The Ubiquitin E3 Ligase Parkin Inhibits Innate Antiviral Immunity Through K48-Linked Polyubiquitination of RIG-I and MDA5

Host Factors Modulate Virus-Induced IFN Production via Pattern Recognition Receptors

Innate immunity is the first line of defense in the human body, and it plays an important role in defending against viral infection. Viruses are identified by different pattern-recognition receptors (PRRs) that activate the mitochondrial antiviral signaling protein (MAVS) or transmembrane protein 173 (STING), which trigger multiple signaling cascades that cause nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3) to produce inflammatory factors and interferons (IFNs). PRRs play a pivotal role as the first step in pathogen induction of interferon production. Interferon elicits antiviral activity by inducing the transcription of hundreds of IFN-stimulated genes (ISGs) via the janus kinase (JAK) - signal transducer and activator of transcription (STAT) pathway. An increasing number of studies have shown that environmental, pathogen and host factors regulate the IFN signaling pathway. Here, we summarize the mechanisms of host factor modulation in IFN production via pattern recognition receptors. These regulatory mechanisms maintain interferon levels in a normal state and clear viruses without inducing autoimmune disease.

Ubiquitin Ligase Parkin Regulates the Stability of SARS-CoV-2 Main Protease and Suppresses Viral Replication

The highly infectious coronavirus SARS-CoV-2 relies on the viral main protease (Mpro, also known as 3CLpro or Nsp5) to proteolytically process the polyproteins encoded by the viral genome for the release of functional units in the host cells to initiate viral replication. Mpro also interacts with host proteins of the innate immune pathways, such as IRF3 and STAT1, to suppress their activities and facilitate virus survival and proliferation. To identify the host mechanism for regulating Mpro, we screened various classes of E3 ubiquitin ligases and found that Parkin of the RING-between-RING family can induce the ubiquitination and degradation of Mpro in the cell. Furthermore, when the cells undergo mitophagy, the PINK1 kinase activates Parkin and enhances the ubiquitination of Mpro. We also found that elevated expression of Parkin in the cells significantly decreased the replication of SARS-CoV-2 virus. Interestingly, SARS-CoV-2 infection downregulates Parkin expression in the mouse lung tissues compared to healthy controls. These results suggest an antiviral role of Parkin as a ubiquitin ligase targeting Mpro and the potential for exploiting the virus-host interaction mediated by Parkin to treat SARS-CoV-2 infection.

Critical roles of parkin and PINK1 in coxsackievirus B3-induced viral myocarditis

Viral myocarditis is an inflammatory disease of the myocardium, often leads to cardiac dysfunction and death. PARKIN (PRKN) and PINK1, well known as Parkinson's disease-associated genes, have been reported to be involved in innate immunity and mitochondrial damage control. Therefore, we investigated the role of parkin and PINK1 in coxsackievirus B3 (CVB3)-induced viral myocarditis because the etiology of myocarditis is related to abnormal immune response to viral infection and mitochondrial damage. After viral infection, the survival was significantly lower and myocardial damage was more severe in parkin knockout (KO) and PINK1 KO mice compared to wild-type (WT) mice. Parkin KO and PINK1 KO showed defective immune cell recruitment and impaired production of antiviral cytokines such as interferon-gamma, allowing increased viral replication. In addition, parkin KO and PINK1 KO mice were more susceptible to CVB3-induced mitochondrial damage than WT mice, resulting in susceptibility to viral-induced cardiac damage. Finally, using publicly available RNA-seq data, we found that pathogenic mutants of the PRKN gene are more common in patients with dilated cardiomyopathy and myocarditis than in controls or the general population. This study will help elucidate the molecular mechanism of CVB3-induced viral myocarditis.

Role of Coxsackievirus B3-Induced Immune Responses in the Transition from Myocarditis to Dilated Cardiomyopathy and Heart Failure

Dilated cardiomyopathy (DCM) is a cardiac disease marked by the stretching and thinning of the heart muscle and impaired left ventricular contractile function. While most patients do not develop significant cardiac diseases from myocarditis, disparate immune responses can affect pathological outcomes, including DCM progression. These altered immune responses, which may be caused by genetic variance, can prolong cytotoxicity, induce direct cleavage of host protein, or encourage atypical wound healing responses that result in tissue scarring and impaired mechanical and electrical heart function. However, it is unclear which alterations within host immune profiles are crucial to dictating the outcomes of myocarditis. Coxsackievirus B3 (CVB3) is a well-studied virus that has been identified as a causal agent of myocarditis in various models, along with other viruses such as adenovirus, parvovirus B19, and SARS-CoV-2. This paper takes CVB3 as a pathogenic example to review the recent advances in understanding virus-induced immune responses and differential gene expression that regulates iron, lipid, and glucose metabolic remodeling, the severity of cardiac tissue damage, and the development of DCM and heart failure.

