Antibodies to specific domains of Plasmodium falciparum erythrocyte membrane protein-1 and its relationship with protection from severe malarial anemia: A prospective study among Ghanaian children.

Background: Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP-1) is important in malaria pathogenicity as it mediates Pf-infected erythrocytes cytoadherence to host endothelial microvasculature receptors. Naturally acquired antibodies against specific PfEMP-1 antigens may be beneficial in clinical malaria protection. This study determined antibodies to DBLα2, CIDRα1, DBLß12, and DBLγ6 domains of PfEMP-1 in children with P. falciparum malaria in Tamale, Ghana. Methods: Sixty P. falciparum-infected children, and 30 controls, aged 1-12 years were recruited for this case-control study from April to July 2023 in Northern Ghana. Participants with uncomplicated malaria had asexual P. falciparum in peripheral blood and Hb ≥ 5.0 g/dL, and severe malaria was diagnosed when participants had Hb < 5.0 g/dL in addition to asexual P. falciparum in peripheral blood. Blood cell indices were measured using hematology analyzer, and IgG antibodies to DBLα2, CIDRα1, DBLß12, and DBLγ6 domains of PfEMP-1 and pro-inflammatory cytokines were detected using enzyme-linked immunosorbent assay. Data were analyzed using SPSS version 26.0. Results: The prevalence of PfEMP-1 IgG antibodies among P. falciparum-infected children and the uninfected group was 65.0% and 6.7%, respectively. PfEMP-1 IgG antibodies were present in 83.3% of uncomplicated malaria cases, and 46.7% in severe malaria subjects. Plasma levels of PfEMP-1 IgG antibodies were elevated in participants with uncomplicated malaria compared to those with severe malaria (p < 0.001). Hemoglobin, RBC, HCT, and platelet were significantly lower among P. falciparum-infected children without PfEMP-1 IgG antibodies than among those with the antibodies. Prevalence of anemia among children with PfEMP-1 IgG antibodies and those without the antibodies were 74.4% and 100%, respectively. Conclusion: The high prevalence of PfEMP-1 IgG antibodies to DBLα2, CIDRα1, DBLß12, and DBLγ6 domains observed in participants with uncomplicated malaria, and the relationship between PfEMP-1 IgG antibodies and blood cell parameters could indicate that the antibodies may be related to effective erythropoietic response in P. falciparum malaria. Immune antibodies against DBLα2, CIDRα1, DBLß12, and DBLγ6 domains of PfEMP-1 may suppress the deteriorating effects of PfEMP-1 antigens and provide immune protection against severe malarial anemia in children.

Rejuvenation factor PF4: a potential gatekeeper for neurodegenerative diseases.

Recently, it is discovered PF4 is a cognitive enhancer that improved the cognitive abilities of younger mice and gave older animals their middle-aged acuity back. PF4 works by reducing inflammation during the aging process. As we all known, aging is undoubtedly the main risk factor of neurodegenerative diseases. Furthermore, inflammation has been extensively investigated and attracted even more interest. Therefore, the aim of the proposal is to highlight the worth of PF4 in inflammaging of neurodegenerative diseases, which might provide a potential therapeutic strategy.

[Management of HIT/anti-PF4 disorders].

Heparin-induced thrombocytopenia (HIT) was widely known as a disease characterized by development of thrombosis with thrombocytopenia after heparin exposure. In addition, vaccine-induced immune thrombotic thrombocytopenia (VITT) has been described as a fatal disease involving simultaneous bleeding and thrombosis after COVID-19 adenovirus vector vaccination. These were caused by HIT antibodies and anti-PF4 antibodies, respectively, but both were autoantibodies that recognized PF4, and were found to have the same pathology with different severities. In recent years, many pathologies in which anti-PF4 antibodies are produced have been reported, and a new concept of anti-PF4 disorder has been proposed. Anti-PF4 disorders are often difficult to identify due to their diverse range of causes, and the prognosis varies greatly depending on whether anti-PF4 antibodies can be measured and early treatment performed after observation of thrombocytopenia of unknown cause or thrombosis at an unusual site. To avoid overlooking anti-PF4 disorders, clinicians should become familiar with the classification of these disorders and accurately select the necessary tests.

