Lupus nephritis (LN) requires long-term immunosuppressive therapy, which is often associated with severe systemic side effects. Therefore, new therapeutic strategies that maintain high efficacy while minimizing adverse effects are essential. Although nanomedicine has advanced systemic and kidney-targeted drug delivery, a reliable method for glomerulus-specific delivery is lacking. Collagen IV (Col4)-alpha 3, located in the glomerular basement membrane at the blood-tissue interface through fenestrated capillary endothelium, represents an ideal target for glomeruli delivery. Herein, we developed a novel liposomal nanoparticle conjugated with a Col4-alpha 3-binding peptide (Col4-α3-NPs) for selective glomerular targeting. Prednisolone-loaded Col4-α3-NPs were administered to lupus-prone mice twice weekly for 8 weeks. Kidney injury and function were evaluated biweekly, and renal immune cell populations were analyzed by flow cytometry at study completion. The results show that rhodamine-labeled NPs predominantly accumulate in kidney glomeruli 48 h after intravenous injection. The Col4-NP system demonstrated stable and prolonged release of the encapsulated drug for over 48 h. Lupus-prone mice treated with prednisolone-loaded Col4-NPs showed significantly improved renal function and histology, including a 30% increase in glomerular filtration rate, a 56% reduction in proteinuria, and decreased IgG deposition and fibrosis. Notably, treatment also enhanced renal regulatory T cell populations. These findings suggest that glomerulus-targeted Col4-α3-NPs hold significant translational promise. This platform may offer an effective, site-specific treatment for LN while minimizing systemic side effects and could be adapted for other glomerular diseases requiring targeted therapy.
Cardiac aging increases susceptibility to cardiovascular diseases, particularly myocardial infarction. Although evidence suggest association between activation of the AIM2 inflammasome and cardiovascular diseases, its contribution to age-related cardiac complications remains unknown. We investigated the role of the AIM2 inflammasome and the cardiac response to ischemia–reperfusion (I/R) injury in aged mice. Male wildtype (C57BL/6) and AIM2-deficient (AIM2-/-) mice were subjected to natural aging (21 months), using 3-month-old mice as controls, and human cardiomyocytes (AC16) were stressed by hydrogen peroxide to mimic senescent. AIM2 expression was upregulated in the aged myocardium and senescent AC16 cells, coinciding with increased levels of cleaved caspase-1 (p20), IL-1β, and IL-18. Functional assays in Langendorff-perfused hearts revealed that AIM2 deficiency significantly attenuated post-I/R dysfunction in aged mice, restoring left ventricular developed pressure (LVDP) and pressure derivatives (+dP/dTmax and −dP/dTmin) toward pre-ischemic levels. While AIM2 absence did not alter age-associated hypertrophy, fibrosis, longevity, or senescence markers (p53 and p21), it reduced the baseline pro-inflammatory and pro-pyroptotic profile of the aged heart (IL-1β, IL-18, GSDMD-N, and ASC speck). In vitro, AIM2 activation using Poly(dA:dT) elevated IL-1β, GSDMD-N, ASC speck, and cell death in senescent cells, whereas pharmacological inhibition with A151 prevented these effects. Concurrently, age-dependent AIM2 upregulation was confirmed in human cardiac datasets. Together, these findings suggest that age-dependent AIM2 induction primes a pro-inflammatory cardiac microenvironment, exacerbating post-I/R injury and highlighting this pathway for future investigation in the context of cardiac aging.