Crosstalk between Autophagy and RLR Signaling

Autophagy plays a homeostatic role in regulating cellular metabolism by degrading unwanted intracellular materials and acts as a host defense mechanism by eliminating infecting pathogens, such as viruses. Upon viral infection, host cells often activate retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling to induce the transcription of type I interferons, thus establishing the first line of the innate antiviral response. In recent years, numerous studies have shown that virus-mediated autophagy activation may benefit viral replication through different actions on host cellular processes, including the modulation of RLR-mediated innate immunity. Here, an overview of the functional molecules and regulatory mechanism of the RLR antiviral immune response as well as autophagy is presented. Moreover, a summary of the current knowledge on the biological role of autophagy in regulating RLR antiviral signaling is provided. The molecular mechanisms underlying the crosstalk between autophagy and RLR innate immunity are also discussed.

Exploiting RIG-I-like receptor pathway for cancer immunotherapy

RIG-I-like receptors (RLRs) are intracellular pattern recognition receptors that detect viral or bacterial infection and induce host innate immune responses. The RLRs family comprises retinoic acid-inducible gene 1 (RIG-I), melanoma differentiation-associated gene 5 (MDA5) and laboratory of genetics and physiology 2 (LGP2) that have distinctive features. These receptors not only recognize RNA intermediates from viruses and bacteria, but also interact with endogenous RNA such as the mislocalized mitochondrial RNA, the aberrantly reactivated repetitive or transposable elements in the human genome. Evasion of RLRs-mediated immune response may lead to sustained infection, defective host immunity and carcinogenesis. Therapeutic targeting RLRs may not only provoke anti-infection effects, but also induce anticancer immunity or sensitize "immune-cold" tumors to immune checkpoint blockade. In this review, we summarize the current knowledge of RLRs signaling and discuss the rationale for therapeutic targeting RLRs in cancer. We describe how RLRs can be activated by synthetic RNA, oncolytic viruses, viral mimicry and radio-chemotherapy, and how the RNA agonists of RLRs can be systemically delivered in vivo. The integration of RLRs agonism with RNA interference or CAR-T cells provides new dimensions that complement cancer immunotherapy. Moreover, we update the progress of recent clinical trials for cancer therapy involving RLRs activation and immune modulation. Further studies of the mechanisms underlying RLRs signaling will shed new light on the development of cancer therapeutics. Manipulation of RLRs signaling represents an opportunity for clinically relevant cancer therapy. Addressing the challenges in this field will help develop future generations of cancer immunotherapy.

Suppression of cGAS- and RIG-I-mediated innate immune signaling by Epstein-Barr virus deubiquitinase BPLF1

Epstein-Barr virus (EBV) has developed effective strategies to evade host innate immune responses. Here we reported on mitigation of type I interferon (IFN) production by EBV deubiquitinase (DUB) BPLF1 through cGAS-STING and RIG-I-MAVS pathways. The two naturally occurring forms of BPLF1 exerted potent suppressive effect on cGAS-STING-, RIG-I- and TBK1-induced IFN production. The observed suppression was reversed when DUB domain of BPLF1 was rendered catalytically inactive. The DUB activity of BPLF1 also facilitated EBV infection by counteracting cGAS-STING- and TBK1-mediated antiviral defense. BPLF1 associated with STING to act as an effective DUB targeting its K63-, K48- and K27-linked ubiquitin moieties. BPLF1 also catalyzed removal of K63- and K48-linked ubiquitin chains on TBK1 kinase. The DUB activity of BPLF1 was required for its suppression of TBK1-induced IRF3 dimerization. Importantly, in cells stably carrying EBV genome that encodes a catalytically inactive BPLF1, the virus failed to suppress type I IFN production upon activation of cGAS and STING. This study demonstrated IFN antagonism of BPLF1 mediated through DUB-dependent deubiquitination of STING and TBK1 leading to suppression of cGAS-STING and RIG-I-MAVS signaling.

