, we demonstrate that the downregulation of GhROD1, a gene encoding phosphatidylcholine diacylglycerol cholinephosphotransferase (PDCT), results in an improvement of fiber fineness. We found that GhROD1 downregulation significantly increases the proportion of linoleic acid (18:2) in cotton fibers, which subsequently upregulates genes encoding small heat shock proteins (sHSPs). This, in turn, reduces H2O2 production, thus delaying secondary wall deposition and leading to finer fibers. Our findings reveal how alterations in linoleic acid influence cellulose synthesis and suggest a potential strategy to improve cotton fiber quality by regulating lipid metabolism pathways.

Localized synthesis of molecular chaperones sustains neuronal proteostasis.

Neurons are challenged to maintain proteostasis in neuronal projections, particularly with the physiological stress at synapses to support intercellular communication underlying important functions such as memory and movement control. Proteostasis is maintained through regulated protein synthesis and degradation and chaperone-assisted protein folding. Using high-resolution fluorescent microscopy, we discovered that neurons localize a subset of chaperone mRNAs to their dendrites, particularly more proximal regions, and increase this asymmetric localization following proteotoxic stress through microtubule-based transport from the soma. The most abundant chaperone mRNA in dendrites encodes the constitutive heat shock protein 70, HSPA8. Proteotoxic stress in cultured neurons, induced by inhibiting proteasome activity or inducing oxidative stress, enhanced transport of Hspa8 mRNAs to dendrites and the percentage of mRNAs engaged in translation on mono and polyribosomes. Knocking down the ALS-related protein Fused in Sarcoma (FUS) and a dominant mutation in the heterogenous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1) impaired stress-mediated localization of Hspa8 mRNA to dendrites in cultured murine motor neurons and human iPSC-derived neurons, respectively, revealing the importance of these RNA-binding proteins in maintaining proteostasis. These results reveal the increased dendritic localization and translation of the constitutive HSP70 Hspa8 mRNA as a crucial neuronal stress response to uphold proteostasis and prevent neurodegeneration.

Intranasal administration of GRP78 protein (HSPA5) counteracts the neurodegeneration in the locus coeruleus in a model of chronic sleep restriction in rats

Chronic sleep restriction (sleep less than 6 hours per day) due to the workload and a decrease in sleep quality is an endemic disease in modern society. Chronic sleep deprivation causes serious neuropsychiatric disorders associated with irreversible neurodegenerative changes in the brain. The search for pharmacological agents that can reduce the risk of neurodegeneration as a result of chronic sleep loss is an urgent task issue for biomedicine. Intranasal administration of glucose-regulated 78 kDa heat shock protein (GRP78) has a neuroprotective effect in a rat model of Parkinson´s disease. The neuroprotective potential of intranasally administered GRP78 in chronic sleep deprivation has not been previously studied. The aim of the study is to find out whether preventive intranasal administration of GRP78 is able to weaken and/or stop the process of neurodegeneration in the locus coeruleus in the model of chronic sleep restriction (SR) in rats. The study was conducted on 6 months old male Wistar rats. For sleep deprivation, a validated method of a swinging platform was used in the mode: 3 hours of sleep deprivation and 1 hour of rest continuously for 5 days. Recombinant human protein GRP78 was administered intranasally two days before the start of SR and during 5 days of SR. Cellular and molecular changes in the locus coeruleus during SR and during the administration of GRP78 were studied using immunohistochemistry and Western blotting. It was shown that chronic SR leads to the degeneration of 30% of noradrenergic neurons in the locus coeruleus, that was associated with an increase in the levels of activated caspases-3 and 9. This indicates the development of apoptosis along the mitochondrial pathway. No signs of reactive microgliosis were found in the model of chronic SR in rats. We have demonstrated that intranasally administered GRP78 penetrates and accumulates in the neurons of the locus coeruleus, GRP78 counteracts the death of neurons along the path of apoptosis. The data obtained allows to consider GRP78 as a potential neuroprotective agent for the prevention of pathological consequences of chronic sleep deprivation.