PF-PEG@ASIV-EXO Hydrogel Accelerates Diabetic Wound Healing by Ferroptosis Resistance and Promoting Angiogenesis.

Astragaloside IV (ASIV) promotes the proliferation of key cells, endothelial progenitor cells (EPCs), during the wound healing process, while exosomes and hydrogels are ideal drug delivery carriers. This study aims to explore the mechanism of action of the "ROS-responsive hydrogel-engineered EPCs-targeted exosomes" composite ASIV delivery system (PF-PEG@ASIV-EXO) in diabetic wound healing. Surface markers of EPCs and PF-PEG@ASIV-EXO were detected separately. The degradation rate of PF-PEG@ASIV-EXO was assessed after coculturing with human dermal fibroblasts (HDF), immortalized human epidermal cells (HaCAT), and human EPCs, and the biocompatibility of EPCs and PF-PEG@ASIV-EXO was evaluated through exosome release and uptake. The effects of PF-PEG@ASIV-EXO on the viability, angiogenesis, ferroptosis, and mitochondria of high-glucose-treated EPCs (HS-EPCs) were investigated. A diabetic wound rat model was established, and the effects of PF-PEG@ASIV-EXO on diabetic wounds were evaluated through HE and Masson staining, as well as levels of VWF, CD31, and ferroptosis in the skin. EPCs were successfully isolated, and PF-PEG@ASIV-EXO was successfully constructed. PF-PEG@ASIV-EXO exhibited a high degradation rate within EPCs, and both EPCs and PF-PEG@ASIV-EXO showed good biocompatibility. PF-PEG@ASIV-EXO promoted the vitality and angiogenesis of EPCs, inhibited ferroptosis, and mitigated mitochondrial damage. Following treatment with PF-PEG@ASIV-EXO, the healing of diabetic rat skin accelerated, accompanied by elevated expression of VWF and CD31, and reduced ferroptosis levels. PF-PEG@ASIV-EXO hydrogel inhibits ferroptosis, promotes angiogenesis, and thereby accelerates the healing of diabetic wounds.

Supratentorial and Infratentorial Ependymoma.

Ependymomas are the third most common intracranial tumor in children, presenting in both the supratentorial and infratentorial compartments. They may present in infants, young children, and adolescents with symptoms depending on size, location, and the age of the patient. The ideal imaging for evaluation and treatment is MRI. This is crucial for preoperative evaluation and planning, as well as postoperative assessment and evaluating the efficacy of treatment. Essentially without exception, aggressive surgery aimed at complete resection is the initial and most important factor in the long-term outcome of all these children. Histopathologic diagnosis for intracranial pediatric ependymoma has been narrowed to grade II and grade III, no longer characterized as classic and anaplastic. Subsequent conformal photon or proton beam irradiation is an established post-surgical therapy, with solid evidence that it benefits survival and offers lower toxicity to the normal brain of the young child. Although chemotherapeutic treatment has not been generally impactful, immunotherapeutic interventions may be on the horizon. Updated molecular subgrouping of ependymoma is changing the post-resection approach of these tumors with regard to both treatment and outcome. Excluding spinal ependymoma and subependymoma, there are four subtypes that are defined by genetic characteristics, two found in the supratentorial compartment, ST-EPN-YAP1 and ST-EPN-ZFTA, and two in the posterior fossa, PF-EPN-A and PF-EPN-B. Younger children harboring ZFTA fusion-positive supratentorial and type A posterior fossa tumors, regardless of histology, tend toward the poorest outcomes. On the contrary, older children with supratentorial YAP1 fusion-positive ependymomas and type B posterior fossa tumors may survive with surgery alone. The paradigm shift regarding the behavior of the various childhood ependymoma subtypes will hopefully lead to targeted, individualized therapies and improved outcomes.

Proteomics of severe SARS-COV-2 infection and paraquat poisoning in human lung tissue samples: comparison of microbial infected and toxic pulmonary fibrosis.

