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Abstract Limited studies examined the interaction effects between summer heat exposure and economic development on the settlement intention, especially for the floating population. Binary logistic regression model was used to examine the association of summer temperature, per capita GRDP (PGRDP), summer temperature × PGRDP with settlement intention. Additive interaction term for summer temperature and PGRDP level was used to test the interactive effects. This study indicates that summer heat exposure will decrease the settlement intention of migrants (OR:1.386, 95% CI: 1.35–1.423), while PGRDP will increase settlement intention (OR: 0.893, 95% CI: 0.870–0.917). There is a negative interaction between summer temperature and PGRDP in the additive model. To a certain extent, summer heat exposure can weaken the attractiveness of economic development for migrants to settle down, they prefer to settle in cities with favorable temperatures and high levels of economic development. Stratified analyses illustrated that summer heat exposure showed lower settlement intention among female, the elderly, engaged in agriculture and industry and living in central China. The government should take measures about mitigation, adaptation and balancing economic development and climate change to reduce the adverse impacts of summer heat, and pay more attention to vulnerable groups and backward regions.

Abstract The poor prognosis of hepatocellular carcinoma (HCC) is still an urgent challenge to be solved worldwide. Hence, assembling drugs and targeted short peptides together to construct a novel medicine delivery strategy is crucial for targeted and synergy therapy of HCC. Herein, a high-efficiency nanomedicine delivery strategy has been constructed by combining graphdiyne oxide (GDYO) as a drug-loaded platform, specific peptide (SP94-PEG) as a spear to target HCC cells, sorafenib, doxorubicin-Fe2+ (DOX-Fe2+), and siRNA (SLC7A11-i) as weapons to exert a three-path synergistic attack against HCC cells. In this work, SP94-PEG and GDYO form nanosheets with HCC-targeting properties, the chemotherapeutic drug DOX linked to ferrous ions increases the free iron pool in HCC cells and synergizes with sorafenib to induce cell ferroptosis. As a key gene of ferroptosis, interference with the expression of SLC7A11 makes the ferroptosis effect in HCC cells easier, stronger, and more durable. Through gene interference, drug synergy, and short peptide targeting, the toxic side effects of chemotherapy drugs are reduced. The multifunctional nanomedicine GDYO@SP94/DOX-Fe2+/sorafenib/SLC7A11-i (MNMG) possesses the advantages of strong targeting, good stability, the ability to continuously induce tumor cell ferroptosis and has potential clinical application value, which is different from traditional drugs.

Abstract Background Cryptosporidium parvum is an apicomplexan zoonotic parasite causing the diarrheal illness cryptosporidiosis in humans and animals. To invade the host intestinal epithelial cells, parasitic proteins expressed on the surface of sporozoites interact with host cells to facilitate the formation of parasitophorous vacuole for the parasite to reside and develop. The gp40 of C. parvum, named Cpgp40 and located on the surface of sporozoites, was proven to participate in the process of host cell invasion. Methods We utilized the purified Cpgp40 as a bait to obtain host cell proteins interacting with Cpgp40 through the glutathione S-transferase (GST) pull-down method. In vitro analysis, through bimolecular fluorescence complementation assay (BiFC) and coimmunoprecipitation (Co-IP), confirmed the solid interaction between Cpgp40 and ENO1. In addition, by using protein mutation and parasite infection rate analysis, it was demonstrated that ENO1 plays an important role in the C. parvum invasion of HCT-8 cells. Results To illustrate the functional activity of Cpgp40 interacting with host cells, we identified the alpha-enolase protein (ENO1) from HCT-8 cells, which showed direct interaction with Cpgp40. The mRNA level of ENO1 gene was significantly decreased at 3 and 24 h after C. parvum infection. Antibodies and siRNA specific to ENO1 showed the ability to neutralize C. parvum infection in vitro, which indicated the participation of ENO1 during the parasite invasion of HCT-8 cells. In addition, we further demonstrated that ENO1 protein was involved in the regulation of cytoplasmic matrix of HCT-8 cells during C. parvum invasion. Functional study of the protein mutation illustrated that ENO1 was also required for the endogenous development of C. parvum. Conclusions In this study, we utilized the purified Cpgp40 as a bait to obtain host cell proteins ENO1 interacting with Cpgp40. Functional studies illustrated that the host cell protein ENO1 was involved in the regulation of tight junction and adherent junction proteins during C. parvum invasion and was required for endogenous development of C. parvum. Graphical Abstract