Erythropoiesis and Gene Expression Analysis in Erythroid Progenitor Cells Derived from Patients with Hemoglobin H/Constant Spring Disease.

Hemoglobin H/Constant Spring (Hb H/CS) disease represents a form of non-deletional Hb H disease characterized by chronic hemolytic anemia that ranges from moderate to severe and may lead to transfusion-dependent thalassemia. To study the underlying mechanisms of this disease, we conducted an analysis of erythropoiesis and gene expression in erythroid progenitor cells derived from CD34+ hematopoietic stem/progenitor cells from patients with Hb H/CS disease and normal controls. Twelve patients with Hb H/CS disease and five normal controls were enrolled. Peripheral blood samples were collected to isolate CD34+ hematopoietic stem/progenitor cells for the analysis of cell proliferation and differentiation. Six samples from patients with Hb H/CS disease and three controls were subsequently studied for gene expression by next generation sequencing analysis. Erythroid progenitor cells derived from patients with Hb H/CS disease exhibited a trend towards increased rates of erythroid proliferation and decreased cell viability compared to those from controls. Moreover, erythroid progenitor cells derived from patients with Hb H/CS disease demonstrated delayed terminal differentiation. Gene expression profiling revealed elevated levels of genes encoding molecular chaperones, including the heat shock protein genes (HSPs) and the chaperonin containing TCP-1 subunit genes (CCTs) in the Hb H/CS disease group. In summary, erythroid progenitor cells derived from patients with Hb H/CS disease exhibit a trend towards heightened erythroid proliferation, diminished cell viability, and delayed terminal differentiation. Additionally, the increased expression of genes encoding molecular chaperones was observed, providing information on potential underlying pathophysiological mechanisms.

MMP-2 Responsive Gold Nanorods Loaded with HSP-70 siRNA for Enhanced Photothermal Tumor Therapy.

Gold nanorods (Au NRs) are a valuable photothermal nanomaterial for tumor therapy. However, when treated with Au NRs for photothermal therapy, the expression of heat shock proteins in tumors will increase, which will induce heat resistance in tumor cells and reduce the photothermal therapeutic effect of Au NRs. By RNA interference, the expression of heat shock proteins would be effectively inhibited to improve the efficasy of tumor photothermal therapy. However, deep and noninvasive tissue penetration remains a great obstacle to applying siRNA successfully. Thus, the nanoplatform AGC/HSP-70 siRNA was designed for enhanced photothermal tumor therapy by RNA interference. In the AGC/HSP-70 siRNA complex, the Au-S bond modified the matrix metalloproteinase-2 (MMP-2)-sensitive peptide GPLGLAG on the surface of gold nanorods. Moreover, the natural basic polysaccharide (chitosan) was reacted with the peptide by an amide bond for delivering heat shock protein 70 silencing siRNA (HSP-70 siRNA). Modifying the MMP-2-sensitive linker could cause more Au NRs to accumulate in tumors to exert a photothermal effect and promote the penetration of HSP-70 siRNA and chitosan complexes into deep tumor tissues. In vitro experiments indicated that the enzymolysis of the MMP-2-sensitive linker for AGC/HSP-70 siRNA could promote the cellular uptake and perinuclear distribution of HSP-70 siRNA in tumor cells, which may be due to the smaller size and positive electricity of the complexes. All of these results ensured the efficient gene silencing effect of HSP-70 siRNA to enhance the photothermal therapeutic effect of Au NRs in tumor tissues, as demonstrated by the gene silencing and cellular apoptotic experiments. In vivo experiments further proved that the AGC/HSP-70 siRNA nanoplatform efficiently improved the photothermal effect of Au NRs. In summary, this work proved that AGC/HSP-70 siRNA is a promising drug delivery strategy for enhancing the photothermal therapy of tumors by regulating the photothermal sensitivity of deep tumor cells as well as retaining more Au NRs in tumor tissues, and also provides a novel strategy for tumor photothermal therapy.