Introduction: Pulmonary fibrosis (PF) encompasses a spectrum of lung conditions characterized by the abnormal accumulation of scar tissue in the lungs, leading to impaired respiratory function. Various conditions can result in severe PF, among which viral infections have emerged as significant triggers. In addition to viral infections, exposure to toxic substances such as paraquat represents another significant risk factor for PF. Therefore, this study aimed to explore the dissimilarities and similarities between PF triggered by viral infections and chemical toxicants, using the mechanism of PF in IPF as a reference. Methods: Data-independent acquisition proteomics technology was employed to identify COVID-19 and paraquat-induced PF from the autopsy of lung tissue samples obtained from individuals who died due to PF. Bioinformatics was employed for differential protein analysis, and selected indicators were validated on pathological sections. Results: Our results showed that the differential proteins associated with the two causes of PF were enriched in similar lung fibrosis-related signaling pathways, such as the Wnt signaling pathway. However, differences were observed in proteins such as CACYBP, we verified the consistency of the results with proteomics using the IHC approach. Conclusion: This study illuminates distinct protein-level differences by investigating pulmonary fibrosis pathways in severe COVID-19 and paraquat poisoning. Although both conditions activate lung-protective and repair pathways, COVID-19 shows limited phosphorylation-independent ubiquitination of ß-catenin compared to paraquat toxicity. These findings shed light on potential therapeutic targets for PF induced via diverse factors.

Paeoniflorin inhibited GSDMD to alleviate ANIT-induced cholestasis via pyroptosis signaling pathway.

BACKGROUND: Cholestasis (CT) is a group of disorders caused by impaired production, secretion or excretion of bile. This may result in the deposition of bile components in the blood and liver, which in turn causes damage to liver cells and other tissues. If untreated, CT can progress to severe complications, including cirrhosis, liver failure, and potentially life-threatening conditions. OBJECTIVE: This research was intended to elucidate the function and mechanism of Paeoniflorin (PF) in ameliorating ANIT-induced pyroptosis in CT. METHODS: CT models were established in SD rats and HepG2 cells through ANIT treatment. Histological examination was conducted using haematoxylin and eosin (HE) staining to assess the histopathological alterations in the liver. Network pharmacology was employed to identify potential PF targets in CT treatment. To evaluate pyroptosis levels, various methods were used, including serum biochemical analysis, Enzyme-Linked Immunosorbent Assay (ELISA), immunofluorescence (IF), immunohistochemistry (IHC), Western blotting, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The HuProt™ 20K Chip was utilized to pinpoint potential PF-binding targets. PF's direct mechanisms in CT treatment were explored using molecular docking (MD), molecular dynamics simulations (MDS), Cellular Thermal Shift Assay (CETSA), and Surface Plasmon Resonance (SPR). RESULTS: PF administration was found to alleviate ANIT-induced liver pathology, enhance liver function markers, and improve cell viability. Network pharmacology and pyroptosis inhibitor studies suggested that PF might mitigate CT via the NLRP3-dependent pyroptosis pathway. This hypothesis was further supported by Western blotting, IF, and IHC analyses, which indicated PF's potential to inhibit NLRP3-dependent pyroptosis in CT. GSDMD was identified as a target through HuProt™ 20K Chip screening. The binding affinity of PF to GSDMD was validated through MD, MDS, CETSA, and SPR techniques. Additionally, the regulatory impact of GSDMD on downstream inflammatory pathways was confirmed by ELISA and IHC. CONCLUSION: PF exhibited a hepatoprotective effect in ANIT-induced CT, primarily by targeting GSDMD, thereby suppressing ANIT-induced pyroptosis and the subsequent release of inflammatory mediators.

A novel peptide pair-based rapid fluorescent diagnostic system for malaria Plasmodium falciparum detection.