Mild Hypothermia Protects Brain Injury After Intracerebral Hemorrhage in Mice Via Enhancing the Nrdp1/MyD88 Signaling Pathway

BACKGROUND

Mild hypothermia has been identified to reduce brain injury following intracerebral hemorrhage (ICH) by protecting neuron cells through several pathways. However, the role of hypothermia in brain function following ICH and the related mechanisms have not been well identified. Ubiquitination-mediated inflammation plays important roles in the pathogenesis of immune diseases. The experiment analyzed anti-inflammatory effects of mild hypothermia following ICH.

METHODS

The model of ICH was induced by injecting autologous blood. Neuregulin receptor degradation protein-1 (Nrdp1) and downstream molecule were analyzed. In addition, brain inflammatory response, brain edema, and neurological functions of ICH mice were also assessed.

RESULTS

We found that mild hypothermia attenuated proinflammatory factors production after ICH. Mild hypothermia significantly inhibited BBB injury, water content, and neurological damage following ICH in vivo. Moreover, mild hypothermia also increased Nrdp1/MyD88 levels and thus affect neuronal apoptosis and inflammation.

CONCLUSIONS

Taken together, these results suggest that mild hypothermia can attenuate the neuroinflammatory response and neuronal apoptosis after ICH through the regulation of the Nrdp1 levels.

E3 Ubiquitin Ligases: The Operators of the Ubiquitin Code That Regulates the RLR and cGAS-STING Pathways

The outbreaks caused by RNA and DNA viruses, such as SARS-CoV-2 and monkeypox, pose serious threats to human health. The RLR and cGAS-STING pathways contain major cytoplasmic sensors and signaling transduction axes for host innate antiviral immunity. In physiological and virus-induced pathological states, the activation and inactivation of these signal axes are tightly controlled, especially post-translational modifications (PTMs). E3 ubiquitin ligases (E3s) are the direct manipulator of ubiquitin codons and determine the type and modification type of substrate proteins. Therefore, members of the E3s family are involved in balancing the host's innate antiviral immune responses, and their functions have been extensively studied over recent decades. In this study, we overviewed the mechanisms of different members of three E3s families that mediate the RLR and cGAS-STING axes and analyzed them as potential molecular targets for the prevention and treatment of virus-related diseases.

Supramolecular organizing centers at the interface of inflammation and neurodegeneration

The pathogenesis of neurodegenerative diseases involves the accumulation of misfolded protein aggregates. These deposits are both directly toxic to neurons, invoking loss of cell connectivity and cell death, and recognized by innate sensors that upon activation release neurotoxic cytokines, chemokines, and various reactive species. This neuroinflammation is propagated through signaling cascades where activated sensors/receptors, adaptors, and effectors associate into multiprotein complexes known as supramolecular organizing centers (SMOCs). This review provides a comprehensive overview of the SMOCs, involved in neuroinflammation and neurotoxicity, such as myddosomes, inflammasomes, and necrosomes, their assembly, and evidence for their involvement in common neurodegenerative diseases. We discuss the multifaceted role of neuroinflammation in the progression of neurodegeneration. Recent progress in the understanding of particular SMOC participation in common neurodegenerative diseases such as Alzheimer's disease offers novel therapeutic strategies for currently absent disease-modifying treatments.

Transcriptome Analysis of Retinoic Acid-Inducible Gene I Overexpression Reveals the Potential Genes for Autophagy-Related Negative Regulation

Retinoic acid-inducible gene I (RIG-I) serves as an essential viral RNA sensor for innate immune. The activation of the RIG-I-like receptors (RLRs) pathway triggers many regulations for the outcome of type I interferon, including ubiquitination, dephosphorylation, ISGylation, and autophagy. However, the autophagy-related regulation of RIG-I is still not fully understood. To investigate the potentially unknown genes related to autophagy-related regulation of RIG-I, we firstly confirm the induction of autophagy derived by overexpression of RIG-I. Furthermore, the autophagy inducer and inhibitor drugs were used in different assays. The results showed autophagy could control the activation of RLRs pathway and expression of exogenous RIG-I. In addition, we carried out the transcriptome analysis of overexpression of RIG-I in vitro. Differentially expressed genes (DEGs) in GO and KEGG signaling pathways enrichment provided a newly complex network. Finally, the validation of qPCR indicated that the DEGs PTPN22, PRKN, OTUD7B, and SIRT2 were correlated to the negative regulation of excessive expression of RIG-I. Taken together, our study contributed new insights into a more comprehensive understanding of the regulation of excessive expression of RIG-I. It provided the potential candidate genes for autophagy-related negative regulation for further investigation.