Abstract Background Cryptosporidium parvum is a zoonotic parasitic protozoan that can infect a variety of animals and humans and is transmitted between hosts via oocysts. The oocyst wall provides strong protection against hostile environmental factors; however, research is limited concerning the oocyst wall at the proteomic level. Methods A comprehensive analysis of the proteome of oocyst wall of C. parvum was performed using label-free qualitative high-performance liquid chromatography (HPLC) fractionation and mass spectrometry-based qualitative proteomics technologies. Among the identified proteins, a surface protein (CpSP1) encoded by the C. parvum cgd7_5140 (Cpcgd7_5140) gene was predicted to be located on the surface of the oocyst wall. We preliminarily characterized the sequence and subcellular localization of CpSP1. Results A total of 798 proteins were identified, accounting for about 20% of the CryptoDB proteome. By using bioinformatic analysis, functional annotation and subcellular localization of the identified proteins were examined for better understanding of the characteristics of the oocyst wall. To verify the localization of CpSP1, an indirect immunofluorescent antibody assay demonstrated that the protein was localized on the surface of the oocyst wall, illustrating the potential usage as a marker for C. parvum detection in vitro. Conclusion The results provide a global framework about the proteomic composition of the Cryptosporidium oocyst wall, thereby providing a theoretical basis for further study of Cryptosporidium oocyst wall formation as well as the selection of targets for Cryptosporidium detection. Graphical Abstract

Abstract Background CDGSH iron sulfur domain 2 (CISD2) is an iron–sulfur protein with a [2Fe–2S] cluster, which is critical for cell proliferation and iron homeostasis. It has been demonstrated that aberrant expression of CISD2 is associated with the progression of multiple cancers. However, the underlying mechanism of CISD2 in regulating tumorigenesis remains obscure. Methods Bioinformatics strategies were used to investigate the protein interaction network and functional annotation of CISD2. In the functional experiment, cell viability was measured by CCK-8 kit. The levels of cellular reactive oxygen species (ROS), intracellular free iron, lipid peroxides, and lysosomal activity were determined by DCF-DA, RPA, C11-BODIPY, and cathepsin B staining, respectively. The glutathione (GSH) content was determined using a GSH assay kit. Results We showed that knockdown of CISD2 significantly accelerated the Erastin-induced ferroptotic cell death with excess lipid peroxidation, GSH exhaustion, and iron accumulation, while overexpression of CISD2 hindered the sensitivity to Erastin. Further assays via confocal microscopy and western blot exhibited that CISD2 knockdown markedly enhanced the lysosomal activity, and activated ferritinophagy under the exposure of Erastin. Pharmacological inhibition of lysosomal function could inhibit the degradation of ferritin heavy chain (FTH), and attenuate the phenotypes of ferroptosis, such as accelerated iron accumulation and lipid peroxidation. Notably, we found that Erastin-induced compensatory elevation of nuclear factor erythroid 2-related factor 2 (NRF2) could be eliminated in CISD2 depletion cells. Mechanically, CISD2 knockdown promoted the degradation of autophagy adaptor p62 and resulted in an increased binding affinity of Keap1 with NRF2, thus leading to the increased ubiquitination and subsequent degradation of NRF2. Enforced expression of NRF2 reversed the sensitivity of shCISD2 cells to ferroptosis both in vitro and in vivo. Conversely, enforced expression of Keap1 exacerbated the degradation of NRF2, reduced the transcriptional expression of FTH and heme oxygenase 1 (HO-1), increased the oxidative damage, and thus further facilitated ferroptosis. Conclusion Taken together, our current results illustrated two parallel mechanisms involved in the shCISD2-mediated ferroptosis. One was that shCISD2 enhanced the accumulation of free iron via ferritinophagy-dependent ferritin turnover; the other was that CISD2 depletion induced the inhibition of the p62–Keap1–NRF2 pathway, which resulted in oxidative stress and ferroptosis.