Advanced diagnostic materials, such as aptamers, are required due to the scarcity of efficient diagnostic antibodies and the low sensitivity of rapid diagnostic kits at detecting the malaria parasite, Plasmodium falciparum. METHODS: Two peptides M2.9 [(KPTAEQTESPELQSAPEN) and M2.17 (KILFNVYSPLGCTCECWV)] were designed using simple epitope prediction tools and modified against the merozoite surface antigen 2 of P. falciparum (Pf.MSP2) by 3-dimensional modeling based on binding affinity. Based on five prediction tools for hydropathy, M2.17 was selected as an appropriate capture peptide. A peptide-based fluorescence-linked immunosorbent assay (FLISA) and a peptide pair-based fluorescent immunochromatographic test strip (FICT) were developed to detect P. falciparum 3D7 (drug-sensitive) and P. falciparum K1 (multi drugs-resistant) strains. RESULTS: Bioinformatic analysis of two peptides demonstrated the potential binding affinity with the merozoite surface protein 2 of P. falciparum (Pf.MSP2) with a positive hydropathy value. The limit of detection (LOD) of FLISA was 10 parasites/µL and of a peptide pair-linked rapid FICT system was 5 and 200 parasites/µL for P. falciparum 3D7 and K1, respectively. Compared to commercial rapid detection systems (RDTs), a peptide pair-linked FICT system exhibited a 20-fold greater efficiency in detecting P. falciparum 3D7 and specifically discriminated another protozoan spp. CONCLUSION: A peptide pair-linked rapid diagnostic strip could be an alternative to conventional RDTs for monitoring wild-type and drug-resistant malaria parasites.

Helmholtz Plane Regulation Empowers PF6- Permselectivity towards High Coulombic Efficiency Dual Ion Battery of 5.5 V.

High-voltage dual ion battery (DIB) is promising for stationary energy storage applications owing to its cost-effectiveness, which has been a hot topic of research in rechargeable battery fields. However, it still suffers from rapid battery failure caused by the severe solvent co-intercalation and electrolyte oxidation. To address these bottlenecks, herein a functional electrolyte additive hexafluoroglutaric anhydride (HFGA) is presented based on a Helmholtz plane regulation strategy. It is demonstrated that the HFGA can precisely enter into the Helmholtz plane and positively regulate anion solvation behaviors near the graphite electrode surface owing to its considerable H-F affinity with ethyl methyl carbonate (EMC), thus alleviating EMC-related co-intercalation and oxidation decomposition during DIB charging. Meanwhile, HFGA can copolymerize with the presence of PF5 at the Helmholtz plane to participate in forming a CF2-rich CEI layer with excellent PF6- permselectivity, conducive to achieving PF6- de-solvation and simultaneously suppressing electrolyte oxidation decomposition. By virtue of such beneficial effects, the graphite cathode enables a 5.5 V DIB with a prominent capacity retention of 92% and a high average Coulombic efficiency exceeding 99% within 2000 cycles, demonstrating significantly enhanced electrochemical reversibility. The Helmholtz plane regulation strategy marks a milestone in advancing DIB technologies.

Synthesis and characterization of injectable thermosensitive hydrogel based on Pluronic-grafted silk fibroin copolymer containing hydroxyapatite nanoparticles as potential for bone tissue engineering.

Injectable hydrogels are promising for bone tissue engineering due to their minimally invasive application and adaptability to irregular defects. This study presents the development of pluronic grafted silk fibroin (PF-127-g-SF), a temperature-sensitive graft copolymer synthesized from SF and modified PF-127 via a carbodiimide coupling reaction. The PF-127-g-SF copolymer exhibited a higher sol-gel transition temperature (34 °C at 16 % w/v) compared to PF-127 (23 °C), making it suitable for injectable applications. It also showed improved flexibility and strength, with a yielding point increase from <10 % to nearly 30 %. Unlike PF-127 gel, which degrades within 72 h in aqueous media, the PF-127-g-SF copolymer maintained a stable gel structure for over two weeks due to its robust crosslinked hydrogel network. Incorporating hydroxyapatite nanoparticles (n-HA) into the hydrogel reduced pore size and decreased swelling and degradation rates, extending structural stability to four weeks. Increasing n-HA concentration from 0 % to 20 % reduced porosity from 80 % to 66 %. Rheological studies indicated that n-HA enhanced the scaffold's strength and mechanical properties without altering gelation temperature. Cellular studies with MG-63 cells showed that n-HA concentration influenced cell viability and mineralization, highlighting the scaffold's potential in bone tissue engineering.