Melanoma differentiation-Associated gene 5 protects against NASH in mice

BACKGROUND AND AIMS

NASH is a complicated disease characterized by hepatocyte steatosis, inflammation infiltration, and liver fibrosis. Accumulating evidence suggests that the innate immunity plays a key role in NASH progression. Here, we aimed to reveal the role of melanoma differentiation-associated gene 5 (MDA5, also known as Ifih1), a conventional innate immune regulator following viral infection, in the progression of NASH and investigate its underlying mechanism.

APPROACH AND RESULTS

We first examined the expression of MDA5 and found that MDA5 was markedly down-regulated in the livers with NASH in human individuals and mice models. MDA5 overexpression significantly inhibits the free fatty acid-induced lipid accumulation and inflammation in hepatocyte in vitro, whereas MDA5 knockdown promotes hepatocyte lipotoxicity. Using hepatocyte-specific Mda5 gene knockout and transgenic mice, we found that diet-induced hepatic steatosis, inflammation, and liver fibrosis were markedly exacerbated by Mda5 deficiency but suppressed by Mda5 overexpression. Mechanistically, we found that the activation of apoptosis signal-regulating kinase 1 (ASK1)-mitogen-activated protein kinase pathway was significantly inhibited by MDA5 but enhanced by MDA5 deletion. We further validated that MDA5 directly interacted with ASK1 and suppressed its N-terminal dimerization. Importantly, blockage of ASK1 with adenovirus-expressing dominant negative ASK1 obviously reversed the lipid accumulation and ASK1 pathway activation when Mda5 was knocked out.

CONCLUSIONS

These data indicate that MDA5 is an essential suppressor in NASH. The findings support MDA5 as a regulator of ASK1 and a promising therapeutic target for NASH.

The molecular regulation of autophagy in antimicrobial immunity

Autophagy is a catabolic process that can degrade worn-out organelles and invading pathogens. The activation of autophagy regulates innate and adaptive immunity, playing a key role in the response to microbial invasion. Microbial infection may cause different consequences such as the elimination of invaders through autophagy or xenophagy, host cell death, and symbiotic relationships. Pathogens adapt to the autophagy mechanism and further relieve intracellular stress, which is conducive to host cell survival and microbial growth. The regulation of autophagy forms a complex network through which host immunity is modulated, resulting in a variety of pathophysiological manifestations. Modification of the autophagic pathway is an essential target for the development of antimicrobial drugs.

Autophagy and antiviral defense

Targeting intracellular components for lysosomal degradation by autophagy not only maintains cellular homeostasis but also counteracts the effects of external stimuli, including invading pathogens. Among various kinds of pathogens, viruses have been extensively shown to induce autophagy to benefit viral growth in infected cells and to modulate host defense responses, such as innate antiviral immunity. Recently, numerous lines of evidence have implied that virus-induced autophagy triggers multilayer mechanisms to regulate the innate antiviral response of host cells, thus promoting a balance in virus-host cell interactions. In this review, the detailed mechanisms underlying autophagy and the innate antiviral immune response are first described. Then, I summarize the current information regarding the diverse functional role(s) of autophagy in the control of antiviral defenses against different types of viral infections. Moreover, the physiological significance of autophagy-regulated antiviral responses on the viral life cycle and the potential autophagy alterations induced by virus-associated antiviral signaling is further discussed.