Abstract Background Ferroptosis is a newly identified type of programmed cell death, which preferentially targets iron-rich cancer cells such as hepatocellular carcinoma (HCC). Ferritin heavy chain (FTH) is a major iron storing nanocage to store redox-inactive iron, and harbors ferroxidase activity to prevent the iron-mediated production of ROS. Our previous studies have demonstrated that FTH acts as a protective role to increase the cellular resistance to ferroptosis. However, the specific role of FTH in the development of HCC and ferroptosis resistance remains unclear. Methods The indicated databases were used for bioinformatics analysis. The abilities of cell proliferation, migration were measured by cell proliferation assay, transwell assay and wound healing assay. The levels of reactive oxygen species (ROS), lipid peroxide, free iron, mitochondrial superoxide, mitochondrial morphology and mitochondrial membrane potential (MMP) were determined by DCF-DA, C11-BODIPY, mitoSOX, mitoTracker, JC-10 and TMRM staining, respectively. The mitochondrial oxygen consumption rate was monitored by the Seahorse XF24 Analyzer. Results The pan-cancer analysis was performed and showed that FTH expression is upregulated in multiple cancers, such as LIHC, CHOL, HNSC, compared to corresponding normal tissues. In addition, the level of serum ferritin is positively associated with the progression of hepatitis, cirrhosis liver and hepatocellular carcinoma. Further investigation shed light on the strong correlation between FTH expression and tumor grades, cancer stages and prognosis of HCC. Importantly, the proteins interaction network elucidated that FTH is involved in iron homeostasis maintenance and lysosomal-dependent degradation. Enforced expression of FTH accelerates proliferation, migration and endows HCC cells specifically resistant to ferroptosis, but does not protect against cell death caused by cytotoxic compounds like oxaliplatin, irinotecan, and adriamycin. Mechanically, FTH reconstituted cells exhibit diminished peroxides accumulation, reduce mitochondrial ROS level, attenuate the impaired mitochondrial respiratory and rescue the mitochondrial homeostasis. Notably, FTH expression boosts tumorigenic potential in vivo with increased PCNA staining and lesser lipid peroxides generation. Conclusion These results provide new insights that FTH acts as an oncogene in the carcinogenesis and progression of HCC, and is hopeful to be a potential target for therapeutic intervention through ferroptosis.

Abstract Background Cryptosporidium is an opportunistic pathogen that infects a wide variety of vertebrates. The aim of the present study was to characterize Cryptosporidium spp. isolates from Bactrian camels and to foster further understanding of the biological characteristics of the pathogen. Methods Fecal specimens were collected from two 4-year-old Bactrian camels resident at the Kaifeng City Zoo in China and examined for Cryptosporidium. Fecal specimens were screened using the floatation method, and then genomic DNA was extracted from the oocysts and identified by nested-PCR amplification of the small subunit ribosomal RNA (SSU rRNA) gene, the actin gene and the Cryptosporidium oocyst wall-protein (COWP) gene. Subtype analysis was performed based on four minisatellite (MS) loci (MS1, MS2, MS3 and MS16) that were aligned and phylogenetically analyzed to determine the species and subtype of Cryptosporidium. We then established a BALB/c mice infection model and further verified the results through clinical status, pattern of oocyst excretion and histological examination. Results Cryptosporidium oocyst isolates from the two Bactrian camels had an average (± standard deviation) size of 7.49 ± 0.13 × 5.70 ± 0.10 μm (n = 50). The sequencing and phylogenetic analysis confirmed the species as C. muris. Multilocus sequence typing analysis indicated that the subtypes were M13, M4, M1 and M5. Following the inoculation of BALB/c mice, we found that the prepatent period and number of oocysts per gram increased with increasing infective dose. Oocysts were first detected in the feces of BALB/c mice at 7–8 days post-infection (dpi), with levels peaking twice thereafter, at 15–16 dpi and 19–20 dpi. Histology and scanning electron microscopy studies showed that the stomach contained gastric pits filled with Cryptosporidium that adhered to the surface of gastric mucosa gland epithelial cells, causing the latter to deform, swell and become disordered. Conclusions The findings of this study indicated that oocysts isolated from Bactrian camels were from C. muris. This is the first report of C. muris isolated from camels in China. More epidemiological data are needed to understand the prevalence and transmission of C. muris in camels in different geographic areas. Graphical abstract