Anti-PF4 positivity and platelet activation after Ad26.COV2·S vaccination in Brazil.

INTRODUCTION: The Ad26.COV2·S (Janssen/Johnson & Johnson) COVID-19 vaccine, has been rarely associated with vaccine-induced immune thrombocytopenia and thrombosis (VITT). We investigated the prevalence of anti-PF4 antibody positivity, thrombocytopenia, D-dimer elevation, plasmatic thromboinflammatory markers, and platelet functional assays following Ad26.COV2·S vaccination in Rio de Janeiro, Brazil. METHODS: From July to September 2021, participants were assessed prior, 1, and 3 weeks post-vaccination. Platelet count and D-dimer were measured at each visit and anti-PF4 at week 3. A positive anti-PF4 prompted retrospective testing of the sample from week 0. Individuals with new thrombocytopenia or elevated D-dimer, positive anti-PF4, and 38 matched controls without laboratory abnormalities were evaluated for plasmatic p-selectin, tissue factor, and functional platelet activation assays. RESULTS: 630 individuals were included; 306 (48.57%) females, median age 28 years. Forty-two (6.67%) presented ≥1 laboratory abnormality in week 1 or 3. Five (0.79%) had thrombocytopenia, 31 (4.91%) elevated D-dimer, and 9 (1.57%) had positive anti-PF4 at week 3. Individuals with laboratory abnormalities and controls showed a slight increase in plasmatic p-selectin and tissue factor. Ten individuals with laboratory abnormalities yielded increased surface expression of p-selectin, and their ability to activate platelets in a FcγRIIa dependent manner was further evaluated. Two were partially inhibited by high concentrations of heparin and blockage of FcγRII with IV.3 antibody. Plasma obtained before vaccination produced similar results, suggesting a lack of association with vaccination. CONCLUSIONS: Vaccination with Ad26.COV2·S vaccine led to a very low frequency of low-titer positive anti-PF4 antibodies, elevation of D-dimer, and mild thrombocytopenia, with no associated clinically relevant increase in thromboinflammatory markers and platelet activation.

Phosphodiesterase-4 Inhibitors Increase Pigment Cell Proliferation and Melanization in Cultured Melanocytes and within a 3-Dimensional Skin Equivalent Model.

Vitiligo is a common chronic autoimmune disease characterized by white macules and patches of the skin, having a negative impact on patients' life and without any definitive cure at present. Identification of new compounds to reverse depigmentation is therefore a pressing need for this disease. The pharmacologic compounds phosphodiesterase-4 inhibitors (PDE4is) are small molecules with immunomodulatory properties used for treatment of inflammatory dermatoses. PDE4is have shown repigmentation effects in patients with vitiligo, in some case reports. We characterized the proliferative and melanogenic potential of 2 known PDE4is-crisaborole and roflumilast-and of a more recently designed compound, PF-07038124. We used 2 in vitro model systems-the primary human melanocyte culture and a 3-dimensional cocultured skin model (MelanoDerm)-with an exploratory testing platform composed of complementary assays (spectrophotometry, melanin and proliferation assays, immunostaining, Fontana-Masson staining, RT-qPCR, western blot, and whole-transcriptome RNA sequencing). We identified that treatment with PDE4is was associated with increased melanocyte proliferation and melanization in both in vitro models and with increase in the melanogenic genes and proteins expression in cultured melanocytes. These effects were found to be enhanced by addition of α-melanocyte-stimulating hormone. Our findings support the further evaluation of PDE4is with or without α-melanocyte-stimulating hormone agonists in vitiligo trials.

Extra Medullary Fixation in Unstable Proximal Femoral Fractures by PF-LCP.