Patients with sepsis frequently experience dysregulation of hematopoietic function in the bone marrow-spleen axis, resulting in hematologic abnormalities, including anemia and leukopenia. We hypothesized that red pulp macrophages (RPMs) in the spleen contribute to hematopoiesis through the bone marrow–spleen axis in septic patients. We established the sepsis model by cecal ligation and puncture (CLP) surgery, and performed bone marrow transplantation (BMT) and splenic RPMs transplantation (RPMT) after CLP. We evaluated splenic RPMs, hematopoietic stem and progenitor cells (HSPCs; LSK cells), and multipotent progenitor 3 cells (MPP3) proliferation and immunomodulatory properties. We performed splenic transcriptome sequencing (RNA-seq) to uncover the mechanisms by which RPMs exert therapeutic effects against sepsis. Sepsis-induced myelosuppression at 24h and MDSCs accumulation at 72h were detected. Both BMT and RPMT effectively restored splenic RPMs and suppressed MDSCs, with RPMT exerting a greater effect on LSK and MPP3 proliferation. RNA-seq confirmed that both BMT and RPMT attenuated sepsis-associated inflammation. Notably, RPMT exerted more targeted effects on hematopoietic cell lineage, cell cycle progression, and energy metabolism than BMT. This study demonstrates that splenic RPMs play a crucial regulatory role in hematopoiesis through the bone marrow-spleen axis during sepsis.
Prader–Willi syndrome (PWS) is characterized by early hypotonia and feeding difficulties, followed by hyperphagia, increased adiposity, and metabolic dysfunction. Although SNORD116 knockout (KO) mice recapitulate several features of PWS, they generally exhibit reduced body weight and adiposity in contrast to the clinical manifestations in PWS patients. Here, we compared heterozygous breeding, which generates mixed-genotype litters containing wild-type (WT) and KO pups, with isolated homozygous breeding, which generates single-genotype litters. Under heterozygous breeding, KO mice exhibited reduced body weight and adiposity, together with no impairment, or even improved glucose tolerance. In contrast, KO mice from isolated homozygous litters developed increased adiposity and impaired glucose tolerance despite remaining lighter than WT. These effects were sex-dependent, with adiposity and metabolic abnormalities generally more significant in males than in females. Food intake was also influenced by age, sex, and breeding condition. Increased absolute food intake was most evident during the juvenile period in KO mice from isolated homozygous litters, particularly in males, whereas adult KO mice did not show consistent hyperphagia. Cross-fostering, large-litter, and CD1 foster-nursing experiments further demonstrated that early-life nursing conditions modify subsequent growth, adiposity, and metabolism. Moreover, pre-weaning KO pups exhibited reduced spontaneous movement, weaker grip strength, and lower muscle mass, supporting a potential competitive disadvantage during lactation. These findings indicate that early-life nutritional conditions may mask genotype-associated abnormalities, with isolated homozygous breeding representing a suitable model for investigating PWS phenotypes.
Congenital heart disease (CHD) is the leading cause of birth defects; most critical (c)CHD newborns will develop neurodevelopmental disorders. Abnormal placental development may be involved, as genetics explains only 30% of sporadic CHD cases. Growing evidence suggests that placental dysfunction may result in heart and brain defects, as it shares a common early development. We hypothesized that newborns with critical CHD exhibit sex-specific alterations in placental mitochondrial biogenesis and function which may affect the fetal growth trajectory. Term placenta and paired umbilical cord (UC) blood were collected at birth from cCHD (n=16) and matched control (n=20) neonates. Mitochondrial lipid complex (phosphatidic acid (PA), phosphatidylglycerol (PG), cardiolipin (CL)), acylcarnitine metabolites and organic acids were determined in placenta by LC-MS/MS. Gene expressions of enzymes involved in mitochondrial biogenesis, dynamics and lipid pathway were measured in placenta by RT-qPCR. Placental protein expressions of β-oxidation and OXPHOS were determined by Western Blot. Mitochondrial dynamics were reduced in cCHD placentas, particularly in male infants. Long-chain acylcarnitine (LC-acar) metabolites decreased in female cCHD placentas and increased in males, while they increased in both sexes in UC plasma. Malonate levels increased in cCHD placentas, affecting the TCA cycle. CL de novo synthesis was dysregulated in the cCHD placentas, though CL concentrations were similar in both groups. The cCHD placenta may compensate for cardiac defect in a potential sex-dependent manner, leading to an accumulation of LC-acylcarnitine in the UC plasma. Placental mitochondrial adaptation to metabolic needs may have a cardioprotective and neuroprotective effects.