Abstract Background Enterocytozoon bieneusi is a parasite that infects humans and a wide range of other animals. The large migratory waterfowl, the whooper swan (Cygnus cygnus), travels through many cities during its migration and can spread parasites. Despite receiving increasing attention worldwide, there have been no reports of E. bieneusi infection occurring in C. cygnus. Therefore, this study aims to assess the prevalence and genetic characteristics of E. bieneusi in C. cygnus in Sanmenxia, China. Methods Altogether, 467 fresh fecal samples were collected in the Swan Wetland Park in Sanmenxia, China. Genomic DNA was extracted from fresh fecal samples (n = 467) and E. bieneusi was identified by nested PCR amplification of the internal transcribed spacer (ITS) region. ITS-positive sequences were aligned and phylogenetically analyzed to determine the genotypes of E. bieneusi. Results The overall prevalence of E. bieneusi in C. cygnus was 7.49% (35/467). Sequencing of the 35 positive samples revealed eight known genotypes (EbpA, EbpC, Henan-III, Henan-IV, BEB6, CD9, Peru6 and PtEb IX) and three novel genotypes (CSW1, CSW2 and CSW3). The phylogenetic tree constructed from the ITS sequences showed that seven genotypes (Peru6, EbpA, EbpC, Henan-III, CSW3, Henan-IV and CSW1) clustered within the zoonotic Group 1 while the remaining novel genotype CSW2 clustered within Group 5. Conclusions To our knowledge, this is the first report of E. bieneusi in C. cygnus. Of public health significance, our results suggest that migratory C. cygnus might play an important role in the water-borne transmission of E. bieneusi. Effective strategies will be necessary to control E. bieneusi infection in C. cygnus, other animals and humans.

Abstract Estrogen plays substantial roles in pain modulation; however, studies concerning sex hormones and nociception often yield confusing results. The discrepancy could be a result of lack of consensus to regard estrogen as a variable when working with animal models; thus, the influence of hormones’ fluctuations on nociception has continually been neglected. In the present study, we designed a novel hormone substitution model to aid us to evaluate the effects of estrogen’s long-term alterations on ovariectomy (OVX)-induced mechanical hyperalgesia and the expression of estrogen receptors(ERs). OVX rats were implanted with slow-release estrogen pellets at differently arranged time points and doses, such that a gradual elevation or decrease of serum estrogen levels following a relatively stable period of estrogen replacement was achieved in rats. Our results demonstrated that gradual estrogen depletion rather than elevation following the stable period of estrogen substitution in OVX rats alleviated OVX-induced mechanical hyperalgesia in a dose-independent manner, and the opposite estrogen increase or decrease paradigms differently regulate the expression of spinal ERs. Specifically, in rats rendered to continuously increased serum estrogen, the early phase estrogen-induced anti-nociception effect in OVX rats was eliminated, which was accompanied by an over-activation of ERα and a strong depression of ERβ, while in the OVX rats subject to gradual decrease of estrogen replacement, both ERα and ERβ increased modestly compared with the OVX group. Thus, the present study demonstrated that estrogen increase or decrease modulate nociception differently through change of spinal ERs.

Abstract Background A growing body of evidence shows that indoor concentrations of airborne particles are often higher than is typically encountered outdoors. Since exposure to indoor PM2.5 is thought to be associated with cardiovascular disease, the health impacts of indoor air pollution need to be explored. Based on animal models, ambient particulate matter has been proved to promote coagulation which is very likely involved in the pathogenic development of cardiovascular disease. However, animal models are insufficient to predict what will happen with any certainty in humans. For this reason, the precise pathogenic mechanisms behind the development of cardiovascular disease in humans have not yet been determined. Results We generated a 3D functional human microvascular network in a microfluidic device. This model enables human vascular endothelial cells to form tissue-like microvessels that behave very similarly to human blood vessels. The perfusable microvasculature allows the delivery of particles introduced into these generated human-like microvessels to follow the fluid flow. This exposure path effectively simulates the dynamic movement of airborne nanoscale particles (ANPs) within human vessels. In this study, we first identified the existence of ANPs in indoor air pollution. We then showed that ANPs could activate endothelial cells via ROS induced inflammation, and further resulted in abnormal expression of the coagulation factors (TF, TM and t-PA) involved in coagulation cascades. In addition, we found that a protein could cover ANPs, and this biointeraction could interfere with heparan sulfate (HS). Human organotypic 3D microvessel models provide a bridge for how research outcomes can translate to humans. Conclusions The 3D human microvessel model was used to determine the physiological responses of human vessels to ANP stimulation. Based on the obtained data, we concluded that ANPs not only disrupts normal coagulation functions, but also act directly on anticoagulant factors in human vessels. These experimental observations provide a potential biological explanation for the epidemiologically established link between ANPs and coagulation abnormality. This organ-on-chip model may provide a bridge from in vitro results to human responses.