Purpose: Perception that extra-medullary fixation of these fractures are fraught with difficulties and deficiencies is becoming inappropriate. This device provides angular stable fixation retaining fracture biology with minimum interference to osseous and soft-tissue vascularity and it does not require reaming which destroys 80% of endosteal vasculature for 6-12 weeks. PFLCP averts iatrogenic fracture in lateral trochanteric wall (LTW) which is frequent with DHS, protects LTW from secondary fracture in post-operative period. Aim is to assess outcome of unstable proximal femur fracture fixation by PFLCP. Methods: Study included 64 from 2016 to 2020, divided in two groups. (A) Unstable intertrochanteric fracture and (B) subtrochanteric fracture (Seinsheimer types II-V). All fractures fixed by MIPO with PFLCP. Loss of reduction, infection, cut-out, cut-through, backing of screws, bending or breaking of plate and screw, malunion, non-union and revision were evaluated. Fracture healing and functional recovery assessed by Reborne Score and Parker Mobility Score (PMS) respectively. Results: Out of 64, 24 achieved pre-injury PMS, 32 declined by 1 point, 6 declined by 2 points and 1 by 3 points, one required revision. Using various parameters 37.5% patients had excellent results and 50% had good results, 9.38% had average and 3.12% had poor result. None reported non-union or breakage of plate. Conclusions: PFLCP provides angular stable fixation, torsional stability with high biomechanical strength to resist deforming stresses. MIPO avoids soft-tissue stripping reducing blood-loss, retains periosteal blood supply to inter-fragmentary bone fragments, enhancing fracture healing, reducing complications, such as delayed healing, nonunion, infection and implant failure.

Progression of gestational diabetes mellitus to pregnancy-associated fulminant type 1 diabetes: a case report.

Background: Pregnancy-associated fulminant type 1 diabetes (PF) occurs during pregnancy or within 2 weeks of delivery. Although it occurs infrequently, it is associated with high fetal mortality rate. Few studies have examined whether PF is associated with gestational diabetes mellitus (GDM). Case Description: A 29-year-old woman diagnosed with GDM at 24 weeks of gestation developed a fever, sore throat, nausea and vomiting at 29 weeks of gestation. Ketoacidosis was considered based on her blood ketone and glucose levels and the results of a blood gas analysis. Since the patient's islet function declined rapidly, fluid replacement, insulin therapy, and other treatments were administered. The patient was ultimately diagnosed with PF, and has required ongoing insulin therapy. She delivered a healthy baby girl by elective cesarean section at 37-week gestation. Her blood glucose has been satisfactorily controlled over the 12 months since her acute presentation. Conclusions: PF is characterized by poor maternal and infant outcomes and a high stillbirth rate. Blood glucose should be regularly monitored in pregnant women with GDM. A sudden increase in blood glucose may indicate the possibility of PF, which needs to be managed in a timely manner to avoid adverse pregnancy outcomes.

PF-05231023 reduces lipid deposition in apolipoprotein E-deficient mice by inhibiting the expression of lipid synthesis genes.

Fibroblast growth factor 21 (FGF21) is a peptide hormone that is primarily expressed and secreted by the liver. The hormone is crucial for regulation of glucose homeostasis, lipid metabolism, and energy balance. Compared with natural FGF21, FGF21 analogs have become drug candidates for the treatment of cardiovascular and metabolic diseases owing to their long half-life and greater stability in vitro. Apolipoprotein E (Apoe)-knockout (Apoe -/-) mice exhibit progressive disruptions in lipid metabolism in vivo and develop further atherosclerosis pathological features owing to Apoe deletion. Therefore, this study used an Apoe -/- mouse model to investigate the effects of a long-acting FGF21 analog (PF-05231023) on lipid metabolism and related parameters. Eighteen Apoe -/- female mice were fed a Western diet equivalent for 12 weeks, and then randomly assigned to intraperitoneally receive either physiological saline (the control group) or 10 mg/kg PF-05231023 (the treatment group) three times a week for seven consecutive weeks. Body composition, glucose tolerance, blood and liver cholesterol, triglyceride levels, liver vacuolization levels, peri-ovarian white adipocyte hypertrophy, aortic atherosclerotic plaque formation, and the expression of genes related to lipid metabolism in adipose tissue were subsequently assessed before and after treatment. The aortic atherosclerotic plaque area was reduced in mice in the PF-05231023 treatment group compared with that in the saline group. Although the effect of PF-05231023 on the plasma biochemical indexes of mice was small, it significantly reduced lipid levels and lipid droplet accumulation in the liver, and reduced adipocyte hypertrophy in white adipose tissue. Transcriptome analysis of adipose tissue showed that PF-05231023 treatment downregulated the expression of lipid synthesis-related genes and inhibited the sterol regulatory element binding transcription factor 1 gene, thereby improving lipid deposition. PF-05231023 effectively improved the lipid metabolism of Apoe -/- mice, demonstrating an anti-atherosclerotic effect and providing a scientific basis and experimental foundation for the clinical treatment of cardiovascular diseases by using long-acting FGF21 analogs.