Histone demethylase LSD1 promotes RIG-I poly-ubiquitination and anti-viral gene expression

Under RNA virus infection, retinoic acid-inducible gene I (RIG-I) in host cells recognizes viral RNA and activates the expression of type I IFN. To investigate the roles of protein methyltransferases and demethylases in RIG-I antiviral signaling pathway, we screened all the known related enzymes with a siRNA library and identified LSD1 as a positive regulator for RIG-I signaling. Exogenous expression of LSD1 enhances RIG-I signaling activated by virus stimulation, whereas its deficiency restricts it. LSD1 interacts with RIG-I, promotes its K63-linked polyubiquitination and interaction with VISA/MAVS. Interestingly, LSD1 exerts its function in antiviral response not dependent on its demethylase activity but through enhancing the interaction between RIG-I with E3 ligases, especially TRIM25. Furthermore, we provide in vivo evidence that LSD1 increases antiviral gene expression and inhibits viral replication. Taken together, our findings demonstrate that LSD1 is a positive regulator of signaling pathway triggered by RNA-virus through mediating RIG-I polyubiquitination.

RIG-I signaling pathway is critical for human cells to defend from RNA virus infection, such as SARS-CoV-2, influenza virus, and Vesicular Stomatitis Virus (VSV). LSD1 is a histone demethylase regulating transcription. The current study reveals a novel function of LSD1 in regulating the activation of RIG-I signaling pathway. LSD1 interacts with RIG-I and promotes RIG-I poly-ubiquitination independent of its demethylase activity. LSD1 facilitates the interaction between RIG-I and its ubiquitin E3 ligase TRIM25, which is crucial for recruitment of downstream proteins. The mice with LSD1 deficiency are susceptible to virus infection and have lower survival rate. Taken together, our findings demonstrate a novel molecular mechanism for regulating the anti-viral RIG-I signaling pathway.

Nonstructural Protein NS1 of Influenza Virus Disrupts Mitochondrial Dynamics and Enhances Mitophagy via ULK1 and BNIP3

Nonstructural protein 1 (NS1) of influenza virus (IFV) is essential for evading interferon (IFN)-mediated antiviral responses, thereby contributing to the pathogenesis of influenza. Mitophagy is a type of autophagy that selectively removes damaged mitochondria. The role of NS1 in IFV-mediated mitophagy is currently unknown. Herein, we showed that overexpression of NS1 protein led to enhancement of mitophagy. Mitophagy induction via carbonyl cyanide 3-chlorophenylhydrazone treatment in IFV-infected A549 cells led to increased viral replication efficiency, whereas the knockdown of PTEN-induced kinase 1 (PINK1) led to the opposite effect on viral replication. Overexpression of NS1 protein led to changes in mitochondrial dynamics, including depolarization of mitochondrial membrane potential. In contrast, infection with NS1-deficient virus resulted in impaired mitochondrial fragmentation, subsequent mitolysosomal formation, and mitophagy induction, suggesting an important role of NS1 in mitophagy. Meanwhile, NS1 protein increased the phosphorylation of Unc-51-like autophagy activating kinase 1 (ULK1) and the mitochondrial expression of BCL2- interacting protein 3 (BNIP3), both of which were found to be important for IFV-mediated mitophagy. Overall, these data highlight the importance of IFV NS1, ULK1, and BNIP3 during mitophagy activation.

CVB3-Mediated Mitophagy Plays an Important Role in Viral Replication via Abrogation of Interferon Pathways

Coxsackievirus B3 (CVB3) is a common enterovirus that causes systemic inflammatory diseases, such as myocarditis, meningitis, and encephalitis. CVB3 has been demonstrated to subvert host cellular responses via autophagy to support viral replication in neural stem cells. Mitophagy, a specialized form of autophagy, contributes to mitochondrial quality control via degrading damaged mitochondria. Here, we show that CVB3 infection induces mitophagy in human neural progenitor cells, HeLa and H9C2 cardiomyocytes. In particular, CVB3 infection triggers mitochondrial fragmentation, loss of mitochondrial membrane potential, and Parkin/LC3 translocation to the mitochondria. Rapamycin or carbonyl cyanide m-chlorophenyl hydrazone (CCCP) treatment led to increased CVB3 RNA copy number in a dose-dependent manner, suggesting enhanced viral replication via autophagy/mitophagy activation, whereas knockdown of PTEN-induced putative kinase protein 1(PINK1) led to impaired mitophagy and subsequent reduction in viral replication. Furthermore, CCCP treatment inhibits the interaction between mitochondrial antiviral signaling protein (MAVS) and TANK-binding kinase 1(TBK1), thus contributing to the abrogation of type I and III interferon (IFN) production, suggesting that mitophagy is essential for the inhibition of interferon signaling. Our findings suggest that CVB3-mediated mitophagy suppresses IFN pathways by promoting fragmentation and subsequent sequestration of mitochondria by autophagosomes.