Author Response: Beyond the Nasal Prongs: A Joust of Oxygen Delivery Methods in Post-op Hypoxemia.

How to cite this article: Mishra S, Kothari N, Sharma A, Goyal S, Rathod DK, Meshram T, et al. Author Response: Beyond the Nasal Prongs: A Joust of Oxygen Delivery Methods in Post-op Hypoxemia. Indian J Crit Care Med 2024;28(6):626-627.

PF127/bleomycin hydrogel promotes subcutaneous extracellular matrix remodeling and fibrosis to construct personalized flaps through the TGFß-Col signaling pathway.

BACKGROUND: Skin flap transplantation is used to effectively reconstruct defects of the hand and foot skin and soft tissues. We here investigated the effect of the PF127/bleomycin (BLM) hydrogel on the extracellular matrix (ECM) remodeling of skin flaps and the underlying mechanism, thereby providing a new reference point for personalized flap modification and overcoming abrasion resistance- and stability-associated difficulties. METHODS: The appropriate PF127/BLM concentration was selected based on the gelation time and drug release curve. Migration assays, scratch assays, and live/dead staining were conducted to verify the effect of PF127/BLM on human skin fibroblasts (HSFs). The effects of PF127/BLM on the ECM were assessed through hematoxylin and eosin and Masson staining. Additionally, we examined the expression of ECM remodeling-related genes and proteins involved in their associated signaling pathway. Finally, the effects of PF127/BLM on organ fibrosis and toxicity to liver and kidney functions were assessed in mice. RESULTS: A 25% PF127/BLM hydrogel was selected as the study concentration. PF127/BLM augmented HSF chemotaxis and proliferation. Furthermore, PF127/BLM promoted subcutaneous ECM remodeling and fibrosis, increased the flap dermis thickness, and reduced the toxic side effects of BLM on liver/lung fibrosis and liver/kidney function. Additional studies confirmed that the PF127/BLM-mediated regulation of ECM remodeling in skin flaps was associated with TGFß-Col signaling pathway activation. CONCLUSION: The PF127/BLM hydrogel promoted subcutaneous ECM remodeling and fibrosis, which aided the construction of personalized flaps through the TGFß-Col signaling pathway, with decreased hepatic, pulmonary, and renal toxicities.

Extraction of Bacterial Membrane Vesicle and Phage Complex by Density Gradient Ultracentrifugation.

The bacterial membrane vesicles (MVs) are non-replicative, nanoscale structures that carry specific cargos and play multiple roles in microbe-host interactions. An appropriate MV isolation method that mimics complex pathogen infections in vivo is needed. After bacterial MVs extraction, flagella or pili can be frequently observed along with MVs by transmission electron microscope (TEM). Recently, MVs from Pseudomonas aeruginosa were found to coexist with Pf4 phages, and this MV-phages complex exhibited a different impact on host cell innate immunity compared with MVs or phages solely. The presence of this MVs-phages complex simulates the real condition of complex pathogen infections within the host. This protocol outlines the extraction of the MVs and Pf4 phages complex of P. aeruginosa PAO1, including the respective isolation and qualification approaches. Our step-by-step bacterial MVs-phages complex extraction protocol provides valuable insights for further studying microbe-host cell interactions and the development of novel phage therapies. Key features • Detailed density gradient extraction procedures of MVs-phages complex • TEM, plaque assay, and PCR to verify the coexistence of MVs and phages • The obtained MVs-phages complex can be used for exploring phage-microbe-host cell interactions Graphical overview.

The effect of intermittent fasting on preventing obesity-related early aging from a molecular and cellular perspective.

Obesity is a global health concern owing to its association with numerous degenerative diseases and the fact that it may lead to early aging. Various markers of aging, including telomere attrition, epigenetic alterations, altered protein homeostasis, mitochondrial dysfunction, cellular senescence, stem cell disorders, and intercellular communication, are influenced by obesity. Consequently, there is a critical need for safe and effective approaches to prevent obesity and mitigate the onset of premature aging. In recent years, intermittent fasting (IF), a dietary strategy that alternates between periods of fasting and feeding, has emerged as a promising dietary strategy that holds potential in counteracting the aging process associated with obesity. This article explores the molecular and cellular mechanisms through which IF affects obesity-related early aging. IF regulates various physiological processes and organ systems, including the liver, brain, muscles, intestines, blood, adipose tissues, endocrine system, and cardiovascular system. Moreover, IF modulates key signaling pathways such as AMP-activated protein kinase (AMPK), sirtuins, phosphatidylinositol 3-kinase (PI3K)/Akt, mammalian target of rapamycin (mTOR), and fork head box O (FOXO). By targeting these pathways, IF has the potential to attenuate aging phenotypes associated with obesity-related early aging. Overall, IF offers promising avenues for promoting healthier lifestyles and mitigating the premature aging process in individuals affected by obesity.

The correlation between serum levels of laminin, type IV collagen, type III procollagen N-terminal peptide and hyaluronic acid with the progression of post-COVID-19 pulmonary fibrosis.

COVID-19 patients often suffer from post-COVID-19 acute sequelae (PASC). Pulmonary fibrosis has the most significant long-term impact on the respiratory health of patients, known as post-COVID-19 pulmonary fibrosis (PC19-PF). PC19-PF can be caused by acute respiratory distress syndrome (ARDS) or COVID-19-induced pneumonia. Individuals who experience COVID-19 pneumonia symptoms (including cough, shortness of breath, dyspnea on exertion, and desaturation) for at least 12 weeks after diagnosis, almost all develop PC19-PF. Extracellular matrix molecules: laminin (LN), type IV collagen (IV Col), procollagen III N-terminal peptide (PIIINP), and hyaluronic acid (HA) are involved in the development and progression of PC19-PF. This study aimed to investigate the relationship between the progression of PC19-PF and serum levels of laminin, IV COL, PIIINP, and hyaluronic acid. This retrospective study included 162 PC19-PF patients treated and 160 healthy controls who received treatment at Shenzhen Longgang District Third People's Hospital, Hebei PetroChina Central Hospital and Changzhi People's Hospital from January 2021 to December 2023. Serum levels of LN, IV COL, PIIINP, and HA were detected by chemiluminescence immunoassay using commercial kits. Predicted forced vital capacity percentage (FVC% pred), predicted carbon monoxide lung diffusion capacity percentage (DLCO% pred), high-resolution computed tomography (HRCT) scores were assessed, and patient mortality was compared with healthy controls. Serum levels of LN, IV Col, PIIINP, and HA were significantly higher in PC19-PF or CTD-ILD patients than in healthy controls (all p < 0.05), and they were further elevated in acute exacerbation cases (all p < 0.01). In patients, HA was positively associated with HRCT scores and negatively associated with FVC% pred and DLCO% pred (all p < 0.05). Serum levels of LN, IV COL, PIIINP, and HA were significantly lower in surviving patients than in those who deceased (all p > 0.05). Serum levels of LN, IV C, PIIINP, and HA may affect the progression of PC19-PF and may serve as indicators of PC19-PF severity.