iTRAQ-based quantitative proteomics suggests mitophagy involvement after Rice black-streaked dwarf virus acquisition in insect vector small brown planthopper Laodelphax striatellus Fallén

Plant viruses trigger numerous responses in their insect vectors. Using iTRAQ-based quantitative proteomics analysis, early responses of the insect vector, the small brown planthopper (Laodelphax striatellus Fallén, SBPH), after acquiring Rice black-streaked dwarf virus (RBSDV) at 3 days and 5 days post first access to diseased plants (padp) were revealed. A total of 582 differentially abundant proteins (DAPs) in SBPH with a fold change >1.500 or <0.667 (p-value < 0.05) were identified. The proteomic analysis in SBPH at 3 days padp revealed 106 highly abundant proteins and 193 of low abundance, while 5 days padp revealed 214 highly abundant proteins and 182 of low abundance. Among them, 51 highly abundant proteins and 42 of low abundance were shown consistently at both 3 days and 5 days padp. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis mapping and Gene Ontology (GO) term classification suggested impairment of mitochondria in SBPH after RBSDV acquisition, and the 77 out of 582 differentially abundant SBPH proteins analyzed by the STRING program revealed the interaction network of the mitochondrial DAPs, showing an overall down-regulation of mitochondrial proteins including the electron transport chain proteins and mitochondrial ribosome proteins. The high abundance of Parkin at 5 days padp suggests that activation of mitophagy induced degradation of mitochondria occurred. Further verification of autophagy/mitophagy-related genes by reverse-transcription quantitative RT-PCR (RT-qPCR) in SBPH after RBSDV acquisition showed up-regulation of the autophagy receptors Optineurin (OPTN), Sequestosome-1 (SQSTM1, also known as p62) and Tax1-binding protein 1 (TAX1BP1) which targets ubiquitinated damaged mitochondria during mitophagy. The phosphorylation of the three autophagy receptors may be up-regulated through an increase of transcription level TRAF-associated NFκB activator (TANK)-binding kinase 1 (TBK1). As a result, an overall reduction in the abundance of mitochondrial proteins was observed and the selective autophagic degradation was up-regulated through increased transcription level of OPTN, p62/SQSTM1, TAX1BP1 and TBK1. Therefore, acquisition of RBSDV associated with up-regulated autophagy and selective mitochondrial degradation in SBPH suggest prevention of mitochondrial-mediated apoptosis and extension of the vector life span. BIOLOGICAL SIGNIFICANCE: RBSDV causes severe yield loss in rice plants. RBSDV is transmitted efficiently only through SBPH. It is important to understand how RBSDV infects SBPH in a persistent, circulative and propagative manner. However, there has been no study on the interaction between RBSDV and SBPH at the early acquisition stage using a proteomics approach. In this study, we combined iTRAQ technique and LC-MS/MS to analyze the vector proteomics at both the initial and latent infection stages after RBSDV acquisition and verified the results by RT-qPCR. Our results revealed that significantly low DAPs were involved in various pathways, including biosynthesis of secondary metabolites, ribosomes, carbon metabolism, biosynthesis of amino acids and TCA cycle. Further clustering of the DAPs revealed significant changes in SBPH mitochondria, including decreased proteins in mitochondrial ribosomes and electron transport chain complex I, II and V. On the other hand, there was a high abundance of Parkin, suggesting the occurrence of mitochondria damage and subsequent Parkin-mediated mitophagy for clearance of impaired mitochondria. Moreover, the decreased level of PMPCB in terms of gene expression and protein abundance suggested decreased PINK1 turnover, promoting Parkin/PINK1-mediated mitophagy. Further analysis on autophagy/mitophagy-related gene transcription level indicated up-regulation of OPTN, p62/SQSTM1, TAX1BP1 and TBK1, promoting selective autophagy in SBPH after RBSDV acquisition. These findings provided new insights into the effects of RBSDV on SBPH after early acquisition by selective degradation of mitochondria, especially on reprogramming of energy metabolism and decreased mitochondria biogenesis, to prevent apoptosis and prolong the life span of SBPH post virus acquisition.